what does .48 ar .49 exahust mean for a turbo?

 

what are the differences between a t3/t4 turbo and a t3 turbo and which one do you guys use?

 

Dude, try combining your posts. You don't have to post a seperate thread every time. This could have easilly been posted with your "what are the differences t3/t4 and t3" thread. In fact, I'll combine them for you.

 

A T3/T4 turbo is a hybrid using a T3 turbine and a T4 compressor. A T3 uses a T3 turbine and T3 compressor.

.48 is the aspect ratio(A/R) or the turbine housing. This is an over-generalization, but a lower A/R will mean quicker spool with a lower "ceiling", while a larger A/R will mean slower spool with more top end power.

 

thanks

 

A/R ratio stands for "area to radius."

Calculate the area of the turbine housing outlet and divide by the radius from the center of the turbine wheel to the center of the outlet and you got your a/r.

Kinda sounds weird yeah.

Look at this picture:



A = area of the imaginary circle drawn by the edge of the turbine housing outlet.

R = area of the imaginary circle drawn by the turbine housing at the turbine wheel.

Basically the port is tapered like an air horn so the area of a hypothetical flat disc in place of the turbine wheel is smaller than the area of the plane drawn at the end of the outlet.

 

Looks like I got my turbo a/r and my tire a/r mixed uph: