Date: Tue, 14 Dec 2004 21:14:44 +0100 From: Frode <fhnospammica.no> Subject: Re: 99 Turbo update - vroom vroom
> Ah, so this is how it measures the boost pressure, through that line. > Pushes down on the diaphragm to open the bypass valve, yes? An elegant > solution. Not very precise, but less prone to oscillations. I'm sure the fact that the valve opens in the upstream direction most likely contribute to the 99-engine's reputation for "ketchup-effect". > So if I turn down the boost until I get a feel for everything, that'll > make > it travel more and un-sticky itself, in thory at least. Sounds > reasonable. Some info from Heynes no. 247, p 246 ------------------------------------------------- PSI Bar Turns in/out to obtain correct 12.5 .86 1 out 11.9 .82 3/4 out 11.3 .78 1/2 out 10.7 .74 1/4 out 10.15 .7 0 (Correct value) 9.6 5 .66 1/4 in 9.0 .62 1/2 in 8.4 .58 3/4 in 7.8 .54 1 in ------------------------------------------------- Another thing just came to my mind: Back in the days when this was my only car, I reduced the pressure to .5 bar or so, since I ran out of spare heads. This resulted in an annoying noise that I chased for a year before I realized it was the wastegate valve hammering the seat almost from idle. Had a minor crack in the exhaust manifold removed and welded without any effect amongst other things! -- Frode