Just bought everything for 3.73 gears
70 mph = 3133 rpm
60 mph = 2685 rpm
Here's the calculator:
http://www.wallaceracing.com/calc-gear-tire-rpm-mph.php
Plus TC slip, if an auto.Which shouldn't be much in a lightweight Demon;100 to 150 rpm.
Sometimes it goes backwards. With a torquey engine, and a tight TC,at 60/65 mph, I have had cars the actually cruise at less than the Zero-slip calculated rpm. Some were over 100 rpm lower.How does that work? IDK.