How Do I Figure Out What Gears I Have?
03-14-2010, 03:58 PM
#1
2nd Gear Member
Thread Starter
Join Date: Feb 2010
Location: Illinois
Posts: 364
How Do I Figure Out What Gears I Have?
I know this question has probably asked a million times, but I keep getting lost in the sea of threads that take my focus away from my question. ADD, I guess. 
So, I took the car out on the highway today. At 80mph, I'm turnin 2300-2400r's in 5th gear.
I have 18's on all four corners on 245/40zr18's.
Another thing I just noticed is that one of the rear tires is a 225/40zr18...I was like, WTF!!!
Can you guys help me out with what gears are in there, and what kind of problems could I have with one of the one of the rear tires being a different size than the rest?
Thanks
So, I took the car out on the highway today. At 80mph, I'm turnin 2300-2400r's in 5th gear.
I have 18's on all four corners on 245/40zr18's.
Another thing I just noticed is that one of the rear tires is a 225/40zr18...I was like, WTF!!!
Can you guys help me out with what gears are in there, and what kind of problems could I have with one of the one of the rear tires being a different size than the rest?
Thanks
03-14-2010, 04:46 PM
#2
5th Gear Member
Join Date: Oct 2009
Location: Oregon
Posts: 2,645
If you could post your RPM and MPH in 4th gear, that would be helpful. I don't know the overdrive ratio of 5th gear.
Short of that, you can jack up the car, mark the drive shaft and the wheels, and then turn the wheel and count how many turns it takes to get the driveshaft to go one rotation. That would give you an estimate.
But if we have RPM, MPH, tire height, and either 5th gear ratio or that info in 4th gear (as I think 4th is 1:1) then we can tell you.
Short of that, you can jack up the car, mark the drive shaft and the wheels, and then turn the wheel and count how many turns it takes to get the driveshaft to go one rotation. That would give you an estimate.
But if we have RPM, MPH, tire height, and either 5th gear ratio or that info in 4th gear (as I think 4th is 1:1) then we can tell you.
03-14-2010, 05:13 PM
#4
2nd Gear Member
Thread Starter
Join Date: Feb 2010
Location: Illinois
Posts: 364
If you could post your RPM and MPH in 4th gear, that would be helpful. I don't know the overdrive ratio of 5th gear.
Short of that, you can jack up the car, mark the drive shaft and the wheels, and then turn the wheel and count how many turns it takes to get the driveshaft to go one rotation. That would give you an estimate.
But if we have RPM, MPH, tire height, and either 5th gear ratio or that info in 4th gear (as I think 4th is 1:1) then we can tell you.
Short of that, you can jack up the car, mark the drive shaft and the wheels, and then turn the wheel and count how many turns it takes to get the driveshaft to go one rotation. That would give you an estimate.
But if we have RPM, MPH, tire height, and either 5th gear ratio or that info in 4th gear (as I think 4th is 1:1) then we can tell you.
I'll go take'r for a spin and post the info. Thanks
03-14-2010, 09:09 PM
#8
6th Gear Member
In addition to the sticker on the pumpkin cover, there's a code on the door jam sticker that tells you what the factory gears are/were. But I'm sittiing in a hotel room and don't have my data with me so you'll need to google the gear code unless someone here has the info. It may even be in the Owners Manual.
How the heck do you manage to JUST NOW notice that one rear tire is 245 and the other is 225???
The 225 tire is turning 20 Revs per mile more than the 245. That'll wreak havoc with your limited slip.
How the heck do you manage to JUST NOW notice that one rear tire is 245 and the other is 225???
The 225 tire is turning 20 Revs per mile more than the 245. That'll wreak havoc with your limited slip.
Last edited by Nuke; 03-14-2010 at 09:14 PM.
03-14-2010, 09:10 PM
#9
4th Gear Member
Join Date: Mar 2006
Location: New Jersey
Posts: 1,609
In 5th gear w/ 4.10 gears, @ 80mph, I'm @ about 2750rpm. I'm trying to remember what I was w/ the 3.55 gears... I wana say 2500(max) @ 80mph. If your @ 2300rpm, there's a good chance there 3.31.
Also, my dif cover does have a 3.55 sticker
Also, my dif cover does have a 3.55 sticker
03-14-2010, 09:13 PM
#10
2nd Gear Member
Thread Starter
Join Date: Feb 2010
Location: Illinois
Posts: 364
In addition to the sticker on the pumpkin cover, there's a code on the door jam sticker that tells you what the factory gears are/were. But I'm sittiing in a hotel room and don't have my data with me so you'll need to google the gear code unless someone here has the info. It may even be in the Owners Manual.
How the heck do you manage to JUST NOW notice that one rear tire is 245 and the other is 225???
How the heck do you manage to JUST NOW notice that one rear tire is 245 and the other is 225???
This is the third time I've driven the car since buying it. I haven't had a chance to mess with it yet, and it's not my dd.
Last edited by dr.apex; 03-14-2010 at 09:18 PM.