Originally Posted by
nutron
There are alot of different compressors within the 49, 52 and 56 range, so the exact capabilities of any turbo without knowing the dimensions of the compressor used is impossible to state. There is only one 59mm and one 60mm compressor available though, but they are only good for extreems. The turbine on the Vectra is larger than used on the VAG 1.9 and 2ltr diesels, so restriction would not be an issue until extreems are reached.
As a guide I would say the following
49mm 150-200bhp
52mm 150-220bhp
56mm 150-250bhp
Obviously some rollers will give much higher figures than others, so those figures are reasonably achievable in MY OPINION. As for torque, the engines can hit 400lbft by 2500rpm potentially, so even the standard turbo can produce enough flow down there for 400lbft but it would tail off quickly and if you try to push a smaller compressor too hard at higher revs, it will overspeed and self destruct.
Bookmarks