Disclaimer: All of the following is correct to my knowledge. Please feel free to jump in and correct anything that is wrong or feel free to add anything. This post is pretty long, but hopefully it will help out some newbies that are getting into turbochargers.

There seems to be some confusion about there about what all of the numbers mean when looking at a turbochargers specs. Awhile back, BlueShadow wrote an excellent post on how to read a compressor map. Find that post, read it, and combine it with this one...voila, you'r a guru! (not really)

Garrett makes several "families" of turbochargers that are targeted for different sized engines, HP goals, and drivability characteristics. Crafty tuners, manufacturers, etc, have mixed and matched these components to produce hybrid turbos that can provide the benefits of several turbo families. The possibilities really are endless, but I'm just gonna list some common ones or else this post would be reeeeeeallly long.

Turbocharger families
The T25 family = super fast spooling "small" turbo that makes good low rpm torque, but lacks top end power. This turbocharger is commonly used where throttle response and low rpm torque are desired without much regard to high rpm power.

The T3 family = "intermediate turbo" that spools slower, but has the ability to make substantially more power than the T25 family. This turbocharger has been used on A LOT of production vehicles (Ford, Nissan, Volvo, Saab). They can make impressive power, but were known to be laggy.

The T04 family = "big turbo" that makes huge power, but is very very laggy. Without the beauty of being able to make a hybrid turbo, a T04 would probably not even be an option.

The 3 main components that have the biggest impact on performance are the a/r of the turbine housing, the size (aka trim) of the tubine wheel, and the size (aka trim) of the compressor housing.

Common turbine housing a/r "sizes"
T25: .64 a/r, .86 a/r
T3: .36 a/r, .48 a/r, .63 a/r, .82 a/r
T4: not listed...see why later

In a nutshell, the larger the a/r, the later the power comes. A small a/r gives you a fast spooling turbo but limits top-end power. A large a/r gives you a laggy turbo with big top-end power.

Common T25 turbines:
DSM trim (?? not sure how big it is, but it's quite small)
60 trim (small)
76 trim (medium)

Common T3 turbines:
Stage 1 (small -- most common turbine on junkyard turbos)
Stage 2 (med)
Stage 3 (large -- most common turbine on new T3/T04 hybrids)
Stage 5 (very large)

Common T04 turbines:
I'm not gonna list any because I don't have info on them and the T4 turbines require so much exhaust energy to spin that they are practically unusable in our application unless you want insane lag and have got a motor that will spin to 10k every day.

Common T25 compressors:
I'm not gonna list any. I do have some info on them, but for the most part, a T25 compressor will struggle to stay in its efficiency range on a boosted Honda.

Common T3 compressors:
40 trim (20lb/min -- haha...don't even think about it)
45 trim (21lb/min)
50 trim (30lb/min -- probably one of the most common on junkyard turbos, works well for SOHC and LS engines)
60 trim (34lb/min -- biggest "production" T3 compressor, excellent power on D series/LS)
"Super 60" (36lb/min -- note: this is NOT the "60-1" compressor)

Common T04B compressors:
S trim (37 lb/min)
V trim (48 lb/min)
H trim (49 lb/min)

Common T04E compressors:
40 trim (36 lbs/min)
46 trim (41 lbs/min)
50 trim (47 lbs/min)
54 trim (45 lbs/min -- note that the 54 trim flows less than the 50 trim)
57 trim (49 lbs/min)
60 trim (50 lbs/min)

Common T04S compressors:
60-1 (flows a shitload, never seen a compressor map for it)
62-1 (bigger yet -- I believe this is a T04S compressor...correct this if it is wrong)


Performance (listed in order of increasing performance):
A T25 is a straight T25 turbo --> T25 turbine + T25 compressor
A T28 is a hybrid T25/T3 turbo --> T25 turbine + T3 compressor
A T3 is a straight T3 turbo --> T3 turbine + T3 compressor
A T3/T04B is a T3/T04B hybrid turbo --> T3 turbine + T04B compressor (used in Drag kits)
A T3/T04E is a T3/T04E hybrid turbo --> T3 turbine + T04E compressor (more performance than T3/T04B
A T3/60-1 is a T3/T04S hybrid turbo --> T3 turbine + T04S (60-1) compressor



Sonny




Modified by Sonny at 5:25 PM 6/2/2003

 

thank you very much man, very helpful!

 

awesome dude! I love posts like these.

 

Good post Sonny

 

did your wife kicked you out and now you're bored ? LOL

good info Sonny..

stan

 

Good post. Just a FYI, the lb/min on the to4e compressors are never the same when i look at them in the turbonetics or garret catalogs. If you search around the internet you see different flow ratings for the same compressors. I am not sure why there is no definate flow #'s, its not that hard to measure the compressor flow.

 

got to
http://www.turbomustangs.com/index2.htm
and click "Knowledge base" and then "compressor maps." I couldn't find the maps on Turbonetics new site. but here they are again.

 

Saving to notepad.

 

Thanks for the info.. that was very helpful for me b/c i just finished puttin on my turbo setup and im tryin to figure out the details of FI now..

 

can you please explain o,p and q trim? and the options for precision turbos?

 

also for TO4b you forgot: T5/6 and for s, v and h you can do super s, v and h...

 

sweet!

 

very nice post!

 

bookmarked

 

Awesome post Sonny.
-Will

 

I did some math and figured out that my CMf (corrected mass flow) @ 8000 RPM is 32.6lbs/min with 12psi of boost. This is for a stock B16A2. Can anyone back this up? Is this about right?

Pr=1.92

 

damn sonny...you expect me to read that whole post? lol

 

great post we need more of these this is going straight to my notepad

thanks

 

here is some wheel info arturbo posted

Ok, here to go for a basic run down of the different familys of turbines:
T3 family:
T31
T350
T04

T4 family:
T04

The T31 is what is most widely used and is a T3. For example in the T31 family we have what many know by as stage 2 and 3. So a T31 .69 trim = stage 2 wheel, T31 .76 trim = stage 3 wheel.

Now, a T350 is an other family that is most commonly used. A T350 .76 trim is what we know as a stage 5 wheel. I will go over the formula for finding the turbine trim later in this post.

The next wheel is the T04 family of wheels. Some of these wheels can be made to fit a T3 flanged turbo or a T4. A .T04 .69 trim is larger than the T350 .76 trim, but smaller than a T04 O-trim. You have probably heard people call some turbine wheels O, P, Q trim. The reason they do this is because they are all .76 trim. But the O is the smallest and the Q being the largest of the three. They had to do this because if you had to order a T04 turbine wheel you couldnt say, "I need a .76 trim wheel." So they had to give it another name of O, P, and Q.

Alot of times people will order a turbo from me and ask for SC61 for example and want the .76 trim. Well, do they want the .76 trim in a T350, T04 0, P, or Q? In most cases people dont know the difference so I sell them the T350 .76 trim stage 5 wheel for hondas.

The formula for finding the turbine trim is the opisite of the compressor:

(exducer^2/ inducer^2) x 100. I dont have anything to reference right in front of me at the moment like I did on the compressor section. But will get some up if people want.

Hope this helps. I am always up for giving out some product info.

art

 

http://64.225.76.178/catalog/compmaps/fig9.html

link to the 60-1 compressor map. *shrugs* happened to run across it

 

i dont understand why a t31 76 trim is the stage III when here

http://64.225.76.178/catalog/twheel.html

it says the major diameter of the stage III and V are the same? thus shouldnt the stage III be a 69ish trim t350 and not a t31 wheel?

 

thanks for the info

 

more info

https://honda-tech.com/zerothread?id=153810