I achieved excellent results with cold starting, no fuel percolation, perfect air/fuel ratios from idle to wide open throttle, elimination of hard hot restarting by installing a Holley Sniper EFI system. My spark plugs are a beautiful light tan color 2 years, and 2,000 miles after install.
I did not drill any holes or modify my car in any way to install this system. A big help is the use of an aftermarket fuel tank with a built-in electronic fuel pump that fits perfectly and works with the Sniper. It is OEM quality with baffling built in. The supply and return lines are located in the factory fuel sender location. I searched for a month to find this tank. All others required holes to be drilled since the fuel lines came out of the top of the tank inside the trunk. That was unacceptable to me. Thankfully, I found this tank and it was less than $300. A home run.
If you drive your car using ethanol fuel, and want it to start and run like your daily driver, this system can be installed for approximately $1,500. It was the best classic car modification I have ever made. Throttle response is so good now it blows me away. Air fuel ratios are always perfectly maintained, as are the target idle speed you set with a touch screen pad. I can monitor air/fuel ratio and coolant temperature at all times using the small screen I keep in my center console.
The computer is located in the throttle body itself. That provides the advantage of all wiring is hidden under the big air cleaner. There are no separate boxes to mount under the dash or on the firewall, etc. All you need is a wideband O2 in one side of your H pipe, a coolant temp sensor, and power connections. I ran the blue power wire to the in-tank fuel pump through the interior so it is invisible from under the car. That took some time to remove the interior.
Here are a few photos of my install.
Where did you get your tank? What is the capacity?
Where did you install your A/F sensor?
Interesting subject, thanks for sharing.
Quote from: 2112 on August 23, 2020, 01:15:50 PM
Where did you get your tank? What is the capacity?
Where did you install your A/F sensor?
Interesting subject, thanks for sharing.
It is stock capacity, and fits in trunk perfectly with no modifications. Fit and quality are OEM. Spectra-Premium F28-CFI. They also make the same tank for other year Mustangs with built in fuel pump. You can find it at summit racing, amazon, and rock auto. I got mine from rock auto. They were back ordered and I had to wait a while to get the tank.
The A/F sensor needs to be within 6 inches of the exhaust manifold donut connection, as specified in installation instructions. I had to remove H pipe to install O2 sensor bung.
Link to fuel tank at summit:
https://www.summitracing.com/parts/sgt-f28cfi
Is the tank galvanized?
I don't think so.
Does the Sniper allow distributor advance lockout and timing/advance control via handheld display?
Quote from: mygt350 on August 23, 2020, 02:14:37 PM
Does the Sniper allow distributor advance lockout and timing/advance control via handheld display?
If you have a Sniper compatible distributor, you can have the Sniper control advance/retard based upon coolant temperature, and A/F, and other inputs received by the computer. You select if you want the Sniper to control timing or not via the hand held touch screen.
I opted to not do that and retained my stock Autolite distributor. I'm not well versed on all of the advanced features, but there are a lot of them, including electric fan control.
Been considering efi of some sort on my Superformance Cobra so originality is not a concern. It has a MSD dist which they tell me can be locked out and controlled.
Have looked at FITech and Sniper and Sniper seems to be the unit of choice.
I chose the Sniper over FITech because I read the tech support at Holley is drastically better than FiTech support. I can say first hand Holley Sniper tech support reps are top notch. Every one I talked to at Holley were excellent and sounded like they worked as a mechanic on a race team.
That's cool stuff, I am considering EFI for the 418w stroker in my 69 350!
My Sniper supports up to 650HP. They make bigger if you need it.
Here is the link to mine:
https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/sniper_4bbl_tbi_kits/sniper_efi/parts/550-516
You have no idea how helpful this is, especially since you've had the unit installed for some time!
Did you have to drill a second hole in the driver's side apron? It looks like two fuel holes - one for input and one for return. Is that correct?
Thanks!
You're welcome. I thought others might find this helpful. I got tired of fighting carb issues and ethanol fuel boiling in the fuel bowls.
On my '69 convertible, there is an unused hole in the lower driver's fender apron that had a rubber grommet plug in it. It's close to the factory fuel line hole that passes into the engine bay. I simply popped the rubber plug out, and made a bend to the 2nd metal fuel line I bought, and routed it through the unused hole.
It took me about as much time to figure out the return line routing, and fuel tank research, as it did to install the system. The throttle bracket and kick down setup was also challenging. I think I returned 3 throttle cable brackets until I found the correct one that fit and worked with the factory accelerator cable.
Thanks so much for this. Been thinking about this for a couple of the toys for a while . . . Time to boldly step into the 20th century????
Thanks!
