Bottom line for a numptie like myself: Is it possible to keep the torque down at low rpms yet increasing bhp at the top end?

You see' date=' I find it confusing that, on one hand, people are saying you cannot increase bhp without increasing torque proportionally, and then reading the spec sheet for the PD160 v PD130 seems to suggest otherwise (PD130 = 130 bhp + 229 lb ft, PD160 = 160 bhp + 236 lb ft... PD160 = approx 23% more power yet only 3% more torque)

:confused:[/quote']

Paul, The PD130 makes 229lb ft @1900rpm. The torque then drops to 170ish at 4000rpm (peak power ish) bhp = 4000 x 170 /5252

A PD160 makes 236 lb ft around 2Kish. To makes 160bhp @ 4K (another guess) it will have to make 210 lb ft @ 4K. So it might only have a peak difference of 7 lbft but at 4K its more like 40lbft.

That make sense?

Ah yes John, that does make a bit more sense yeah... so the trick presumably is to do what TaviaRS was saying and try and get an equal spread of torque throughout the revs?

That suggests to me then that torque can in fact be limited at low revs, and peak torque would be moved higher in the rev range?