Picking gear ratios question?
01-08-2013, 04:37 PM
#1
Safety Car
Thread Starter
Picking gear ratios question?
I'm working on a '92 ZR1-based track/road race car, and want to know how to select the right gear ratios?
Is there a web site where I can input the engine HP/TQ curve, the rear end ratio and find the best gear ratios for a 6-speed trans? I don't want a tall 5th & 6th for fuel mileage...I want them to continue like 1-4 so the RPM's stay in the powerband and can push the car at high speed.
I want to take this open road racing as well...and want to be able to push the car in the upper gears without needing to downshift more that a gear to allow it to accelerate.
Thanks for any suggestions...
Is there a web site where I can input the engine HP/TQ curve, the rear end ratio and find the best gear ratios for a 6-speed trans? I don't want a tall 5th & 6th for fuel mileage...I want them to continue like 1-4 so the RPM's stay in the powerband and can push the car at high speed.
I want to take this open road racing as well...and want to be able to push the car in the upper gears without needing to downshift more that a gear to allow it to accelerate.
Thanks for any suggestions...
01-08-2013, 06:20 PM
#2
Melting Slicks
Member Since: Sep 2003
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http://www.f-body.org/gears/
This website will give you a speed calculator, you can just select the car at the top of the page or put in you tire size (better yet go to the tire rack and find out what the actual diameter is) then select the gear box - the ZF gear ratios should be in there, then put in your diff gear ratio and see what it comes up with.
Having a dyno graph to work with will also help to let you know how much of an RPM drop there is between shifts (just look at what the speed is at your shift point and match it with the next higher gear).
I've used this site for to figure out RPM drop as well as torque multiplication for optimum shift points. It's a little bit of work but kinda interesting.
This website will give you a speed calculator, you can just select the car at the top of the page or put in you tire size (better yet go to the tire rack and find out what the actual diameter is) then select the gear box - the ZF gear ratios should be in there, then put in your diff gear ratio and see what it comes up with.
Having a dyno graph to work with will also help to let you know how much of an RPM drop there is between shifts (just look at what the speed is at your shift point and match it with the next higher gear).
I've used this site for to figure out RPM drop as well as torque multiplication for optimum shift points. It's a little bit of work but kinda interesting.
