Holley Sniper EFI, Cost Effective, Easy to Install!

Posted by Chris Myer 11/18/15 67 Comment(s) EFI Product Deep Dives,Sniper and Terminator X,
Holley Sniper EFI Logo

Holley Sniper Throttle Body (Polished)You might think that EFI and vintage cars go together like engine oil and coolant. And I am the first to admit that there is something especially cool about a retro-rod that runs cleanly on a well tuned carburetor. But at some point the average owner gets tired of the difficult cold starts, hesitation, less than ideal fuel economy and other carburetor challenges. But are the benefits of electronic fuel injection worth the cost and effort of installation?

That question is so 2015! Holley is released their new Sniper EFI system that is exciting for several reasons. Let's start with the price. A full-featured throttle body EFI system that starts at only $999. That is what we're looking for! And because the ECU for the Sniper system is built right into the throttle body, the wiring requirements are reduced to almost nothing! If you can bolt on a carburetor and attach some throttle linkage then you are half way done.

This is no weak sibling system either. Look at these standard features:Holley Sniper 3.5-inch Touchscreen Display

  • Bolt on carburetor replacement (designed to fit single & dual carb manifolds)
  • Throttle body mounted ECU – no extra boxes to mount
  • Supports up to 600hp (4 injector version) and 1200hp (8 injector version)
  • 4 wire vehicle connection (Battery +, Battery - , Switched ignition & RPM)
  • Integrated fuel pressure regulator
  • Integrated ignition timing control & coil driver
  • Color touchscreen for setup and gauge views
  • Calibration Wizard (Answer a few questions about your engine and it creates the base map, then starts tuning on its own!) - No laptop required!
  • Self-tuning ECU means you don’t have to be a computer/tuning wiz to have EFI!
  • Available in base & master kits (Master kits include complete fuel system: fuel pump, filters, feed and return hose and all fittings including fuel tank return line bulkhead fitting.)
  • NOW AVAILABLE! Full-featured laptop tuning software for those who want to do even more with their Sniper system.

And just because your ride is old school doesn't mean that you can't benefit from a touch of technology. The included 3.5" Touchscreen Display serves two purposes. In addition to giving you an easy, guided setup process, this jewel can digitally display various critical sensors after the system is running, or even datalog. Bet your carburetor never offered to do that for you!

Where To Buy?

There are many places to buy the Sniper EFI System. But be sure to buy from a supplier that can support what they sell. Here at EFI System Pro, we are passionate about your success. Big-box parts stores will see you a Sniper EFI System and give you Holley's tech support number. We give you individualized attention before the sale and provide our in-house Holley certified level III tech staff's on-call phone number. Call us anytime, evenings or weekends--we're excited to hear from you and share the expertise that will make you successful!

Choose From:Three Sniper EFI System Colors:  Shiny, Ceramic Black, Classic Gold

Sniper EFI System (Shiny Finish)

Sniper EFI System (Black Ceramic Finish)

Sniper EFI System (Classic Gold Finish)

Sniper EFI System Replacement And Upgrade Components

...with our without the fuel system Master Kit!

Join the discussion below or click here to read more articles from Chris about the Sniper EFI System!

67 Comment(s)

Norm Adams:
12/18/15, 02:09:00 PM

What price for master kit?

Chris Myer:
09/29/16, 06:09:19 PM

The master kit adds $250 to the price of the $999.95 Sniper EFI System (for a total of $1249.95.) For that $250 you get an inline fuel pump, pre- and post-filters, fuel line with Earl's push-lock fittings, a fuel bulkhead fitting for the return line, as well as assorted clamps and mounting hardware.

adrian alvarez:
01/2/16, 04:43:19 AM, a

I am very interest in this product but i want to know how much gasoline im going to save between the efi system and a carburator sistem

Chris Myer:
09/29/16, 06:12:48 PM

Adrian:That is a good question--but also just about an impossible question to ask. It has everything to do with how efficiently tuned the carburetor is that is being replaced. In most cases, 10% fuel savings is not out of the question. However, there is an additional benefit of the Sniper that may have a negative impact on your fuel savings: additional horsepower. You see, I have yet to meet anyone who can bolt on a new go-fast goodie, feel the improved performance it produces, and then manage to stay out of the throttle. So, if you can keep a muzzle on your need for speed, I think you will see an impressive horsepower gain. But, if you are like the rest of us, just settle for a moderate gain as you enjoy your new toy.

chris rhinehart:
01/5/16, 03:59:41 PM

Can the sniper EFI work on a small block Chevy with 142 Weiand Supercharger on it. About 500HP Car is more a driver. some autocross and some drags once in a while.Thanks

Chris Myer:
09/29/16, 06:15:15 PM

Thanks for the question, Chris. Unfortunately, no, the Sniper is not suited for any application that boosted manifold pressure above atmospheric. I'm sorry! The Terminator system can be used in this role if configured by a professional tuner. Contact us via phone or chat and we can give you more details about how to meet your objectives.

Darin MacDonald:
01/20/16, 12:43:19 AM

I'm definitely excited to try out the new Sniper system, is it still slated for a March-April release?. I've been running a 2Di pro-jection in my 1970 Bronco since I went to Fort Lewis College in 1999. It was nice for wheeling but can be a pain to keep tuned and I could never get it dialed in just right on my 302. To much gas down low, cant get enough up high and I used to work at a performance off-road shop installing and tuning EFI systems! Is the Sniper going to have a c-4, c-6 kickdown linkage provision and will a standard air cleaner housing fit the throttle body or does it have to be lifted up a significant way to clear the larger base? Thanks for any info you can provide! Curiously the shop I used to install EFI systems at was an off-road shop called Avalanche Engineering in Durango, CO and one of our tube buggies was called the Sniper!

Chris Myer:
09/29/16, 06:21:55 PM

Wow, Darin, you seem as excited about the Sniper as we are! Let me try to hit all of your points.As you now know, not only did Holley miss the March ETA but then they blew through the June ETA. The good news is that these just started shipping to dealers TODAY so you are definitely closer to seeing one of these than ever.I fully sympathize with the issues keeping the Pro-Jection unit working, though it really sounds like your experience in tuning EFI systems did pay off. As with any early technology, there is a price to be paid for being on the cutting edge, but that is all gone with the Sniper. And with a HP range from 250 to 650 HP, I don't think getting enough fuel up high is going to be a problem. Tuning essentially disappears in the Sniper, as the setup wizard asks a few simple questions and the Wideband O2 sensor ensures that the system keeps your air/fuel ratio right in the optimum range.I hope you got in on the pre-order so that we will be shipping your new system next week. I look forward to hearing how it works on your Bronco!

Brian Roberts:
02/29/16, 11:50:35 PM

is there any update on a release date for the sniper Efi I'm in the process of building a motor and in the final stages of completing the top end and trying to make sure everything matches up for best performance.

Chris Myer:
09/29/16, 06:05:34 PM

No new release date yet, Brian. We're waiting on pins and needles here ourselves!

Oney Crowley:
03/9/16, 03:51:23 PM, highway92servicecenter.com

Is this new Sniper efi ready for purchase?

Chris Myer:
09/29/16, 06:03:58 PM

Not, yet, Oney. Hang in there!

Update, September 29, 2016: They are shipping TODAY. Our initial order of Sniper EFI systems is inbound. If you placed a pre-order, then your system will be shipping middle of next week. If not, please get your order in quickly.

03/23/16, 09:09:10 PM

I currently have a dated Holley TBI ( Projection 4 )on my GMC Classic Motor Home , the 455 Olds Tornado front wheel drive. The system functions to a degree but is not performing as what the newer systems doPlease detail me the advantages of your system as to my tired Holley. Thank you Robert

Chris Myer:
09/29/16, 06:01:00 PM

Excellent question, Robert. I'm not sure I am the best one to answer it, since the Pro-Jection pre-dates my involvement with Holley by a bit. For those who don't know, the Pro-Jection uses a high-performance version of the GM TBI throttle body with injectors placed above the throttle blades. The flow characteristics (for one) are quite a bit higher on the Sniper (the old Pro-Jection TBI only flowed 675 CFM.) The HP range is completely different. The PJ maxed out at 275 HP and the Sniper starts at 250 HP and goes to 650 HP, with a 1200 HP version in the works.

I can't speak at all to the tunability of the PJ, but I suspect it has a bit more flexibility (or complexity, if you prefer.) The Sniper is designed specifically for a very narrow range of engines--fortunately, your 455 Olds sits squarely in that range.

Ultimately, I do think that the Sniper would be an outstanding system for you. The PJ throttle body can be rebuilt (a gasket kit is available here.) The entire throttle body could be replaced, but I don't think that would be money well spent at this point as the PJ throttle body costs over half the cost of a complete Sniper EFI system.

Weigh out your options and please let us know if we can answer any other questions in the process. Thanks for writing!

Leslie Allen:
03/24/16, 05:25:37 PM

Sure wish we could get more information about the Sniper EFI system. Sounds as if they're having problems getting it on the market because now they say it won't be available until June. I don't like being kept in the dark about what's going on with this system. I've got to make a decision soon to be able to get my car on the road. Just may have to go with another system if we don't get some kind of info about the Sniper EFI system soon.

Chris Myer:
09/29/16, 05:47:58 PM

I certainly feel your frustration, Leslie, and understand completely. We get an earful on a daily basis about folks who would appreciate something as basic as an instruction guide.

