The fuel management thread.

ASSISTANCE Forced Induction
1

I will be running a 75hp wet kit and I want to take every precaution possible. Now I know what to buy and what not. The thing is I’m trying to figure out how fuel management aftermarket parts will work all together.

So here’s the thing:

I don’t know what part I should buy to manage my fuel. Is an aftermarket fuel pump a good thing, what about the FPR? And if I’m buying the Apexi S-AFC fuel computer, will I need the FPR or the computer will adjust the fuel pressure to give the right amount of fuel?

Also with the Apexi, is there a way to have preset settings like when I spray and when I don’t spray. Or maybe it sense the boost and adjust fuel accordingly?

I’m trying to do searches on the internet but its not very clear, if someone could clear things up for me that would be great.

I know the Apexi isn’t necessary, but if I don’t need a FPR with that, I would save on the FPR at least + I will have more tuning capabilities with the apexi.

2

For nitrous, its not so much the fuel as it is the timing. The wet kit should inject enough fuel, but doesnt have the control to retard the timing.

Look into a nitrous timing retard feature. (only retards when you spray)

3

I’ll use a Jacobs mastermind nitrous unit to retard timing.

4

The pump is a good idea, and the regulator is nice to have, but not a necessity. The SAFC2 has 2 seperate maps, so you can have one for running on motor and one for the bottle. Most of the time when spraying , the a/f isnt that stable. For example, the nitrous had way more pressure behind it then the fuel, so the juice will get there first. On the dyno most kits will go lean at first then richen up. You can get rid of this inital lean condition by making the injectors add more fuel at said rpm via the SAFC.

And as chris said, the timing is key. Something to pull timing when the solenoid sees 12v is great to have. The digital sci by msd is what i have used for a few different nitrous setups. Pulls timing, built in 2 step…

5

yea i was wondering the same thing becasue I am currently in the process of redoing a 1992 ls, the body was shoton it so i have been working on that, and I also was gonna run the same wet kit, so da6 thank you very much for the helpfull info it is much appreciated :slight_smile:

6

What is the use of a aftermarket fuel pump if I’m still using the stock FPR? I’ll be stock with the stock fuel pressure anyway?

As for the SAFC, how is this device work with the injector. If there is not more pressure in the fuel rail, how does this unit provide more fuel? By letting the injector spray fuel for more time?