*Boostwerks*

I keep hearing this pop up. That the 57 trim T3/T4 flows more, or is a better overall compressor than the 60 trim. However, from the graph the 60 trim obviously flows more, and is slightly more efficent at low and moderate boost.

I am completely clueless to why this is, so fill me in!!!

BlueShadow

AFAIK the 60 trim flows the most but the 50 trim flows more then the 54 trim and less then the 57 trim. I could never remember which 5x trim turbo it was, all I knew is both turbo trims started with a 5. So it was either 54 trim greather then the 57 trim, 50 trim greater then the 54 trim, but it was never 57 trim greater then the 60 trim.

sonny made a post about this a while back and hre are hte flow numbers:

https://honda-tech.com/zerothread?id=523242

TheShodan

iTrader: (14)

Look at the lbs/min please..... It goes in the order of lowest to highest .... 54,50,57 between all three

*Boostwerks*

Ok you guys have the same results as I have...and of course I trust you TheShodan...

For some reason I keep seeing these posts where people are telling me, or others to go with the 57 trim rather than the 60trim. Why this is, I have no idea. I was just wondering if there was some technical basis for this, which it doesn't look like.

yee SERIOUS

iTrader: (1)

maybe they say it depending upon setup?

M.A.R.C.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson &raquo;</TD></TR><TR><TD CLASS="quote">Ok you guys have the same results as I have...and of course I trust you TheShodan...

For some reason I keep seeing these posts where people are telling me, or others to go with the 57 trim rather than the 60trim. Why this is, I have no idea. I was just wondering if there was some technical basis for this, which it doesn't look like. </TD></TR></TABLE>

really? i've never heard that, only the opposite. and yeah as far as i know

it's 54, 50, 57, 60 interms of flow

AndyFloyd

The 50 trim is the best out of all those compressors...its got the best map and it will make more midrange than any of the other compressors.

*Boostwerks*

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M.A.R.C. &raquo;</TD></TR><TR><TD CLASS="quote">

really? i've never heard that, only the opposite. and yeah as far as i know

it's 54, 50, 57, 60 interms of flow</TD></TR></TABLE>

Yeah, Wantboost, and 3 other members have all told me personally to go with a 57 trim over the 60 trim just because it is a "better turbo" None of them had any reasons to back their statements so I was just curious if there was a reason why.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AndyFloyd &raquo;</TD></TR><TR><TD CLASS="quote">The 50 trim is the best out of all those compressors...its got the best map and it will make more midrange than any of the other compressors.</TD></TR></TABLE>

the term "best" is realative upon goals, setup, and personal preference.

TheShodan

iTrader: (14)

This is one of the main reasons why I never liked people asking "What's the best turbo for BXX motor, or H22?" It all depends upon what the purpose of the car is, responsiveness, setup, stroke, bore, etc. It's funny how those individuals that ask believe that EVERYONE is the same in tems of preference.

BlueShadow

hey dood,

I found some interesting info that you might find useful. Over the last 2 days I've been researching how to swap out compressor wheels and housings on my T04E 60 trim to make it into a SC61. I found a lot of good info on the relationship between inducer and exducer diameters and what trim really is. Before I started doing my research two days ago all I knew was that inducer is inner and exducer was outer diameter. And that higher the trim the better, but after reading this post from another site I found out the part about bigger trim = better isn't always true.

When referring to compressor trim, trim is just the ratio between inducer diameter and exducer diameter. If the exducer size stays the same, then increasing the inducer size increases the amount of air the turbo pushes. When you increase the inducer size the ratio aka. trim between the inducer and exducer increases. Increasing the inducer size has the downside of slightly increased lag at the expense of added airflow capabilities.

