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What might be the cause?

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turbov6joe

Signal 1 J-12
Joined
May 22, 2002
Messages
2,220
For some starnge reason my TTA seems to loose boost on the
2-3 shift. I have the max boost set at 25 psi, and in first and second gears it's at that boost level the entire WOT pass. However, when the tranny is in the process of shifting into third gear, or so it seems to be, the boost drops down to around 12 psi then, ever so gradually, increases back up to 25 psi the rest of the pass??? I'm loosing valuable time and MPH with this little problem and would like to get it figured out ASAP! Here are my thoughts on the matter. Recently I switched to 50's and have noticed that this problem is more pronounced. I'm thinking that my Joe L. chip, which I know for fact was designed to pound the injectors (for my old car/combo...BIG turbo), might have too much fueling going on just when the tranny is going into 3rd, thus causing it to be SO rich I'm loosing exhaust velocity and boost (just using a TE44 on the TTA). The second thought I had was maybe JL programmed some kind of 3rd gear boost scale down to avoid KR, again maybe a reason why the boost drops so dramatically? Lastly, maybe the tranny is taking so long to shift (100% stock), it's unloading the motor and making the boost drop? Any other ideas or comments in reference to this matter? I'm all ears!
PS> I'm in the process of having my JL chip file burned onto a 16 position thumbwheel chip with a 5% decreasing fuel table at each level...maybe this will allow me to get the EGT up over 1400º???
PSS> Is there a direct correlation between timing and fuel needs? This current JL chip was at 23.9º WOT timing to begin with. We re-burnt it down to 21º to get rid of some detonation at high boost and noticed that the EGT wouldn't go over 1400º no matter how low I turned down the FP regualtor (40 psi static is as low as it will go). I seem to recall with the 23.9º WOT timing, the EGT was around 1450º...a far cry from where it needs to be, but better! I usually tune for the high 1500's to low 1600's.
 
Come on guys, someone must have seen something like this before and have some input to give....ANYONE???
 
I've seen a bad MAF do that.
It was really strange.
If you have a DirectScan look for the waste gate DC display to be really weird looking.

Boiled down to a serious case of MAF drop out.
 
well i just went on a little run with a 13 sec honda and i had the same problem at full throttle 1-2 fine im hold 19psi then 2-3 the throttle will close on its own and reopen,causing compressor surge. which drops my boost and then goes back to normal.
MAF is good
I wonder if the fact that im running a chip for 36# injectors when im running 38# would cause this??
 
Jim,
I am indeed using the HD actuator and an external spring to boot. I had a slight problem with boost flutter that was cured with the spring, and was hoping it would solve the loss of boost problem as well. My buddy that's re-burning my JL chip said it was programmed for 100% DC on boost, so that takes out my hypothosis of 3rd gear boost scaling. Now it's back to the too much fuel hypothosis.
 
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