Originally Posted by Twigg
I think it has a lot to do with the FD ratio. I'm guessing neither Thomas nor Blue Bird want any part in creating 90 mph buses.
With my FD ratio of 5.38 I expect no trouble from Thomas. Speed in 6th at the rev limit would be 80 mph.
I was referring to underpowered buses. IE: A full size skoolie with a 5.9.
Also, to clarify: every MD3060 equipped skoolie that I have seen in service has 6th gear locked out. Members here with 3060 equipped Thomas's have had good luck getting the letter from the manufacturer that Allison requires in order to unlock 6th gear. Members with Bluebird's have not been so lucky.
Final drive absolutely affects top speed. Acelleration as well. A low numeric value gives higher top speed and reduced acelleration. A high numeric value yields a lower top speed and better acceleration.