Help me understand gearing (total newbie to RWD and domestics).

paradigm

Member
Jul 18, 2007
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Can someone please help me understand gearing, as I am totally new to domestics and RWD's (current nissan fwd fanboy).
I see a lot of people talking about upgrading their "gearS" to 3.73's and 4.10s. Does this reduce the final drive ratio's, such that each gear is "shorter" and acceleration is faster? What is the stock ratio on a 99-04...2.73?

And where is this modification made? In the rear differential?

Sorry about the foolish questions, but I do not know anything about RWD domestics.


Thanks
 
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Newbie questions are always welcome.
Yeah, the ring and pinion is in the rear differential. It's a complex swap, needing some specialized tools. Expect to pay around $200 for labor alone.
The results are huge though. Acceleration is greatly improved. Stock final drive ratio is, I believe, 3.27 for the SN-95. Most will tell you 4.10s are ideal. I'd agree. I have both 3.73 and 4.10 (in our 2 GTs) and I wish both had 4.10. 3.73 certainly helps, but 4.10 is perfect. With the tall overdrive gear (on manual transmissions), you can still cruise and get decent mileage.
 
Can someone please help me understand gearing, as I am totally new to domestics and RWD's (current nissan fwd fanboy).
I see a lot of people talking about upgrading their "gearS" to 3.73's and 4.10s. Does this reduce the final drive ratio's, such that each gear is "shorter" and acceleration is faster? What is the stock ratio on a 99-04...2.73?

And where is this modification made? In the rear differential?

Sorry about the foolish questions, but I do not know anything about RWD domestics.


Thanks

stock gearing ratio on 99-04 GTs is 3.27:1 that is the relationship between the rear wheels and driveshaft. so for every 1 rotation of the rear wheels, the driveshaft will spin 3.27 times. so changing your gears for, say, 4.10:1 means that for every revolution of your rear wheels, your driveshaft will rotate 4.10 times, thus increasing acceleration. also, as you may know, torque is spinning or revolving power, so more spinning of the rear wheels means more torque, although its not able to be measured. im sure someone has a long writeup or more info than me, but thats the basic concept. and the gears are located in the rear, in the differential. you may have heard it called a pumpkin. there are two gears that are replaced, the pinion gear (which transfers power from the driveshaft straight back) and the ring gear (which takes the straightline power and changes its direction, transfering it to the sides, to the rear wheels).
 
stock gearing ratio on 99-04 GTs is 3.27:1 that is the relationship between the rear wheels and driveshaft. so for every 1 rotation of the rear wheels, the driveshaft will spin 3.27 times. so changing your gears for, say, 4.10:1 means that for every revolution of your rear wheels, your driveshaft will rotate 4.10 times, thus increasing acceleration. also, as you may know, torque is spinning or revolving power, so more spinning of the rear wheels means more torque, although its not able to be measured. ...

Fixed it for ya.
 
Transmission gearing also figures in, lots of guys run the 4.10, but I run autocross tracks and that's too much gearing, it seems that Ford put a "tall" first gear in the T45s , so you run out of first gear pretty fast (IMO) with anything under 3.73. In my case it means the shift points come at exactly the wrong time, so I run 3.55 rearend gearing so that I can run out first gear for a longer period of time before I have to shift.
It depends on the application, and I would say generally speaking, an automatic would like more gearing than a stick car.