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Saab 9000 Build - Boot Cut Issue - Help Please

Posted: Mon Jul 25, 2016 2:28 am
by TurboBudapest
Not sure if I am posting this in the right place...I have a 1997 Saab 9000 Aero. This car has been extensively rebuilt and modified over the last several years, and last year received a Maptun stage 3 chip upgrade. I have had a the car for four years now and have always had boost cut issues - even before I had it chip tuned. This summer we decided to put the T7 boost control valve in it and have the ECU modified to allow for the T7 BCV's use. The T5 boost control valve is notoriously unreiable. Still am having boost cut issues and am getting very frustrated. My tuner already sent back one ECU and still having the issue (throwing a lot of money at it).

We put a manual boost guage on it, and it is clear that the car is not boosting past 1.5 bars, so not sure why this is happening. Even more wierd is that the boost spikes to 1.5 bars then goes back down to 1.0 bar pretty much right away. I know that the boost spike was pretty standard from factory, but my Saab tuner says that this is a bigger decrease than usual. My family have owned a variety of 9000s through the years (including an Aero), and I feel that the highway acceleration is not what it would have been even with factory standard tuning.

Any ideas as to what the issue could be? I even put in a new factory blow off valve last year with no effect.

One thing I was thinking is installing an electronic boost control system. Has anyone ever done one of these conversions?

Many thanks in advance!

Ed

Re: Saab 9000 Build - Boot Cut Issue - Help Please

Posted: Mon Jul 25, 2016 3:01 am
by Krizzie
You need a 3+ bar mapsensor in order to go past 1.5bar of boost..

Re: Saab 9000 Build - Boot Cut Issue - Help Please

Posted: Mon Jul 25, 2016 11:45 am
by 99Super
I agree w/ Krizzie about the 3 bar MAP sensor.
Also, there is also a parameter in T5 that limits boost to 1.5 bar max that is outside of the standard boost control.
Perhaps that parameter wasn't changed?

John

Re: Saab 9000 Build - Boot Cut Issue - Help Please

Posted: Tue Jul 26, 2016 4:57 am
by Jordan
If you have a copy of the bin file or could get me the ecu I'd be happy to look at it. without that it could really be a lot of things. The biggest contributor I see to boost control problems is improper base-boost settings and too high initial boost requests.