Rear End Ratio question

67Dart273 said

According to this site

http://www.audiworld.com/forums/tt-mk2-discussion-120/tire-diameter-chart-2704424/

Those tires are 25.7" in dia

There are tons and tons of mph / gear/ speed / rpm calculators on the 'net

"Wallace" is just one
http://www.wallaceracing.com/Calculators.htm

http://www.wallaceracing.com/gear-speed.php

Which generates this chart

and that means "something is wrong." Either you don't have a 3.54, or the tires are different, or the speedo is wrong, or you have a converter with a VERY high stall

Cheapest easiest way in my opinion, in this day, is to use a GPS for speed.

Click to expand...

Thanks for the info. That chart says at 3,000 rpm, the speed should be 64 mph. This would lead me to believe that I'm not too far off and it's running correctly or I'm missing something.

The tires are definitely 245/40-18s that are 25.72 inches tall so we can rule that out.

I haven't verified the rear end gear ratio. I am just going with what the shop told me.

My goal is to be able to cruise at highway speeds (60-70mph) around 1,700-2,000 rpm but no loose any of the low end torque the car has.

Any thoughts???