4.10s
10-26-2005, 12:50 PM
#2
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depends on rpms. here are the calculation for RPM and MPH.
For RPM
(MPH x Trans Gear Ratio x Gear Ratio x 336) / tire size = RPM
For MPH
(RPM x Tire Size) / (Gear Ratio x Trans Gear Ration x 336) = MPH
Trans Gear Ratios for an A4 are:
1st = 3.06
2nd = 1.63
3rd = 1.00
4th = 0.70
For RPM
(MPH x Trans Gear Ratio x Gear Ratio x 336) / tire size = RPM
For MPH
(RPM x Tire Size) / (Gear Ratio x Trans Gear Ration x 336) = MPH
Trans Gear Ratios for an A4 are:
1st = 3.06
2nd = 1.63
3rd = 1.00
4th = 0.70
10-26-2005, 06:56 PM
#3
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What were are talking about is "rollout" - how far the car travels per engine revolution. A 275/40R17 (which I am familier with) is about 25.5" in diameter or about 80.1" in circumference. Therefore in .7:1 (4th in an A4) with a 4.10 rear end for each rev of the motor the car moves fwd 27.9". At 6200RPM the car traveles 14400 or so feet per minute or 163mph. This assumes you have the power to overcome aerodynamic drag to reach 6200 in OD. I wouldn't drive my car that fast, even on a race track. The sticky at the top of the section may also be helpful.