6th Gear Sucks with 3.42s

**BaddBird** · 09-08-2007, 06:32 AM

99 TA M6 Besides the fact that I get mid to high 20s in mpg my 3.42s suck in 6th gear. 3.90s or 4.10s? What do you guys think?This car has never seen the track but I m sure it will happen sooner or later.It is a 3rd car but it is driven alot [and by driven I mean Rodded the hell out of].Anybody running 3.90s or 4.10s let me know the pros & cons

**Mr. Luos** · 09-08-2007, 06:54 AM

Don't use 6th gear as a racing gear.
For that matter, don't use 5th either. Those are overdrive gears and they aren't nearly as strong as 1 through 4.

I have 4.11's. Top speed in 4th gear is 124MPH at 6700 RPM's.
You want a gearset that matches your power range and output.
4.11's are a little too much for me on a 26" tire at sea level. Car will trap faster than 124MPH off the mountain. But most of my racing is here on the mountain, so I went with the 4.11's.

I turn 2,000 RPM's at 75MPH in 6th gear with the 4.11's.

**BaddBird** · 09-08-2007, 07:22 AM

I know you run a cammed and built 402 but what kind of mileage do you get?

**Mr. Luos** · 09-08-2007, 01:35 PM

19-20MPG on the highway it seems. Don't really pay that much attention to it...don't own that car to get good mileage.

**clg82** · 09-08-2007, 02:06 PM

Originally Posted by Mr. Luos

19-20MPG on the highway it seems. Don't really pay that much attention to it...don't own that car to get good mileage.

how good is 3.73 in an automatic?

**Mr. Luos** · 09-08-2007, 02:24 PM

That is what I would go with unless I was building a drag only car. In the A4 anyways.

**9T8W66** · 09-08-2007, 02:30 PM

Yeah like Mr Lous said 5th and 6th are overdrives.
A stock car will top out at 160mph in 5th gear, The stock engine doesn't make enough HP to push the car faster in 6th gear cause it can't overcome the air drag.
4.10's are optimal for stock or mild M6 cars
3.73's are optimal for A4's

**INMY01TA** · 09-08-2007, 04:02 PM

4:11's here. No cons.

**ImpalaSSpeed96** · 09-08-2007, 07:14 PM

What does the 3.73s in a M6 equate to? Its gotta be like a 2.9X final drive in an auto??

I was thinking at least 410s in a M6 car. Car I'm getting has 373s in it but was gonna upgrade to at least 410s if the rear ever went on me.

**Mr. Luos** · 09-08-2007, 07:36 PM

www.f-body.org/gears

Great calculator for our cars.

**Jays00ss** · 09-09-2007, 02:09 AM

I have 3.90's. When I get my 9" I'm going with 4.10's or even 4.30's. I agree with Luos, I didn't buy the car for gas milage, thats what my little daily driver '06 Kia Rio is for.