1st - does WALLACE quote RW 0r FW HP. ?.Heres a challenge for you - pump in the avge mph and weight of a stock 6.1 LX car of 107 mph @ 4300 lbs and see what HP you get......Im betting it will be the quoted factory Engine hp and nowhere near rwhp. :)
You can use the formula to compare your power to the ground vs an lx power to the ground, but realize the output 'hp' numbers probably aren't correct. Also, given you have a different tranny, it's not going to be a spot on comparison (lx's have more gears, thus tighter rpm band used, though probably more driveline loss).
2nd - By corrupt - I meant that drivetrain losses vary from car to car - so why would I use Rear Wheel HP as a guide on whether my car is down on power?