Gear Ratio's

[cuda_426]

I have a 79 Camaro Z-28 and it has a low gear ratio like going 90 is really high rpm's , whats a good highway gear ratio also could someone tell me how to determine gear ratio's and how to tell and how they work i know its alot but im young and not in tech school yet and dont feel like waiting

[robz95xj]

the higher the number the more RPM's you will turn at highway, like exsample, last spring my friends put 4.88 gears in his cherokee, we were turnin 3k at 55-69mph with stock tires, now with stock gears wich are 3.55 you dont turn 3k untill about 90 with a Cherokee. now you ask what numbers mean, ill use 3.55 gears as a exsample, your driveshaft will turn 3.55 times for every 1 revelution of your tires,
lower gears(numericaly higher)=greater aceleration, but higher RPM at highway speed and lower top speed

higher gears(numerically lower)=crappy aceleration but less rpm's at highway speed and greater top speed

[BOTLFEDLT1]

I'll add that lower (final drive) gears dont always mean lower top speed. You have to consider the gearing of the transmission and not just the final drive. For instance, in a T-56, you have a an overdrive 5th (0.8) and ridicuously high double overdrive 6th gear (0.5). I think theoretical top speed of if you redlined 6th is like over 300 mph. Obviously, you will never be be able to power the car to redline in those gears. Lowering the gearing probably wont lower top speed at all, and may actually help improve it in allows you to get into a fatter part of your powerband in 5th.

Originally Posted by robz95xj

the higher the number the more RPM's you will turn at highway, like exsample, last spring my friends put 4.88 gears in his cherokee, we were turnin 3k at 55-69mph with stock tires, now with stock gears wich are 3.55 you dont turn 3k untill about 90 with a Cherokee. now you ask what numbers mean, ill use 3.55 gears as a exsample, your driveshaft will turn 3.55 times for every 1 revelution of your tires,
lower gears(numericaly higher)=greater aceleration, but higher RPM at highway speed and lower top speed

higher gears(numerically lower)=crappy aceleration but less rpm's at highway speed and greater top speed

[01mmmz28]

what all is done to the 79 camaro?? Is it the stock 350ci ? Or is it a different motor? Any cam? Heads? All this needs to be taken into consideration. If you have a high lift high revving cam you will need something like 4.10 gears. If it is stock and has a 3 series carrier, go w/ something like 3.42's, they are very streetable. Or if you still want streetable and power gears 3.73's are about the best for both worlds. Summit or Jeggs has killer prices and great customer service, they will walk you through what you need and get you all set up.