S-AFC and stock fuel system

[marcmsj]

i have a small 16g and a S-AFC. i haven't upgraded the injectors or fuel pump yet. will be doing that real soon. should i leave the S-AFC at 0% across the board for the time being?

 

[2-0turbo]

Yes. Your only other option is to go with an AFPR and set base fuel pressure to 43 psi and make your correction negative across the board to compensate. Then, based on datalogging/dyno/whatever, you can richen (some) where needed. I can't find my formula right now, but this change in base fuel pressure will only give you about 8% correction to play with.

There are some caveats to this, but with a 16G and stock fuel system, if you datalog, I think you'll find your duty cycles about maxed out. That is why you should not put in plus% corrections until you adjust base fuel pressure. This may not be the case, but I could max my 450cc's out on a 14B, so I'm sure you can do it on a 16G.

Ultimately, you are limited by your stock fuel pump. Proceed with caution. It's a hot topic, but I cannot recommend anything over 15 psi on a stock fuel system, whether you've got an SAFC or not. The stock pump just doesn't have much spare capacity, especially when the boost levels start going up.

 

[marcmsj]

thanks for the input.. you've only confirmed what i already suspected.

i've been having a problem with my wastegate and have not been able to go above half throttle otherwise i would go above 15psi and would lean out really bad, engine would go pop pop pop

last time i went to the track, that's how it was and even at half throttle, i still got a 13.7
not worried about the actuator though since i'm going with a 20g set up with an external wastegate, but i did want to know what to set the S-AFC for the time being. i tried turning the fuel up but i'm sure it's been maxed out.