rx7_

Hey guys, would like to know what are the differences between a T3 .48 hotside and .63 hotside? Any difference in power output? Im currently using a china turbo, its a T3 but no a/r stated on the turbo, guy i bought from doesn't know the a/r of it too. also, what are the start spools of both in a d16? Thanks.

TheShodan

iTrader: (14)

this depends a lot upon what exhaust wheel is used, but generally, max torque output for a given level of boost pressure is shifted higher in the power band the larger the volute size is. "spool" doesn't change a lot, the differences are a bit subtle compared to the other factors such as exhaust wheel size.

Joseph Davis

If it's an OEM-equivalent piece of china garbage, you aren't going to see a big difference. 200 rpms quicker spool and you'd need a dyno to measure the power difference as the butt dyno can't pick up 10-15 whp on that scale.

Garretts express their turbines in a wierd fashion, the actual "nozzle" size varies as a function of the A/R ratio and the turbine wheel size. Basically, as either AR or turbine gets larger so does the nozzle. With smaller turbines the nozzle size doesn't change much as the AR changes, but it has an amplified effect when combined with larger turbines.

Can't really say where your turbo will spool at. Or, I could but don't care to type that much to properly relate it all. Can you give me an idea which turbine you have? If you are at a loss, measure the turbine wheel's exit and we will ASSume that the turbo behaves like a Garrett.

TheShodan

iTrader: (14)

If you're not sure how to measure, here you go.

Wheel measurement


A/R Measurement


Trim measurement