T-31 or P-trim turbine wheel?

[soldave]

Am looking at this 50-trim turbo for my Evo 1. Would be going for an internal wastegate and high pressure actuator. What I am wondering about is the turbine wheel type. There are 2 options: a Stage 3/T-31 wheel or a Stage 5/P-trim wheel. Surprisingly to me, the stage 3 wheel is more expensive. What would be the difference between these 2 turbine wheels?



Many thanks to anyone who can explain this to me

 

[1992awdlaser]

I'm pretty sure the t31 is standard in most 50 trims and the p-trim is standard in turbos like the t67.

 

[kahl23]

IIRC, the P-trim wheel is pretty old tech, which might explain why there's the price differential.

 

[dsm-onster]

a t3 stage 3 turbine wheel is a turbonetics term for a t31 garrett wheel. Both are pretty much identical. The t3 stage 5 turbine wheel is like the garrett t350 turbine wheel. The p-trim is not a "stage 5" wheel.

<a href="http://pneumakinesis.multiply.com/photos/album/4/DSM#18"><img border="0" src="http://images.pneumakinesis.multiply.com/image/13/photos/4/500x500/18/Garrett-t-netics-wheel-diameters.JPG?et=YZD0OuIQU0bRwBtNXzVgPw&nmid=41285128"></a>

I'm not sure why there is a stage5/p-trim option as if it's one wheel. The stage5 wheel not the same as a p-trim wheel. Call and ask for dimensions and then you'll know. Andy is very friendly an helpful.

The t3 stage 3 / t31 turbine is plenty for the 50-trim compressor. The stage 5 / t350 turbine would really guarrantee pushing the 50-trim to the outer limits of it's operating range. But rather laggy. A p-trim is way too bigg IMHO for the 50-trim. A waste of spool time for no more real gain up top with a smaller compressor like the 50-trim.

 

[The Shodan]

The T31 stage III wheel would more correctly match the 50 trim compressor wheel. When matching a compressor wheel to an exhaust wheel, it is best to have no more than a 20% differential between the wheel diameters of the compressor wheel and exhaust wheels. And that is correct. the Stage 5 is NOT the same as a P-trim. For the response characteristics that you're looking for in the Evo, I'd use the T31 stage III or even O-trim.