thats absolute bullshit, you telling me a nismo coppermix twin or ATS or ORC for the avergae skyline making 500hp is not purpose built??? if you are you are brainwashed beyond belief. in my experience going the proven route is always a winner, some random (not talking JB here)slapping together a clutch will often end in unsatifactory results.... direct clutch is one perfect example there... got f**ked around for months trying to get a decent clutch to handle 500hp in the RX7 and in the end an ORC worked perfectly and my old lady even drove it to the shops... the GTR has a nismo coppermix twin in it..... stock pedal feel and no dramas handling 350rwkw..... the old lady uses it daily.
custom is a needless waste of time unless you are doing something out of the ordinary....