I have an SFMU with 440cc injectors and the safc2. I understand the job of the SFMU is to add fuel when it sees boost, for each pound of boost it adds a certain amount of fuel depending on which spring/disc is inside. I understand the safc2 can only lean out your fuel it can not add fuel. My friend swears i don't need the sfmu and i only need the safc2 to tune my fuel. He says my stock regualtor will be able to add fuel. He has an rsx that he turbo'd it has 440cc injectors and the greedy emanage and he has his stock regulator he does not have the sfmu. Can you please explain why he doesnt need an SFMU and i do, so i can tell him he is wrong and i do need an SFMU.
Thank You,
-Brian

I might be wrong but I'm pretty sure you stock regulator won't raise your fuel pressure to the level that you need because it wont read any boost. Thats why you need a fmu or an sfmu. And Like you said the safc only leans it down so you'd have no way to increase your pressure.

Originally posted by normajean
I might be wrong but I'm pretty sure you stock regulator won't raise your fuel pressure to the level that you need because it wont read any boost. Thats why you need a fmu or an sfmu. And Like you said the safc only leans it down so you'd have no way to increase your pressure.

correct

Just point out to him that he drives a Honda and therefore knows jack shit.

Originally posted by thedawg
Just point out to him that he drives a Honda and therefore knows jack shit.

I almosst bought a honda, then I realized that. haha.

Every car will have a slightly different fuel system. It will use different types of sensors and react differently to abnormal operating conditions. You will need a strategy specific to that car to get the fuel you want without damaging the engine. You could probably get away with 440's and e-manage with injector control harness and auxiliary MAP sensor. An S-FMU is just an easy fix for us.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

The safc and the emanage both remove fuel by lowering the map voltage. The emanage can add fuel by providing a ground for the injectors so no voltage is added to the map signal. the safc can only add fuel by increasing the map voltage which you don't want to do. The only way to safely run a safc is to go overboard on fuel supply using a sfmu and then removing fuel using the safc.

Originally posted by dandv1977
The safc and the emanage both remove fuel by lowering the map voltage. The emanage can add fuel by providing a ground for the injectors so no voltage is added to the map signal. the safc can only add fuel by increasing the map voltage which you don't want to do. The only way to safely run a safc is to go overboard on fuel supply using a sfmu and then removing fuel using the safc.

cut and paste that to him.

Don't forget that as you drop the MAP sensor voltage, you also increase your ignition timing as you decrease your fuel delivery. If you use your safc to make alot of fuel correction (especially at WOT) the motor will start pinging.