Strange 3rd gear boost fluctuation

[Syclone0044]

Hey guys, I've tried getting help on this elsewhere but nobody is as hardcore about alcohol as you guys are, so maybe you can help? My problem is when I get beyond 22 PSI boost or so, with 93 octane and dual nozzle SMC Alcohol (M10 and M15) running 100% methanol, once I get into 3rd gear or so, the turbo will begin to "surge" and the boost will fluctuate and I lose power. I can't figure this out. I wrote about it extensively here if anyone has time to help:

http://www.syty.net/forums/showthread.php?t=40264

Here is an example of what I mean. Look at the pink line. The boost goes crazy.

And so far I have found that it is not the TCC lockup (sometimes it happens in 2nd gear before the TCC locks up), and it doesnt seem to be related to the AFR either. I tried running from stock heat range NGK UR5 @ .028 plugs down to .025 and .022" but no difference.

Thanks in advance,

 

[Razor]

Your problem is not alcohol related.

I'd look into your WG solenoid if your using one, or triple check your bleeder.

 

[QUIP'6']

mine did that when the puck wasnt sealing had to put more tension on wastgate and turned down the bleeder. then i solved the problem going to a thdp

 

[J Banning]

I used to run a PT51 turbo a while back. With stock heads and stock intercooler is was great. Lots of fun on the street (12.51 @ 107mph, unlocked converter & 100% pump gas).

Then I went to ported heads and a front mount intercooler...

Once I made those mods I got wicked compressor surge at anything between 5psi and full WOT. At WOT there was no problem, but if I tried to half-throttle the car on the street at say 12psi, the compressor surge was so bad that the engine shook the whole car!

I eventually beat the turbo into submission, and briefly replaced it with a TE62, and then a PT67 (on the car now). Those compressor surge problems never surfaced with either turbo. NO other changes were made. None.

Take that for what it is worth.
-Banning.