perana wrote:hey mtcookson what ratio would you suggest for 200mph with stock gearbox and tyer size? also what aero aids would one need? cheers
With stock sized tires you could put in the Q45 3.538 differential and run the engine to 7,250 RPM for exactly 200 mph. If you keep the stock TT 3.692 differential and run the engine up to 7,550 RPM you would hit 200 MPH. Depending on how your engine is tuned, I would aim for a higher limit than 200 so that when you actually get to 200 you're in a decent power band. It may still be able to pull you up to that at redline but, like I said, just depends on how your engine is tuned. With that engine you have, it probably wouldn't be a problem having the total limit closer to 200 (running it close to its redline).
If the engine is setup for a limit of 7000-ish RPM you'll probably want to go to the 3.538 differential and get some slightly taller tires.
Just thought of another potential option. The Armada is available with a 3.36 and 2.94 differential. The 3.36 would definitely get you past 200 mph with stock sized tires and a 7,000 RPM redline. As far as actually using that diff... you could probably put the ring and pinion in a TTZ case as they're both R230's.