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Discussion Starter · #1 ·
I was wondering my WRX is stock and when i pull uphill there is a dpi in the power curve i can feel a little after the turbo spools up like 5.5 rpm then goes back up like 6 rmp this is weird and i can actually feel the power go down.. i read import tuner DEC 01 issue and the dyno chart of the power curve seems to correspond with what i feel.. do you guys feel the dip too?? what do you think causes it? the intake resonator??anything else ?? for you guys that have modified WRXs what did you change that eliminated this dip??
 

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Stock turbos limitations, and the stock ECM attempting to compensate for said limitations. Boost is bleed starting somewhere up there 5500rpm, and a lot more timing is added to compensate. It dosent compensate. The boost is bleed because the stock turbo can only hold 13psi tops at redline.

How to fix, new turbo, and or ecm tunning. I recommend both. I did, I love it. You'll like it to. I'm in Vallejo also, do you drive a stock black sedan? If so I've seen you.

Ken
 

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Discussion Starter · #3 ·
Actually i have a blue sedan all stock, you said you've changed your turbo?? id like to see your car sometime.. please let me know when you have some free time
 

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Discussion Starter · #4 ·
correction.. now i have a JDM i emblem and claer side markers... i thiink im the only 1 in vallejo with those thing on my WRX
 

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Nothing to do with the turbo whats so eva. Its the wastegate. In its atempt to preserve your engine it makes it spool down. The ECU knows you are coming up for red line so it tells the wastegate to close. If you have a boost guage you will see it drop. In any gear. More so in first. The only way to compensate for this is to chip the ECU. A new turbo will only help if it over spins.
 

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Wheels...new to all of this, so what exactly does the wastegate do?

Rod
 

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The wastegate regulates boost. The ecu controls it. I took that control away early, Blitz DSBC. Love it, fast response and stable.

Ken
 

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A manual boost controller will allow you to hold about 16 psi all the way to redline in any gear. The effect is almost flat torque from 4,500 rpm to 6,500 rpm, dropping off slightly before redline.

-Jim
 

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Jim,

How do you get your MBC to hold all the way to redline?? With mine, the boost falls off, but not as much as it was when it was stock.

Later,

Dale
 

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Baluch,

Boost varies according to a lot engine parameters: atm pressure, air temp, air flow in, and exhaust flow out. I have all of the mods listed in my signature and as long as I stand on the thottle, the boost stays at peak until I left to shift. My car has a butt load of miles on it and I have changed the oil regularly. I have done everything in my power to get the engine breathing well, including an ECU reset so the computer would learn the engine configurarion (much) faster. Keep it mind that I live near sea level and it has only been about 55 degrees around here lately. When it was hotter out, the boost would retard when the engine approached redline. Now that it is nice and cold, that gauge stays pegged until I tell it other wise. Also, the Joe P MBC is a great unit.

-Jim
 

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I also maintain full boost to redline with a MBC. Running 16psi in 3rd, but will exceed 17 at WOT in 5th. I just watch my right foot while in top gear.

Shawn
 
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