Here is what I'm trying to get a grasp on. I have a RX6 single with 850 primary and 1600 secondaries running under 45 psi of fuel pressure. I seem to have run into a fuel limit at only 15 psi boost. My wide band is showing 12.2-12.7 afr at 15 psi and injector duty are both at 90% +.

Here's my question, what setup are you guys running and what injector duty are you seeing at ?? boost level? It seems to me that with 850/1600 at 45 psi, I should have plenty of room at 15 psi on a RX6 (it's a fairly small single as compared to T78 and a few others). Am I wrong??

 

you need to increase the fuel pressure
what regulator are you useing
45psi is just right for idel and off boost

 

Yeah your fuel pressure is pretty low. With that much fuel you shouldnt hit a fuel cut at all and you definetly shouldnt be at that high of an IDC. and 12.7 AFR is getting pretty lean. Im sure with your modifications you have a fuel pump that can handle the demands of the engine. Check the fuel filter. Or just adjust your FPR . Idle fuel presssure should be about 38-40 lbs. You should see an increase of 1 psi of fuel pressure for every 1psi of boost. (i.e. if idle pressure is 40psi then at 15 psi of boost you should see 55psi if fuel pressure)

 

Dude, there is something very wrong with your setup. That much fuel is good for well over 500 rwhp....

What fuel pump are you using?
Are you sure your wideband is reading right?

Base fuel pressure should be 38-40 psi IIRC. Are you sure you are getting base+15 psi of fuel pressure at 15 psi?

 

Idle should be 28-32PSI.
0 boost 38+PSI.
boost pressure = "0 psi fuel pressure" + boost.

 

I have the Automotive FPR that came with the fuel upgrade kit. I have it set at 45 psi at idle. The fuel pump is the Supra Denso pump. I really don't know if I'm getting 60 psi of fuel pressure under boost, I have no way of looking at the fuel pressure gauge while driving.

 

which fuel rail and which 1600 injectors are you using? have they been cleaned recently? fuel filter clean?