What performance gains can one expect with the 4.57 gear set from Ricks? I am interested in 0-60 & 1/4 mile improvements. I am thinking about a supercharger but don't want to drop that much cash.

Also, what are the drawbacks for changing the gear set? Is there a decrease in engine life and reliability? Thanks in advance for your input...

 

My car is stock, but I've read a thread about a month ago of someone who changed their gear set, and they were disappointed with it. I think there's a lot of controversy on if it makes a difference or if it is just in people's heads. I would do a search for threads that people have made in the past where they give their impressions.

 

Just my point of view, but coming from a purely scientific position, changing the gears in your car should not affect the speed of the car. The only thing which will noticably change the car's speed (not including drag, pwr train losses, etc...) will be to add horsepower or to remove weight.

The power to weight ratio of a car will be the biggest factor in determining it's speed. If you think about it, with a lower gear set you will be accelerating faster in, say, 1st gear, so it will feel like the car is going to get up to a higher speed. However, it's important to remember that you will also be running through the gear faster because you will have to rev the engine higher for the same wheel RPM (speed). So when you (with the lower gears) hit red line and shift to 2nd gear, the other guy with stock gears will still be in 1st gear since he hasn't hit redline yet and will have a lower overall (engine to wheel) gear ratio.

So the guy with stock gears will make up any lack of acceleration he had by running in a lower gear for a longer time. So the final speed in the end will not change. It really makes sense since a basic law is: power out = power in minus efficiency losses. So by changing the gears you aren't changing the power, or the efficiency (drag, friction, heat loss, etc..) so power output cannot change.

I will say though that a change in gears may make a car more drivable, and the power more "usable". By being able to launch harder in 1st gear, you may see a slight decrease in a 1/4 mile time, but this is purely the result of being able to use the power more effectively, and will probably be minimal. Racing from a rolling start, gears should lend little if any advantages.

 

What gears do is allow you to optimize how power is used for a specific track or test. High level motorsports, like F1, do track simulations to find the right gear ratios to be in their powerband for most of the track. The teams have different gear ratios for every track. This really doesn't help you out in the "real world" where you can't optimize for every different situation.

Now for drag racing it would help, but not as much as the change in ratio would suggest. The hand-wavy explaination (the math guys now) is that the higher gear ratio shifts the torque/power from the higher speed ranges to the lower speed ranges. This allows the car to use more torque/power in the 0-100+ mph range in the 1/4 mile and less in the unused higer speeds. This is nowhere near the advantage that the gear multiplication would suggest. Of course you can loose this "small" advantage by getting an extra shift that adds back time to the drag run.

 

AZS2000,

Using your logic the rear end gear ratio doesn't matter at all. We might as well have 1:1 gears back there cause then we'd never have to shift which would make up for the fact that you'd have a lot of trouble even getting the car to move. Obviously, I disagree with your scientific opinion. Jumping from 4.10 (stock) to 4.44/4.57 will only require 1 additional shift in the 1/4 mile. The slight time lost by that extra shift is more than made up for by the additional torque that you have the whole time, in all gears. 4.44's have been shown to improve 1/4 times by approximately .5 seconds. I would expect 4.57 to slightly improve upon that.

 

I agree with strike here, although azs2000 has everything down pat except for the minimal gain from the bigger gears. it's true that you will most likely need to squeeze in an extra shift because the top-speed in each gear is lower. that extra shift would only cost a few hundred milliseconds (assuming a good driver), but the added wheel torque from the gears would outweigh the cost as you could get to your power peak faster.

by adding bigger gears, all you're doing is shifting the 6 horsepower curves (one for each gear) in your wheel rpm (x) vs. wheel torque (y) graph to the left. important to keep in mind there is *no* power gain from added gears as already explained