Top Post Dawg
- Apr 27, 2003
- 1997 Passat TDI White,99.5 Blue Jetta TDI
My Scangauge II came today. I programmed the boost x-gauge and first EGT per the initial post in this thread. EGT works fine and responds very quickly when you get into the throttle.
The boost gauge seems to work but gives slightly odd readings. When the engine is off it actually reads around -15psi, at idle it is about .6psi and then when you get into it it will jump up to 23.4psi which should be about right.
Two odd things I've noticed...
1) When cruising it reads about 1psi and when "engine braking" the PSI actually goes up to around 3psi. Not sure what that is, EGR maybe?
2) I think this is actually displaying commanded boost, not measured boost. When you floor it the boost jumps immediately to max even before you feel the turbo kick in.
UPDATE: This was showing commanded boost. Changing RXD to 4810 gave me actual boost and you can clearly see the turbo lag now. After it was showing actual boost I tweaked the MTH number to give me 0.0 with the engine off. I think I changed the last two digits to 75. Basically count in hex for each 0.1 PSI change you want.
I have a scan gauge I & II, up in the metro Denver area my pressure readings at idle read around 11.5-12.5 psig......while closer to sea level back home it runs around 14.2-14.5......under normal conditions in an alh engine you can add ~12 psig to that reading at maximum boost......