Well, I over-thought this event (500pp series with no tuning allowed, right?) and crunched a lot of power-to-weight ratio numbers for cars in the 480-500pp range. The
TVR Tamora was the clear winner at
3.072 (!!!)
and also can be used for the
British Lightweights event in I-B. Great little car, can't recommend it highly enough. Just don't change the oil first, it'll kick it up to 505pp & 361hp. Although, you
can use the power limiter to bring you back down to 500pp.
TVR Tamora '02: 345hp, 290 ft-lb torque in a 1060kg FR car for only 71,000 credits?
SHUT UP AND TAKE MY MONEY!
Someone also mentioned the RUF BTR, it had the second-best results coming in at 3.206 kg per hp.
If anyone is interested in the stock power-to-weight-ratio results for about 20 cars in the 480-500pp range, let me know and I can post the full list.