The only thing I can offer to placate your feelings is the assurance that anything that Holley does, they do 100% right. When the Sniper system is released, it will be the finest EFI system of its kind on the market for the money, bar none. They don't get that kind of reputation by putting things out in "beta" and letting the customers be the guinea pigs. On the other hand, sometime the best ETAs of brilliant and well-intentioned engineers slip. I believe that is exactly what has happened here. As soon as we can get some more info, be sure that we will be posting it here!

terry laughlin:
03/26/16, 12:44:34 PM

Does the sniper system require an O2 sensor? What sort of fuel pump is required? Thank you

Chris Myer:
09/29/16, 05:40:21 PM

The Sniper EFI System requires and includes a wideband O2 sensor. That jewel is the key to its self-tuning success!

A fuel pump capable of producing fuel at pressures as high as 60 PSI is required for the Sniper EFI System. We are big fans of the Walbro 255 LPH inline fuel pumps, and Holley will be releasing a master-kit version of the Sniper that includes this very pump. No fuel pressure regulator is required, because that is included in the throttle body. You will need to run a return line back to the fuel tank, and that may required things like a bulkhead fitting or fuel tank vent. Don't worry about any of this though, Terry. If you buy your Sniper system with us one of our technicians will sit down with you via phone and engineer a fuel system that will precisely meet your requirements. We are committed to your success in this.

Douglas C Cline:
03/26/16, 03:02:15 PM, brooklinmillwork.com

Please tell me this new product is marine friendly. My current TBI lacks essential sensors you know the model.... 21-700 :( My Larson 5.7 L Volvo Penta came with a stock Holley 2 bbl carb, installed the 21-700 2008 still using your product. I'll Spare you the stories. Sincerely' Doug ClineOntario Can.

Chris Myer:
09/29/16, 05:37:17 PM

I wish I had good news for you, Doug, but I don't. :-/ As I wrote in my response to your response to our post about Holley EFI in Marine Applications, if there is going to be any system that I would recommend for a marine application it's not going to be this one. Marine EFI systems need very advanced tuning capabilities. Holley makes systems with very advanced tuning capabilities, but that is simply not the market at which the Sniper is pointed. It is for an extremely narrow range of users, V8 only, who need to replace a carburetor with EFI and don't need any ignition control. The setup wizard (the only means of tuning the Sniper EFI) simply does not have the resolution required for something as complex as a marine application.

Know that we are huge cheerleaders for Holley to come out with an marine-ready EFI system. It is not on their planning horizon, but we will continue to be hopeful.

Brent Anderson:
03/27/16, 11:19:14 AM

Can you let me know when these are available?

Chris Myer:
09/29/16, 05:32:35 PM

Ok, these are available. We are expecting our first pallet of these to ship from Holley today. We are SO excited we keep putting the tracking number into FedEx just to make sure we really believe it! We should have these here next Tuesday (October 4th.) Keep in mind that these first orders will go to those who pre-ordered and were patient enough to wait through all of those delays. But if you've not already ordered then ABSOLUTELY GO AHEAD AND GET THAT ORDER PLACED! Holley has warned that they will take a few weeks to get up to full production speed and there are SO many backorders to fill that every day you wait to order is going to extend your receipt date.

Tom Benno:
04/29/16, 06:29:46 PM

I would love to see a picture of the wiring harness coming off the EFI, also the installation instructions.

Chris Myer:
09/29/16, 05:21:12 PM

As you know, Tom, I've been lobbying to get the Sniper installation instructions published ever since you initially wrote this question. Your patience has paid off. I've placed the instructions and the quick start manual on both the 550-510 and 550-511

Lynn A Pomeroy:
06/7/16, 02:16:37 PM

Would the Sniper work on my 454's in my boat? Plus, any and all information on marine applications.

Chris Myer:
09/29/16, 05:18:26 PM

Sorry, Lynn, the short answer is "no". I encourage you to read the separate writeup I did regarding Holley EFI in Marine Applications for more details.

Mike horn:
06/16/16, 04:16:12 AM

Just wondering, what style of distributor does this setup run?

Chris Myer:
09/29/16, 05:16:45 PM

The Sniper EFI is designed to use the existing ignition on the engine. All you need to do is provide a tach signal to the ECU built into the Sniper throttle body (use the tach-out signal from your MSD CDi box or the Coil (-) if you're not running a CDi box.) Your exiting distributor, coil, and wires will continue to do what they do.

07/2/16, 03:47:03 PM

What is the part number for the 1200 hp version. Your website states available in March 2016, but it looks like September 2016. In addition can this be used with Holley 12-133? I have a 555 with a crank trigger, locked at 36 degrees, any issues with this? Can the MSD 6AL be replaced by this EFI? Thanks

Chris Myer:
09/29/16, 05:08:42 PM

Holley has not yet released the part number for the 1200 HP version nor an ETA. Now that the standard 650 HP versions are starting to roll out the door, I expect those will be announced soon afterward.

You know, I made such a diligent effort to update the ETA dates on the website each time Holley pushed the date out. So I was very surprised when a few folks were saying that the site still said March 2016 (the original launch date.) It wasn't until recently that I saw where they were seeing that--in the graphic on this blog post. Oh well, the Sniper is finally rolling out the door in initial production quantities to those who have placed pre-orders so that's good news.

The 12-133 In-Tank RetroFit Fuel Module- Returnless Style was designed specifically with the Sniper in mind, so that is an excellent choice. Note, however, that the Sniper does not do ignition timing control. The good news is that your investment in high-end ignition components does not go to waste. You simply hand the Sniper a tach signal for fuel injection timing and the existing ignition on the engine continues to do its job.

Daniel R. Logan:
07/2/16, 07:00:32 PM

1950 Mercury 4-door...New "Flathead" (600 miles) with new Ford AOD transmission (Performance Automatic) Scat - 286 ci - 3 5/16 bore and 4 1/8 stroke Melling - OP15M oil pump Hi-Volume Isky - Max-1 (Duration @.050 / 226; Gross Lift .364) Edelbrock - #1107 (2) heads, 65cc Edelbrock - #1115 Intake 4 barrel manifold Edelbrock - #1801 Thunder AVS 4 barrel carburetor 500 cfm ??? MSD - #8573 Electronic Distributor??? Holley Sniper EFI ???Daniel R. Logan (68 yr.)

Chris Myer:
09/29/16, 05:05:28 PM

Your application was born for a Sniper system, Daniel, provided you are making between 250 and 650 HP. It will be a fairly simple matter to remove the 4-barrel 500 CFM carburetor on the engine and replace it with the Sniper throttle body. The biggest challenge on this install generally has nothing to do with the super-straightforward Sniper EFI installation but rather with the fuel system upgrade. Even then, we're right here to help you.

We just posted the new quick start guide and installation instructions. Give them a quick look and let us know what questions you may have.

Nick Medina:
08/20/16, 07:50:40 PM

will it CARB certified for calif.

Chris Myer:
09/29/16, 04:39:41 PM

Holley has classified the Sniper as a Emissions Category 3 product, meaning it is only "legal for use on Uncontrolled (Non-Emissions Controlled) Vehicles or Racing Vehicles". So, sadly, it is not CARB certified (which makes no sense when you realize that your engine will be running far cleaner than with the OE carburetor that you might be running currently.) Sorry about your predicament!

alan parrott:
08/28/16, 08:56:32 PM

newsletter for efi sniper

Chris Myer:
09/29/16, 04:35:25 PM

We haven't yet started a newsletter for HolleyInjection.Com, Alan, but we do have a Facebook page where we try to keep our customers updated. Do join us there!

09/11/16, 08:58:29 AM

can i use sniper efi like blow thru turbo 454 twin gt45

Chris Myer:
09/29/16, 04:32:18 PM

Unfortunately, no. The setup wizard for the Sniper system is not advanced enough to support pressures over atmospheric. This can be done with the Terminator system but, again, you won't be able to use the setup wizard. However, in the case of the Terminator you can download and use the Holley laptop software and a professional tuner should be able to get this set up as a boosted application.

Michael Hoffman:
10/1/16, 03:28:32 AM

I am pretty interested in the sniper system for my 84 k10 but i have dual tanks which i would like to keep.is this possible?

Chris Myer:
11/3/16, 05:37:46 PM

Absolutely! It is going to take a bit of engineering to make this work the same as the factory setup, though. In this case it would be best to call and talk to one of our technicians. It's not rocket science, nor will it be terribly expensive, just a bit more than practical to discuss in writing. The number is at the top of this page, technicians are available M-F from 9:00 AM until 7:00 PM. Thanks!

10/24/16, 03:12:35 PM

I have a ford 289 with a duraspark II distributor setup. Will this setup allow me to use the timing control on the Sniper or do I need to upgrade my distributor?

Chris Myer:
10/25/16, 12:56:29 PM

Good question, Kevin. The Sniper ignition interface is a bit different than that on the other Holley ECU's. To do timing control you have one of two options. Both involve upgrading your distributor.

The easiest option would be to buy the Holley EFI Dual Sync Distributor. Model 565-102 should work in your 289 CI Ford. This, in conjunction with the 558-493 adapter harness should make this a slam-dunk.

