What trim? What A/R?

[pinoyboy]

ok, a 50trim is perfectly matched to the stage III wheel, and 60 trim matches up good with the stage V wheel.

the A/R of the turbine side is important b/c it determines spool-up characteristics. the .63 A/R spools up faster than the .82

good street turbo for 300+ whp50 trim stage III T3/t04E .63 A/R exh sidespools up pretty quick

400+whp50 trim stage III T3/T04E .82 A/R exh sidepretty laggy, buts makes more power

So, if I were looking for a turbo between these two would this be good turbo since it has a larger compressor trim. This would create a little more lag correct?

57 trim T3/TO4E .63 A/R exh side

or click here

I was basing this off of what I read from a person on another forum and ITR_KILLR

Generally, with the compressor wheel (cold side of turbo) lower trim numbers = wider range of efficiency, but lower overall flow capacity. Most compressors wheels are in the 40-65 trim range.

With the exhaust wheel (called turbine wheel often) lower trim numbers mean more energy is recovered from the exhaust gas, meaning a quicker spool, but flow capacity is lower than higher trim wheels. The exhaust turbine wheels are normally in the 60-90 trim range.

A/R ratio refers to the size of the housing. A = area of the entry into the housing. R = radius from the center of the turbine to A. Is he correct?Oh, and thanks in advance

[240marcuSX]

BEST POST EVER :ylsuper but im still confused about the wheel sizes?

smaller ex. wheel = faster spool uplarger ex. wheel = better overall airflow/ top end power

smaller comp. wheel = less airflowlarger comp. wheel = more airflow

so in theory you could put a huge comp. wheel, and a small ex. wheel, and have the best of both worlds?

is this accurate????

i didnt even know that you could mix and match the wheels :oface

you guys rule, sorry i didnt mean to thread jack

[C-Kwik]

So, if I were looking for a turbo between these two would this be good turbo since it has a larger compressor trim. This would create a little more lag correct?

57 trim T3/TO4E .63 A/R exh side

The 57 trim will likely have very little noticible lag if any comparted to the 50 trim. Lag will be most affected by turbine specs and the weight of the wheels. The 50 trim is kind of an oddball compressor wheel though. It has a slightly larger major diameter than other T04E's. The 57 trim has a larger minor diameter. The two could have very similar spooling capabilities. Or in other words, they probably have similar rotational inertias. But even with other trims, you won't see a dramatic difference in sppol up between any of the trims. The best thing to do is pick the compressor based on efficiency at the boost level and flow rate the turbo will be used in. Probably a very small few will be exploring the uppe flow range of the T04E compressor or even the T04B compressor for that matter.

[C-Kwik]

BEST POST EVER :ylsuper but im still confused about the wheel sizes?

smaller ex. wheel = faster spool uplarger ex. wheel = better overall airflow/ top end power

smaller comp. wheel = less airflowlarger comp. wheel = more airflow

so in theory you could put a huge comp. wheel, and a small ex. wheel, and have the best of both worlds?

is this accurate????

i didnt even know that you could mix and match the wheels :oface

you guys rule, sorry i didnt mean to thread jack

As far as the smaller and larger, you are correct, for the most part. It's more of a generalization. But it just depends. And to add on, larger compressors tend to have higher peak efficiencies than smaller ones. But that's still more of a generalization.

As far as mixing and matching, they have been doing this for years. The T3/T4 hybrids are just that. I'm not as familiar with mitsu turbos, but I belive something similar is commanly done with those as well. Hell, I've even heard of Garrett-Mitsu hybrids. But there is a limit to this. If a compressor wheel is significantly larger than the turbine, it could lead to some problems. I can't remember the specifics on why, but it was mentioned by Mike Kojima in one of his articles in SCC. And this would already be a bad idea with compressors designed to work in a high flow rate ralative to boost(T-xx series turbos) with a small compressor. Most of these turbos would surge with a small compressor.

[cnichols]

http://www.hksusa.com/products/?id=713

Just get one of these...and there won't be any problem unless you're looking for a TON of HP.....HKS GT3037:D

[hannibal]

IIRC compressor surge is the result of having the compressor too big compared to the turbine so a huge comp would work with a tiny turbine up to that limit.

Jay

[hannibal]

IIRC compressor surge is the result of having the compressor too big compared to the turbine. So a huge comp would work with a tiny turbine up to that limit.

Jay