I've been wanting to try out the high boost setting but have been reluctant since I still have the stock IC, but it was a very cool night last night and I said what the hell lets try it. I was very surprised to see that at WOT in 3rd gear I hit .92 Bar and I was only hitting 83% Duty on the injectors. I ran it up through 4th gear but it never peaked higher than that. I'm running a completely stock fuel system at this point. Does that surprise anyone else? Maybe this is normal, but I have always been paranoid about results that vary widely from the accepted norm and I've always thought the stock fuel system couldn't handle that much boost. Comments?

 

The duty cycle you see has nothing to do with the adequacy or inadequacy of your fuel sustem. It is simply what the PFC is programmed to do at that boost level. You could see 50% or 100% depending upon your programming.

You overestimate its intelligence ;-)

Alan

 

Ha, so true! I overestimate my own sometimes too!

Thanks for the reply, I am running the base map supplied by Apexi. Relevant mods are M2 Intake, RX-7 Fashion DP, Efini Y-Pipe, and Racing Beat Dual Tip Cat Back. Still have the stock main cat and stock IC. I know AF Meters are fairly useless in tuning, however they do help establish a baseline. I'm running a Greddy O2 sensor (the one that comes with their AF Meter) and an Autometer AF Meter and the 3rd green light never went out which has been pretty much what it has always shown at WOT.

 

The base maps were too lean (wideband tested) on my car for about 12-13psi. I have all the bolt on mods though, stock engine and basically stock turbos. Seems like these maps have been plenty rich for other cars with fewer mods. The only way to be sure about your fuel programming is to use a wideband lambda meter.

It is possible you only saw 83% duty because you didn't run your RPMS up high enough. You will only have problems with high duty cycles right near redline.

Wade

 

Thanks for the info Wade. I wasn't paying much attention to the RPM's, I believe the Peak Hold showed a little over 7K, I'm not one to take it up to the buzzer too often. Like you said, I need to get on a dyno with a wideband and get this thing tuned, but I'm waiting for my mid pipe and IC so I don't have to go back more than once.

 

Your welcome. Good luck with the dyno tuning!

Wade