Got a question...

[Dr.Drew]

I always hear guys talking about turbos and it's always like "I'm thinking about putting a [XXXX] turbo in there." (With the X's being numbers).

I've been looking but I can't really find a good explanation of what exactly these numbers represent. Can anyone give me a quick explanation.

Thanks!

[wonton]

i dont really think those numbers have much to do with the turbo. like my turbo is a GT2860rs, but there is 2 versions on it. the numbers that are important are the A/R numbers stamped on the housings. mine is a A/R 63 exhaust side and the other version of my turbo is a A/R 86 on the turbine housing...thats pretty much all i know.

[Dr.Drew]

If I've read correctly the numbers on the housing are MM Diameter correct? So you have a 63mm exhaust port?

[wonton]

yup!

[RotorNutFD3S]

The numbers have a lot to do with the turbo and can tell you quite a bit about it. GT2560R says that you have a T25 frame sized turbine coupled to a 60mm exducer diameter compressor wheel. The "R" on the end means ball-bearing. You might ask "Don't T25 and T28 turbos have the same flanges?" Yep, but T25 turbos have a 53mm turbine wheel (measured at the inducer) while T28 turbos have a 53.85mm turbine wheel. So the GT28R, aka GT2560R, is truly a T25 turbo. If you see an "S" at the end of the model number, such as Sean's GT2860RS, that means it's a higher flowing model than the GT2860R.

The numbers on the housing are the a/r, or aspect ratio, which is "the inlet (or, for compressor housings, the discharge) cross-sectional area divided by the radius from the turbo centerline to the centroid of that area". To be clear, it's not the outlet port alone.

http://www.turbobygarrett.com/turbobygarrett/images/tech_center/tech_102/compressor_housing_showing_A-R_characteristic.gif

If you're bored and want to learn a ton about turbos, names, measurements, how or why certain things work, go here: http://www.turbobygarrett.com/turbobygarrett/tech_center/tech_center.html

[Dr.Drew]

Thanks for the info and link. It will give me something to do these last two hours at work.

[wonton]

i forgot about the first two numbers standing for the flange type!

idk bout other turbos such as TDO4's, IHI's ect ect.....