John
Quote from: JohnHouston on August 24, 2020, 11:30:11 AM
Thanks so much for this. Been thinking about this for a couple of the toys for a while . . . Time to boldly step into the 20th century????
Thanks!
John
You're welcome John. You won't regret it. I installed clear fuel bowl site plugs on my carb and could actually see the fuel boiling and bubbling. That forced it down into the engine and made my garage smell like gas fumes after hot shut off. That problem is now 100% eliminated with the Sniper since no fuel is stored on top of the engine.
Cold starting is much easier now. I have a pretty high lift cam with some overlap and rough idle. The Sniper allows me to cold start the car, and drive away in 5 seconds after a cold start without stalling with an automatic transmission. Even in cold temperatures. Even with my electric choke set properly on my carb, I used to have to rev the engine for at least 1 minute to keep it from stalling when putting it in reverse. We all know the routine... Smelling up the garage with rich exhaust fumes, wifey complaining it stinks up the house, etc. That is all a thing of the past with the Sniper. Even when driving the car, you smell less fumes because the a/f ratio is perfect, even with an overlap cam like I have. Your engine is healthier with perfect a/f, and will last longer. Less plug changes.
The sniper computer mimics the cold start of a choke and carb, and it primes itself without touching the gas pedal. It starts and holds 1400 rpms for a few seconds, then drops down to your specified idle speed. You drop it in reverse and go. It never stalls - a/f is perfect. If coolant temps rise when stuck in traffic, it adjusts a/f accordingly. I got stuck in traffic jam and my coolant temp reached 215 - no issues. It is really nice to have the small screen and actually see and know your coolant temp and a/f ratio. The temperature gauge is pretty much useless since you don't know coolant temperature.
Since I want to preserve my numbers-matching engine, having the Sniper is one of the best ways to not hurt the engine if you drive the car at all. JMO.
We have installed about quite a few of these on cars that roll thru the shop. YOu can do a retrunless style also with pump in tank and only 1 line .
chris
have one on my 67 350
starts perfect every time and also have just the one line system
cant go wrong with everything preset to what you want it to be
and nobody any difference unless you take the air cleaner off
Quote from: acapulco350 on August 24, 2020, 07:05:38 PM
have one on my 67 350
starts perfect every time and also have just the one line system
cant go wrong with everything preset to what you want it to be
and nobody any difference unless you take the air cleaner off
How did you do a 1-line system? I thought the sniper required a return line. I know the FiTech has a seperate fuel resevoir that needs mounted if you don't want to install an electric fuel pump.
"TANKS" for sharing this, very cool!
Good to hear.
I've seen a few sniper builds and heard good things.
I've also built a few FItech delete kits. I have no hands on with any of them, but that one makes me view it with suspicion.
Quote from: 67 GT350 on August 24, 2020, 08:58:41 PM
"TANKS" for sharing this, very cool!
Tanks Inc. makes efi fuel tanks for classic mustangs, but the fuel line connectors are on top side in the trunk. I didn't want to drill holes to get the fuel line out of the trunk.
guy that did all the work for me said its all done at the pump which is in the tank
having just one line is nice and clean
also put in a 22 gallon tank which makes more sense as the standard is just a touch small
I run the FITECH on my small block. Same concept, very happy with the drivability and performance, easy to hide.
I went for the return line to the tank, so the fuel pump stays constant. Yes, an extra line, but after trying both thier surge tank set-up, and a single line, I found the system worked best with the return line. Use the 255 lph pump.
Many companies make gas tank adapters with pumps for the Mustangs.
Also remember under the hood you'll have alot of extra wires, so route carefully, add extra GOOD grounds.
The returnless system is VERY tempting, but I was curious as to whether anyone has used the existing line for a return?
Have you all left the mechanical pump in place or used a block off plate?
I even wondered about gutting and using a parts store fuel pump so it could occupy the spot and not be moving all the time.
Thanks! John
I used a fuel pump block off plate. I bought 2 new complete OEM fuel line kits. One for supply and one for return line. It is challenging to fit 2 front lines through the hole into the front wheel well. It is only meant for one line, but it can be done with patience. Using front standard steel lines makes it easier to bend them to get through the hole. The stainless steel lines are very hard to bend.
Quote from: 67 GT350 on August 24, 2020, 08:58:41 PM
"TANKS" for sharing this, very cool!
+1
Seems like Forum 1.0. Useful and no drama.
A few things I learned about the sniper. If you use a dual plane intake, like my shelby 351w, you will hear a whistle sound on moderate acceleration. There's no way to eliminate it according to Holley.
Also, if you use the spectra premium tank I used along with a transverse muffler, the fuel line connectors at tank are close to muffler.
What size hole do you need to make in the firewall? What size is the flange for the air cleaner? Thanks in advance.
