i just want to know the size of the stock s4 turbo (hot side) if any one know please tell me
thanx andy

 

if my friend was to put a 60-1 on his stock s4 motor do u think he would have a problem with spooling it?
the turbo is .84 hot side
and .70 intake side
thanx andy b.

 

It should spool up OK.

 

I believe the Jack Yamaguchi book states the S4 dual scroll exhaust housing has a primary scroll A/R or .4 and a secondary scroll A/R of 1.0.

edit- and this is smaller than T4 sized housing so T4 A/R numbers do not coincide...

 

Its a 0.88A/R with them both open isn't it?
its basically the equivilant of a T3 as far as comparitive numbers go.