Does anyone know what inside dia. the prop centre bearing would be for my Hawk STi?

Ebay seems to have 2 choices both of which say they will fit!

25mm ID: http://www.ebay.co.uk/itm/FOR-SUBARU...MAAOSwn51Uai1g
30mm ID: http://www.ebay.co.uk/itm/FOR-SUBARU...gAAOSwtnpXokY8

Cheers

 

I thought your vibration was Map related ?

 

In as much as the stock map doesn't cause it, which as you said before could be due to the torque / rate of change of torque at particular RPMs. When I inspected the bearing, the rubber bush seemed pretty soft, it was easy to get the inner part to touch the outer part by pulling the prop down, and my thinking is that under stock conditions the bush is sufficiently stiff enough, but that under the mapped conditions it isn't and prop lashes about more. Certainly there was evidence that the prop is moving off axis more after the map because of the witness marks on it and the diff guard, as in the pictures from my previous post on this. My thinking is that it's a sort of resonance is the best way to describe it, and changing the bush would change the characteristics of it.

The weather is crummy at the moment, but I plan to add some white paint to the inner face of the outer part of the rubber bush and test under stock and mapped conditions to see if there is contact in either or. If the paint transfers to the inner part of the bush I know there is contact. I reckon a new bearing/bush one that is not stock could be stiffer and perhaps more resilient.

Just a thought at the moment.