Taking the EFI plunge ... wish me luck!
 

Well, I bit the bullet and scrounged for some deals on an EFI setup. I wound up a with a refurbed Holley Sniper from the Holley store for $400 less than retail, an in-tank pump retrofit kit w. Walbro pump and baffled tray, a braided PTFE hose kit w. AN fittings and a Wix 33737 filter regulator w. return.

The plan is to mount the regulator where my current Holley red pump is currently located ( just ahead and below the tank) and use my existing 3/8" fuel line. The supply and return (short lines) will be plumbed w. PTFE as well as the supply line to the throttle body. I will also swap out my ProComp dual plane intake for a Torker II I bought a while back.

I am going to try to retain my old mechanical pump to carb hard line and picked up the compression to AN fittings to do this just to maintain a "stock-ish" appearance. I just have to come up with a bracket to secure the end of the hard line coming off one of the fuel pump block-off plate bolts. My tank and fuel lines are only a couple years old so I decided to retain them and do the retrofit rather than purchase a new tank.

I have seen them plumbed this way but something tells me I should locate the regulator closer to the throttle body using the high pressure on the long supply run and regulated pressure on the short run to the throttle body. I have 3/8" supply & 5/16" return hard lines in the stock location (both are new) and could just as easily mount the filter/regulator right on the frame rail and plumb to my supply and return.

For you guys that have done this type of install, which way did you go?

I mounted ours in font of the tank. That way there is just one feed line running up the car. This was for a multi port setup. Make sure your sniper can be dead headed if you go this route

Good luck with your project. My return regulator is close to the intake manifold. It works well. When I find the time/motivation/ and money I would like to go to a pwm dead head set up. Will you be controlling spark as well? Dual sync distributor or crank trigger wheel?

No, just basic throttle body w. HEI and MSD Box. No synch.

That should be pretty simple and trouble free. Pay attention to the wiring, especially grounding and you'll get what you expect from it.

I’ll be doing it along with you bro.

My terminator X kit just got here today after a long back order.

For what it’s worth I’m going to set mine up like the OEMs do with a fixed regulator near the tank.

I’m asking questions, here, wondering how other folks installs and usage have fared???
Typically the minimum pressure side is advised to be 1/2 shipped inch, with the return also being 1/2 inch.
The theory being that a too small return line can cause excessive pressure, not allowing easy return of unused gas to tank???

Just asking, wondering, hope it works out.

The LS filter I have comes with bracket so it looks like a simple mount. I have the 3/8" and 5/16" AN6 fittings to use the 3/8" PTFE hose between tank and regulator for the supply and return including a 180 for the return line back to the tank. I'll my existing 3/8" hardline to the engine compartment and just cap off the existing 5/16" return line as unused.

I already have my existing electric fuel pump wiring w. relay right in front of the tank to connect to the in-tank leads so that's all set. I wired the old electric pusher through a hidden toggle which will now serve as a fuel delivery interrupt anti-theft device.

The only thing I am concerned with is the lack of a flat surface on top of the tank to mount the pump inlet/outlet flange but the kit comes with a thick foam gasket to fill in the "ribs" on top of the tank where I cut the access hole so I am guessing it's a non-issue.

I looked real hard at a similar "complete kit" with an EFI ready tank that was only $120 more than what I spent for my parts but there were some trade-offs. The hose supplied with the tank was the plain CPE type rather than the braided/PTFE lined I bought, the pump and regulator were no-name parts (I have Walbro and Wix) and the AN6 fittings are of unknown quality. The kicker was the tank drop ships from the manufacturer and would not be available to ship until the end of October, so, no bueno.

slightly different but similar stuff here. You need ot make sure the Sniper will work dead heading the fuel. I did my multiport back in '09 (commander 950) but different set-up with different requirements DEAD HEAD on multiport is NOT a great idea so mounted my return regulator on END of fuel rail using the original feed line as a return. Made NEW 1/2 FEED line from the LS1 fuel pump bucket in the tank to the rails.

Given the sniper is a throttle body type unit dead head SHOULD be OK. The 1 advantage of mounting the return regulator UP FRONT is fuel circulation.

I know you asked about fuel but RFI/EMI is a real issue for many with the Sniper so attention to wiring is key. Keep the pink ECU trigger wire isolated. Some use a relay for this wire to avoid RFI/EMI issues. Use heavy ground cables - don't rely on ground straps. Us resistor spark plugs and for plug wires, many have had luck with the MSD Super Conductor sets. If you have a FB account you should look at the Holley Sniper Owner's and Tech group: https://www.facebook.com/groups/100847380485430

Do you need to use a vacuum referenced fuel regulator? My Proflo4 needed one.

The Sniper has a regulator built into the unit. You don’t need an external regulator.

Depends on which Sniper you use. The Stealth has no regulator and is purposely designed to be dead headed so you can keep the stock appearances under the hood. Some of the others they sell can be dead headed but they generally recommend full flow and regulating the return to minimize injector pulse issues.

