With a piggyback, it is a relative adjustment. For example, the stock ECU will make a decision on how much fuel should be added and the timing, and the EMU intercepts this signal with a

 

I was thinking the same thing...

It seemed to run perfectly fine in vacuum though with my AFR's right at 14.7 ish.. Boost it at all and it just seemed as if the E manage wasnt adding any fuel and afrs went instantly lean.

Without my wideband I would have blown the motor for sure, but I keep a sharp eye on it all the time.

 

Did you happen to go WOT? Did it go rich? I'm just wondering if the BPS affects the entire fuel map, or just part throttle.

 

[QUOTE=devs2k,Sep 29 2008, 03:46 PM] With a piggyback, it is a relative adjustment. For example, the stock ECU will make a decision on how much fuel should be added and the timing, and the EMU intercepts this signal with a

 

[QUOTE=8kGoodENuff,Sep 29 2008, 04:37 PM] Oh I see... I thought it would just completely throw the ECU command out the window.

 

Partial throttle was perfect at 14.7 untill it saw any positive pressure and immediately went lean to 16. I did press full WOT once or twice to see if it would correct but it just went more lean and I had to get off of it ASAP as it would start to detonate.. Believe me I thought of that cause usually WOT goes 10.0-10.5 for me..

I never really boosted over 1.5-2 lbs and only did this two or three times, but with my wideband next to my tru boost in my dual gage pod, I could see how one was effecting the other.. I wasnt going to do much more "testing" cause I need my motor.

 

It's amazing how important those two gauges are!! I have them both with my Greddy kit and look at them all the time. I am tuned and am staying very rich. My tuner said I may richen up some in the lower WOT RPMs, so i need to take it back in to lean it out to about 11-11.5 at lower RPMS instead of the 10 it is at now!! I also, love the peak boost feature of the tru boost. I am always checking the peak boost, clearing it and later making another WOT run and checking the peak boost setting again, just to see how consistant it is. It is usually between 9-9.2 peak, which is where I want it. One more tune and I may push it up to about 10 psi.

Way to keep an eye on those gauges! You probably saved yourself several thousand dollars for a new motor.

 

im confused, shouldnt you be running richer since you have less air at higher altitudes, thus your afr would decrease