2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Boost Problems.

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Old Feb 5, 2008 | 10:18 AM
  #1  
Dugwillis84's Avatar
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'91 Savanna GTX
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From: Courtenay, BC, Canada
Arrow Boost Problems.

Hey guys, I have a few quick questions regarding a problem i've got with my new RX7.

The previous owner had Ported the Wastegate, and it was running about 9.5-10 psi.

Now, all of a sudden the turbo has just developed waaay more boost. When i put it to the floor, the car is hard to control in any gear.... If its wet...and im in fifth gear, i can step on the gas...and it'll spin em..

What happened? did the wastegate go flying out the exhaust?

Seriously though, under full accel...it will go up to about 1 bar.. then, when the revs come up, the boost goes down?

I've got a video of the issue, but its kind of long. If you want zap ahead to about 3:10.

http://youtube.com/watch?v=0D1eKcSEe6E

Car Specs

91 Savanna GTX.

Basically stock besides ported W/G, exhaust, BOV, intake.

Any thoughts are greatly appreciated.

Yes i have ordered a boost controller, new fuel pump, and fp regulator.
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Old Feb 5, 2008 | 11:07 AM
  #2  
arghx's Avatar
rotorhead
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Boost controllers can't lower boost, only raise it. Your wastegate is still not big enough. I had the same problem with my car that had an s5 turbo just like yours. I had a ported wastegate (to the edge of the flapper) and it still creeped. The problem is that in cold weather it will creep up more, which is common.

You have two options. Pull the turbo and port the wastegate further--this will require some welding to the flapper door and careful port work--or install a more restrictive exhaust that will keep the boost down.

And lay off the boost until you get this under control or you will pop your motor.
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Old Feb 5, 2008 | 11:12 AM
  #3  
Aaron Cake's Avatar
Engine, Not Motor
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Sounds like the vacuum line to the wastegate actuator may have popped off.
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Old Mar 18, 2008 | 10:16 PM
  #4  
polito Racing's Avatar
so you got pistons oh wow
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^+1 that is the exact thing i taught of.
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