3.91 gears on my v6?

[GretchenGotGrowl]

I picked up everything I needed except the drive shaft for $800. Don't remember how much the install was. That was with 3.45 gears, so you would still need to figure in the price of the 3.91 gears and installation.

I think you should really do some research beyond price. 3.91 is a lot of gear for the V6 A6. You will have to shift to third just to get up to 70 MPH and you will be running about 2200 RPMs at 70 in sixth gear.

[AmericanMuscleCars]

Originally Posted by GretchenGotGrowl

I picked up everything I needed except the drive shaft for $800. Don't remember how much the install was. That was with 3.45 gears, so you would still need to figure in the price of the 3.91 gears and installation.

I think you should really do some research beyond price. 3.91 is a lot of gear for the V6 A6. You will have to shift to third just to get up to 70 MPH and you will be running about 2200 RPMs at 70 in sixth gear.

Meaning what I'm not too familiar with the gear systems.

[E.T.]

Gears are an awesome upgrade and made a big difference on my SS. Unfortunately, it sounds like an awful lot of work to do shorter than 3.55 on the V6. For the SS, the common recommendation is 3.70 for the auto, and 3.91 for the manual. So maybe in your case, 3.70's would work a little better. As for the install, that's something I wouldn't mess with myself. They have to be set up just right, or you will have problems.

[FaytalsCamaro]

exactly what he is saying....getting gears if i remember correctly actually lowers your top speed. Youll also be using more gas at highway speeds due to being at higher rpms

[FaytalsCamaro]

and to be completely honest i dont think 3.91 gears is worth it on a auto v6. considering the swaps youll have to make. On top of everything youll need a tune

[AmericanMuscleCars]

Originally Posted by FaytalsCamaro

and to be completely honest i dont think 3.91 gears is worth it on a auto v6. considering the swaps youll have to make. On top of everything youll need a tune

Gotcha, I guess I'll just stick with getting my catch can then lol.

[IneedAZ]

Had mine done a couple weeks back. I went with 3.73's though. IF u are going to pay someone to do it figure $2k-$2300 depending options for everything. I went with BMR bushings and JRE clutches in the LSD unit.

[GretchenGotGrowl]

Originally Posted by AmericanMuscleCars

Meaning what I'm not too familiar with the gear systems.

Here is the MPH for each gear at 3800 RPM for the stock 3.27 gear on a A6 V6.

1st: 43
2nd: 76
3rd: 113
4th: 151
5th: 207
6th: 262

At 70 MPH in 6th you are running ~1800 RPM

Now with the 3.91 gear

1st: 36
2nd: 63
3rd: 95
4th: 127
5th: 173
6th: 219

At 70 MPH in 6th you are running ~2200 RPM

You gas mileage will be worse. Your first gear will be just about worthless, and you will probably have to tune it to shift sooner from 1st to 2nd to keep from hitting the rev limiter. That will put you lower in the RPMs when you hit second, below the sweet part of the power band. First fear might be fun with these gears, but it will probably make your car slower, not faster. I would not go above 3.55 on a A6 V6 unless you have something that really bumps up the low-end torque, or you got a custom torque converter to keep you in the power band. In my opinion, it isn't worth the effort until you have built the car to the power you want and you have the right torque converter. When all that's done get the right gear to match your power and output and get the greatest acceleration you can.

[SC2150]

We do the 3.55's in the open diff v6 A6 cars, or complete conversions to add the LSD diff and all components as well. Usually have it all in stock.

[AmericanMuscleCars]

Originally Posted by SC2150

We do the 3.55's in the open diff v6 A6 cars, or complete conversions to add the LSD diff and all components as well. Usually have it all in stock.

Price?

[AmericanMuscleCars]

Originally Posted by SC2150

We do the 3.55's in the open diff v6 A6 cars, or complete conversions to add the LSD diff and all components as well. Usually have it all in stock.

Originally Posted by GretchenGotGrowl

Here is the MPH for each gear at 3800 RPM for the stock 3.27 gear on a A6 V6.

1st: 43
2nd: 76
3rd: 113
4th: 151
5th: 207
6th: 262

At 70 MPH in 6th you are running ~1800 RPM

Now with the 3.91 gear

1st: 36
2nd: 63
3rd: 95
4th: 127
5th: 173
6th: 219

At 70 MPH in 6th you are running ~2200 RPM

You gas mileage will be worse. Your first gear will be just about worthless, and you will probably have to tune it to shift sooner from 1st to 2nd to keep from hitting the rev limiter. That will put you lower in the RPMs when you hit second, below the sweet part of the power band. First fear might be fun with these gears, but it will probably make your car slower, not faster. I would not go above 3.55 on a A6 V6 unless you have something that really bumps up the low-end torque, or you got a custom torque converter to keep you in the power band. In my opinion, it isn't worth the effort until you have built the car to the power you want and you have the right torque converter. When all that's done get the right gear to match your power and output and get the greatest acceleration you can.

Thanks! This is awesome info, I appreciate it! Cleared it up for me!

[Netraa]

Originally Posted by GretchenGotGrowl

Here is the MPH for each gear at 3800 RPM for the stock 3.27 gear on a A6 V6.

1st: 43
2nd: 76
3rd: 113
4th: 151
5th: 207
6th: 262

At 70 MPH in 6th you are running ~1800 RPM

Now with the 3.91 gear

1st: 36
2nd: 63
3rd: 95
4th: 127
5th: 173
6th: 219

At 70 MPH in 6th you are running ~2200 RPM

<snip>.

Well, that's one way to cut down on the drone....

[GretchenGotGrowl]

Originally Posted by Netraa

Well, that's one way to cut down on the drone....

Never thought of that.

[jbrantner24]

Originally Posted by FaytalsCamaro

exactly what he is saying....getting gears if i remember correctly actually lowers your top speed. Youll also be using more gas at highway speeds due to being at higher rpms

It will only lower your top speed if you plan on going over 200mph. Never happen in a 6. it should actually raise what you can achieve by adding more torque to the wheels to fight the drag that will limit you without a governor.