I still think that a front wheel drive GTi/Leon would be quicker round a track than an S3. Look at why all the Leon Supacopa's are front wheel drive rather than 4.
Its a fairly simple conversion that I looked into a few years back. The subframe just swaps over and its quite simple to wire the haldex up too.
I follow you on the supercopa's theory, but thing is the are limited in bhp and torque due to regulations, us streetgeeks aren't 
The Supacopa that ran the Barcellona 24 hour that came 1st in the FWD class and around 3rd overall ran an APR 2871 turbo kit!
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That's below 400 bhp right We might consider passing 500, but again i agree that a fwd can be quicker and definatly safer driving on the limit, which is the reason i haven't converted to 4wd,,,,,,,,, yet
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