For those with twin turbo 1UZ's

[4000GT]

So you couldn't get there with a K27? Surprising as it's a big compressor, i understood it to be around a Garrett GT30 ? There's definitely more left in mine, 17psi is barely getting started.

Mine are genuine KKK, flange is slightly different to a T3

Its a million miles away from the GT30, even the GT3076R. Its not a big compressor. You could get there with enough boost on the 944, but it would be pretty inefficient. The 6cm housing is very small, on the later models they went to a number 8cm. The 26/6 is reacing its limits around 17psi in terms of efficiency, the garden variety 27/6 around 21psi and its near the surge line. That should not be a problem for you though since you are not running at kind of boost. Your turbo is not a garden variety though...

 

[4000GT]

PS I think I once worked out the number 6 exhaust housing was around a .56 A/R.

 

[JustenGT8]

Hmmm better check my compressor maps again. At the time the K27 MAP i downloaded off the Blitz site i'm sure had very similar flow capacity....a different gradient surge line for sure and the islands were a bit fatter for the 30 but near enough...hmmm.

 

[4000GT]

Im sure the blitz one is closer, else you would just buy the Porsche / Audi 26/6 and rbuild it to K27/6 for $500. I am pretty sure Blitz wouldnt do that