First of all, stock supra's arn't that quick, however they are like GN's, rare to find one that runs stock boost. Second of all they have very peaky HP cuves, that's why they call them dyno queens. Especailly one's with a big single turbo conversion, and being on a small displacment engine, it takes longer to spool the turbos. They make plenty of power, but it's all up top and it takes longer to get boost, so not until they get where they can ride out a gear do they really pull. Third thier suspensions suck, they can't get traction very well. Maby you can make them hook, but the only one's I have scene do this are full drag cars with 4 links in the back. I've heard of these stock one's but never scene it happen. Forth, a 700HP mustang will kill a 700hp Supra.
Maby not all but every Supra owner I have met are white collar, deep pocketed, cocky snobs. They had the work done for them, and don't have any pride in thier country. They want to prove america sucks but they don't suck because they are with the "internationalist" and they think they can bend the rules to do so. Enough with the politics.
If I had the money, I wouldn't waste it on a Supra. For the same money, I can get double the power from a V8. Example. RP Motorsports built '02 z06, C500 Race block, 427 stroked, Twin Turbo running 700HP at 5psi, and 1200RWHP at 13psi. It looks stock and sounds mean but not that mean.