The second option would save you about $100 but does involve a bit more engineering to implement. MSD makes a Rotor Phasing Kit (PN 84211) that can be added to any of their distributors (the MSD 8579 would be a great choice.) It is necessary to lock out the built-in mechanical and vacuum advances on this distributor and then follow somewhat technical instructions (included in the Sniper kit) to implement the timing control using these components.

Either way, keep us in the loop! We love being of assistance to our customers. We are committed to guaranteeing the success of your efforts!

10/27/16, 04:20:08 PM

Thanks Chris.One more question. I'm at altitude and have pretty low manifold vac right now 4-5" in gear. Will the sniper work okay with that low of vacuum?

Chris Myer:
10/27/16, 07:12:14 PM

While we are in Florida (which isn't known for it's mountain ranges) and I haven't yet received feedback on this, I think I can safely assure you that it will work just fine. Regardless of the manifold pressure the wideband O2 sensor will read and precisely adjust the air/fuel ratio. Since you're not in the same situation as a carburetor (where you have to create adequate vacuum drop to draw the fuel into the air stream) you don't face the same challenges. Proceed with confidence and keep us updated on your success!

Larry Spring:
10/24/16, 08:48:10 PM

Will it keep the engine rpm even when the air conditioner kicks on ?

Chris Myer:
10/25/16, 01:21:37 PM

Absolutely! :-) The handheld programmer allows you to enable something called "IAC Kick". The IAC Kick provides a temporary increase in IAC position to keep engine the RPM from dropping. Typically this is used in conjunction with an A/C system keep the engine speed from ‘dipping’ as the compressor cycles on and off.

The IAC Kick is triggered when the orange wire on the 10-wire connector (included with the Sniper) is grounded. By using the A/C compressor clutch wire to generate this ground (via a relay) it will increase the idle air whenever the compressor kicks on, preventing the idle from dropping. How cool is that?Great question, BTW. Thanks for asking!

10/25/16, 03:14:24 PM

Using your master kit I am installing this on a 68 corvette with a 327 it allready has a return line on the system I would just tie into that and not need to do any different. I also would assume that it would eliminate the mechanical pump?thanks for your help

Chris Myer:
10/25/16, 06:03:24 PM

Yes, you will remove and cover the mechanical fuel pump. Fuel pump blockoff plates are on this page., If you have an existing return line on the car then connect the return from the Sniper to that line--otherwise, install one. You'll need a good EFI fuel pump as well. I generally recommend the Walbro 255 LPH Inline Fuel Pump. Be sure to install with a good pre-filter (20-40 micron is good) and a good post-filter (10 micron is preferred.)

10/25/16, 05:38:13 PM

Hello.. has any release date for the 8 injector version been announced. I'm currently running a zz502 with a different cam, some head work and victor jr with 900 Holley on nitrous in a 71 442. Also, I have a plate system on now with a wot switch. Would I be able to use the same system with the sniper? Thanks in advance

Chris Myer:
10/25/16, 06:23:15 PM

You are going to be thrilled with the Nitrous capabilities of the Sniper, Rob. You can keep the plate system and get rid of the WOT switch. And provided that keep your nitrous tune within the HP capabilities of the Sniper, you can run a dry nitrous system. The Sniper provides for both the activation of and the EFI tuning for your nitrous system.

For the activation, the Sniper provides an input to which you can wire an activation switch. Then you can use the handheld programmer to set the min and max RPM, the delay (if desired) and the duration.

For tuning you can either set a fixed ignition timing or timing curve to be implemented when the nitrous is active. You can also set a target air/fuel ratio for use when the nitrous is activated.

Unfortunately, there is still no ETA on the 8-injector Sniper. Stay tuned to http://www.holleyinjection.com and we'll let everyone know as soon as it is available!

11/12/16, 06:56:43 PM

Hey I have a 4.3 vortex gm in a yota with a Holley carb edelbrock headers and intake dual exhaust will the sniper work for my truck Live way up north and cold weather a carb can be a pain

Chris Myer:
11/14/16, 11:58:57 AM

Unfortunately, the Sniper would not be a good choice for your 4.3ll Vortec. Currently, the Sniper only works with 8 cylinder engines, so it won't work with your engine.

As long as you are pushing less than 275 HP, you might want to consider the Avenger 2-BBL TBI System. A link to that system is below. Note that it includes the fuel pump, filters, and regulator.

Holley Avenger 2-BBL TBI System

LIke the Sniper, the Avenger system is designed for V8 engines only. In the case of the Avenger, however, thsi only means that you cannot take advantage of the system's setup wizard. A qualified tuner can use the Holley tuning software to access the ECU and create a custom tune that will allow the Avenger throttle body to work with a V6 engine.

11/21/16, 07:09:03 AM

I see some people inquiring about the ignition control on this system and I am curious as well. I have 3 questions. I have an MSD 6al-2 box, so will all the features of this box still work with the sniper system (the two step is what im worried about)? Also will I need to run the Holley dual sync distributor to control the timing through the controller or is an MSD ready to run dizzy ok? And finally, does the sniper have the capability to be computer controlled similar to the terminator or other advanced systems? This is all going on a 429 bbf swapped into a 1955 fairlane.

Chris Myer:
11/28/16, 11:51:08 AM

Rather than diving right into the questions, let me clarify something that might simplify things a bit: If you have a working ignition system and want to keep it, you can. That's the truth, not just a political promise! If you are pulling a carburetor off of a working engine and installing the Sniper EFI, it is not mandatory to touch your working ignition. It will work just as well with the Sniper EFI in place.

However, in almost all cases you will benefit by having the Sniper EFI ECU control the timing. And, in almost all cases, you will find that the Sniper EFI ECU can do anything that most entry-level ignition boxes can do--including 2-step rev limiting! The only reason to couple a CD ignition box with the Sniper is for capacitive discharge ignition. Most other features can be implemented using the touchscreen display.

I always recommend initially installing the Sniper with your existing working ignition and then moving to timing control. At that point, you will either have to install the Holley Dual Sync Distributor or, if you already have an MSD distributor, then simply install the MSD 84211 Rotor Phasing Kit and lock out the mechanical timing advance. Installing the Holley is a bit easier but most won't want to spend the money to replace a perfectly good MSD distributor just to avoid a bit more complicated setup. For the Holley DS Distributor, just use the Sniper Dual Sync Distributor Adapter Harness and follow the setup instructons.

I hope I've answered all of your questions. If not, please use the phone, chat, or email options to reach back and get the rest answered.

11/25/16, 11:44:42 AM

I was wondering if the sniper efi would work with the Fitech fuel command center?

Chris Myer:
11/28/16, 12:25:52 PM

Short answer: It absolutely will!

More detail: The Fitech Fuel Command Center relies on your car having a existing/working carburetor-type fuel pump when many installers would just as soon do away with that entirely. The old pump (not to mention the decades-old fuel line) are have much potential to fail. By the time to replace all of that you could have simply installed a good EFI fuel pump.

Our bias is certainly showing here, but we prefer the Holley In-Tank Returnless RetroFit Fuel Pump. A bit more cost and a bit more effort, but this is more of a complete solution rather than a work-around. Or, for a few more dollars, Holley has introduced their own line of replacement fuel tanks complete with EFI fuel pump for a broad range of classic cars. Certainly the Fitech has its place in the market but if you're looking for a more complete and permanent solution I would recommend one of these two ideas. Good luck!

Jason Forster:
12/2/16, 10:31:50 PM

Hi there, I have a unique situation for you. I'm currently looking for a system to convert a 502ci Boss Hoss trike (v8 motorcycle) that currently sports an overly rich running quad on it. Super short tight headers and straight pipes. The bike weight about 1300 lbs. will this sniper work with this engine? It seems we can tune it with a smaller carb but sacrifice some power or as it is now, over carb it and run rich. I'm in Alberta, Canada, so a little north.seems this Sniper may be too goo to be true? Thanks, Jason

Chris Myer:
12/5/16, 12:35:23 PM

I think the Sniper would be perfect for your application. One of the beauties of fuel injection is that you are no longer trying to "tune" the setup with a larger or smaller carburetor. To some extent as large as the throttle body provides adequate air flow (which the Sniper should do at 800 CFM) then the ECU is responsible for nailing the air/fuel ratio. The Sniper does this perfectly.

The only concern I have in your particular application is placing the O2 sensor. For one, the sensor must be a minimum of 18 inches from the end of the exhaust pipe. Any closer than that and you can get reversions of air that throw the sensor off. Also, you want it after at least one of the collectors so you are getting an average of 4 cylinders. Finally, you want the sensor angled downward a bit so that moisture cannot collect in it. If you can accomplish those then I think that the Sniper is going to be perfect!

Jason Forster:
12/6/16, 11:36:17 AM

Because of the unique situation of the motorcycle's fuel tank my concern is the fuel return and the 3psi. I have access to four bungs on the bottom of tank, fuel delivery, crossover, and two are plugged. Can I plumb the return into one of the unused holes and return from bottom up or will the volume of fuel in the tank hinder the return. Would a low volume fuel pump inline with the return help?

Thanks again

Chris Myer:
12/6/16, 01:49:59 PM

I follow your thinking but don't think that the weight of the fuel will create a big problem.

If you notice the diagram of the master fuel kit in the Sniper Installation Instructions you will see that it includes a fuel cuff that returns the fuel below the level of the fuel. Because in both cases the fuel is entering the tank and lifting the fuel level, it makes little difference whether it is entering top-down (like in the master fuel kit diagram) or bottom-up (as it will be doing in your situation.)

