HouseWS6

iTrader: (1)

It's a head and cam A4 that will see some spray... I am going with a 12 bolt w/spool but not sure what gears..Running a 26" ET Street tire and the car makes power @6300 and pulls to 6900. Shift at 6700/6800. I'm not sure if 3.73/4.10 will be enough or 4.30 will be too much? I will also be spraying at least a 100 shot on it but Im needing it to perform on motor as well for the street. Thanks Tech.

HouseWS6

iTrader: (1)

I know, a spool on the streets not to fun as Ive had them in my last 2 cars but Im not interested in destroying a posi like it seems is happening everyday..I know the A4 cars arent as violent on the launches as m6's but I'd rather be safe..

Dragula

iTrader: (5)

Assuming: 3rd gear is 1:1
Car stays in 3rd up to 6700 rpms
O.D. of tires is 26.00"
No tire growth

3.73 gear will hit 6700 rpms at 139 mph / rpms in 4th@ 70 mph ~ 2700
4.11 gear will hit 6700 rpms at 126 mph / rpms in 4th@ 70 mph ~ 2600
4.30 gear will hit 6700 rpms at 121 mph / rpms in 4th@ 70 mph ~ 2400


Depending on your weight and HP (with N2O), you should be able to calculate what your max speed will be at 1320'. Pick the highest numerical gear that will not put you over 6700 rpms in 3rd at 1320'.

Remember the 2nd part of the equation. How many rpms you'll be doing at highway speed.