From personal experience and probably 20+ races with a friend of mine, the ZHP BMWs don't match the G. To 60 it's a dead heat but the G starts pulling through 3rd and beyond.

This is with manual transmissions in both cars btw.

 

BMW correctly rates their HP ratings like anyone else. However, they have a flatter torque curve than the VQ35 engine does, and they optimize the transmission gears to each model of the car (325 auto/manual, 330 auto/manual, and 330 performance.. there are 3 or 4 different sets of gearings for those models). That really makes a difference.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

BMW's I-6 may have a flatter torque curve but after a few k rpm's, the G's torque will overtake the I-6 and will be more "torquey". Also, BMW rates their hp on the crank just like everyone else, however they're more conservative on the final number.

'03 G35c DG/G 6mt, full options

 

The 330i performance package is reported to be quicker to 60 and the .25 mile. It'll be a great race though. Where as the 330ci 0-60 time is identical. Interesting to know what the outcome would be from a roll. Advantage...G. Higher and top speeds G owns the ci. Keep in mind the PP goes to 155. I would love to race one from zero to 155!

 

I'm almost positive BMW rates hp at the crank like everyone else. I think the reason why the BMW can hang is due to the horrible drivetrain efficiency of the G compared to the BMW and gearing. Plus, maybe the person driving was a little 100 lb dude. If you weigh, say, 200, that's another big advantage he'd have. This is all assuming your driving skills are similar.

 

The combined weight of me and my passenger was probably around 500lbs. So I'm sure that came into play. I'll probably get a chance to run the kid againthen we'll see.