The concern is that the pressure on the return will increase the pressure in the feed. The truth is, because of the way that the Sniper algorithm determines the amount of fuel to inject, a small change in feed pressure doesn't have that much of an impact. The increased pressure will flow a bit more fuel through the injectors than is expected. But then the O2 sensor would sense the enriched fuel ratio and would reduce the time the injectors are open and again dial in the precise AFR.

In other words, the Sniper is always seeking the target air/fuel ratio (AFR) and a small change in pressure won't really have any impact. My recommendation is to run with the installation exactly as you plan. If something acts oddly after the system has time to tune you can always adjust course. I suspect it will work perfectly. ;-)

12/17/16, 04:34:30 PM

Any release date or info on the eight injector system?

Chris Myer:
12/27/16, 09:17:14 AM

No release date yet! Stay tuned here at EFISystemPro.Com and as soon as we get some insight to the 8-injector Sniper release date we will share it!

12/24/16, 05:52:09 AM

Hi from France,

Does O2 sensor necessary on exhaust with the Sniper?

thanks a lot


Chris Myer:
12/27/16, 09:22:35 AM

Good question. At least from initial start-up through the point when learning is satisfactorily completed, the O2 sensor is necessary. The default fuel map that is provided is so unlikely to be tuned to your application that you can put that chance out of your thoughts. So the O2 sensor is necessary to do that tuning.

Once tuned, it is theoretically possible to disable the learning and the closed-loop operation, but I do not advise that. The O2 sensor and the Sniper EFI System's ability to learn are one of the key benefits to this system. Even after you have established a great fuel map for your application the closed loop will continue to provide a more robust range of operation over virtually any change in atmospheric pressure, ambient temperature, or anything else that might affect the air/fuel ratio.

Jonathan Henson:
01/1/17, 08:53:55 AM

I have looked all over the website and not seen one place that mentions what fuel types this thing can handle... e85? Methanol? 112 octane? Etc

Chris Myer:
01/3/17, 10:22:39 AM

Good question. I've seen nothing that indicates the Holley officially supports anything other than gasoline. That said, there should be no issues with high-octane racing gasoline, although I can hardly envision a case where 112 octane would be necessary given the other limitations currently in place on the Sniper (V8, 600 HP or under, no boosting.) On the coming 8-injector version you might have HP/boost/rpm levels that combined might be high enough to warrant higher octane numbers (but 112 still seems a lot.)

E-85 / Methanol is another issue. Again, I've seen nothing from Holley that suggests the Sniper will support these very harsh fuels. However, from an algorithmic standpoint, I theorize that there would be no problem. The ECU doesn't read or target the gasoline air/fuel ratio (AFR) but instead reads and targets a specific lambda. An appropriate E85 AFR is quite different from an appropriate gasoline AFR, but the lambda value for both is the same, so it should self tune the same with either fuel.

Three big caveats. First, this purely theoretical endorsement that the Sniper EFI would tune itself correctly on E85 is not to imply that there might not be other concerns. Specifically, I would wonder how long the built-in fuel pressure regulator would last in the presence of E85.

Secondly, E85 may destroy other components installed with the Sniper, and in fact will kill the fuel pump included in the Sniper master kit. An E85-compatible pump must be used.

Finally, the maximum HP capability for the Sniper must be degraded by approximately 28% if using E85. In other words, the maximum horsepower that the 4-injector Sniper can support on E85 (if indeed the Sniper EFI System can support E85) would be closer to 430 HP instead of 600 HP.

Can your performance parts supplier provide EFI system technical support like this?
If not then you should be buying from EFISystemPro.Com.
Remember, no one is as passionate about or as able to guarantee the success of your EFI project as EFISystemPro.Com!

01/3/17, 10:24:25 AM

Page 2 of the QuickStart Manual mentions "Unleaded Fuel Only."

Mark LaJeunesse:
01/19/17, 08:39:02 PM

Good evening Chris; Does running a mechanical fan effect the efficiency of this system? unless i missed in reading, i did not see much about having to run a mechanical fan. It appears that this will be a good product. Will the display screen show something if the system fails? if not how would you diagnose what is faulty. Thank you

Chris Myer:
01/20/17, 11:26:26 AM

Running a mechanical fan will not have any effect on the efficiency of the Sniper system.

There is a huge amount of diagnostic information available via the included 3.5-inch touchscreen display. Using this, is is possible to detect quite a number of problems. For example, while it will not directly sho a failure of an electric fan (should you choose to install one) it does allow you to monitor engine temperature. Also, keep in mind that the Sniper works with Holley's amazing Analog-Sweep Digital Gauges.

I hope this is helpful!

Gary Holman:
01/22/17, 01:09:33 PM

Hi Chris , I have ordered the sniper, and I saw you Duraspark comment above. Currently my Duraspark runs an MSD through the two wires. I I lock out my Duraspark can I use the sniper to run the distributor and eliminate the MSD? Thanks in advance Gary 65 sunbeam tiger

Chris Myer:
01/23/17, 06:45:26 PM

Oooh--Sunbeam Tiger. Very nice! :-)

When you say "MSD", I'm understanding that you mean a MSD CD box, like an MSD-6. Yes, you absolutely can run with or without a CD box, whether you are letting the Sniper ECU control the ignition timing or whether the timing is independent.

But since you mention locking out the distributor it is clear that you want to let the Sniper control the ignition timing. In that case, and as mentioned in that earlier post, you have to either install an MSD distributor / lock out the advance / add the rotor phasing kit or install the Holley Dual Sync Distributor / add the Sniper-to-DS Distributor adapter.

If you do away with the CD box you will need to include the coil driver module that comes with the Sniper. Otherwise, the CD Box acts as the coil driver. I hope that makes sense. :-)

Ashley moroz:
02/2/17, 11:25:55 PM

Will the holley sniper kit work on a motor that doesnt produce 250 horsepower stock 1968 ford mustang with a 289

Ashley moroz:
02/7/17, 12:46:44 PM

Thank you for your reply I'm still going to give it a go the car will eventually be getting a more powerful engine maybe sooner than later lol

Chris Myer:
02/7/17, 11:30:33 AM

As you have seen, Holley publishes an upper and a lower HP limit for the Sniper. The upper limit is much more fixed. The current 4-injector sniper can only flow enough fuel to feed 600 HP of naturally aspirated horsepower on gasoline. You can't reasonably alter that.

The lower limit is a bit more flexible, but there are no guarantees. If you try to install this on an engine with less than 250 HP, you might find that the initial tune delivered by the setup wizard is not as accurate as it would be were you in the 250-600 HP range. Some manual tuning might be required (which is not what Holley had in mind for this product.) It might even require you to install an adjustable fuel pressure regulator in front of the Sniper and lower the fuel pressure to the unit. And there is no guarantee that this would work.

So if you are looking for the safe, conservative answer: No, don't try to install this on your stock '68 Ford Mustang 289 making less than 250 HP. If you really want to try this and are willing to absorb the cost in the event it does not work to your satisfaction on your particular application, great! We respect that adventurous attitude when correctly paired with an understanding and acceptance of the risk and will eagerly lend whatever expertise we can provide in the process.

03/31/17, 06:49:36 PM

Can I run the main positive wire to the starter? My battery is trunk mounted. Thanks!

Chris Myer:
04/3/17, 06:15:51 PM

That wouldn't be a good idea! The starter is such a power hog that it can really cause some ugly voltage surges. That is precisely why the battery is specified. It is so much more than just a power source. It also acts like a big sponge to absorb and clean up power transients. Even though you are mounted in the trunk I recommend that you run your power and ground to the battery. The extra effort is going to pay off!

04/3/17, 06:21:51 PM

Thanks Chris! One more quick one. Can the fuel pressure gauge be installed on the return side?

Chris Myer:
04/5/17, 03:59:01 PM

Well, technically, yes. But it's only going to read the pressure on the return line, which should be less than 3 PSI.

To read the feed pressure you need a fuel pressure gauge on the feed side. We have the PERFECT solution. This 100 PSI Mechanical Gauge can be ordered with the optional -6 AN Male / -6 AN Female port that lets you attache the gauge right at the inlet of the Sniper. Never again guess about your fuel pressure.

We also have an entire page of Sniper EFI System repair and accessory items.

04/13/17, 07:25:48 PM

One last one Chris...I already have an electric fuel pump and wiring installed so can I connect the blue Sniper FP wire to the switched 12v wire in the harness?

Chris Myer:
04/18/17, 10:49:17 AM

No, those wires need to stay separate. However, regardless of your fuel pump setup, it MUST be activated by the blue Sniper fuel pump line. This is a critical safety feature. It is the only thing that guarantees that if the fuel line is cut in an accident that the fuel pump is shut off instead of just continuing to run, pumping fuel all over the vehicle.

05/2/17, 08:46:00 AM

Will the sniper set up work with an edelbrock performer intake or will I have to buy a holly specific intake?

Chris Myer:
05/3/17, 02:34:07 PM

The Sniper works great with any intake manifold that will accommodate a 4150 style (square bore) carburetor flange.

06/2/17, 12:19:00 AM

I am reading through the wiring instructions and I do not see the ability to have both coil and cd. Am I looking at the instructions incorrectly? I have 6al,msd pro billet and msd blaster coil.

Chris Myer:
06/2/17, 12:03:43 PM

You might get a better perspective by looking at the article I wrote specifically on Sniper and Terminator ignition. If that doesn't answer the question let me know.

