3.73 or 4.10 gears for new 12 bolt

ruble50 · 11-06-2009, 03:27 AM

Im about to get a new rear end and thinking about 3.73 or 4.11.
I only drive on the freeway for an extended amount of time when I come back from school for holidays which is 235 miles away. I dont commute on a daily at all mainly just street.

Are the RPMs with 4.10 really that much higher than with 3.73 on the freeway at around 70 mph?

You guys with both 3.73 and 4.10 if you could please chime in with your expriences that would be nice.

Thank you

TRANS-DAD · 11-06-2009, 09:09 AM

Hey bro. If your talkin bout the M6 camaro in your sig. then def. do tha 4.10's! 70mph is only 2000rpm's w/4.10's

01ssreda4 · 11-06-2009, 10:17 AM

4.10s for M6, 3.73s for A4

ruble50 · 11-06-2009, 12:18 PM

If 4.10 are only 2K going 70 i dont know why anyone would go with 3.73 over 4.10. i think i decided on 4.10, that is not much of a difference between stock gears as far as rpms and gas mileage.

Thanks

ssick1 · 11-06-2009, 12:23 PM

so 410s would work better on a m6 for racing

Jimmard · 11-06-2009, 12:32 PM

I have had both, and let me tell you, to me, the 3.73s are much muuuuuch more enjoyable. I had a 9" with 4.11s that was FUN at the track, but everywhere else I didn't like it. You may think a few hundred RPM arent bad, but my gas mileage went down 3-4mpg on the highway and the car was much louder and just less enjoyable to drive overall. I do mostly city driving, lots of traffic, and sometimes open freeways. I switched to a 10 bolt with 3.73s because I dont do much racing at the track at all anymore so I didnt need the strength of the 9" along with all it's headaches. With 3.73s, it feels like it doesnt pull quite as hard from a stop, but its really not THAT big of a difference. My vote is 3.73s unless you plan on taking it to the track a lot, in which case you'll benefit from the 4.11s. Also, if you're just accelerating normal, the 3.73s are more enjoyable just because you wont have to be shifting as much or as fast. You can hold a gear longer with 3.73s before you have to shift. Like I said, it may not SEEM like much, but after having both, 4.11s to 3.73s was a night and day difference for my style of driving.

ruble50 · 11-06-2009, 01:01 PM

Quote:

Originally Posted by Jimmard

I have had both, and let me tell you, to me, the 3.73s are much muuuuuch more enjoyable. I had a 9" with 4.11s that was FUN at the track, but everywhere else I didn't like it. You may think a few hundred RPM arent bad, but my gas mileage went down 3-4mpg on the highway and the car was much louder and just less enjoyable to drive overall. I do mostly city driving, lots of traffic, and sometimes open freeways. I switched to a 10 bolt with 3.73s because I dont do much racing at the track at all anymore so I didnt need the strength of the 9" along with all it's headaches. With 3.73s, it feels like it doesnt pull quite as hard from a stop, but its really not THAT big of a difference. My vote is 3.73s unless you plan on taking it to the track a lot, in which case you'll benefit from the 4.11s. Also, if you're just accelerating normal, the 3.73s are more enjoyable just because you wont have to be shifting as much or as fast. You can hold a gear longer with 3.73s before you have to shift. Like I said, it may not SEEM like much, but after having both, 4.11s to 3.73s was a night and day difference for my style of driving.

hmmm, makes me think now.
Any more opinions from people that have expriences with both set of gears?

Jimmard · 11-06-2009, 02:11 PM

Quote:

Originally Posted by ruble50

hmmm, makes me think now.
Any more opinions from people that have expriences with both set of gears?

Just remember that there are people driving around with 4.56 gears in their daily driver cars with MS4 cams and think that it's great. It all comes down to how much tolerance you have really. I found what I like with 3.73s.

Mr. Trick · 11-06-2009, 02:21 PM

I stepped up to 4.10s from 3.73s when I did a cam swap, but I never got to drive the car before it spun a bearing. Jimmard your post has me thinking of swaping back because I dont for see going to the track much, plus my 3.73s pulled good with the stock cam. Oh well I guess I will have to see what my car does when I get it running again.

Jimmard · 11-06-2009, 02:26 PM

Quote:

Originally Posted by Mr. Trick

I stepped up to 4.10s from 3.73s when I did a cam swap, but I never got to drive the car before it spun a bearing. Jimmard your post has me thinking of swaping back because I dont for see going to the track much, plus my 3.73s pulled good with the stock cam. Oh well I guess I will have to see what my car does when I get it running again.

There are downsides to 3.73s with a bigger cam as well. I wouldn't go any bigger than my cam with 3.73s. The major difference in driveability with the cam is that it surges a little more now than it did before only when driving and holding a gear below 1500ish RPMS. Now this is most likely because I am at a slightly lower RPM than I was with 4.11s, but a quick push in of the clutch, blip of the throttle, and let the clutch back out and the surging goes away. If you're split between the two, go with a 3.90 gear ratio.

MeentSS02 · 11-06-2009, 02:34 PM

I originally ordered 4.11s with my Strange 12-bolt, and am strongly considering going with 3.73s when I have it rebuilt next spring (the gear whine is horrible). Granted, I'll have to get 3.73s for a 4-series carrier, but it looks like they are available, but I don't know if that will make them inherently noisy or not (or more prone to failure since they will be a thinner ring gear).

Anyhoo...the 4.11s are nice and all, but as already stated, you can't hold each gear as long (unless you have a raised rev limiter due to a cam swap and tune), so you'll be shifting more quickly, and wheel spin becomes a rather large issue, especially on street tires. Now that it is colder out, I can punch it in 2nd gear and the tires will spin...great for showing off, but it won't get you anywhere fast (my car is bolt-ons only).

The most annoying thing to me is where it puts the car in the RPM band when cruising down the interstate...my exhaust is very loud once it reaches 1900-2000 RPMs, and gets worse from there on up. You just end up with a lot of extra noise while cruising, and that definitely makes the car less enjoyable to drive around for fun, which is really all I do.

Play with some gear ratio calculators, and you'll quickly figure out that unless you run a really tall tire or really raise the rev-limiter, you might end up limiting yourself in 4th gear to something lower than you can possibly trap in the 1/4 if you go with a big cube motor like I am planning on doing. For me and my future plans, the 3.73s make more sense all around.