Hot Gas Tank

[Turbo Deuce]

Originally Posted by clill

How much is a new Aeromotive controller ? I have a used one off the Mule I'll sell you for whatever is fair. Less than new. I switched over to two Bosch pumps.

IMO the bosch pumps are the way to go. Quite and oem stuff that is made to run for long periods. I also went to two of them and used the aeromotive controller for them.

The cool can might help, but is just something else you have to package and plumb inside the trunk.

I think I gave 150.00 for my Aeromotive controller used.

[Overkill]

Does anyone know for sure if it is a PWM device? I tried looking on their website, but there are no technical specs other than the install document. They do say that it "automatically steps voltage down", but I don't know how to interpret that.

[Steve1968LS2]

I just spent an hour talking with Bret at Aeromotive about my fuel system and we discussed your problem.

The main issue is that you are moving way too much fuel in a circle since you pump is so big for your current need.

You could go to a smaller pump or Add a voltage controler to the pump you have.

You could also add a cooler with a fan (permacool?) to the return line back by the tank. This would cool the returned fuel quite a bit.

Having the regulator after the fuel rail (I was told) is the best setup with the "horseshoe" method (before the rail) being second. Returning back by the tank is the worst of the three.

I suggest you call up thier tech line, nice guys with lots of info.

[camcojb]

Originally Posted by Steve1968LS2

I just spent an hour talking with Bret at Aeromotive about my fuel system and we discussed your problem.

The main issue is that you are moving way too much fuel in a circle since you pump is so big for your current need.

You could go to a smaller pump or Add a voltage controler to the pump you have.

You could also add a cooler with a fan (permacool?) to the return line back by the tank. This would cool the returned fuel quite a bit.

Having the regulator after the fuel rail (I was told) is the best setup with the "horseshoe" method (before the rail) being second. Returning back by the tank is the worst of the three.

I suggest you call up thier tech line, nice guys with lots of info.

I'm all for any return other than after the rails; grab ahold of the fuel rails after the engine is completely up to temp and been driven for a while. The gas is in there much longer than if the exhaust pipe gets close at a small point in the line. Neither are good however, but I think insulating the fuel line near the exhaust will definitely help, but if you're going through the rails to bypass you still may have issues.

By the way, many of the new oem cars are regulated in the tank (Vettes, GTO's, etc.) or do not have a bypass from the fuel rails back to the tank (Lightning, etc.). I ran a couple cars regulated back by the tank and they worked flawlessly.

Jody

[Damn True]

Originally Posted by camcojb

I'm all for any return other than after the rails; grab ahold of the fuel rails after the engine is completely up to temp and been driven for a while. The gas is in there much longer than if the exhaust pipe gets close at a small point in the line. Neither are good however, but I think insulating the fuel line near the exhaust will definitely help, but if you're going through the rails to bypass you still may have issues.

By the way, many of the new oem cars are regulated in the tank (Vettes, GTO's, etc.) or do not have a bypass from the fuel rails back to the tank (Lightning, etc.). I ran a couple cars regulated back by the tank and they worked flawlessly.

Jody

I may be mistaken, but I believe the vette LS7 fuel system is set up just as you describe. Regulated at the tank, or somewhere way back aft, with no return from the engine compartment.

[V8TV]

The Aeromotive Controller - looks like it varies voltage to the pump.

http://www.aeromotiveinc.com/pdetail.php?prod=31

[Steve1968LS2]

Originally Posted by camcojb

I'm all for any return other than after the rails; grab ahold of the fuel rails after the engine is completely up to temp and been driven for a while. The gas is in there much longer than if the exhaust pipe gets close at a small point in the line. Neither are good however, but I think insulating the fuel line near the exhaust will definitely help, but if you're going through the rails to bypass you still may have issues.

By the way, many of the new oem cars are regulated in the tank (Vettes, GTO's, etc.) or do not have a bypass from the fuel rails back to the tank (Lightning, etc.). I ran a couple cars regulated back by the tank and they worked flawlessly.

Jody

The reason is that you get the most consitant fuel rail pressure (at the injectors) by having the reg after the fuel rail. This also eliminates cavitation and other problems.

Also, having the reg after the rail means the fuel flows through the rails at a pretty quick pace is not sitting there when the car is running.

The Aeromotive fuel guy says OEM companies regulate at the tank only to meet emissions standards an evap not necessarily because it's the best way. Also, what works for a 400hp engine may not work as good for a 600hp engine.

I think he could go a long way to fixing his prob by running the return line through a cooler (heat sink) and/or going to a smaller pump (or pump controler)

This is just from my discussions with Aeromotive :shrug:

[Steve1968LS2]

Originally Posted by Damn True

I may be mistaken, but I believe the vette LS7 fuel system is set up just as you describe. Regulated at the tank, or somewhere way back aft, with no return from the engine compartment.

It is, in fact 4th gen fbodies return INSIDE the tank. Just cause the OEMs do something a certain way does not make it the best way. They have to confirm to a whole set of regs we don't.

Also, the only constant flow of fuel is before your regulator. After the reg it fluctuates a bit based on need. When the return and reg is way back by the tank the regulated fuel has to flow quite a ways to the engine. This leaves room for changes in the pressure and such. This is why in a factory deal there's a supplemental "regulator" up in the fuel rail.

Anyways, it sounded more intelligent when Bret explained it to me.. lol

[Damn True]

Nah, that makes perfect sense and in fact with that sort of OE setup your fuel may actually pick up more heat sitting in the rail waiting to be deployed to an injector than it would if it were being circulated. Of course, it wouldn't be going back to the tank either.

Looks like both have their +'s and -'s.

[camcojb]

Originally Posted by Steve1968LS2

The reason is that you get the most consitant fuel rail pressure (at the injectors) by having the reg after the fuel rail. This also eliminates cavitation and other problems.

Also, having the reg after the rail means the fuel flows through the rails at a pretty quick pace is not sitting there when the car is running.

The Aeromotive fuel guy says OEM companies regulate at the tank only to meet emissions standards an evap not necessarily because it's the best way. Also, what works for a 400hp engine may not work as good for a 600hp engine.

I think he could go a long way to fixing his prob by running the return line through a cooler (heat sink) and/or going to a smaller pump (or pump controler)

This is just from my discussions with Aeromotive :shrug:

I agree on most of that, but I still won't run the regulator on the back side of the rails, if it bypasses fuel to the tank. I made well over 800 rwhp with the regulator at the tank, worked great, no pressure issues at all. The closer to the injectors the better probably, but doesn't mean the rear ones don't work fine.

The Vettes have been regulating back there for several years. My GTO was the same and the fuel pressure cannot be more steady.

I also agree with you, the cooler is a good idea along with a pump controller if available, or better yet OEM pumps.

Jody