S4?
Rotary Enthusiast
Joined: May 2002
Posts: 885
Likes: 2
From: Canberra - Aus
Different.
The S4 has a smaller exhaust housing, .85 I think. While the S5 is 1.1.
The S5 has a twin scroll exhaust housing setup, which keeps the exhaust gasses seperate until they hit the turbine, so there is less turbulence which should aid spool up.
Obviously they use a different flange because of that. The S5 has a more rounded hot side (bigger A/R) while the S4 is flatter.
There's prolly more, but I can't think of anything at the mo.
No, wait... Another thing and quite useful too. The S5 has dual wastegate flaps that allow better boost control.
The S4 has a smaller exhaust housing, .85 I think. While the S5 is 1.1.
The S5 has a twin scroll exhaust housing setup, which keeps the exhaust gasses seperate until they hit the turbine, so there is less turbulence which should aid spool up.
Obviously they use a different flange because of that. The S5 has a more rounded hot side (bigger A/R) while the S4 is flatter.
There's prolly more, but I can't think of anything at the mo.
No, wait... Another thing and quite useful too. The S5 has dual wastegate flaps that allow better boost control.
Rotary Enthusiast
Joined: Dec 2002
Posts: 1,228
Likes: 0
From: Darwin, NT, Australia
Originally posted by S2-13BT
Different.
The S4 has a smaller exhaust housing, .85 I think. While the S5 is 1.1.
The S5 has a twin scroll exhaust housing setup, which keeps the exhaust gasses seperate until they hit the turbine, so there is less turbulence which should aid spool up.
Obviously they use a different flange because of that. The S5 has a more rounded hot side (bigger A/R) while the S4 is flatter.
There's prolly more, but I can't think of anything at the mo.
No, wait... Another thing and quite useful too. The S5 has dual wastegate flaps that allow better boost control.
Different.
The S4 has a smaller exhaust housing, .85 I think. While the S5 is 1.1.
The S5 has a twin scroll exhaust housing setup, which keeps the exhaust gasses seperate until they hit the turbine, so there is less turbulence which should aid spool up.
Obviously they use a different flange because of that. The S5 has a more rounded hot side (bigger A/R) while the S4 is flatter.
There's prolly more, but I can't think of anything at the mo.
No, wait... Another thing and quite useful too. The S5 has dual wastegate flaps that allow better boost control.
S5 does not..
Senior Member
Joined: Jan 2002
Posts: 725
Likes: 14
From: Northern California
twin scroll exhaust housing is ment that it's a divided exhaust housing, but that isn't only on S5, my S4 has a divided housing also, just that manifold doesn't have a true divide version, but instead twin scroll.
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Rotary Enthusiast
Joined: May 2002
Posts: 1,203
Likes: 0
From: Boston
Im thinking of posting a thread on this but i dont want to be flamed...SO if someone where to intalle a S5 turbo on a S4 Tii would there have to be any mods done to anything? Im saying can someone install a s5 turbo on a s4 easily? Im thinking of performing this mod