Given what I suspect is improved efficiency, responsiveness, and accuracy of distribution from ITB, as well as improved delivery and control (possibly adjusting individual cylinders) of injectors of the ITBs, that might outweigh the KISS principle. In a pure race environment, finer control and increased response would seem to be the priority as miniscule improvements from all aspects of performance could result in a more cumulatively noticeable advantage. Look at the engines from turbo F1 era (BMW BT52 M12/13 4 cylinder), and most appear, to my untrained eye, to have ITB, but I might be missing something. Perhaps it gives greater access to optimizing average power in the different rev ranges of a race motor.michaelmount123 wrote: ↑Wed Jun 26, 2024 4:17 pm I never ran any of my intakes on a turbo car. Interesting, however, that Porsche turbo racecars (and even the NA racecars) used the ITB's. 944GTR, 924GTR, all the water cooled R's and RSR's, 956, 962, etc, etc. This doesn't mean a single TB won't work well, only that Porsche saw some advantage to using ITB's. That said, there's an advantage to applying the KISS principle with a single.
Now on a purely street car, maybe less influence on useable real world street performance making it harder to justify increase cost and complexity. Looks to be a widely debated topic for several years based on Googling the topic.