I am surprised the 240 was able to compete in the GC class, I would of figured it would be considered a GT.
Since you let the cat out of the bag, what car are you going to run?
The Fiat X19.
There are cars out their with better stock Cd #'s (Fiat=.38) but the car is very narrow with a "stock" frontal area of a VERY good 16.6 (9 inches more narrow then the 91 MR2) and should be a good deal less because of the 5 inch shorter roof and the 4 inches off the tires/ suspension. The drop in height alone should yield somewhere about a .09 improvement in Cd making it somewhere in the .29 but I suspect is better because the roof chop minimized the dip behind the back window (a huge cause of drag) and will soon have a new nose that will get rid of the up turned air shovel nose the X19 was born with.
This is only on paper and only the salt will prove if my BS is correct.
One of the problems with the motorcycle motor approach is that when you get it out to 1500 cc's and and make the mods so that it is making 600+ hp the tranny and the clutch won't take it. Ask Rick Yacouci. I remember several years ago when he was running the 1000 cc motor he was dead in the pits because the output shaft snapped off!
If I was looking for the killer 1-1/2 liter killer motor I would call Jon Romero and have him do one of his Hondas. I think that I remember him saying that his little screamer was making over 650 HP at the wheels which would be well over 700 at the crank, and his car has been very reliable, at least from the motor end. Now one of his motor hooked to a DG300 Hewland and you are ready to start setting records in just about any class.
Anytime you are making 3X-5X+ the HP a motor was originally designed for (not to mention the added weight of a bike powered LS car) you are going to run into the next weak link. Rick was one of the first to make that sort of power in a busa motor and made many of his own parts and I am sure along the way was the first to discover many of the stock parts limitations. You can now buy billet output shafts and external output shaft braces.....you can also buy clutches and trannys they say are rated @ 1000 hp.
I think that in some respects bike motors have gotten a bad rap because of this.....it is so easy to add a turbo kit and make 275-350+ Hp on a stock bike but I hear people whine because they break something that was left stock but most people only see HP and not that you need to have stronger parts down the road. (I drive a non LSR turbo busa as well and am speaking of the motorcycle community).
The honda is a good motor and because of the rise in import drag racing has made aftermarket HP parts widely available BUT the DG300 Hewland is a very expensive gearbox (I think in the 10K range) and the stock hondas trannys, clutch and especially the axles, can not handle that sort of power without some sort of high performance upgrades as with the busa motor.
