I know using twin turbo's by having two turbo's of the same size is less efficient than using a single larger turbo. I've also heard using two turbos, one of a larger size and a smaller size has potential to increase performance. I know this is the prefered setup to create astronomical boost levels in diesel applications. Does anyone have information on using two turbo's of a dissimilar size on a gas engine? Could it offer an advantage over a single turbo... potentially with the smaller turbo coming to boost faster and the larger turbo providing more boost at higher rpms?