I have seen a thread on this in the UK, but no official answer just comments on how fast people had gone. Does anyone know what top speed, is in a RX8(stock)?? And also top speed of fastest RX8(modified) to date??

 

Aaarghhhh... not again!

Unfortunately, mate, this is not a question you can get an accurate answer on because it depends on too many factors. However, the usual answer given is somewhere between 240 and 250kph.

The top speed of the RX8 (along with most other vehicles) is not determined by the upper rev limit. The RX8 runs out of puff long before 9,500 rpm in top gear. There are many limiting factors including air temperature, wind direction, and simple things like whether you're going down hill or not! The biggest factor is plain old air pressure, so get behind a furniture fan doing 300kph (or a dragster with wind shield, as has been done in bike speed records) and stick close and you'll definitely better 250kph ... :D