The 16G 50 Trim!

[->PrOjEcTGS<-]

I think a lot of people throw around the terms 50 trim, 57 trim, 60 trim, etc. Without knowing exactly what and how the trim of a turbo is calculated. Did you know that a 14b is a 55 trim turbo? And a small 16g is a 60 trim? While a Big16g is only a 50 trim? Why would a larger turbo have a lesser trim? Simple calculations will show how this works.


To calculate trim of a compressor wheel use this equation: TRIM = (Inducer / Exducer)^2 X 100

Now let's practice!

14b's Inducer: 1.695
14b's Exducer: 2.285

1.695 / 2.285 = .742
.742 * .742 = .550
.550 * 100 = 55 TRIM

S16G's Inducer: 1.830
S16G's Exducer: 2.365

1.830 / 2.365 = .774
.774 * .774 = .599
.599 * 100 = 59.9 or 60 TRIM

B16G's Inducer: 1.892
B16G's Exducer: 2.680

1.892 / 2.680 = .706
.706 * .706 = .498
.498 * 100 = 49.8 or 50 TRIM

You can see just by doing these calculations that the if the TRIM is larger it doesn't necessarily mean that it's a larger turbo does it? What TRIM shows is the comparison of the exducer's size to the inducer's size. This means that you cannot use only TRIM to figure the size of the turbo. What you need to know are the dimensions of the compressor wheel, then compare the trim.

What this reminds me of is when you create a box in MS Paint and you want to resize it what do you do? Drag it from one of the corners. Naturally due to unsteady hands you end up making one leg longer than the other. (Changing the trim) How do you keep the box proportionate? Hold shift this keeps the same proportions (TRIM) But makes the box larger.

Hope everyone finds this informative.

Here are my sources:
TurboByGarrett.com - Turbo Tech102
Turbochargers 201

[Stapl3]

Why does your title say "the 14b 50trim" when it is a 55?

50 or 57 trim

We've gone over this before.

[->PrOjEcTGS<-]

Originally Posted by Stapl3

Why does your title say "the 14b 50trim" when it is a 55?

50 or 57 trim

We've gone over this before.

Sorry about the information I offered. I have been reading multiple threads where the only description they give of the turbo is " 50 trim." When I don't think people fully understand what they mean. Plus your answer to the mentioned thread doesn't go into detail or have any sources behind it.

As for the title... I was going to name it "The B16G 50Trim" and forgot to edit it before I posted it.

Mods will you please correct that?

Thanks

[BigSorn]

you can change it.

just click edit and go advanced or whatever it is.

good info!

[99gst_racer]

Yes, "trim" size is about as generic as someone saying "T3/T4".

One thing you'll notce is that certain 'trims' work better than others on specific displacements, regardless of the size of the turbo. That's why the 16G and Garrett T04E 50-trim both work very well on the DSM platform, even though one is larger than the other.

[KiNg MaRtY]

Good info. You clarified some things for me.

[jusmx141]

Another post explaining why trim has nothing to do with a turbo's size.


Ever own a boat with adjustable trim? Turbocharger trim works in a very similar way. If you adjust a boat's trim with the engine at a steep angle, the boat will tear ass from a stop but never come up on plane. Compare this to a turbo with a smaller trim number which spools quickly but doesn't make a ton of power on top. Now a boat with trim set at a low angle will take FOREVER to get going, but once it does it'll FLY. A turbo with a higher trim number will do the same.

There a million other variables in determining a turbo's spool characteristic and max power output....turbine size, turbine housing a/r, compressor housing a/r, compressor wheel type ("B" wheel versus "G" wheel), etc. This example simply shows how wheel trim can effect spool time and maximum airflow.

[BleedingSilver]

I never looked at it like that. I always wondered but never took the time to look, thank you. Its nice to know that when people say there putting a 50 trim on there car wether it be a honda or nissan. I can just sit back and think to myself. "Been there done that." But if trim is pretty much a ratio of inducer and exducer then couldn't a larger turbo still be considered a "50trim" or "60". T3/T4 really isn't that just a bolt pattern for an exh manifold and a slight size difference between the two?

[jusmx141]

T3/T4 is a very general description meaning a Garrett turbo utilizing a T3 hotside for quick-spool mated to a T4 compressor side which can flow a lot more air.

[andy4g63]

Just for example:

GT35R and..... GT42R, are the same 46 trim on the compressor side. You get the idea.

[havoc742]

Info on trim and what it is/means has been posted before. Things to consider when selecting the right turbo for you!!

[The Shodan]

For the Lazy..

[hpexperts]

good info,

[Steve93Talon]

Originally Posted by andy4g63

Just for example:

GT35R and..... GT42R, are the same 46 trim on the compressor side. You get the idea.

The 3582R and 4294R are both 56 trim, but the larger "42R" (4202) is a 53 trim.

[andy4g63]

Originally Posted by Steve93Talon

The 3582R and 4294R are both 56 trim, but the larger "42R" (4202) is a 53 trim.

Yeah, I know Steve, I just put that info to show how useless is that"what trim is it?" info.
It is just plain confusing.