Shorter Gears & top end speed.

Why couldnt you run at 5050rpm's with the 3.27's? I know I lost some top end speed but I get there alot quicker with the 4.10s ;)

HP and torque have a lot to do with it also. With a shorter gear (3.27) you're applying less torque to the rear wheels than you would with a taller gear(4.10). So you should be able to go at least as fast

- if not faster - with the higher rpm's. You have to figure in things like wind resistance, drag, torque curve, etc. There's a formula for that, but I don't know what it is. I remember a few years back, some magazine was shooting for top speed in their Fox body. So they decided to use 4th gear only, and avoid OD, since that would apply more torque and keep the revs further up in the power band for their motor.

If you could get to 5050 RPM with the 3:27 gears you would be doing 175mph. I don't think that is possible.

Is that right? Aren't shorter gears ones with the higher numerical values (4:10) and taller gears the ones with the lower numerical value (2:73).

Do we all agree that the 4:10 gears will not reduce the top end speed?

Top speed is a function of three things: Peak horsepower, vehicle drag (aero, mechanical, etc), and unfortunately gearing. The objective would be to have your top speed occur at the horsepower peak. If it doesn't, your not optimally configured with respect to gearing. Where is the HP peak on a near-stock 5.0? Isn't it around 4,000 (or a little higher, 4,200?) RPM. In your example of 140 MPH @ 4,050 RPM with 3.27 gears (assuming this relationship is correct), you are very near the horse power peak and you aren't going to see any significant increase in top speed with a gear change.

If you move the RPM @ 140 MPH to 5,050, you are way past the HP peak. You would be making less power, which would mean you couldn't be running 140 MPH.

I vote for a speed decrease with 4.10's.

Some may find this interesting:

Wow... that's a pretty exhaustive list of formulas for figuring out how a car will behave.... the trick is to find the constants necessary (aerodynamic drag, tractive effort of the tires, etc).

That's an eye opener for anyone who enjoys a good racing game and doesn't know what kind of work goes into them...

JS

This isn't really an issue. Most people are more concerned about the rpm's at cruising speed and the negative effect on mpg. Add tot hat that a lot of cars have electronically limited top speeds (that you can remove ) Remove NO-SPAM from email address when replying