88WHITE VETTE

Just wondering if anyone installed it on C4 and what challenges they came across if any.
I'm thinking about doing it on my car since my car has carburetor.

856SPEED

I have an 85 and I assume you have an 88; that being said, I had the Holley HP installed which I think might be similar, I would think unless it's throttle body injected vs. multi-port.

I love my HP Holley. No issues and I eliminated the original 870 ECM.

88WHITE VETTE

It looks like this.
Everyone says that it's easy to install but I never seen one on C4. Looks like C3 guys are doing it quite often though.

856SPEED

Yea, that’s throttle body injection. If you already have a 4 BBL intake that might work out. Does it come with a high volume electric fuel pump and return lines?

-=Jeff=-

Ziggy?

Whats up man?? I have not seen you post in quite a while.. Hope all is well

88WHITE VETTE

The one I'm looking at comes with the pump, filters and fuel lines. The TB has 58 PSI pressure regulator in it.

856SPEED

Nice; If you get it to fit on the intake, you may have a nice setup. Holley has become quite an electronic fuel injection specialist. Their software is very good in most cases.

In my 85, it was a slam dunk over the stock stuff, but I don't have VATS, antilock and other things to consider. I am not sure if the 88 has those issues with this system, but if not I think it would be nice over the carb.

88WHITE VETTE

Everything is good! I have not being active as my car was in storage for the past few years. Marriage, kids, house projects etc.. it all takes priority over car projects. Several years ago I converted my car to carburetor and never really got it running good. I think I want to convert it to TB EFI so it's at least drive-able. I will than decide if I'm going to keep it or let her go to new home. It's been with me for the last 20 years!
I have been auto-crossing for the past couple years (not in the vette) and even did track day in September (first time in 10 years). Got my wife to autocross too so that helps .
What's new with you? I see you have been upgrading your car a LOT!

88WHITE VETTE

So after more researching I decided to do IT!
The project started actually little over a month ago with couple hours here and there. Haven't really had much time to just concentrate on it but I'm happy to announce that the project is ongoing.
The fuel delivery was little difficult as I used the external pump with pre and post filters that comes with the kit. I tapped into the fuel pick up on the top of the tank and used that as my fuel feed and return. So far no issues with fuel delivery.
Than I tapped into the lines where the old filter is located and run rest of the lines with the high pressure hose to the sniper.
Electrical was always my weak point and it showed with this install. After I initially wired everything I started the car with no problem. It actually started right up, first try, less then second into cranking. I was happy. I also wired it so it would control my timing and there's procedure that I had to do in order for the sniper to take over. As soon as I did it, the car died. So yes, I messed up somewhere. Instead trying to figure that out I changed the set up to have my distributor advance the timing mechanically like it did with the carburetor. The car is back running and starting. Tomorrow I'm planning to take the car on the side streets to see how it does. Since then I watched couple videos of how to properly wire the set up that I have and I think I know where I made mistake. After I have little more time I will change it back so I'm getting all the benefits of this system.

So I think I might be the first one on this forum to install sniper on the C4.

ctmccloskey

Please post some pictures of how it looks installed.

I am getting ready to do it to my C3 but am having a really tough time deciding which to choose. I am currently looking at the Edlebrock "Pro Flow" system which replaces the entire intake manifold and has installed injectors for a Multi-Port injection system using eight individual injectors or to go with the new Holley Sniper throttle body.

At least with your C4 you already have a return line going to the fuel tank, there are issues with each type of system. Your experience is great news having heard it firsthand from a Corvette owner.

On my C3 I have a dual Plane Edlebrock RPM Plus air gap intake manifold and it would be so much simpler to use a throttle body. I have heard that EFI works better on a single plane manifold, are the enough benefits to warrant changing the entire intake system. What intake are you using on your C4? Does your new system have any kind of data acquisition built into it?

How is the performance side? Another problem I have is that I have 4 carburetors for my C3, they are set up and they work. Using high compression the engine likes to diesel after a shutdown when it is hot because of the vacuum pulls fresh gas out of the carb while it diesels. When you turn off a EFI system they can't diesel as the gas flow is shut off.

Holley "Sniper" or multi port Edlebrock "Pro Flow" that is the question for me....

88WHITE VETTE

I was reading about fuel delivery system for Sniper that didn't require the return line. Forgot where though. If you contact Holley they should be able to give you more information on it.
Still have not driven my car due to lock of time. Once I do I will post more info on it and some pictures.
My intake is the Performer RPM. The engine makes little over 450 hp with it.
Your carburetors work, I on the other hand could never get my carburetor to run good.

anesthes

Are you wiring the dizzy pickup to the sniper ignition input so you can get timing control?

Sniper is good stuff.

-- Joe

MatthewMiller

I'm obviously late to this thread. I just wanted to toss in that one challenge may be finding an air cleaner that gives adequate hood clearance. Other than that, I'm just curious how this all turns out for you.

bdake8230

I am very interested in this topic. I have an 84 I am wanting to do exactly this with. Trick flow top end package and holley sniper, I am curious as to what intake manifold I can get to fit with the sniper under a stock hood. thanks for any information

BLUE1972

was thinking of it , well maybe … it's running on a carb - very nicely with roller cam ..

E85 RACER

When I did this last year, I used a summit racing stage 1 dual plane intake for perfect stock hood height. After performance issues, I got Weiand team G single plane intake 7530, for perfect height under stock hood. The single plane is best signal and fuel flow. Happy now for sure. I have Brodix 200cc heads, but if you can also try edelbrock torker II 5001 intake if you have stock heads.

cadmaniac

I have the FI Tech which is similar. Don't believe the "It will only need 6 Lbs of vacuum to self tune". I would think you'd need at least 12 Lbs of vacuum for it to run correctly. The sniper will however, allow you to tune from a laptop. So do your homework before you get one.

That said, The FiTech power adder runs my 421 quite well (I had to put a smaller cam in it). I assume the Sniper is even better.

E85 RACER

I wish I had gotten the Fi tech power adder unit. It will run E85 tune properly. My sniper has to modified and after a dyno it showed 27 less HP and after calling Holley they said the unit is not intended for E85 and the ECU has to be tricked into running it because the AFR is much lower with ethanol verse gasoline. So maybe keep in mind if you want to run E85. In my area there are 25 gas stations selling E85 for around $2 gallon. My drag car uses only E85 and has QuickFuel carb for that. The savings alone switching to ethanol has been amazing over race fuel at $9-$12 gallon.

Orange1224

I have an 85 TPI looking to switch to Holley sniper efi. Ill have to get a new intake manifold. Can the stock pump be used since its already an electric fuel pump? Also can the electronic spark advance distributor be used?

AZSP33D

yes on all of those, please don’t use this thread as any sort of an installation guide for reasons that I’m not going to take time with. I will say that Holley does have excellent installation manuals available in line, and also good forum support for Holley EFI, and their classes in Bowling Green are also great. The challenge here is the limited amount of room you have for an intake manifold + sniper + air cleaner and then the Sniper is very sensitive to EMI RFI and Transient Voltage spikes created by relays, ignition, alternator, etc so it’s important to properly shield and also connect power and ground straight directly to the battery (battery acts like a buffer or sink for transient voltage.) Once again, Holley EFI forums, I reference this all the time even though I have good experience with EFI systems and dyno tuning for decades.