Stock turbo trim?

[motox-010]

So alot of people around my car scene in South Dakota are ALL about trim. People brag about .50 trim. So I did some research and found that trim is nothing but a ratio of the compressor wheel inducer size and exducer size (or turbine wheel).
Now I think I did my math right. Would doing this equation lead me to the result of about .55 trim on my stock 14B?

You must be logged in to view this image or video.

(1.695^2)
----------- =.55
(2.285^2)

 

[JusMX141]

Newsflash- compressor trim doesn't mean dick when describing any turbo other than a Garrett. It sounds to me like these guys have participated in one to many "which one's bigger" contests when they were growing up.

It's not like you have trim options when it comes to Mitsu or Holset turbos- their wheels are each in a completely different category than the next. About the closest you'll come is the Mitsu Big 16G / 18G / 20G series of wheels, all of which use the same size exducer.

The reason Garrett wheels are described as such is there really isn't a distinct way to tell one apart from the other when you're speaking in terms of size. All of a Garrett "E" compressor wheels have the exact same exducer diameter- the 46, 50, 54, 57, 60, and 60-1. The way Garrett chooses to describe these wheels in succession is their trim spec, meaning the difference between the two measurements of the inducer and exducer.

A compressor with a 2" inducer and 3" exducer would have the same trim spec as one with a 4" inducer and 6" exducer. The same trim, but which would flow more air, and which would also be the laggiest?


You should bone up on all info this so you can spew it back in their face when they start their trim talk as if it's really meaningful. If you really want to push their buttons, start quizzing their turbine wheel spec and turbine housing a/r ratios and how they relate to spool and overall airflow potential. Guaranteed the conversation will change direction in a hurry.

 

[motox-010]

I know the trim doesn't matter shit when talking turbos. Why I want to know is so I can make fun of all the guys who list their trim in their sig on the local forum. But according to that equation, and the inducer and exducer of the 14B, would 55 be right?

 

[Steve93Talon]

All of a Garrett "E" compressor wheels have the exact same exducer diameter- the 46, 50, 54, 57, 60, and 60-1.

Technically, the 50 trim and 60-1 have a 3" exducer, all other T04E wheels are 2.95".

And to the OP, the 14b is a 55 trim, you are correct. Incidentally, a big/evo 16g is a 50 trim and a 20g is a 60 trim. Not that any of this amounts to anything in the real world.

 

[motox-010]

I know. That's why this I think its funny that everyone around here brags about their trim.

 

[The Shodan]

Newsflash- compressor trim doesn't mean dick when describing any turbo other than a Garrett. It sounds to me like these guys have participated in one to many "which one's bigger" contests when they were growing up.

It's not like you have trim options when it comes to Mitsu or Holset turbos- their wheels are each in a completely different category than the next. About the closest you'll come is the Mitsu Big 16G / 18G / 20G series of wheels, all of which use the same size exducer.

The reason Garrett wheels are described as such is there really isn't a distinct way to tell one apart from the other when you're speaking in terms of size. All of a Garrett "E" compressor wheels have the exact same exducer diameter- the 46, 50, 54, 57, 60, and 60-1. The way Garrett chooses to describe these wheels in succession is their trim spec, meaning the difference between the two measurements of the inducer and exducer.

A compressor with a 2" inducer and 3" exducer would have the same trim spec as one with a 4" inducer and 6" exducer. The same trim, but which would flow more air, and which would also be the laggiest?


You should bone up on all info this so you can spew it back in their face when they start their trim talk as if it's really meaningful. If you really want to push their buttons, start quizzing their turbine wheel spec and turbine housing a/r ratios and how they relate to spool and overall airflow potential. Guaranteed the conversation will change direction in a hurry.

This is true, but SLIGHT correction. 46 through 60 trim use a 74.8mm exducer, while the 60-1 uses a 76mm exducer wheel. Similar to a GT3076R.