Havent read all the replies yet having to do some of that funny work stuff so don't have loads of time, I looked into it and did lots of research... I will pass on all my bookmarks links etc when I recover my hard drive if you like?

Basically, its not really compound charging if you use a switch over valve.... The problem with the switch over valve comes from the transition from blower to blower... It took VW A LONG time and lots of RnD to get this right, im sure you would live with a less perfect solution but its still meant to be a big task.

The waste gate idea has been used before, I will try ad dig out the guy who used it (think it was on a nissan in the states), this was the simplest solution. But again not perfect....


By far and away the best results that I have read about have come from true compound charging. Big turbo feeding a supercharger, no switch over valves etc. People have had gt35's coming on boost at the same kind of engine rpm as a gt28 with all the efficiency advantages of a big exhaust housing, and a compressor thats big enough to sit right in its peak efficiency zone for most of the time.

Have a look at this nutter

http://www.youtube.com/watch?v=DD2XAs-871o

And here is a compound charged evo

http://www.youtube.com/watch?v=hrLsnR8gNiA It doesn't really look 'fast' but it really is! I think the power delivery is so smooth its deceptive. He calls it twin charged but i remember reading about it and its compound charged, again no switch over.