Just added some new ones.

Gearing Calculator The Race Technology Gear Calculator will calculate vehicle speeds in the different gears at various engine speeds, as well as calculating the rolling circumference of the tyres and rev drops when changing gears.

Aero Drag and Rolling Resistance Calculator This tool will calculate the aerodynamic CD and Rolling Resistance of a vehicle by performing deceleration tests.

 

The Gearing Calculator is handy. Here's what you get from an FD with stock gear ratios and a stock 4.1 manual trans rear end rolling on 245/45/16 tires shifting at 6500 rpm:

Speed 1000 2000 3000 4000 5000 6000 7000 8000 Rev drop on shift
1st 4.9 9.9 14.8 19.7 24.7 29.6 34.5 39.5 2740
2nd 8.5 17.1 25.6 34.1 42.7 51.2 59.7 68.2 2013
3rd 12.4 24.7 37.1 49.4 61.8 74.1 86.5 98.9 1827
4th 17.2 34.4 51.6 68.8 85.9 103.1 120.3 137.5 1827
5th 23.9 47.8 71.7 95.6 119.5 143.4 167.4 191.3

Engine speed at 70mph in 3rd =5664rpm

Engine speed at 70mph in 4th =4072rpm

Engine speed at 70mph in 5th =2928rpm