Evening all just wondering what is the most bhp and torque my standard internals can take before I start encountering probs. I am aware that my gearbox will strugle to handle anything over 350 lbs of torque but what about my internals the car is a Turbo 2000 Classic uk spec?

 

would think about the 340-350 mark.

shame its not a later sti

 

We have ran up around 400bhp reliably on the 99/00 cars with cast pistons, the Sti's with forged pistons will run more.
92-96 cars seem to break ring lands with sustained use over approx 370bhp.

 

As Andy has said 400bhp is within reach for standard internals but it will require the right turbo , decent fuel , a decent intercooler and careful mapping .....
Ideally you would require a turbo capable of 400bhp @ no more than 1.5bar boost to keep it reliable for an extended period...