Had a new AP Organic clutch fitted last week to my 2006 STI. Drives well but get a lot of vibration when putting foot down at 3000rpm in 6th. Doesnt do it at 3000rpm in other gears.

Any ideas what it could be ?

What's the running in process for the clutch ? Was no instructions in the box.

Whilst fitting it the garage found that my downpipe is split, could this be causing some odd boost control issues that only appear in 6th gear ??

New downpipe ( H&S sports Cat version ) is on its way so hoping that will fix it.

 

Did you ever find out what this problem is? Iv been having the same symptoms and finding it hard to locate the problem.