I'm currently fiddling with mine but i'll only be hitting 300bhp with the help of nitrous. Im fitting a Trophy inlet manifold, fully bespoke decated manifolds, one off active exhaust system, after market managment to operte the pair of throttle bodies and better suited cams if I get a long list of over mods completed over the winter. Im hoping for around 270-280bhp. The later maybe being very optomistic. Anywhere over 300 bhp and the box starts to complain anyway.
As a side project, me and a friend are trying to mate a Civic Type R gearbox to an early v6 to sort this little issue out. If succesful, it will be a cheap and easy way to get hold of a much better box complete with various LSD options aswell as easy to find uprated clutches. Will also take shed loads more torque and bhp reliably.