Fuel System Critique

[ShadowGrayGuy]

All,

Trying wrap up work on my '70 Chevelle so we can make it to some of the upcoming summer track events here in the Midwest. This is definitely a case of "learning as we go", as evidenced by the fact that I had the Rick's tank & fuel pump for 8 months before I found out you need to use a fuel pump controller with the A1000 on a street-driven EFI car (who reads the fine print first anyway?). I'm having "second thoughts" on the fuel system configuration. We already have all the parts shown in the diagrams below, so it's a question of which configuration would best suit the needs of the car. Car will be street driven, with some abuse on the track & local autoX events. Has a 4L80e controlled by an FAST/TCI EZ-TCU. Modern suspension & go-fast parts under a nearly-stock wrapper (sheet metal, paint & interior).

Option #1 (How the car is set up now):


Option #2 (cleaner look, but at the cost of performance?)



Here's a shot of the engine/fuel system as currently set up. Final configuration will have a cowl induction air cleaner fabbed to fit the FAST throttle body and clear the throttle linkage to help complete the almost-stock look.


What do you think? Option #1 the best? Or is there no significant difference given the car won't be "full-on" race.

Rob

[Vegas69]

I'd put the regulator pre Y on the feed side and dead head it into both rails with the crossover hose/tube in front. Also, the return should be equal to the return. So I choose neither of your designs.

[Musclerodz]

I agree with Todd.

[ShadowGrayGuy]

I thought the regulator was supposed to go after fuel rails so that the injectors would see full pressure/flow from the pump. I think your suggested configuration would make for a cleaner look and minimize the appearance of the EFI - which is a goal of mine.

I've seen some guys suggest mounting the regulator all the way in the back just outside of the tank and deadhead it all the way to the front of the car. What are the impacts of that configuration? Will the car take longer to start or will the fuel pressure stay in the line under this configuration?

Rob

[MaxHarvard]

Your filter placement confuses me. In my experience, it should be right after the pump on the feed side if the pump is in the tank.

[speedjohnston]

Option #1 looks fine to me. I believe that is almost exactly how Aeromotive recomends you do it.

[SuperB70]

Same song. #1.

There you feel both rails at same end and out the other. Second options was big down side, if you run in to fuel delivery problems, your lambda show ok but you will melt your right bank pistons.

Only thing I'd chance is the nylon hoses to teflons one, they hold ethanol and E85.

My current project was #2 when came in but I'm chancing it to #1 with teflon hoses.

[ShadowGrayGuy]

Originally Posted by MaxHarvard

Your filter placement confuses me. In my experience, it should be right after the pump on the feed side if the pump is in the tank.

Sorry - my diagram isn't to scale. I had planned to install the 10 micron filter on the inside of the passenger frame rail just in front of the rear wheel; maybe 3 feet "downstream" of the in-tank pump (which has a 100 micron filter on the bottom of it, I believe).

I've been intrigued by the various threads/discussions about dead heading the fuel line out to the engine, but didn't know if it was something that could/should be done on this type of set-up; seems like I see discussion about it used on LS engines, but I haven't seen anyone use it on a big-cube BBC. Is there a reason or is the routing more of a personal preference issue?

[bentfab]

System one is the way to go. In all my experience's and dealing with the customers wants and needs. System one is the most common. Every one always try's to get technical and tell you this and that or thats wrong and this is right. I've plumbed every conceivable way and never had anyone tell me they had a problem. From 2000HP Nelson motors to 200hp small blocks. I've done dead head systems as well,but it's not really a dead head because there is still a return style regulator back by the tank. The customer insisted we do it that way and the tuner would adjust the injectors and set-up according to the demand of the motor. Thats what I was told so that's what I did.

I think the best way w/ an A1000 is to run a -10 feed w/100 micron pre filter up to a -10 micron post filter(usually as close to the front so I can route a hose from the frame to the motor) into a tee or one of my distribution blocks and out to each rail with a -8 line to feed the front side of the rails. Then out the back of the rails into a regulator. Out of the regulator back to the tank with a -8 line. Or vise versa depending on space and looks. Supper simple and strait forward.

The biggest thing is to make sure your system has the least amount of bends and 90s as possible and to make sure not to bottle neck the system with different size fittings and hose. Just remember if you have a small fitting coming out of the tank or some where else in line that's going to be the size of your system and could choke the entire set-up no matter how big a line you have. I hope this makes sense and helps.

Here's a few pics to look at

Mark

[ShadowGrayGuy]

Thanks for the input ( & engine eye candy! ), Mark. Also thanks to those who were kind enough to NOT post how I have my regulator plumbed wrong. Got a PM from a member pointing out that I should have two -8 lines running into the sides of the regulator and the -8 return to the tank on the bottom of the regulator (see engine pic in my initial post). How embarrassing!

What is everyone doing in terms of fuel line type from the tank up to the engine compartment? I have nylon braided hose (as you see in the picture) from Jegs or somewhere similar. I thought I read on the forum that this will produce a gas smell no matter how tight I've got the fitting? What's the best way to plumb it to the front? Rigid stainless steel lines?

Rob