Quote:
Originally Posted by classicauto
Personally, I think taking the general idea and adjusting it to suit the rotary's strengths is the best approach. I would personally like to see the small turbo fed first, but reversing the direction of the intake air. Have the large turbo suck through the smaller one. Thoughts behind that being: the smaller turbo would have -essentially- vaccum on the compressor which is going to help it gain shaft speed very early. These babies like the air volume as we all know  And once that snowball effect starts to roll on as the exhaust pumps out more and more pressure and volume - well we're off the races |
The big turbo sucking through a small turbo is the same as a big turbo sucking through an inch and a half inlet; the big turbo is going to pull vacuum on it as soon as it starts to spool, and then the smaller turbo is just a restriction.
What you'd want is a sequential system with a reasonably large turbo for the top end, and a small turbo to create boost down low; that's what I'm working on with my sequential controller. It uses electronic controlled valves to control the secondary turbo and the wastegate, and allows a small turbo to boost to say, 14 PSI almost immediately, and allows the big turbo to make as much boost as you care to let it when it spools. And since the wastegate is electronic, it doesn't even start to crack until the second turbo is at full boost.