Generally when you dead head them you'll need a pulse damper to calm down the fuel pressure pulsing which will skew the AFR a bit and make it's ability to learn a little erratic, also makes it easier to dial in and read the fuel pressure much more accurate.

They'll also tell you they really prefer the regulator to be as close to the unit as possible for more accurate results. Especially if you are dead heading it.

Another tip that a lot of the dealers and pro tuners recommend is a vacuum referenced fuel pressure regulator. It gives more accurate fueling at higher vacuum situations. I always had one but didn't hook up the vacuum at first. I found that it really settled down my fuel trims once the vacuum was operational.

There are going to be a lot of ways to make it better, many of them they don't bother to mention when selling the kit. But it will all make the EFI swap much more enjoyable in the long run.

Some great information here, all appreciated.

The Holley instructions say it is OK to deadhead the fuel supply and running it the way it was intended (with a return) is probably best. It really is just one more hose connection but that said is my existing 5/16" return line too small? A buddy of mine installs these all day long and says they do it all the time with no self-learning or fuel curve issues and typically installs the Corvette style filter/regulator in the recess of the frame rail under the car. I guess there's lots of way.

In a new development last night, a damaged box Holley Sniper tank pump and sending unit magically appeared at the Holley Store for $350 delivered. Holley says it is a damaged box only, contents same as new. It is a Buick GS stock number and only differs in the length of the filler neck. I figure it will be simple enough to saw my fill neck off and mount it on the Sniper tank since they all have separate tank and filler neck anyway and pocket the $300 difference. Having the pre-configured setup will speed things up.

As cheap as that was, I couldn't pass it up for ease of install and will return the other pump and pickup when it arrives. I hate to do that but you know how it goes. I wish I had a dollar for every time this kind of thing happens. I pull the trigger on what fits my budget and wham! a better deal magically appears that wasn't there the day before. In this case, I had to act on it.

Some great information here, all appreciated.

The Holley instructions say it is OK to deadhead the fuel supply but running it the way it was intended (with a return) is probably best. It really is just one more hose connection but that said is my existing 5/16" return line too small? A buddy of mine installs these all day long and says they do it all the time with no self-learning or fuel curve issues and typically install the Corvette style filter/regulator n the frame rail under the car in-line with the supply and return lines for GM just behind the front wheel. I guess there's lots of way.

In a new development last night, a damaged box Holley Sniper tank pump and sending unit magically appeared at the Holley Store for $350 delivered. Holley says it is damaged box only, contents same as new. It is a Buick GS stock number and only differs in the length of the filler neck. Given the price, I am willing to saw my fill neck off and mount it on the Sniper tank since they all have separate tank and filler neck anyway.

As cheap as that was, I couldn't pass it up for ease of install and will return the other pump and pickup when it arrives. I hate to do that but you know how it goes. I wish I had a dollar for every time this kind of thing happens. I pull the trigger on what fits my budget and wham! a better deal magically appears that wasn't there the day before. In this case, I had to act on it as it will simplify the install.

Duplicate posts all of a sudden?

The size of the return is really dictated by 2 things. How long the return is and how big the pump is you're using. The pump size is going to be determined by the HP you're trying to feed.

Most systems that are supplying a very mild engine can get away with a smallish pump and won't need a big return line. Keep in mind if the return is too small you won't be able to regulate the pressure down enough, especially with a good sized pump.

When you get up around 500 hp carburated you'll want a 255 LPH pump minimum. That number changes with EFI pressures. In those situations you might get away with a 3/8 return but I always just do the 1/2" feed and return when I reach this level. It then has the ability to increase the pump for more power later without the need to redo any of the lines. Basically making it a permanent system for any engine that you'll never have to revisit again. The price difference isn't really enough to warrant one way or the other.

You can do the corvette filter/regulator deal, I've done that myself on installs. It's mainly popular because of it's ease of install and it's initial cost is cheaper. It worked fine for me on very stock or very mild setups. If you start making HP there are better ways to do it.
When or if you plan to really get into tuning these things and talking to people like Chris at EFI System Pro, some of the improvements I mentioned above will start to make more sense. For most that just install these things at a bare minimum, never look at anything but the touch screen, and let the system do it's thing, and will never actually see or realize some of the smaller things I mentioned and it will probably run fine for what most everyone is doing.
It's when you really want to dive in with a laptop where you'll find fuel trims and learning and many other tables can be even better with more finite tuning, and having precise fuel pressure is a player in all of that since it's a multiplier in the fuel tables.
If you're not into that, then I'd put it out of mind, let the unit self tune and enjoy.

Don’t remember if it was in the install guide, but the Edelbrock reps on there forum say there fuel maps where designed to be used with one. I Used the Edelbrock regulator made for the Proflo4.