Boost not turning up till 4500rpm...

[kaptainballistik]

:/

Ive got a VR4 (der) Rallycar (yay) with a Rs Motor

So thats a Bigport Cyclone intake motor...

Now the issue is.. It only gets 5psi boost up to 4200-4500 rpm and then it boosts, but it will hit 5 psi by 2000 rpm

Its got a EX Works "small" 16G with a restrictor so the party should be started well before 3500 rpm! Now ive been told that it could be the vacuum lines for the cyclone actuators....

Any ideas?

 

Make sure the wastegate actuator arm is actually attached to the wastegate flapper. I've forgotten to do this a few times after swapping turbos or hotsides /ubbthreads/images/graemlins/grin.gif

Check for exhaust leaks before the turbo.

Pressurize the intake tract from the turbo to the intake manifold and find any leaks.

 

[RedTwo]

As I understand it, the restrictor sounds like it's working if you're making boost way down like that. It should choke out the turbo after about 5000 rpm.
Exhaust leak around or in the exhaust manifold or exhaust housing on the turbo?