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Discussion Starter #1
Ive finally got my car up and running.... ive noticed that i have a flat spot in the power band. If im in 3rd or 4th gear and stomp on the throttle, the power comes on linearly until i hit 7-8psi and feels sluggish all the way up to around 14-15psi, once it passes that point, it seems to pull properly again. I had this problem with my stock IC pipes, so i upgraded to Cooleeze hardpipes. Ive also changed bov's. Neither of these corrected my flat spot. The gauge is reading correctly and the boost needle rises properly. I can actually hear the air being ingested but no power. If i start in 2nd gear, it pulls like a mofo and feels strong through 3rd gear. My timing is set to 10degrees, my AFPR is set to 38 psi base pressure. Also, no codes.

Here's my setup:

Exhaust
DP
Testpipe
Intake
550's
Lexus AFM
SP61GT
AFPR

Would a bad 02 sensor be the problem? I do notice my street driving mileage is around 12mpg. The car holds boost at 17psi. Any ideas what the problem could be? Thanks
 

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O2 wouldn't affect WOT power, but will cause that crappy mileage.
Go to a dyno and check AF's, and check your TPS- That's all I can think of.
 

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i agree with above, get on a dyno and see if the flat spot really exists and if so check your afr in that area. what you use to control fuel?
 

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i bet you are running really rich in that range, get on the dyno and see if a good tune takes care of it.
 

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if you havent tuned and you have 550s....your running crazy rich probobly.....like everyone said get on the dyno and that should take care of the problem
 

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Discussion Starter #9
its possible, probably not though. i had the problem with stock pipes, and now that ive upgraded to hardpipes. id really doubt the leak would still be there or at least exhibit the same exact problem.
 

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Fatty McFatty pants
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I passed by your house today messing testing the shimmed turbo and how much it'll hit up to, sorry for hijacking your thread, maybe you heard my bov going off a few times :rolleyes:
 

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Hardtop FTW
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I'm going to go with the crowd and say get it tuned. It sounds like an A/F ratio issue. Good luck!
 

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BMM
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^ :werd:

BTW, did you ever fix yours RTA??
 

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Discussion Starter #14
Update, i recently changed my spark plugs and found out they were bosch platinums which are pre- gapped at .043! I put some Autolite 3923 gapped at .030. Huge difference, it pulls hard. Now i have 2 other problems, the SP61GT is still having boost creep and my idle is definitely not as smooth. I can hear the idle pop once in awhile and the car wants to stall more often.
 

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Hardtop FTW
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twinturbozs said:
Update, i recently changed my spark plugs and found out they were bosch platinums which are pre- gapped at .043! I put some Autolite 3923 gapped at .030. Huge difference, it pulls hard. Now i have 2 other problems, the SP61GT is still having boost creep and my idle is definitely not as smooth. I can hear the idle pop once in awhile and the car wants to stall more often.
I still say get it tuned!
 

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Escaped from infinite lag
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i spent the money on the wide band and use my SAFC2 to setup the fuel man it made a huge difference i pickedup so much more power...
 

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Moderator, l337 M0d3r4t0r
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12,222 Posts
if you are going too rich there,, say 10:1 then you'll feel real slow in that area
 
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