Dimensions of an RX8 Induction/Throttle body hole size?
 

I'm looking to make up my own Induction kit, similar to the AEM model.
I was wondering what the sizes are of the rubber pipe that connects the air box to the throttlebody?

My car isn't road legal.. therefore it stays at my yard most of the time, so I can't look at it to measure it up and wanted to order some stainless..

If anyone could help me out it would be a massive help!