thx Arct1k, didn't know that uptill now.
My FDR now is 7.04, gas engine revs 20.000, tire circumference 53cm will give topspeed of 56 mph.
Can't imagine going that fast in a race. The longest straight i've been on was 70 meter.
With the FDR i can go up to 9.
To give you an idea what i race, have a look at the link below.