Now here is where what I found the answer to your question. From what I've seen the exducer size for all the T04E turbos is 2.950". From 40 trim all the way to 60 trim. The smaller trim turbos just had smaller inducer sizes and the inducer would increase slightly raising the trim level. Remember what I said about how increasing inducer size increase the inducer to exducer ratio (aka your trim). When I was looking at the different exducer sizes I said that all of them showed 2.950". All of them EXCEPT the 50 trim compressor! According to my source the 50 trim compressor fan has an exducer diameter of 3.0" and an inducer diameter of 2.122". That's how the 50 trim is able to flow more then the 54 trim. The slightly bigger exducer diameter helps to move air faster then the fan with the smaller exducer.

Read the whole post:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Originally posted by RacerXtreme7

Inducer / Exducer and how they affect one another..............

First, the basics.....

TRIM. Trim is a ratio of inducer vs. exducer of a compressor or turbine wheel.

Formula for determining trim: (Minor wheel diameter would be the inducer on a compressor wheel and the exducer would be considered the major diameter. For a turbine the minor and major are called the same (small dia = minor, larger dia. = major) but the inducer of a turbine is the major diameter and the exducer would be the minor or smaller dia. Just think like this.. does the wheel "induce" air or "exduce" it........

[(minor wheel diameter)x(minor wheel diameter) / (major wheel diameter)x (major wheel diameter)] x 100= compressor / turbine wheel trim

T04E 60 trim (inducer = 2.290", exducer = 2.950")

[(2.290)(2.290)/(2.950)(2.950)] x 100= trim
(5.2441/8.7025) x 100= trim
.6026 x 100 = trim
60= trim

There are trim levels for separate sub families within a series family. EXAMPLE: a T04B 60-1 is a 2.34" inducer and 3.00" exducer wheel, a T04E 60 trim is a 2.29" inducer and 2.950" exducer.... more on the subject a T3 60 trim is a 1.83" inducer and 2.367' exducer. All three comp wheels have a 60 trim. The T3 will NOT flow nowhere near the to4B 60-1 or T04E 60 trim. Also note, even though the T04B 60-1and T04E 60 trim have very close wheel specs, the T04B flows much more, (partly due to the "B" width {b-width is blade height}).

Now with that said.. I'm going to generalize some aspects on how inducer vs. exducer affect one another and refer only to compressor wheels and NOT turbine. There are other factors I'll ignore for ease of discussion like overall size of the compressor, B-width, mach numbers, back sweep etc.

Your inducer is a good place to start to determine a turbo's general power potential for moving air since this is were the air is "introduced' to the turbo system. Larger the inducer the larger amount of air can be swallowed. (again, there’s many other factors like blade design, angle of attack, number of blades, etc.). The larger the inducer the more power it takes to spin it up also (lag) because with each rotation its swallowing up more air so the harder the turbine would have to work. The exducer is were the air that has entered the compressor axially from the inducer gets slung out radially by the exducer blades and gets compressed as it enters the snail or scroll of the compressor housing. The larger the exducer the higher the tips speed for a given turbine shaft speed, so the faster and more compressed the air gets slung out. Generally, the smaller the trim number (smaller trim = bigger difference between the inducer and exducer, larger trim number = closer in size between the inducer and exducer) the more effient the turbo will be at higher pressure ratios. The larger the trim the more air the turbo can move, but will not be as effient at higher pressure ratios. It’s always a trade off. This is why it’s really important to be able to read compressor maps and match the turbo to your engine needs and performance goals. Fortunately for many, most of this leg work and math have been done and all you have to do is ask knowledgeable people on the forum to get the answers.
As I stated above, the larger the inducer the more lag or longer spool-up time will be realized. BUT, with a larger exducer (with same size inducer) an interesting thing happens. In certain circumstances your spool-up time can DECREASE. This is due impart to the tip speed of the larger exducer is faster for the same shaft speed as the smaller exducer comp wheel. The higher tip speed flings the air out with more force. This only works in moderation and in the smaller to mid sized framed turbo compressors (t3 – T4 sized). There is diminishing returns in this phenomenon. So don’t expect to place a 3 inch inducer monster turbo on your ride with an 8 inch exducer and expect it to spool like a stocker. This is practiced quit frequently in hybrid or (HiFlo) stock/upgraded turbos. The turbo shop will “up-grade” the comp wheel by adding a larger inducer for overall more flow potential, then up-size the exducer as well to gain back some responsiveness and decrease spool time that the larger inducer took away from. Think of it this way: it takes X amount of exhaust energy (flow and pressure) to spin up your stock turbo in Y time, but your producing X1 exhaust. So you have great spool-up. Then you stick a larger comp wheel on there, it has the same exducer (major) wheel diameter but it has a larger trim and larger inducer for added kick. It now takes X2 energy to spool it up like your stocker did but your only making X1 exhaust flow before your wastegate opens. You now have more power, but at the expense of less responsiveness, otherwise known as turbo lag. Now if you take and replace that “up-graded” comp wheel with another one with the same inducer dia. But have a larger exducer on it lower your trim (but overall still a larger comp wheel physically then the stocker). Now because the tip speed will be greater for the same shaft speed as the first upgrade, you’ll make boost sooner. Its now only taking X1 exhaust energy to spool it. This is how in moderation you can upgrade and have similar responsiveness to a stocker but with more flow. Some of this same responsiveness will be also do to a most likely up-graded exhaust system also. Again, this doesn’t work well with larger framed turbo’s do to mach differentials (blade speed from the base of the shaft to the tip gets a greater and greater differential the larger the turbo gets. Back sweep in the blade design helps a little. Many other factors such as overall mass {more inertia} and aero factors as well). Turbonetics makes exclusive wheels just to take advantage of this. They have a t3 H trim wheel with a 60 trim configuration. They come out with a “Super 60” wheel (its actually a lower trimed number when you do the math, but its basically the same exact wheel {same inducer size} with a larger exducer) to spool like the smaller 50 trim, but flow like the 60 trim. And because it has the same exact blade design and contours, it fits within a 60 trim housing with no mods.

