Apexi AVCR boost issues, exhaust restriction maybe?

[Lee H]

Rev 3 turbo engine fitted in a mk3 now.

Had the engine in my mk1 with very short 2.5" exhaust system and was making 1.1 bar at 82% duty on the AVCR.

Put engine in the mk3 and only difference is the exhaust is 2 3/8" with two silencers and a lot longer with some sharper bends in. Now car is only making 0.9 bar on the same settings on the AVCR.

Could this be down to the more restrictive exhaust. Have increased the duty a little and boost goes up slightly but not sure how high I should take the duty. Was at 82% previously to make 1.1 bar, increased to 86% now and gone up to 0.97 bar but not sure what other issues I might be creating doing this so reluctant to take it much higher.

Also changing the boost figures on the AVCR doesn't seem to do anything, only the duty makes more or less boost, is this normal?

Cheers for any advice.

[Lee H]

Current exhaust system.

[Marf]

More restrictive exhaust -> less boost.

Yes, you will need to change the duty to get the boost back where you want it. The settings you had before were good for the larger exhaust.

[Lee H]

Thanks. From doing some reading on here a lot of people seem to have the duty around 60% so that's why I was a little concerned. Guess it will also depend on how good the stock actuator still is as well.