Ryan Mackey:
06/5/17, 10:03:35 AM

I have a ford 2.3 turbo engine in a tube frame hillclimb race car that blows through a Holley double pumper 650 at max boost of 10 psi. I wanted to convert over to stock type fuel injection but cost and complexity have kept me from it. I have read conflicting info about the sniper regarding turbo applications below 15 lbs boost and use on other than 8 cylinder engines. The sniper packs so many devices into 1 small package, I am interested to know if it could be used in my setup. The current configuration dyno tuned at 301 hp to the ground at 6800 rpm.

Chris Myer:
06/5/17, 04:48:34 PM

You are right--lots of conflicting information! But I think I can clarify things a bit.

In it's basic configuration the current Sniper is intended to be a plug-and-play solution for naturally aspirated V8 engines. But when you learn more about the Sniper you start wondering if it can't do more.

It turns out that Holley built this with a 2-bar MAP sensor, which leads one to believe that it could be used in a boosted application (under 1 Bar of boost.) Further, the Sniper Software allows you to select from 4-, 6-, or 8-cylinder configurations. So does that mean it can work with your 2.3l engine?

The answer is a qualified "yes". Obviously the handy setup wizard that is provided on the handheld is not going to work for you. But because you can change the settings using the Sniper Software, and since there is a 2-bar MAP sensor, in theory this is all doable.

But the better question is not if the Sniper will work but should you use the Sniper. And only you can answer that. A couple of things to keep in mind. First, this is going to take a good bit of "discovery learning". From your existing setup I don't think that should scare you. But if you are the sort that might bolt this on and expect it to work with any hiccups then I'd say stick with your double-pumper.

Second, the next iteration of the Sniper (the "Super Sniper") has some impressive boost control capabilities. Unfortunately, we have neither price nor ETA on the Super Sniper at the time of this writing. And Holley has been notoriously inaccurate with ETA's lately, so even if we had one I'd say push that date out by 6 months easy.

Finally, I would not be doing my job if I didn't point out that for your setup I'd recommend a Holley HP ECU and multi-point fuel injection setup. By the time you're all through it will cost about 2-3 times as much but it is really the system someone at your level should be using. But I certainly understand that the Sniper is tempting.

Ryan Mackey:
06/13/17, 04:20:48 PM

Thank-you for you thoughtful response. Stock type fuel injection will cost me about $2500 by the time I upgrade all the parts to support the 300-350 hp platform. Aside from the economy advantage, the sniper could simplify the array of components needed. The combination of sensors and controllers built into sniper would allow me to remove many devices and simplify. I believe in "simplify and add lightness". Sniper is a powerful device in a compact design at an amazing price point.

Chris Myer:
06/13/17, 04:46:25 PM

You've clearly done your homework and I certainly can't argue with your logic. The only test you have to pass now is the "Where To Buy?" test. Be sure to buy from someone who not only knows the system intimately but is committed to their customer's success. Hint: We have two of the Silver Sniper's in stock today and expect a shipment of black ones within the the next week or so. :-!

Wes Rager:
07/17/17, 03:41:09 PM

I finished installing and plumbing the Sniper system. All gauges read properly per the instructions. When I crank the engine it won't "sync" so no fire. It is a GM large cap HEI (no timing control) and the yellow wire from the harness is connected properly to the tach output of the dizzy. I replaced the module and still no sync. Any thoughts?

Chris Myer:
07/17/17, 05:12:40 PM

Since you're not set up for the ECU to control the ignition, sync with the ECU isn't required for the ignition to fire the spark plugs. If you're not getting fire then you have another problem.

Start by looking at the RPM on the handheld monitor when you're cranking. Does it ever say anything other than "stall"? If so, the yellow wire from the distributor is working. If not then' you're going to have to troubleshoot the ignition. That's a bit beyond this venue but if you've replaced the cap and the module you might need to consider replacing the coil.

Eric Rourk:
07/29/17, 05:07:19 PM

I have the msd 6al-2 programmable already installed. Is it possible to run these together? I read that the sniper doesn't have to control timing but can the 6al-2 just do ignition and let the sniper control it?

Chris Myer:
08/2/17, 03:13:54 PM

The Sniper EFI System can control timing or not. The choice is up to you. If you choose not to control timing with the Sniper EFI System then it will have no input to the ignition system--regardless of the components. In the case of your MSD 6AL-2, it will simply receive the tach signal from the box.

08/19/17, 11:25:06 PM

Is the sniper 1200hp out i cant seem to find it anywere

Chris Myer:
08/21/17, 02:42:00 PM

Not at this time. Not even an ETA (which is probably good since Holley's ETA's are pretty wild speculations at best.) Keep watching the link below. As soon as an ETA is provided we will start offering the 8-injector Sniper for pre-order.


Barry Slaydon:
09/9/17, 03:58:56 PM

I have a question about sniper throttle body.I currently bought a 1997 gmc truck with vortec 5.7. Wondering how to set your system up. The Vortec has spider injection and I want to get rid of that system. Can I run this on my truck with existing harness that runs everything except throttlebody system?

Chris Myer:
09/15/17, 12:44:42 PM

There is no question that you can replace the existing fuel injection system on your '97 GMC Pickup with the Sniper EFI system. The question is whether or not you can maintain the correct operation of the rest of the computer-controlled systems on the truck--the ignition, the ignition and dashboard, to name but a couple.

The answer of this question is a bit beyond my experience level. And while I am usually one to urge such a venture, I can easily see where this might leave you in a bad situation where nothing works--OE or Sniper. So I will conclude by pointing out that this is absolutely not the target vehicle for the Sniper system. This is something that should be approached by a very experienced EFI technician, with an ECU more akin to the Holley Dominator than the Sniper (if you are interested in keeping the rest of the vehicle in factory operation.)

Erik Miller:
10/13/17, 01:13:55 AM

Hi. Can I run a low (25-50hp) power dry nitrous setup with the Sniper EFI? Will it sense the change in A/F ratio and compensate with fuel up to the 600 hp limit? Would I need to bring it in slowly with a progressive controller or would the system react fast enough?


Chris Myer:
10/17/17, 06:27:41 PM

That's a great question, and Holley must have known you would ask it because they put an absolutely amazing nitrous tuning section in the help file that comes with Holley Sniper Software.

I'll try not to turn this from a helpful reply into an advertisement but the Sniper Software is what truly puts the Sniper EFI System in an entirely different class than comparably-priced EFI systems (or even many higher priced systems, for that matter.) This is not some dumbed-down software built for a $1000 EFI system but is essentially the same software that runs the HP and Dominator ECUs with surprisingly few limitations.

Nitrous control may be the single best example of this capability. Want progressive control? You can do it with the Sniper ECU without the need for an additional controller. Need to account for pedaling? Rich/Lean cutoff for the nitrous solenoid? Stage activatoin and duration? All this and more. And it costs you nothing more than what you paid for your Sniper EFI System.

You can download the Sniper EFI Software for free on this page. After you install it on any Windows-based PC/Laptop, open the software and click on the "Help?" button at the top. This opens a PDF file that is an amazing wealth of information on the Sniper, with a section specifically for Nitrous. It will answer all of your questions above and then give you more great ideas. Check it out!

Calvin Lawrence:
11/2/17, 09:25:13 PM

Can the ecu on the sniper system be used to control a 700R4 trans. ?

Chris Myer:
11/8/17, 06:09:35 PM

When you say 700R4 I presume you mean the electronic version, the 4L60E. Unfortunately, no, it does not have the capability to control that transmission. There are a few relatively low-priced 4L60E controllers on the market, but they all need to read the throttle position sensor. Here's where it gets tricky.

In theory, the TPS signal should be able to be tapped to feed two ECUs, provided they are both high-impedance inputs (as they almost certainly are.) But in practice, it's not so simple. I have one customer who has been working on this for some time now and isn't having success. It seems that the Sniper ECU is seeing RFI being induced on the throttle position sensor and it's wreaking havoc.

I have a gut feeling that I might be able to make this work. And I had a chance to buy a '94 Silverado with the 4L60E and try my luck. But I ended up not buying the truck so I'm left wondering if this is doable. Still, I think that the right combination of shielding and or diodes/etc might alleviate this problem.

11/23/17, 11:50:23 PM

Can the Sniper be used for a turbo car ?

Chris Myer:
12/6/17, 02:32:07 PM

Absolutely! We have one customer who is running the Sniper EFI System on his boosted Mustang 5.0 with great results. The system ships with a built-in 2-bar MAP sensor that will allow you to run up to 1 bar of boost.

Let me quickly point out that running the Sniper on a boosted application is not as easy as a non-boosted one. First, recognize that because it takes more fuel per horsepower to run a boosted application, the maximum horsepower limit imposed by the injector size on the Sniper is closer to 500 HP. Second, there is nothing in the setup wizard to install turbo-specific settings to the configuration.

If you go this route, I'd recommend setting the displacement in the setup wizard based on the boost you expect to run. In other words, if you want to boost about 7 PSI (roughly 1/2 BAR) then multiply your projected displacement by about 1.5. A little less if you have a low-compression engine, a little more with a higher compression engine.

