Actually looked into doing the compound turbo. According to the fabricator, he says theres plenty of room to do it, but would require a custom manifold. For the twin turbo to make any sense if that was even possible the twin turbo would have to be dinky small, like smaller than stock which even if it was practical wouldn't make sense. The compound setup on the other hand would be stellar. The whole issue with the larger turbos is spin up, so if you had a motor that could take the power, and axels that could deal with the torque and you could put it down to the road, if I remember correctly the larger turbo feeds the smaller turbo to make it work. That sounds counter productive, but im pretty sure thats what he said. The whole question brings up a interesting thought, do you need it? The 2860 and S280 and S290 seems to be the largest you can go before it doesnt make any sense. Sure you can go bigger, but if your only making big power for 2000 rpm whats the point? For the car to be fun, it needs to make its power from 2-6K, the turbos mentioned start making reasonable power around 3000-3400. Any thing higher and its just a numbers game of who makes the big peak numbers aka the dyno queen. There are several different ways to go about using twin turbos in this car, the compound is one, and the split is the other. By split I mean, you use the small turbo off the manifold and you do the old LS1 setup of putting the larger turbo on the back end of the exhaust. There is a more plumbing but it would give you the best of both worlds.
