P-trim/.81 vs stg3/.63 for Z6
 

So, will a Z6 ever make any boost with the P wheel/.81 T4 before it hits the rev limiter? More than a little lag is OK, to around 4000-4500 or so. But lag until infinity+1 would not be, LOL. I also have a T3 hotside here, .63 with a stg3 wheel. Anybody have experience with both/either of these on a ~300hp Z6 and where they start working?

A T3 .63 hot side will not start spooling till 4000+ and you won't have any useful boost until 4500+ or so.

The other turbo (T4) will be much worse. It would barely do anything unless you rev it higher than 7500. Even then, it would be near usless on the motor. T3 with .63 hot would be a much better match.

Thanks for the info. I'm a V8 guy, and in that alternate universe even a mild motor w/twins with P-trim wheels can be too small sometimes.

You could try the T4 compressor with the T3 hotside; it will prob surge a bunch though.

The little one is ready to run, T04E 46 trim (51-ish mm).