Secondly, as soon as you complete your configuration I'd suggest modifying MAP axis on the fuel map. To do this you'll need to use the Sniper Software. By default, the setup only gives you two rows of positive manifold pressure--way too little to effectively tune. I suggest the following:

Start by going to the top cell and set it to the maximum amount of boost you wish to run or a bit over. The cells below this will automatically change to be linear from the lowest pressure (-13.8 PSI by default) to the new top setting. Be sure you're running a good boost controller--this new top row represents the maximum amount of fuel that the Sniper is going to provide based on boost.

Next, go to the 11th cell from the top (1/3 of the way down) and entering a '0'. The cells above and below will again auto-index. This will give you 2/3 of the MAP range at off-boost, where you need a bit more resolution for tuning.

This is a bit of an over-simplified guide but it should get you started. I do recommend that anyone who is running boost with their Sniper consider two important investments. First, I'd opt for the Holley Dual-Sync Distributor and set up timing control. Then, I'd take the entire finished setup to a good dyno shop and spend a couple hundred dollars to have it tuned by a professional. Yes, the Sniper is self-tuning but boosting can be unforgiving to errors in either fuel or ignition. By setting up the Sniper to control ignition timing and getting a top-notch tune I think you'll find that the Sniper EFI System can do amazing things in your boosted application.

12/22/17, 11:48:57 PM

Will this work on a 1985 Ford F-250 running a carbed 460 7.5 liter with air injection pumps for smog controll? Dual tanks with return lines and electric in tank pumps already in truck.

Chris Myer:
12/29/17, 06:11:04 PM

The good news is that by having a fuel pump already in the tank and return lines in place all you'll need to do is upgrade the in-tank fuel pump, replace the rubber lines with high-pressure capable EFI lines, and your fuel system will be done.

Unfortunately, I'm no experience trying to keep the air injection pumps operational. From a purely theoretical perspective, the engine should only operate more efficiently and with less carbon emissions with a highly tuned fuel injection system. But you'll have to find someone with more experience on how those smog pumps integrate to find out if that can be done. Good luck!

03/14/18, 07:59:21 PM

Will this work with my factory duel electric in tank pumps controlled via my selector switch on the dash? already has fuel pump relay from factory. Or do I need to figure something out to run each one individually? I really want this for my truck but this seems like my only hold back but don’t want to wire a maze up just to run one pump in the front tank and then run another pump in the rear tank. I’m hoping it can just be wired to the factory power wire for the pumps. Please tell me this is possible and I’ll be buying one for my truck.

Chris Myer:
03/20/18, 04:27:16 PM

This is absolutely doable--however it generally takes some engineering. First, recognize that it's not going to work with the existing fuel pump. It produces far too little pressure. So plan on a fuel pump upgrade (one of these Walbro 255 LPH fuel pumps with installation components might work great.)

Next, you have to remember that there must be a fuel return to allow the EFI regulator to correctly regulate fuel pressure. So if you are using two pumps to push fuel to the Sniper, you have to return fuel to the tank from which the pump is sending it. That can get tricky. You are now not only switching power but you will also need to mechanically switch the fuel flow for the return.

Here's what I've seen (but don't necessarily recommend): Only return fuel to the primary tank and only run the secondary tank long enough to fill the primary tank. It works like this: Install a pump in both tanks. You can tee them together (they have an internal checkvalve) and run both to the Sniper. Run from the primary pump until that tank is low, then switch to the secondary pump. When you do this, however, you must watch the gauge and only run until the primary tank is full or the secondary tank is empty, whichever comes first.

If you are easily distracted this may not be the best solution. All it would take is a moments inattention and suddenly you're out of gas--or trailing a spray of gasoline behind the vehicle. Note too that you may well need to run an larger vent to accommodate the greatly increased amount of fuel displacement that will be occurring when you are transferring fuel between the tanks.

Brent Cates:
01/17/18, 12:29:01 PM

Hey Chris, quick question,wiring instructions say that unit must be hooked directly to battery(pos/neg). my battery is located in the trunk with ground to frame and frame to engine block. Is this acceptable or should I run cable from battery directly to engine block. Also, if I choose to buy this system, I would get complete fuel tank also. would the sending unit work with my factory gauge?

Chris Myer:
01/22/18, 06:07:56 PM

Holley is absolutely unwavering on this: Both the power and the ground from the Sniper must be run to the battery. I wouldn't worry about changing how your engine block is grounded if it is working for you. But Holley says the Sniper EFI System power and ground are important and they are in a position to know. :-)

Yes, the fuel tanks come with a sender that is suited to the factory gauge for that specific make, model, and year. If you are buying a tank GM that overlaps the years 64 anf 65 (such as the tank system for the 1962-65 Chevy II Nova) I would use an ohm meter and confirm if you have the early sender (0-30 Ohms) or the late sender (0-90 Ohms). 1964 was generally the last year for the early sender but there are a few rare exceptions. If you have a GM that falls into this range then let us know what you have and we'll be glad to make sure you get the right one the first time.

You can check out all of the available Fuel Tank Systems here!

Colter Morris:
01/27/18, 11:45:22 AM

How hard is this to install. I have a 1985 Chevy 350 and wantin to do fuel injection. And have heard good things about this set up. Wanting to know overall cost for pros and cons. Thank you.

Chris Myer:
01/29/18, 04:06:29 PM

Ok, let me give a "full disclosure" response here. The Holley Sniper EFI System is easy to install if you have moderate-to-advanced "shade tree" mechanic skills, have a good head for troubleshooting, and aren't easily frustrated.

Admittedly, this description does not include everyone. If that's not you then don't worry--we've got you covered. We don't ship you a box and send you to Holley tech support with a "Good Luck!" If you buy it here I and the team are going to personally ensure your success. Try me: Use the "Sales Support" feature at the right hand side of this page to chat with us, or visit our Contact Us page to email or call. It makes my day to take your call and give you the benefit of my years of EFI experience. I'll answer your every question and help customize your order into exactly the components you needs to be successful.

Listing the pros and cons could get a little long here but let me say this: There is not a single EFI system that can do as much as the Sniper EFI System for the price. Others will argue that point but to me the software has everyone else beat. However, if you need to do electronic transmission control or if you wanted to run a dual throttle body setup, there are better options. Short of that, the Sniper EFI System is your best bet.

Ryan Bringel:
02/28/18, 06:30:16 PM

I am looking to put EFI on a small motor. Basically a 1.8 Isuzu(Chevy Luv, 1980). It currently has a Holley 4bl (Crazy big I thought) on it. But it is still a small motor at 109Ci. Would the 2300 Sniper work out for my small motor? Looking over some of the replies here and some seem to indicate V8 only but a more recent one mentions it working on a ford 2.3. Trying to determine if I should try this or the MSD setup. Thanks !

Chris Myer:
03/2/18, 05:29:50 PM

I think that the Sniper 2300 EFI System would be a good choice for your Luv pickup provided you are trying to make some significant power.

When Holley originally released the Sniper, some of their literature suggested it was only for V8 engines. That was incorrect. All of the Sniper systems can be used on 4-, 6-, or 8-cylinder engines, provided that other criteria are met.

This is going to be a big throttle body for that engine (especially if it is unmodified.) But that is the beauty of EFI versus a carburetor. EFI does not require a certain amount of air flow to draw fuel through a venturi. There can be throttle response issues but if you're looking for something that will let that engine (coupled with other upgrades) make some big horsepower then it will work.

On the other hand, if you are happy with something close to the stock horsepower and want nice, smooth throttle response, the 400 CFM that this throttle body can provide might be a bit much.

If you decide to go this route know that I will be available to talk you through the planning, installation, and tune/learning process so you won't be on your own.

03/8/18, 11:00:40 AM

Considering the Sniper EFI for a 1986 C4 Corvette with L98 engine to replace the currently failed TPI system. The stock ECM controls spark advance. It has the stock large cap GM HEI distributor. The stock set up has provisions for the required throttle valve cable for the 700R4 transmission. I understand the intake manifold will have to be swapped to a carb manifold. Here are my questions:

1) Can the Sniper ECU control the factory spark advance?

2) Does the Sniper have provisions for attaching the throttle valve cable on the throttle arm?

3) Is there a carb manifold that will work with the stock 1986 L98 cast iron heads and have provisions for the bracket to mount the throttle and throttle valve cables?

4) Can the Sniper ECU control the torque converter lockup switch?

Thank you!

Chris Myer:
03/9/18, 03:49:32 PM

I won't oversimplify your situation but at the same time let me assure you that the Sniper was made to solve situations like this. To your questions,

Q1. With enough effort generally anything is possible when it comes to ignitions. But the best way would be to yank the factory setup and go with the Holley Dual-Sync Distributor. This will give you complete ignition control with a modern distributor that uses a hall-effect pickup. Works great, fewer headaches than other options. (Read also my post on Sniper Ignition Setup.)

Q2. Absolutely!

Q3. Don't worry too much about the throttle linkage or TV cable hookup. In addition to a dedicated linkage connection for the 700R4, the Sniper EFI Kit includes a bracket to accomodate the throttle and TV cables (regardless of what's available on the manifold itself.) Few folks run into trouble with this.

Q4. The original Sniper EFI System has a very limited number of inputs and outputs and none of them were really directed for this purpose. Still, you might be able to make this work using that system. However, on the new Super Sniper EFI System you get an additional 8 pin connector that should allow you to do what you want with no problem!

