I made my first trip down the 1/4 mile over 45 years ago and have heard a lot since then about performance. But, I just don't follow your equation:
more horsepower + taller gear = lower et's
I guess it could depend on how an owner intends to use his car. Obviously, the more hp you have the quicker you are going to hit shift points and have to shift. If an owner is just a casual driver, I might understand not wanting to shift gears as often. I certainly remember the days when even with really low gears you would stay in 1st gear several seconds under full throttle. Driving a car today with a huffer, you barely have time to count thousand and one before shifting out of 1st. I wouldn't even be surprised if the GT500 is the first manual shift car that a lot of owners have driven because for years and years the only thing that had manual shift were econo boxes. If I had done my math and a little more research and found out that I would be turning only slightly over 2000 rpm's at 70 mph, I would have gone with the 4:30's. I have even run 4:88's in some of my daily drivers in the past. And if you can't imagine what low gear is like with those gears, I can tell you. Brutal acceleration.
The biggest resason for wanting a lower gear ratio is to multiply
torque to get the car moving from a standing start. Many have added the new TVS , Whipple or KB blowers to their cars.
These blowers have altered the
torque curve so that max torque (usually over 600ftlbs of torque)is achieved by 2500 rpm and doesn't fall off till close to 5000rpm and only by a small amount .
That's why a taller gear is better with these blower cars once the 600+rwhp and rwtq barrier is reached. For any street car 600+ rwtq is way too much and even on the track with slicks it is a challenge to get it to hook properly.
On another note:
One problem with the 6 speed trans on these cars that actually makes the problem worse is that 1st gear is geared too low and there is too much of a gap between 1st and 2nd. A bit higher ratio 1st gear would help with the drivability and make it easier on the 2nd gear syncros making it a smoother 1-2 shift .
I would also like to see a higher 6th gear ratio for better fuel mileage. Since there is plenty of pull in 6th with a 600+rwhp car a higher ratio would be no problem for the car to handle.
