Hallo,

i'am a bit confised about the different data's for a exact turbo specification:

as far a i know there are:

- Housing Type (i.e. T03, T04 etc.)
- Inductor Size
- Exductor Size
- Trim (what's that????)

and how to read a turbo spec like: Sc61 .63 PT67 P-Trim .68

please don't blame me but i realy didn't know it and have also no idea how to search for this special information.

Thanks
Malte

 

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

i'am a bit confised about the different data's for a exact turbo specification:

as far a i know there are:

- Housing Type (i.e. T03, T04 etc.)
- Inductor Size
- Exductor Size
- Trim (what's that????)

and how to read a turbo spec like: Sc61 .63 PT67 P-Trim .68

please don't blame me but i realy didn't know it and have also no idea how to search for this special information.

Thanks
Malte </TD></TR></TABLE>
very good post id like to know as well

 

id like to know too.

 

Trim is the squared ratio of the inducer and exducer multiplied by 100. There is a trim for both the compressor and turbine side, but when most people say "this turbo is an x trim" they are referring to the compressor trim.

For example, the SC61 has a compressor inducer of 2.416" and an exducer of 3.227".

(2.416/3.227)^2*100 = 56 trim

Some of the Garrett compressor families are T22, T25, T3, T350, T04b, T04e, T04s and T04r. You can have the same trim in different familes because the ratio of the inducer/exducer is the same, but the overall size may be quite different.

Some turbine families are T31, T350, and T04. The T31 is sometimes referred to as the stage 3 blade and the T350 the stage 5 blade. The smaller the blade, the faster the spool, but the less top end you will have.

Where you list .63 after the SC61 in your example, that is the A/R of the turbo, or Area Radius. Just like with trim, there is an area/radius for both the compressor and turbine side of the turbo, but most people are referring to the turbine side with A/R. A/R measures the ratio of the area of the compressor or turbine housing to the radius of the compressor or turbine wheel. I can tell you how to measure this if you want, but all you really need to know is the bigger the A/R number, the bigger the housing is.

 

Hallo,

first, thanks for this very good post... that helps a lot.

but i have one question left.
from what information can i see how fast the turbo will spool? i know that a bigger turbo spool later then a smaller one, but thats only guessing... is there any parameter where i can def. say that turbo a will spool later then turbo b i.e.

Thanks
Malte.