Rider 327:
03/15/18, 10:57:40 PM, www.efisystemspro.com

Howdy!! I'm installing a sniper on a 427 k20. I heard about the sniper from a friend that's has the sniper set up on a blown 454. He's had great results so far. His sniper does not have a return line. The return line port on the sniper is caped off. He is also running the edelbrock fuel pressure canister. He said when he ordered it from a local dealer in our town he said they could set it up so the return line wasn't needed. Is that an option to not have a return line if I were to order a sniper kit? It would be very handy and cut down on installation time. That's for the help

Chris Myer:
03/20/18, 05:18:32 PM

If I understand you correctly, your friend is running the Edelbrock Universal EFI Sump Fuel System Kit. These kits are internally regulated, which means that they do not require a return between the Sniper and the sump. They do require a return line to the tank to act as a vent, allowing the sump to stay at a neutral pressure.

There are a few different ways to avoid running a return line for your Sniper. But they generally all involve spending more money for that convenience and/or leaving in place mechanical fuel pumps that I'd just as soon see removed from my engine. Nothing against mechanical fuel pumps, but as soon as you double the number of fuel pumps you also double the likelihood of fuel pump failure.

The possibilities for EFI fuel systems can be numerous depending on the specific application and are a bit beyond what we can cover here. However, if you contact us we can gladly lay out all of the options available to you and help you select the one that is best. I look forward to hearing from you soon!

03/19/18, 04:26:36 PM

Chris, Did you ever find a solution or did your customer find a solution to running a sniper with in conjunction to a Quick 4 controller either sharing a TPS signal or mounting a way to obtain another one?

Chris Myer:
03/20/18, 07:00:06 PM

I just this week circled back on this subject and contacted US Shift to get the ground truth. Their technician assured me that they have lots of installations out there that are running their transmission controller products and are sharing the connection with the Sniper EFI TPS signal.

So I am a bit confused why the obvious RFI that we saw on that one customer's TPS that was only present when the TPS splitter was attached to the US Shift box. One thing I suspect--the splitter which US Shift recommended (they don't make on themselves) was quite long and did not have enough twists for my comfort level. Any time you can twist a signal wire like that it always helps reject RFI. And the shorter--the better!

We just had another customer who bought a Sniper for his '94 Suburban with plans to use the US Shift controller. Based on their comments I'm eagerly looking forward to better success on this try.

Eric Rourk:
04/2/18, 10:31:58 PM

What is recommended fuel pump wise on the sniper. My pump now is from a 90's TBI camaro.

Chris Myer:
04/4/18, 11:59:51 AM

Great question! Cars that came with the GM TBI engine are fortunate in that they have a very easy path to upgrade to a Sniper EFI System-capable fuel pump. Simply order one of these Walbro / TI Automotive GSS-Series Fuel Pump Kits and select the F20000169 Fuel Pump Kit option and you get absolutely everything you need to drop a 255 liter per hour high pressure capable fuel pump right in place of your original low-pressure TBI fuel pump.

This pump is an OE-quality, made in the USA in-tank fuel pump so it will give you years of reliable performance and low noise for a high-performance fuel pump. Be SURE to replace all of the existing fuel hose on your car with a high quality EFI fuel hose that is capable of handling the additional pressure created by this fuel pump. Plumb the fuel feed to the Sniper and from the Sniper's return through the existing hard lines under the car. Don't forget to install a 10 Micron Fuel Filter between the tank and the Sniper and replace the worn out factory spring-type clamps with quality EFI hose clamps.

Warren Johnson:
04/11/18, 08:34:43 PM

I have a 1984 ford 460 with duraspark II ignition. Can I use the negative side of the coil for the tach signal without hurting anything? Not looking to control timing. Thanks

Chris Myer:
04/17/18, 02:58:47 PM

Yes. Provided that you aren't running any sort of capacitive discharge ignition box (like the MSD 6) then just connect the yellow wire from the Sniper 7-pin harness to the negative side of the coil. If you are running a CD box, you should not use the yellow wire but instead use the included purple wire with the two-pin connector to attach the purple wire to the tach output on the CD box.

Ed Hunter:
04/23/18, 10:34:30 PM

Chris - I race a mustang in American Iron with NASA. These are road course cars (two of them), with Boss363 pushrod engines in them. RPM ranges widely, and often, running from 3k - 6500. Throttle response is critical. One car is carbed, looking at the poss of switching the other to the sniper efi system. I run a mix of 93 and 100UL fuel for safety purposes. HP is approx 400 to the tires, torque close to that. Wondering if one of these systems would work well for this type of racing.... Thanks, ed

Chris Myer:
04/24/18, 02:48:19 PM

I think that the Sniper would be a great choice. The 800 CFM throttle body is going to be more than adequate to feed your 400 HP engine, and it will work well on any gasoline combination you might throw at it (though it always works best if you tune for a specific fuel octane and BTU rating, of course.)

Regarding throttle response, that is very driver dependent. The throttle feel on the Sniper tends to be quite aggressive due to the large flow capacity and the fuel injection, but realize that is very tunable. Between changing return springs, extending the throttle lever arm, or switching to a progressive linkage setup, you can pretty much dial in whatever throttle response works best for you. I think you'll like it!

Hunter Dias:
04/24/18, 04:36:54 AM

How do I know which EFI system is best for a certain size engine? I have a 496 BBC with a large cam producing 4 to 6 inHg at idle. Currently have the holly mech double pumper 750 cfm and with mods to the carb the accelerator pumps floated at about 5500 rpm on the engine dyno stand. Pulled 510 HP and 600 lb-ft of torque. I was told the carb was adequate but the engine shop would have like to have seen a 950cfm carb on top too get more impressive numbers. Is the 650 HP kit with 800 cfm more than adequate? Or do I need to go to the 1200 HP and why?

Chris Myer:
04/24/18, 02:57:46 PM

I think that the standard Sniper EFI System a good choice for you, Hunter. Let me explain why.

The 800 CFM throttle body should be enough to feed 600 HP without undue restriction. Keep in mind that even on throttle body injection units like the Sniper, a simple CFM-to-CFM comparison with a carburetor is not going to tell the entire story. However, if the engine builder thinks that bigger CFM will produce more HP, then I think that a well-tuned 4-barrel Sniper should produce the expected results.

Since the Super Sniper is the same size throttle body (it just gives you the opportunity to choose from either four or eight injectors) that would not really be an alternative if you are trying to get to 950 CFM. Instead, you would be looking at the Terminator EFI System, which is fully 950 CFM. However, this is a much more expensive EFI system to begin with, and it only has 80 PPH injectors compared to the Sniper's 100 PPH injectors. A 205 PPH injector upgrade is available, but at this point you're looking at fully four times the cost of a standard Sniper EFI System.

In the final analysis, however, I would not base your decision to go with the Sniper EFI on a few more horsepower. If you have a custom-built and dyno'd engine with a carburetor on it then you are in a situation where you really need to have the engine professionally dyno-tuned with the Sniper EFI System in place to expect to see an increase in horsepower. And if you are going to do that for the additional 40-50 HP that you might gain, I would suggest you have a desire for the other many benefits of EFI, namely easier cold starts, avoiding vapor lock, better idling and response at lower RPM, less gasoline smell. If none of those really matter to you the additional few horsepower may not justify the cost in money, time, and effort.

Terry D:
04/25/18, 03:09:58 PM

I am very interested in purchasing this EFI carb. Will the Sniper EFI work for my 1966 AMC Rambler with a 287 V8? The car currently has a Holley #2209 2 Barrel on it. Do I need any type of adapter plates to mount to the current intake manifold?

Chris Myer:
04/26/18, 05:00:32 PM

I think that the Sniper 2300 would be a marvelous choice for your '66 AMC Rambler. I am not that aware of the baseplate differences between the two carburetors but a cursory search seems to indicate that an adapter plate would be needed. It might be worth the effort to find an old Holley 2300 carburetor laying about and do some measurements on the 2209 manifold. I couldn't find any references to a 2209 to 2300 manifold adapter, but since that would seem like a natural upgrade for this rather unusual carburetor it could be that it would fit without any adapter or with just some modifications to a 2300 spacer.

Kyle G:
06/3/18, 11:51:21 PM

I have received multiple recommendations to purchase this kit from some friends; however, none of them were unable to answer certain questions regarding the system. I have looked through the manual and these posts, and didn't find what i was looking for.

I would like to apply this kit to a 1987 Toyota 22R Engine 2.4L 103hp stock, w/ slight mods to include cam, head and o/s valves, exhaust. The stock carb flows at 326 cfm, will this system be too big for my application? I also noticed there is a 3/16 vacuum line. Can this be used to be used to run a vacuum advanced distributor AND have the ECM account for it? Lastly, is this kit able to be used in conjunction with a remote starter? Thank you

Chris Myer:
06/6/18, 06:45:51 PM

I cut my teeth on the Toyota 20R engine and was quite the guru on these back when I was much, much younger. So I can tell you with assurance that the Sniper EFI System would be a great choice on that engine--with some caveats.

First, recognize that fuel injected systems don't have the same requirement for air velocity to draw fuel into the air--it is injected. Still, there are some concerns with going too large with the air door but those largely revolve around throttle response and fuel puddling.

So, there is an easy solution to that--opt for the 2-Barrel Sniper 2300. That flows 400 CFM (instead of 800). You'll have to source a 2300 to Toyota adapter plate but I know from experience those exist. You will want to run a standard electronic vacuum/mechanical advance distributor to start. I'm not going to say it's impossible to make the Sniper control ignition on your 22R but I will say it will be a challenge and point you to this in-depth article I wrote on Sniper timing control. I see no reason why a remote starter would not work.

