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BSiple BSiple is offline
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Join Date: Feb 2002
Location: Fort Collins Colorado
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When I got my 92 turbo, the overboost sensor was grounded out. My car was insanely fast, and running super super rich. I am guessing to compensate for the high levels of boost. Once I pulled the engine, and fixed a couple of minor things (12 new plugs, plug wires, timing, mixture, etc.) I took the little ground wire off the sensor, and almost instantly starting hitting the overboost is 2nd through 5th. As my car has a Tial wastegate, we pulled it apart and found .8 and .3 bar springs in it. I removed the .3 bar spring and left the .8 bar one in and hooked everything back up. I was still hitting the overboost, but not as early in the RPM range or as often, so I went to Porsche and bought a new sensor and screwed it into the intercooler (which was somewhat of a PITA).

Long story short, no difference. I was frustrated, and did searches on here and Rennlist and did lots of reading. I read about incorrect sized header pipes, etc. Since I have B&B's on my car I was worried about that. So I went out to the garage to lay under the car, and while under there was thinking, hmmm, something doesn't look right.

Yeah, the Tial was hooked up wrong, so 5 minutes of time under the car and I was out for a test drive. I could hear the WG opeining and to this day have never had a problem with the overboost.

While that doesn't answer your question on the switch, my experience taught me to make sure everything is operating the way it should, since even with a 1.0 spring, you shouldn't be hitting the 1.2 bar cut off, unless of course it really cold where you are, smile.

Bill
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2003 996TT
1992 964 Turbo (sold) Holy crap are these expensive now!
1986 911 Cabriolet (sold)

I don't know why I do the hillbilly things I do.
Old 06-17-2007, 08:06 PM
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