Turbine Wheel Style and Trim confusion

[BigBoosh3712]

Hey guys, My room mate is buying a SC61 turbo and he was asking me something about the different turbine wheels they come in and it got me thinking and I was confused. So maybe someone can help clear the confusion.
I don't know if you are familiar with Precision turbos but they make an SC 61 turbo. They make 3 different types, in which all of them use the same compressor wheel. The only difference in them is their turbine wheel style and trim (they all have the same A/R). The first one uses a T350 turbine wheel and is a 52 trim, the second one uses a T04 (which flows more than the T350) wheel and is a 69 trim. The third one is a T04 wheel as well but it is a 76 trim.
They all are rated for the same power...so my questions are this....First, why would you get a larger turbine wheel (hence, causing more lag) if either way you'll get the same power. And second..why would getting a larger trim turbine wheel help at all, if any. Still putting into consideration that the 69 trim and 76 trim T04 turbine wheel net the same power. Thanks for the help.

 

[Cesar]

I'm not to familiar with the turbo your speaking of but a larger turbine wheel is less of a restriction for the motor. Yes, it does increase lag, but lag is dependant on the amount of gasses leaving the motor (displacement), and the compression of the motor. A stroked motor with higher compression can run a larger turbine wheel, spool it relatively fast and have a lot of power top end. Top end power is one of the main advantages to having a large turbine wheel. It is efficient at higher RPMs.
You pick your turbine wheel depending on your motor and what RPM you intend on runing.

 

[BigBoosh3712]

Thanks, that makes a lot more sense. So the same goes for a larger trim size turbine wheel, right?

 

[ItsStockOfficer]

When they rate the turbos power potantial it is based soley on the compressor.

 

[sweet97]

Cesar was giving info on larger trim turbine wheels. i am far from even calling myself knowledgeable but i do know that with turbo Conquests guys would go with big 16G's with TD06 hot wheels in place of the stock 05 wheels and they loved them. Apparently once that bigger "HOT" wheel got going it really pulled!

 

[gasguzzler]

First off, if you're going to bolt it to the factory manifold the SC61 becomes an SCM61 On smaller displacement engines (such as the 2.0L Mitsu), it is highly recommended that you use the 52mm (not trim, it's actually a 76 trim) T-350 wheel. The only time one should remotely even possibly in a long shot use the 69 wheel in a Mitsu would be a drag only car with nitrous (at least that's my opinion). I would almost never use the 76 P-trim wheel on a Mitsu, the engine doesn't have enough velocity to spool it quickly enough for these purposes. The bigger exhaust wheels will flow a little more, but the SCM6152E will support at least 630 Peak flywheel horse. The SCM6169 are rated around 650 peak flywheel horse and the SCM6176 is rated at 680 peak flywheel horse just for comparison sake. If you want a little more, the S-cover (4" in/2.5" out) will add roughly 10 more horse.

So, order a SCM6152

 

[sweet97]

thanks for setting it straight. I always appreciate information, never know I may be in that range someday...Mark

 

[swordfish]

The larger turbine wheels are better for guys running the 2.3 and 2.4 engine. Like myself. I run the P trim turbine on the black car and the red car. The red car is a T66 P trim though.

jeff

 

[gasguzzler]

Swordfish: At what rpm does the P-Trim spool up? Just curious