My car came with Mobil-1 of unknown weight from the PO, and was about 1.1bar hot idle, rising to 3 bar off idle (probably the same ~1200 rpm). I just changed the oil and filled with the new Mobil-1 5W-40 weight (Delvac-1), now hot idle pressure is a little higher, around 1.4-1.5 bar, which makes me think the previous stuff might have been 10W-30. Zero change in performance but I prefer the 5W-40 weight.
I believe the cam timing is an on/off affair, not variable. Something like it goes adavanced by 5 degrees or so at ~1500rpm, then back to normal (retarded) around 3500rpm, or something like that. I have the exact numbers at home. The PWM idea is interesting, I wonder if that's what's going on...? Hmmm.
My 603.960 (1987 300D) is mostly stock but I am VERY interested in getting more power from it - safely! - for street use. I'd be thrilled with 180-200hp (up from 148 stock). Mosselman makes an intercooler kit good for 20% gain (175hp) but the cost is steep, about $1800 USD thanks to the poor exchange rate. If you have any specific info on souping up the OM603 turbo, please let me know!
