I just put 4.10's in today and My Speedometer is way off. What can I do to fix this? Also how much torque should I have picked? Because its kind of feels like I lost some. When I nail the gas down there is a little lag, like I am dragging ***. I still feels fast but not what I was expecting. Any help with this would be great..

 

You need a speedcal to correct the speedo...You can go to www.dallasmustang.com or www.brothersperformance.com
Expect to pay about 80-100 bucks

 

Speedcal or Tuner Chip/Xcal.

 

Well... I'd get a tune.. SCT, Diablo which ever you want. They can fix your speedo, and grab you some extra hp. You don't actually gain any torque with gears, it just multiplies the torque put to the ground, you should have felt a big difference with 4:10's, if you car is dragging *** you might have else wrong, or whoever put your gears in screwed something up.

 

Yea, there should be NO dragging of the ***. Your car should run like a raped ape, incorrect speedometer or not, trust me. When I got the 3.73s, it was huge, so I can only imagine what the 4.10s are like. I kinda wanna find out...

 

Problem Fixed Thanks guys

 

Don't leave us hangin'...what was the problem?

 

I took it back and got a Speedcal for it. And about the dragging ***, I don’t know what that was But its moving now.

 

Looked down and the emergency brake was on. Saved a lot of money by releasing it myself, and not getting a "hey stupid" look from the mechanic.

 

I just made my appointment today to have gears put in (Aug. 19th) I also got 4;10s but Im scared as sh//t................I still dont know if I should of got 3;73s, Ive never driven in a car with either. Whats first gear like??

 

FUN!!...It's a lot shorter but so are all the other gears...trust me, you'll like your car a lot more.

 

like he said, it's alot shorter, but you'll love it. It's the only mod you'll never get used to. Every time I drive my car I'm so happy I got the 4:10's, and the fact that my buddy has pretty much the same car, and mods, except he does't want to do gears(because he's scared!!!!) and I beat him every time we race, really makes me happy.

 

Yep I agree,thinking of doing the 4:10's.

 

Yea you guys are right! The last stang I had I always went the safe route like not getting the louder exhaust set up and I always regreted it. I wanted magnaflow but I was'nt sure about the packs but I said screw it Im getting the Packs and man I love them.........so that's it Im getting the 4.10 and not looking back!!

 

I just got my 4.10 gears in yesterday.. and they are freakin awesome :thumbsup:

btw.. you don't gain any torque from gears.. this is the best paragraph I've seen explaining it..

"Gears mulitply your engine's torque to get the car up to speed easier. Without gears to mulitply the engines torque, you will never be able to get your car to take off from a stoplight. Gears are numbered as a ratio, for example 3.27:1. This means that the drive gear (pinion gear) must rotate 3.27 times for the driven gear (ring gear) to rotate once. Let's look at some math to better illustrate this. A stock Mustang GT weighs in at about 3500lbs, its engine has a horsepower rating of 225hp and a torque rating of say 300 lb./ft of torque. Without gears your engine only making 225hp and 300lb./ft of torque will have to try to move a 3500lb mass. That simply isn't gonna happen. Now lets see what gears can do for us. Your typical Mustang has a first gear ratio of about 3.3:1 (in the 96-up cars.) So by taking it's torque of 300*3.3, you now have 990lb/ft of torque to help your car take off. That's still not enough to make for trouble free take-off's. Now take that number and use rear-end geras of say 3.27:1 to mulitply that onto the wheels you now have 3237lb/ft of torque to accelerate you. While this is a healthy number, its still less than your car weighs. Let's see what happens when we install say 4.30:1 gears to the car with 3.27's 300*3.3*4.30=4257lb/ft of torque! That's over 1000 lb/ft of torque, 1020lb/ft to be exact that will help your car off the line. This means less bogging, and a car that is extremely fun to drive. By this example, you can see the advantage of a numerically higher gear ratio."

 

I dont know if i want 3.90's or 4.10's in my cobra since I do Highway driving.

 

Same here I think i'm going to do 3.90's just for the fact theres little difference between the 3.73's and 4.10's in gas mpg. But I would like to hear some info from a expert on this matter. I really don't want to lose any mpg maybe 1.

 

I just got my gears in last week (put them in myself), and let me tell you- it's freakin' awesome. I went with the 4.10's. at 2k rpm, I'm sitting dead on 60 mph. So that should give you some idea about what rpms you will be turning on the highway ( 85 mph is a hair under 3k rpm).

 

Thats not bad for the highway. How hard was it to put in by yourself?

 

4.10s at LEAST on a cobra. Dont be a baby. Youll regret it. I promise.

 

gears are easy to install.. if you know what you're doing. Because you have to use a dial indicator to check it, and if its not right you have to add shims until it be comes right. You also need a press to remove the bearing from the pinion gear.

 

If you fear the gear then 4.10s but 4.30s will be better remember you have a DOHC and we rev higher than GTs.

 

:wav: He hit the nail on the head.