Comparing T3 A/r To T4 A/r

[joe blo]

hi guys. i have been thinking about this for quite some time and cant figure it out properly. is it possible to compare the flow rates of the rear housings of say a t3 0.82 housing to like a t4 housing?

say for example something like this.

- a t3 0.82 might flow close to a t4 0.63

- a t4 0.84 might flow close to a t3 1.06 sorta like that

[JonnoHR31]

start reading

http://www.turbobygarrett.com/turbobygarre...tech102.html?#b

[joe blo]

yer ive read that one before and a few others.

[discopotato03]

It not really as simple as that because not all turbine and housing families are created equally .

They are in any case a two piece combination meaning the turbine and the turbine housing , neither does anything useful without the other .

The Area Radius ratio relates to the volume of the passage leading to the housings nozzle section . It makes the grand assumption that no ones bored the housing out for a larger diameter turbine as well .

If the question you are asking is can the mass flow rates be compared then the answer is yes . If you are asking is there a direct numerical conversion ratio wise from T3 to T4 then I would say no . The reason being that the turbine wheel has a lot of say about how the combination flows and there can be a big variation in what people call "T3" turbines and a few different T4 ones .

You have to understand that what say I call a T3 turbine is the heavy inefficient little horror fitted to Z18's FJ20's RB30's etc . There is a range of TA31/TB31 turbines that many call T3/Sierra dash 1/2/3 . Not really T3 but jammed into old T3 housings not really suited to them .

The Buick Grand National stuff was called "T3" But I think they come under the TB41 family .

Also confusion exists because you can have internally T3 dimensioned housings with T4 mounting flanges on them and T4 housings with a T3 like flange on them . I kid you not some diesel tractors have 1.06 A/R twin scroll T4 International mount flanges on them but with quite small gas inlet ports . Inside lives a dinky little early 70's tech T3 turbine .

What exactly are you looking at ?

A .

[joe blo]

i sorta wanna compare gt3582 t3 to t04z t4 housings. just wanna get a rough ideas of the t4 flow rates compared to the gt35 ones coz im sorta up to speed with them ones but am unsure about choosing a t4 housing.

[JonnoHR31]

gt35

http://www.turbobygarrett.com/turbobygarre...8-allturb_e.jpg

unfortunately the garrett site doesnt seam to have one for the t04z, only has a compressor map.

[joe blo]

thanks for that link. its a good one. il try find one for the t04z then il be able to figure out what i want.

[JonnoHR31]

found this one

http://www.atpturbo.com/root/maps/images/t04zturbine.gif

[GTScotT]

I think your query is a little more specific than the flow of T3 to T4, more so the flow of your specific turbos you have just mentioned.

I gather you are trying to make a turbine housing to one of your options to match the flow rate of your other option in its set housing. As disco said, they are not directly comparable, but looking at the turbine maps more so than the AR sizes is a good start.

GL