M-Ten

iTrader: (2)

I will be putting a 9" in within the next couple of weeks and I wanted to know gear ratio I should go with.. The car is driven everyday on the street/highway and will probably see SOME time at the 1/4 mile strip. Later this year I plan on procharging it as well and having a good 500-600HP... I was wondering what would be the best ratio to pick...

3.50?
3.70?
3.89?

Any info will help.. Thanks

BREWS02WS6

iTrader: (6)

I dont have a 9", but I do have 4:10s and would never look back.

Maybe a little higher gear (lower number) for the highway, depending on where you want the RPMs. Im sure others will chime in w/ more specifics on cruising RPMs at certain speeds w/ other gears. FWIW my RPMs are about 2grand at 70mph.

Also, they might want to know what you're trying to get out of the car. Hope that helps.

ICRAZY6

iTrader: (68)

Are you an A4 or M6?

M-Ten

iTrader: (2)

Oh sorry, an M6. And I don't want to go to 4.11's because I think with the power I'm planning on being at, they won't work well. I was thinking about some 3.70's myself, but wanted to get some other opinions before I do it.. The 9" is a big investment....

BLK85

iTrader: (1)

I have 4.11s in my 12 bolt and they do fine on the highway, 2100 at 70mph. But since thats not a choice I would go with the 3.70s.

Billiumss

iTrader: (11)

I had a 3.89 US Gear in my 9" last year, great on the street, just right in my opinion. Felt like it gained 20 RWHP.

I just got my 9" rebuilt with Motive 3.89 gears since the guy that built it before, didn't know what the hell he was doing plus didn't give me the gear I wanted, it made a ton of gear noise.

Installing the "new" setup today!

Jawsgear

iTrader: (2)

All depends on where you want to be rpm wise. Check out our RPM calculator to find out which ratio works best for you.

Jeff

M-Ten

iTrader: (2)

How was the power range on the highway? I don't want to lose too much up top.. Also what power level are you at?

_JB_

iTrader: (33)

I'm going to say 3.50s

Billiumss

iTrader: (11)

6th gear was much more usable when on the highway with the 3.89, less down shifting when you need to pass someone.

I drove a few 4.11 gear cars and first gear is a joke on the street, you just spin when you stab it. Kinda fun but useless if you really need to get going. I almost went with a 3.70 gear but I am VERY happy with the 3.89 gear ratio.

I'm making 412 RWHP N/A

linegtdt52

iTrader: (12)

I honestly would go 3.70 because hell you are already gonna be making torque with the supercharger earlier and there is no need to blow tires off just blipping the throttle. Plus It'll put you around 1850 with a 16" tire on the hwy in 6th at ~73 mph

M-Ten

iTrader: (2)

Yeah Bob @ EPP recommended 3.70's, I just wanted to get a few more opinions on it before I make a decision...