Im looking to upgrade from my stock AP1 pulley to an AP2 pulley and get around 6-7psi (right now im getting on average 4psi, and on occasion 5psi with my UR FMIC). I have the AEM Wideband and Boost gauges in my car so I will be attempting to tune the car myself with the COMPTECH/CT-Engineering Supplied Fuel Mangement Unit.

My question is how does the FMU work? Does it adjust the variable rate, or the actual fuel pressure for idle/peak WOT. (the fmu is a stock fuel pressure regulator and FMU built in one). My other question is if I tighten the screw, will that increase the Fuel pressure or decrease it. Or do i loosen the scrw to increase the fuel pressure.

I tried emailign CT-Engineering about it a while ago with no responce. Thank you all for your time.

 

you can call them for quicker answers to your questions. but i think tightening the screw increases pressure

 

thank you, any other opinions/answers?

 

Tightening in the screw will increase fuel pressure which makes it run richer. The increase fuel basically pushes more fuel through the injectors increasing duty cycle. Hopefully someone else can shed some more light as I'm still learning.

 

Yes tightening the allen screw will increase the fuel pressure which will make the car run richer. But at 7psi your going to be a the max for stock injectors. Not to mention most likely running lean. At that point you'll need to get bigger injectors and some engine management.

 

I understand that 7psi will be "pushing the limits" of my stock injectors. I will be pushing more like 5-6psi from the boost lose from my FMIC.

Thank you for the replies everyone!

 

The duty cycle stays the same. The pressure behind the injectors increases proportionately to boost pressure. This results in more fuel.

The is the same as what a normal fuel pressure regulator does, except a normal FPR is 1:1 ratio and the Comptech unit has a range around 10:1.