hi, im a complete newbie with turbochargers. but a friend has offered me his fairly new garret T04B15 turbos (2) He says that the compressor wheel is 47mm S trim and the turbine wheel is a P trim. exhaust housing is a .84 A/R with a T3 flange, and the compressor housing is a .60 A/R

first of all, will these fit on my 99 Trans Am? and are they very powerful, meaning, will they be worth my time or are they something more appropriate for a 4 cyl??? I dont understand all the A/R #'s so i wanted to ask.

by the way, what is the ideal A/R to make good power while being safe on the ls1.

 

Only real way to know would be take the compressor cover off and turbine housing off and measure the compressor and turbine wheels exducer. That way we can look it up and see what may match. Right now it sounds like the compressor side is aT04B-46trim. The exhaust I can't quite match, cause first I don't see a p-trim wheel listed for a T3, and the only .84 A/R housing is for a T4 flange. As for A/R for a T/A, with small turbos usually you want to run a .63 to .82. But that will also depend on combo, cubes...etc. You would have to be a bit more specific.

Jose

 

If your planning on building a setup you may want to find some bigger turbo's. Those two are kind of small for a twin kit. Are you planning on building up the shortblock? Heads or cam? Give your plans on what you wanted to do.

 

Those are to small.
I have twin 52mm comperssors with a ( have to go to my car domain site) 51 trim.
They are on the small side for a 3.4L V6.
Turbo to small is in the eye of the beholder, for my car the K03 turbos will make killer mid range power and will spool up in an instant and will run out of steam tord the 5500 rpm range. They will still make enough pressure at 6500 rpm for a stock bottem end.
"S trim" dosen't tell me $hit, but 47mm does.
If you have a 60 or more trim that would be about right (they could move a lot of air but not make a lot of pressure.
I think they are to small you shoud get some thing bigger.
It would be mild daily driver TT at best.
Are you going to build the engine?