Personally, what I think would be a really great project is to do a 20R/22R with the 2300 Sniper and a turbocharger. We could only dream about having access to such an awesome, tunable EFI system at a price like this back then.

07/18/18, 12:28:09 PM

I have a 1994 chevy pick up c1500 with 5.7L im looking at putting the sniper efi on but cant find a answer on if the computer will still run the trans and dash ect.

Chris Myer:
07/18/18, 05:11:02 PM

The primary challenge with the transmission control is that it needs throttle position that is normally provided by the factory TPS. Some have tried to splice into the Sniper EFI System's TPS but the results have not been good. In theory, you could find a way to mount the factory TPS in parallel with the Sniper TPS but that would be challenging to say the least.

US Shift makes an aftermarket controller for the transmission, and it can be paired with a stand-alone TPS that can be remotely mounted, which should be a better solution but it not inexpensive. Or you could swap transmissions for about the same amount of money.

As far as the gauges, they should all continue to work correctly as long as you leave everything in place (factory ECU, wiring, sensors.) There will certainly be some issues with various check engine codes that would need to be compensated for. So it's doable but there will be a little bit of engineering involved. I'm currently rebuilding an L98 to drop into our '92 Chevy Pickup shop truck and will be facing some of those issues. However, I limited our search to '92 because that is the last year before the C1500 went to the electronic transmission. :-)

08/28/18, 11:34:49 PM, Ecosystem pro.com

Since the sniper systems have been out a while now can you tell me if I can run E85 on the 4500 version? I know it is 1550hp N/A I have bbc that will be around 1000-1050 hp and I would like to use the 4500. Thanks for your time.

Chris Myer:
08/30/18, 05:13:49 PM

That depends a lot on who you're asking!

Nothing in Holley's instructions manuals for any of the systems (Stealth 4500, Super Sniper, Sniper 4150, or Sniper 2300) say what fuel can be used with the system. On the Holley.com product pages for the Super Sniper (all colors, both 4- and 8-injector models) it says, "E-85 - Not Recommended" without giving any idea why. There is no such warning on any of the other Sniper models.

That this warning is only on the Super Snipers is a bit surprising since I am not aware of a thing that makes it unique when compared to the other Snipers. And "not recommended" is hard for me to interpret. It doesn't say, "Thou Shalt Not" nor imply that it could affect the warranty. Further, I know plenty of folks that are running E85 with their Sniper EFI Systems and have never heard so much as a hint of a problem.

So I'm going to leave that right there. I'm not giving anyone permission, just laying the facts out as I see them. :-D

Louis Belloisy:
12/22/18, 08:25:22 PM

Hello Chris, I have a couple of questions on the Sniper EFI that I plan on purchasing this coming spring.

First, when I remove my computer controlled Rochester carb, I will loose the trans lock up feature of the ECM. Will the Sniper be able to control transmission lockup and how does it work?

Secondly, The Sniper specs say that it is good for engines from 200 HP to 650 HP. The engine I plan on converting is a 1987 Firebird GM 305 engine that has 170 HP. Will I have a problem with the engine being 30 HP below min, specs? If so, what can I do to fix this problem. I have my heart set on the Sniper.

Chris Myer:
12/27/18, 03:57:31 PM

Good questions. I think this is a good point for me to provide the technically correct answer of "I don't know." I think that, using the basic I/O capabilities of the Sniper that allow you to activate an output signal based on the throttle position sensor you could implement a super-simple type of torque converter control. I also think that while this may be adequate for some there will be many others out there who would point out the shortcomings of this. There are various lock-up control modules available at fairly reasonable prices that will do this for you. I think that would probably be the best route, ultimately.

I've always been curious about the minimum HP specifications that Holley implements on their Sniper EFI Systems. Forced to guess, I'd say that the far and away majority of Sniper EFI System installations out there are on engines that only very occasionally produce over 200 HP. So obviously it doesn't mean that a Sniper can't be used to produce less than 200 HP. I tend to think that this is just sort of a general benchmark, and should suggest that maybe one of the Sniper 2300 2-bbls could also be a great solution for anyone that is producing a maximum HP at or under the 200 HP mark. I think the only real challenge you will face is a lack of throttle resolution, as the 800 CFM throttle body is going to be flowing enough to make 100% of your horsepower at only a small portion of throttle input. And for you a progressive throttle link is probably going to be mandatory.

Andrew Mueller:
01/20/19, 05:40:57 PM

Hi Chris. I have a carbureted Chevy 350 swap in my '93 Toyota Pickup which was originally EFI. I still run the stock Toyota EFI pump with a return style pressure regulator. I'm very interested in the Sniper setup but would like to continue to run the stock pump since I've spent good money replacing it not too long ago. I found that it's good for 41psi and 21gph. Could this be sufficient to run the Sniper? My 350 is a pretty mild setup.

Chris Myer:
01/22/19, 06:54:54 PM

Ah, the mighty Chevota! I think the Sniper EFI System would indeed be a good choice. If you are well under 300 HP then you might even consider going with the 2-bbl Sniper 2300 system, but if you ever have plans to push above that you're probably going to wish you'd gone with the standard Sniper 4150 4-bbl setup.

I certainly understand your desire to leave the pump you have in place. The numbers you quote are likely the requirements of the stock fuel system and not strictly a maximum pressure or flow rating. That said, you can be assured that the flow will drop as the pressure increases. And 21 GPH is only good for about 210-220 HP.

What you don't want to do is run out of fuel pressure at high load. That can be tragic. If it's me (I'm a bit of a risk-taker) I would install the Sniper with the fuel pump you have. Be sure to fit it with a Fuel Pressure Gauge. Crank it and see what sort of fuel pressure you have at idle. If you have 60 PSI then it is a contender.

Continue by removing the return line to the tank, direct it into a separate fuel cell, and catch one minute of returned fuel with the engine idling. That will tell you how much excess fuel capacity you have at 60 PSI. Measure in liters, multiply by 60 and gives you liters per hour. Divide by 0.38. (Example: 1.5 liters per minute is 90 LPH. 90 LPH divided by 0.38 is about 240 HP.) If based on accurate measurements, your calculation will provide a conservative estimate of how much horsepower that fuel pump can support. Provided your engine won't make more than that then it's worth a try. Monitor your fuel pressure and ensure the pressure doesn't drop when you are loading up the engine.

Or, if the geek in me is making your head swim, do the smarter thing, install a Walbro 255 LPH Fuel Pump, and be done with it. :-)

Henkka J:
03/9/20, 06:55:08 PM

Importing a nice American 1950 Styleline street rod to a european country with tough limitations on modified vehicles. It's got a 350+350 and appears to have the Holley Systemax II kit installed with a 4-barrel carb. It will be nigh impossible to get it registered here with this motor as it is and I'd love to turn it into EFI anyway so I'm going to replace the carb with a Sniper. Main question is whether I can use the Sniper software to seriously restrict/limit the power output of the motor? I know this is pretty much opposite to the normal intended usage of the Sniper but it will still give me the trouble-free usage, fuel economy and torque of an EFI system even if I'm not pumping out insane 400hp dyno pulls with it. Original I6 was rated at 90hp so I just might be able to get a special permit on this with like 200hp dyno pull. I've searched extensively but for obvious reasons have not found any info on how to restrict engine power using a Sniper. With kind regards Henkka

AJ Ramos:
03/11/20, 06:43:48 PM

You could use launch control to do what you suggest. That's a built-in feature for all Sniper EFI Systems.

Anthony S:
11/3/20, 02:57:52 PM

Wondering which system would work best with what I have. Street/strip car ,Sbc 550hp with a plate nos system(200-250 shot),locked msd distributor 6al box, msd timing control,and progressive controller. I drive the car more than I race it just wanting better drivaebility and easier tuning

Chris Myer:
11/16/20, 06:03:23 PM

We would be glad to put together a custom EFI System recommendation just for you, Anthony. In fact, we've recently made it easier than ever to have that done. At the bottom of every single page on this website you will find a link that says, "Personalized EFI System Recommendation". Click that and it takes you to a simple form that lets you provide exactly the information we need to respond with a customized recommendation specific to your situation--usually right down to the last hose clamp! It takes less than two minutes and is without cost or obligation. Give it a try! On most days you should have an answer within a few hours.

02/26/21, 10:07:55 AM

I currently have a base 2300 sniper on a for inline 6 200. I just purchased a paxton blow-through supercharger capable of 4 to 6 psi of boost. I have an MSD 6AL2 and Holley Hyper spark Distributor. Am I able to use my base Sniper 2300 or must I upgrade to the Super Sniper? If can stay with my Base Sniper, what modifications will I need t make?

Chris Myer:
03/2/21, 02:08:14 PM

As long as you stay under 1 bar of boost (as it sounds like you most certainly will) then you can do what you are trying to do with the Sniper 2300. It has a built-in 2-bar MAP sensor. Holley doesn't classify these as boost capable only because there is nothing in the setup wizard that will allow you to set fuel, boost, and timing configurations for a boosted application. However, by using the software (which is free and identical for all Sniper EFI Systems) a gifted tuner can build a great configuration file for your newly-boosted Inline 6, including timing and boost control.

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