15 Z06 loosing throttle and boost

Bolt on 15 Z A8, intake, headers o/r X, heat x, expansion tank, ported snout and tb, 2.3 upper, IW 18% lower, flex fuel (on e10 in these logs). One log it wasn't as noticeable but at about 5800 the throttle drops in the 60s and boost falls off as well. The 2nd was a 4th gear 60-130 pull its worse and I could feel the power drop for sure. Have a dyno session scheduled soon and hoping to have this corrected before then so I can focus on dialing it in. Also in log 2 the first blip the car spun hard (TC was off, stability on) on the first hit and it seemed to hit max boost (14.4 which has been what I normally see on my aeroforce) but on the 2nd hit it never does. Any help or insight greatly appreciated.

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You maxed out Peak TQ so the car never goes into PE mode to alter the TQ & DD Table equation all the way which is a good portion of the problem. Make sure the VE and MAF is very good. Zero out PE TQ enable and you can move Peak TQ down later. Drive the car normal, decent throttle, put it in open loop and do the same, then full throttle. More data the better for the graphs and filtering I have. Your car holds power then tries to give ower but limits itself. Negative numbers are error areas. Repost or PM me a new log


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I had a longer file but it didn't save for some reason. I read your reply half awake and did the opposite. lowered the peak torque and didn't touch the pe torque enable charts :banghead: I'll try to get better logs when the weather cooperates. Thanks for the info.

your fuel pressure is not getting as commanded

make sure you log HPFP actual and commanded

Looks like your maxxing out injector PW.

throttle closes and boost drops coz the ECU thinks you are out of fuel.

Do you have a flex fuel sensor installed? Log Alcohol % too and see what that is reading.

Yes and its on the logs. 11.4 percent

Update. After I added the 18% lower I was on an E30 mix and the car was not losing the throttle until I went back to straight E10. I added a 30% E mix and did a log. in the file you can see the throttle boost pull is better. The little being pulled early is probably traction control. This time at about 120 mph the car went in to Reduced Engine Power and logged a P2281 code. Is there a factor I'm missing in the tune? Also it seems that my LP fuel psi is dropping to 57 psi on a command of 73. Does this mean I'm running out of fuel pump on the low side?


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You ever get this figured out? I had a similar issue where I would lose throttle and boost under WOT because my stock heat exchanger at a rock chip in it that slowly leaked coolant out over time. When I went into WOT, there wasn't enough coolant in the reservoir to keep it cool, so it lost throttle/boost at a certain MPH which I assume was a certain IAT. Once I installed a new heat exchanger and filled the coolant, never had the issue again. I never could figure out what part of the tune was causing the throttle to die.