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BSiple BSiple is offline
Gotta Jibboo
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Join Date: Feb 2002
Location: Fort Collins Colorado
Posts: 5,117
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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.

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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