anyone know what the exhaust a/r size of a stock s4 and s5 turbo is?

 

1.00 T3 sized for both.

the series 4 has 2 seperate A/R's, but they average 1.00 and the series 5 just has 1.00 A/R.

~Mike.........

 

interesting.

so if someone wanted to make a 250 whp or so autox car could they go as low as say a 82 a/r exhaust and get great throttle responce?

i had a stock s5 a while back with a 60 a/r compressor and it made great power but didnt really make boost early on as i would have liked.

 

Its a T3 sized...... A/R is ONLY relative to turbine frames from a family. 1.00 A/R T3 will not flow nearly as much as a 1.00 A/R T4 frame.

Going anything smaller then the stock turbine and A/R is just plain dumb. A stock turbo with a full 3" exhaust and TID has great response (like a n/a engine) (REALLY great respnse if a street port motor) and I can't imagine needing anymore response. Anything smaller and you'd be boosting during cruising. More wear on the engine and horrible gas mileage.

BTW, T3 sized turbines are really too small for 13b's. If you want extremely fast response, a hybrid will work great (stock manifold and turbine, upgraded compressor). Even a full T4 with a .84 divided turbine and a T04E sized compressor will spool simular to a stock turbo car (Turbo II). Don't waste money / time upgrading to a new turbo set up when actually you'll be down grading by gong T3. (And YES the GT30\40 and APexi' RX6 have T3 sized foot print on there turbines, but there turbine wheels are MUCH bigger then any T3 turbine wheel).

~Mike............

 

heh. I posted that first post.. odd it gave me someone else's username.


anyways I have been conscerned about using the .82 a/r T3 style turbine. but as you say it is much larger than a conventional t3.

i hope it works well

 

let me correct that. an .82 a/r GT35 housing

i have the t4 tang verison from atp turbo its pretty nice ill post pics soon its my manifold and clears everything nicely. It is a bit snug for the exhaust housing but im happy.

the vband is a tad larger than 3 inches and is part of the housing not welded on like the standard

gt35r