View Full Version : Holly Sniper install
Falcondriver
11-20-2022, 12:36 PM
I purchased the EFI package from FF when I ordered my complete kit. It came with the in tank fuel pump AN lines and fuel regulator. I purchased 427 engine from Blue Print with the Holly Sniper installed. Where do i hook up the fuel and return lines. The FF regulator has a fuel input and return on it and a fuel output to the engine. Do I need this regulator as the Sniper instructions say the unit has an internal regulator?
Gordon Levy
11-20-2022, 01:08 PM
Which snyper do you have?
weendoggy
11-20-2022, 02:51 PM
I purchased the EFI package from FF when I ordered my complete kit. It came with the in tank fuel pump AN lines and fuel regulator. I purchased 427 engine from Blue Print with the Holly Sniper installed. Where do i hook up the fuel and return lines. The FF regulator has a fuel input and return on it and a fuel output to the engine. Do I need this regulator as the Sniper instructions say the unit has an internal regulator?
The 4150 (most common) Sniper has a built in regulator. Fuel input is on the L/R side and regulator (return) is on the R/R side. You don't need to use an external regulator with that model.
first time builder
11-21-2022, 10:40 AM
I just finished a Sniper install on a( SIC) 427 BB Camaro and added an inline fuel pressure gauge permantly. A big help for first start and for future use. Follow the directions to the letter !! It paid off for me . First start was uneventful. Was just to easy. I had used the lower cam spec setting as I didnt know engine vacuum. After started I found I had 8" vac so I went back to program and changed spec to the middle setting. The car would not start as easy, ran rough and idle was low. Went back in and changed back to lower cam setting and all is good again.
Theshandman
11-21-2022, 05:06 PM
Do I need this regulator as the Sniper instructions say the unit has an internal regulator?
Got the same as you except a 347 not a 427. But, I would imaging the plumbing would be the same as I did it. I upgraded the fuel pump to a Pro-M pump (has a return line going down to the bottom of the tank to eliminate cavitation as opposed to what F5 provides) feeding a 10 micron filter. From there, up to the input of the Sniper with a 0-100 psi pressure gauge in-line. Out of the Sniper's regulator port is a 0-10 psi gauge then on back to the Pro-M pump's return port. Works great.
FF33rod
11-21-2022, 09:00 PM
Here is the fuel inlet and return lines diagram from the Sniper manual... there are options.
175282
As for a regulator, you are correct, you do not need an external regulator - feed and return lines go direct to the Sniper unit.
Steve
Got the same as you except a 347 not a 427. But, I would imaging the plumbing would be the same as I did it. I upgraded the fuel pump to a Pro-M pump (has a return line going down to the bottom of the tank to eliminate cavitation as opposed to what F5 provides) feeding a 10 micron filter. From there, up to the input of the Sniper with a 0-100 psi pressure gauge in-line. Out of the Sniper's regulator port is a 0-10 psi gauge then on back to the Pro-M pump's return port. Works great.
Just out of curiosity, what does the 0-10PSI gauge on the return indicate?
Thanks!
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Jeff
Mike.Bray
11-22-2022, 11:27 AM
Just out of curiosity, what does the 0-10PSI gauge on the return indicate?
Thanks!
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Jeff
Since after the regulator it's an open line to the tank I'm guessing it will only show a restriction.
If you choose to use the internal Sniper regulator, I strongly recommend that you install a pressure gauge at the inlet to monitor the functionality of the regulator. If If fails, you'll see it as high pressure at the inlet. Replacing the internal regulator is inexpensive and simple to do. If you choose to use an external regulator, plumb the Sniper using the front-side ports and cap the rear ports.
Namrups
11-22-2022, 02:32 PM
If you choose to use the internal Sniper regulator, I strongly recommend that you install a pressure gauge at the inlet to monitor the functionality of the regulator. If If fails, you'll see it as high pressure at the inlet. Replacing the internal regulator is inexpensive and simple to do. If you choose to use an external regulator, plumb the Sniper using the front-side ports and cap the rear ports.
Just to double check this. My Sniper documentation states that the DS rear and both front ports are input ports. The PS rear port is the return port.
Since after the regulator it's an open line to the tank I'm guessing it will only show a restriction.
That's what I thought. I'm not sure of the value-add of that.
I guess gauges are cheap....
Just to double check this. My Sniper documentation states that the DS rear and both front ports are input ports. The PS rear port is the return port.
True, but if you dig into Holley's documentation, they recommend that you use the front inlets when using an external regulator. If you deadhead the Sniper, I don't think it matters which inlet you use.
Namrups
11-22-2022, 05:51 PM
I might be wrong but I read that as either front port is recommended as the inlet but the PS rear still needs to be the return. I might be way out in left field but logically if you use the PS front as the return aren't you eliminating the whole PS of the Sniper? Or are you not running a return?
first time builder
11-22-2022, 07:05 PM
Holley says the gauge after the regulator is not needed. I used the complete Sniper kit that came with the fuel pump and two filters and all the necessary hose , clamps and brackets.175352175354
first time builder
11-22-2022, 07:06 PM
There are three possible inlets and one return line.
175353
I might be wrong but I read that as either front port is recommended as the inlet but the PS rear still needs to be the return. I might be way out in left field but logically if you use the PS front as the return aren't you eliminating the whole PS of the Sniper? Or are you not running a return?
The two sides are connected with a line that is part of the factory configuration. The PS rear is where the built-in regulator is. If you want to bypass that regulator, you need to use other ports.
Namrups
11-22-2022, 07:39 PM
The two sides are connected with a line that is part of the factory configuration. The PS rear is where the built-in regulator is. If you want to bypass that regulator, you need to use other ports.
Ok. Learn something new every day!!
I found this...
https://thefactoryfiveforum.com/attachment.php?attachmentid=175351&d=1669164178
Theshandman
12-02-2022, 09:40 AM
That's what I thought. I'm not sure of the value-add of that.
I guess gauges are cheap....
Jeff, not horribly expensive. I went with an Aeromotive gauge (0-15) at $42.70 but Summit has their branded unit at $25.99 (as of Dec '22). Frankly, the return gauge doesn't add much -if any value assuming the Sniper internal regulator stays on the job and the return fuel line remains unhindered which I'm hard pressed to think it wouldn't; it just adds a bit of eye candy to the looks of the engine. In my case (and most likely others) it never gets above 1-2 PSI if that. As others have mentioned, the feed gauge is a huge value-add.
Art