3800 L67 - Getting serious KR at part throttle only

Morning everyone. Here's the scoop:

2002 GTP Sedan

New build mods include:
3" C-less DP
P-LOG
180 T-stat
Ported outlet/inlet Gen3
Ported Stage 2 ZZP Throttle Body
ZZP 9" open cone intake
1.8 Yella Terra Roller Rockers
New stock heat range plugs
3.3 Modular Pulley
60# Deka injectors

I just got the top end put back together and have been doing some tuning and scanning with HP-Tuners.. My issue:

Under part throttle ONLY, I get HUGE KR spikes.. this mainly happens when cruising in 4th gear and then gradually getting on the throttle. See snapshot of log screen below. Note that it does not happen when I really get on the throttle from a dig or off the line, etc. I have been up to 90%+ throttle on side streets from a standstill boosting up to 10 psi thus far with minimal to no KR (less than 1* or so).

http://i1133.photobucket.com/albums/...pszoslrxiq.png

I have currently set PE mode to come in around 32% throttle across the board. As you can see above, I am not even in boost yet and am seeing 5* of KR at 24% throttle....

Anyone know what I am should be doing next? Should I make PE come in even sooner to try and add fuel where I am seeing this KR? (PE mode at 20% TPS sounds crazy to me.. but not positive)

is the 3.3" pulley too much for my current mods?? (if it is, I will do E85 on my next tank :))

let the thoughts/suggestions start flowing please!

can u up load the ur tune?

Quote:

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Originally Posted by 507

can u up load the ur tune?

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Unfortunately not on the computer I am currently working from but I can do that this evening when I get home.

I know this is a bit of an outdated thread at 2 weeks, but, have you checked for anything rattling around in the engine bay? GPs are horrible with part throttle false KR.

Also, those seem like really big injectors for the mods you're running. I didn't run them that big even with the Whipple on my GTP. If you are planning on going E85 though then that would make sense.

3.3 seems pretty small for your mods but not hugely so especially with the roller rockers.

The majority of the time, part throttle kr in these cars especially with 4th loaded up is the tcc hanging up and not releasing soon enough. I'd bet its all tcc related. I had this issue after going from 2.93s to 3.29s in my built trans, mess with the tcc apply and release speeds and all is well. Just get that tcc to unlock sooner.

^^Agreed. I had great success with overall responsiveness (and less KR) by unlocking the TCC sooner. It helps avoid "bogging" situations.

What did you find out. b/t/w e85 is the only way to go with the l67.

You can take pump gas pretty far with a intercooler but if you want big power or a turbo, then E85 is easier to run mainly because you aren't likely to see knock anymore.

Quote:

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Originally Posted by 5FDP

You can take pump gas pretty far with a intercooler but if you want big power or a turbo, then E85 is easier to run mainly because you aren't likely to see knock anymore.

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True. My 3800SC fiero has the stock L67 engine, free flow exhaust, larger injectors & ZZP VZ cam and I run E85 with 20 degrees timing, no KR and ETs of 11.8 at 114mph. E85 upped the fun factor big time with this engine.

Edit - E85 is in fact liquid intercooling.

Sorry for the delay. Ended up posting the same thread up on the grand prix forum and figured it out there but forgot to post my updates here as well.

It was all TCC related. I was able to release the TCC earlier and it completely eliminated the part throttle KR. Since then, I have made the full-time switch to E85, and have since change the TCC tables back to stock-ish and there is no part throttle KR, since the ethanol is so much less prone to detonation. All is well and I would highly recommend E85!! I am now running a 3.0 pulley with pretty much the exact same mods and this little grocery getter pulls pretty hard :cool: