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Old 09-24-2017, 12:42 PM   #1
OC_Nooby
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Member#: 311781
Join Date: Feb 2012
Location: Canada
Vehicle:
2003 WRX w STI V8

Default Power Dropping, BW S363, T3/82 A/R, questions

I'm sorry to have posted this in 3 sections.

I'm trying to figure out why I can't hold boost up top.

Here are the specs that should matter:

BW S363 63-68 @ 29PSI, no filter (robbed me 50WHP!!!)
Ported heads D25, BC 272 Cams, Manley Springs
Long runner N/A intake
8.9:1 Wiesco Pistons
E85
Agency Power ELH
P&L uppipe (1 3/4 inner diameter)
No AVCS
2.5L Block
3" turbo back exhaust with resonator as a muffler
Ebay FMIC with 2.5" tubing
Intake Temps at 115 MAX during pull on dyno

Wanted to rev to 8K, power dropping by 7200RPM (link below)

https://1drv.ms/i/s!AlgdYt1DEBlRhWymloxw8qJ46Rxq

click on view original

I had the same issue with a smaller turbo, figured it was just the turbo.

Things on my list to test:

Back Pressure before Turbo
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Last edited by OC_Nooby; 09-26-2017 at 10:19 AM.
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Old 09-25-2017, 11:42 AM   #2
OC_Nooby
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Location: Canada
Vehicle:
2003 WRX w STI V8

Default

I guess ill do a back pressure test. See where i'm at.
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Old 09-26-2017, 08:39 AM   #3
Scuby04STi
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Join Date: Aug 2012
Chapter/Region: NWIC
Location: Portland*
Vehicle:
2004 STi GTX3076R
Rally Blue

Default

Did you work the boost up to that point when tuning or just start there? Seeing how the curve changed with added boost would tell you a lot, it's just an air pump so there is always a sweet spot and a bottleneck point in what it can move.

Stock valve sizes or oversized? Head/cams combo should be fine at those levels. Not experienced with the header/up-pipe.

What fuel is this running?
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Old 09-26-2017, 10:19 AM   #4
OC_Nooby
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Join Date: Feb 2012
Location: Canada
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2003 WRX w STI V8

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Quote:
Originally Posted by Scuby04STi View Post
Did you work the boost up to that point when tuning or just start there? Seeing how the curve changed with added boost would tell you a lot, it's just an air pump so there is always a sweet spot and a bottleneck point in what it can move.

Stock valve sizes or oversized? Head/cams combo should be fine at those levels. Not experienced with the header/up-pipe.

What fuel is this running?
Stock valves
E85

I have a thread in built motors, figured that may have been a better spot.
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