My LS7 put down 468rwhp and 437rwtq stock. I suspect the units in the Z28 are putting down at least that.
Aside from getting into the motor, there is no change a stock S85 will make that grunt. Hp yes, but not the torque. The LS7 is a torque monster.
I suspect even if BMW made an E63 M6 CSL, it would struggle to match the lap time of the Z28 ~ which was made strictly as a track tool for the street. If the new M4 is significantly slower than the Z28 on a track, then any S85 powered car would be even far behind as the M4 is BMW's best track tool to date.
Keep in mind that the Z/28 is running track tires and the Corvette is running street tires. The tires alone are worth 4+ seconds a lap on a 4+ mile lap.Surprised that the Z/28 beat the Stingray by 3 seconds. I know it had a lot of weight reduction from the SS and ZL1 models, but it's gotta still be heavier, and have a worse hp/weight ratio than the Stingray, right?
Keep in mind that the Z/28 is running track tires and the Corvette is running street tires. The tires alone are worth 4+ seconds a lap on a 4+ mile lap.
For the money, I would rather have the Vette with some sticky tires.
You can make a heavy car go fast around a track, but it costs a lot of money. Basically they consume wear parts like brake pads, brake rotors, tires and gas at an excessive rate.
And of course all the parts are larger and more expensive.
For me, a $75,000 Camaro, built for the track, weighing close to 2 tons, makes no sense.