No holes were drilled in the firewall, or anywhere to install the Sniper on my car. The flange on Sniper is sized for Holley 4150 so your air cleaner fits on it the same as a 4150 carb.
I removed the speedometer cable grommet in bottom of firewall to pass the blue fuel pump power wire, and the touch screen wires into the interior. I think I was able to insert them through the center of the grommet so it could be replaced with a good seal around the perimeter of grommet. If you don't want the touch screen monitoring full time, or you want to see the blue wire running to fuel tank under the car, then you would not need to pass any wires into the interior through the firewall. Your choice.
I did splice and solder the engine gauge feed harness to get the tach signal to the pink wire of sniper. The sniper needs rpm feed. My engine gauge harness was not original so it was no big deal to me. I also deviated from the instructions, which say to connect main power directly to the battery - that looks terrible IMO. I connected main positive to the starter solenoid post, and the main negative to the engine block ground the negative battery cable goes to. I checked voltage with a multi-meter - it was identical at the battery versus where I installed the wires. I used electrical tape to cover the sniper wires that are not under the air cleaner to conceal them.
I let my buddy drive my car after the Sniper install. He bought one for his 442 a few days later. Yes, I installed it for him for free. That's what I get for sharing. :)
FYI, Holley now offers the Sniper Stealth that looks like a 4150 based carburetor. Using one on my ERA replica Cobra with a 14" HiPo air cleaner and it will fool you until you take a closer look.
I have been thinking about putting it on my 59 Cadillac convertible. I would like to use the factory air cleaner which I believe is 4-5/8" opening and I have very few openings in the firewall. I asked Holley support, but haven't heard back.
Quote from: countrysquire on August 26, 2020, 12:39:12 PM
FYI, Holley now offers the Sniper Stealth that looks like a 4150 based carburetor. Using one on my ERA replica Cobra with a 14" HiPo air cleaner and it will fool you until you take a closer look.
Is there a minimum displacement or H.P. needed for that unit?
It supports up to 650 horsepower, but don't know that there's a minimum since the fuel flow is not tied to the vacuum signal, so I think it would work on most any V8. The do offer a 2bbl version, and just came out with an Autolite 1100 style for inline sixes.
we personally do not have them, but have friends that have retrofitted their carburated vehicles. Start up is instant and throttle response is crisp
Well worth the expense
Sniper EFI - Holley Performance Products
https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/
Is that the Holley Sniper Stealth? Thought that was a 4500 series.
Maybe someone will know.
Does the Sniper perform better with a Dual plane or Single Plane intake such as a air gap on a 408 windsor, roller and big heads with a 5-speed?
Quote from: mygt350 on August 26, 2020, 04:48:47 PM
Is that the Holley Sniper Stealth? Thought that was a 4500 series.
Yes, that's the Stealth, but it does look like a Dominator with the air cleaner removed.
Quote from: mygt350 on August 26, 2020, 05:28:05 PM
Maybe someone will know.
Does the Sniper perform better with a Dual plane or Single Plane intake such as a air gap on a 408 windsor, roller and big heads with a 5-speed?
The sniper will perform better than a carb with either option. The sniper does make a whistle sound on my dual plane intake.
This is probably for someone who has done a returnless system. . . Do you just replace the sending unit with the supplied pump/sending unit assembly? Do you have to drill the tank for it? Or is it just better to replace the tank???
Thanks,
John
Quote from: JohnHouston on August 27, 2020, 01:11:55 PM
This is probably for someone who has done a returnless system. . . Do you just replace the sending unit with the supplied pump/sending unit assembly? Do you have to drill the tank for it? Or is it just better to replace the tank???
Thanks,
John
They make one just for stock Mustang gas tanks.
https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/muscle_car_efi_modules/parts/12-305
Quote from: countrysquire on August 27, 2020, 01:23:00 PM
Quote from: JohnHouston on August 27, 2020, 01:11:55 PM
This is probably for someone who has done a returnless system. . . Do you just replace the sending unit with the supplied pump/sending unit assembly? Do you have to drill the tank for it? Or is it just better to replace the tank???
Thanks,
John
They make one just for stock Mustang gas tanks.
https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/muscle_car_efi_modules/parts/12-305
For $20 more you can get a brand new tank with electric pump and built in baffling for the pump from Spectra Premium - see link below. It is a drop in replacement that allows for accurate fuel gauge readings. You don't have to mess with adjusting the depth of the pump, etc. You probably need to drill the tank for a return line provision if you buy the electric pump only, but not sure.
New tank with EFI pump built in that I used:
https://www.summitracing.com/parts/sgt-f28cfi
Air gap single plane or dual plane. What are benefits and drawbacks for both when fitted with the Sniper?