Reviving this old thread. It's an audi 80 b4 with the "old gen" ECU, MSA6 i believe. The maf is actually a vaf (bosch). So, i fitted a boost gauge and AFN injectors. Found out my n75 was badly connected. The car was slowly building boost up to 1.5 bar ! It's been driving like this for over 8 years, never had it in limp mode.
Connected properly, it responds quicker and peaks at 0.9bar, but drops slowly to 0.7-0.6 in high revs in high gears (5th gear-close to 4000rpm). This drop doesn't happen in gears 1, 2, 3. Even with this pressure difference i took it for 2 runs on an uphill, i would say it drives better with 0.9bar because of the faster spool up.
I adjusted the wg rod so that the peak boost is now 1.1 bar but it's quickly corrected to 0.9bar.
Now the question/problem : Considering the extra fueling, how could i make it keep a constant boost of 1-1.1 bar? Would a boost controller work? But where should it be fitted? Between the n75 and wastegate? Or between the intake and MAP (in this car, the MAP sits behind the airfilter, connected to the IC via a long hose).
Note : the ecu is 55 pin, with eprom. The only way to reflash it i heard is by having it under a UV lamp etc. Haven't found anyone to map it; there is one guy but he swears there is no way to adjust the boost values.
Sorry for the long post