Noob Turbo question

[ndubz]

Ok, i know a decent bit about turbos, but i want to know more. What exactly does it mean when a turbo is 20g or 30g. what is "g" and how does it relate to like ""GT35R" or similar codes. I mean, I know that a 20g is less than a 30g, but what exactly does it mean. and how do they vary?

[sherwood]

different sizes...different branch positions and inducer and impeller sizes. different trim sizes and different bearing types...those are basically all the numbers mean..different specs to different company's. a gt35r could be the same size as another company's 25r or 40h...its just the specs for that company..get it?

[SovXietday]

As far as I'm aware it's just a part number. Just like td05h, TO4e, etc etc etc.

The "GT" series is a Garrett manufacturer term. All GTXXR series turbos are ball bearing, etc.

You're better off looking at wheel specs, CFM, and flow charts for comparing sizing rather than trying to determine the differences by name alone.

[ndubz]

So there's no broad standardized system to tell turbos apart? U have to go company by company. also, i been lookin at turbo websites. and many dont specify weather its whp or bhp in their "max power" ratings. Im assuming its bhp cuz it makes more sense for a turbo spec.

[Nick 95 6sp]

20g, 30g, GT35R, and other turbo designations are just different names for turbos by the manufacturers of the turbos, each manufacturer has their range of sizes and designs. Mitsubishi turbos are 20g, 30g, etc. Garrett turbos are "GT" series like the GT35R with various numbers and letters that have meaning. Like you said, larger numbers mean bigger turbos, and the letters can mean things like the type of shaft bearings (journal bearings or ball bearings) or even exhaust and compressor turbine wheel designs. Since there are so many combinations of compressor and exhaust turbines, even similar size turbos have quite a few possible varieties. I don't know of any simple way to sum it up, I suggest you look at sites for turbo manufacturers and those who assemble and package turbos and see how all the sizes and other parameters vary. Google for links to sites for Garrett, Turbonetics, ATP, Precision, Mitsubishi, IHI, and other turbos and look around.

[SovXietday]

No, there is not.

Max flow CFM, compressor maps, and overall wheel/inducer/exducer sizes is really the best way to tell what a turbocharger is going to do.

Turbo's are always rated bhp, never whp.

[ndubz]

Ive been doin some of that, and it seems to me, that itd be a hell of a lot easier if they had a standardized system for all the companies. But i guess they dont so its one big CLUSTERF*CK.

[ndubz]

Originally Posted by SovXietday

No, there is not.

Max flow CFM, compressor maps, and overall wheel/inducer/exducer sizes is really the best way to tell what a turbocharger is going to do.

Turbo's are always rated bhp, never whp.

thnx bro. It seems like flow is the most universal way to tell between them.

[crexxy90]

you can sorta go by trim size but it depends on the housing size as well, if you have a specific power goal for an engine in mind do a search and see what other people are using to make that power.