the 850 is a VERY different beast to the b230...for instance the 2.5 20 valve not only has exhaust headers as standard but also dual length inlet tracts with EMU controlled vlaves controlling which tract is in use at a given engine condition to maximise torque..

i guess what im saying is that either in NA or turbo mode its a reasonably maxed engine anyways...so things like injector upgrades have a low rate of payback wihtout other majour surgery...

of ocurse one can buy a t5 and 'chip' it and drop a drain pipe on the back and make it go very very very quickly indeed..but then again as standard they aint exactly slow...

I havent much experience with t5's but do own botha 940t and a 2.5 20valve na 850...(not the performance by the book is about equal!) and i have to say that the 850 is NOT slow...it just feels it because of the almost flat torque curve of the engine...as apposed to the 940t where it sort of goes..then the turbo arrives and kicks you in the ass!.....performance about the same but the 940 FEELS quicker!