The inlet manifold is designed for low down torque. (caravan puller)
Change the 2.2 manifold for a 2.4, and the powerband shifts.
Decent exhaust and a remap, and you are in the 170/175 area.
More then that and you´re looking at more aggressive cams, head porting, light flywheel, balance shaft removal etc. With that it goes up to 190/200 isch.
When aiming for sheer power, you may need to make a choice between staying NA and tuning becomes expensive, versus an SC conversion, which is then in the same expense area. (and giving 250 bph)
Edited by smiley, 18 April 2017 - 09:51 PM.