I think I went too deep into this..LOL… and yet I feel like I left out a lot of details, but this would have been a ridiculously long post. I also feel one should go out and get books, articles, etc if one is really interested and wants to know more on there own. All the statements I made were generalized and doesn’t necessarily apply to all comp wheels (trim does apply to all, mainly within Garrett and Garrett clones {Turbonetics, Innovative, Majestic, Master Power, early Borg Warner, AiResearch, etc. etc.}). Hope this helped anyone looking to know the “basics”.

In short. Larger inducer the more flow, more lag. Larger exducer the more effient in higher pressure ratios, but hurts overall flow, produces boost quicker for the same given inducer size. Higher the trim (closer the inducer and exducer ratio), the more likely the turbo will flow more at lower boost ratios and longer spool up time. The higher the trim (larger variance from inducer to exducer ratio) the quicker it will make boost, and it be happier at higher pressures and lower flow numbers. The lower trim comp wheels also tend to come on sooner and more linear, were the higher trim comp wheels tend to come on abruptly (again, just generalizations, as turbine trim, turbine housing A/R and motor port work will effect spool and how it comes on also. Comp housing A/R can also determine how abruptly a turbo will produce boost as well).


NOTE:

I am NOT claiming to be a turbo / centrifugal compressor expert. This is a accumulation of knowledge I’ve stored in my dome piece from reading books on turbo charging (like “Maximum Boost, “Centrifugal SuperChargers” etc., magazine articles from “Turbo”, “Sport Compact Car”, “Hot Imports”, “Import Tuner”, “Nitrous and Induction Systems”, books and tech articles about centrifugal compressors and such from my library here at work (NASA), tech articles from writers from turbonetics, Inovative Turbo Systems ETC. ETC. None of the above info was copied or “cut and pasted” (with the exception of the trim formula which I copied from one of my older post) but was from my memory. I am NOT making any new claims and am simply stating what I know is fact from my studies (free time investigating just for my own personal curiosity). Stating that I find nothing here a “debate” and am not looking for the typical “show me proof” or “give me numbers” crap. Do the research yourself if your in doubt. Again I gave the knowledge I have learned in a brief post on the subject very generally for inquisitive minds.

~Mike………………</TD></TR></TABLE>