I know that the standard TD04 runs out of breath at about 265 - 270bhp.

Question is this. Is it the compressor or the exhaust turbine that is the limiting factor ?

I know the Subaru spec exhaust turbine is the smallest one used on the TD04 family, so is this the bit that chokes the system ?

 

check out Andy F's ( Andrew Forrest ) webpage, as he sells modified TD04's, and i'm pretty sure he goes into detail re what he does
ray

 

Nahhh not that much detail

Trade secrets I bet

 

Without testing any modded TD04s I'd suggest the turbine.........

 

Ansy gave away a few clues in the project WRX Scoobymag- I seem to recall both being mentioned! I'll see if I can dig out the issue.

Ns04

 

The compressor flow output will be a restriction along with the size of the turbine housing

Cheers

 

I run a TD04 at about 270 bhp.
and measured the outlet temperature during continuous boost at the german autobahn. And suprisingly it wasn't as high as I expected.
To me this indicates together with it's inability to give more boost than 1 bar at 7000 RPM that the turbine is rather restricting things. If it was the compressor it's outlet temp should be going to the roof.
Also a 3" exhaust isn't really doing much on the TD04 which also indicates the turbine is the main restriction.

 

Thanks for your thoughts and info guys.

S'pose I ought to bite the bullet / write the check and do what I thought I would have to anyway.

Guess we mostly think its the exhaust turbine.