3.15 Performance Axle Ratio
Drifting
Joined: Jul 2004
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From: Celina ohio
I have an auto with the 3:15. I struggle to get the tires to break loose, with 3:15's. I would think that the 2:73's would be even worse.
If you have a choice I would get the 3:15's if possible. From what I have read you only loose about 1-2 mpg.
If you have a choice I would get the 3:15's if possible. From what I have read you only loose about 1-2 mpg.
Team Owner
Joined: Apr 2001
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From: S.W. Ohio. . . . . . NRA Life Member
Le Mans Master
Joined: Dec 2003
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From: That dam place where it rains all the time
Stupid!
Ok, I'm gonna show some stupidity now! When I got my 99 A-4 I did'nt know that it had the G-92 (3.15). I wanted 3.15 or 3.42's bad! Well then I drove a friends A-4 and thought he had some motor issues because it was weak. Then I had SpongeVette do a born on date and wala, I have 3.15's. So my point here is GET 315's or get the 2.73's with the understanding that you MUST replace them soon! 
P.S. Now I want 3.73's BAD!
P.S. Now I want 3.73's BAD!
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If you want some decent acceleration performance from the automatic, you should get the 3.15 axle. However, a number of forum members have ultimately swapped it out for 3.42's or lower gears.
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Team Owner
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Originally Posted by JDs00PewterCoupe
If you want some decent acceleration performance from the automatic, you should get the 3.15 axle. However, a number of forum members have ultimately swapped it out for 3.42's or lower gears.
I don't know what the allure with 3.15s is. "Performance" differential???? If you want performance, you'll have to go beyond 3.15s.
Having driven a 2.73 geared car, my own, before the 3.42s and an '04 3.15 geared car, there is not a dimes worth of difference between the 2.73s and the 3.15s. As evidenced by the 0.15 difference in quarter mile times described above.
You'll have to replace either one if you are looking for real performance.
Burning Brakes
Joined: Sep 2003
Posts: 1,230
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From: baton rouge la
Originally Posted by Sully C5
3.15's provide better acceleration. Here is GM's info:
Axle....0-60 MPH...1/4 Mile
2.73...4.90 Sec....13.65 Sec
3.15...4.75 Sec....13.50 Sec
Axle....0-60 MPH...1/4 Mile
2.73...4.90 Sec....13.65 Sec
3.15...4.75 Sec....13.50 Sec
it's like bolting 100hp to the car.
as mods go, this is the most defining seat of the pants performance mod
in its price range.
GM suggests the 3.15 performance ratio.
I suggest what GM doesn't deliver in a 3.42 gear as A4's go.
Burning Brakes
Joined: Sep 2003
Posts: 1,230
Likes: 0
From: baton rouge la
Originally Posted by EB20003
I don't know what the allure with 3.15s is. "Performance" differential???? If you want performance, you'll have to go beyond 3.15s.
Having driven a 2.73 geared car, my own, before the 3.42s and an '04 3.15 geared car, there is not a dimes worth of difference between the 2.73s and the 3.15s. As evidenced by the 0.15 difference in quarter mile times described above.
You'll have to replace either one if you are looking for real performance.
Having driven a 2.73 geared car, my own, before the 3.42s and an '04 3.15 geared car, there is not a dimes worth of difference between the 2.73s and the 3.15s. As evidenced by the 0.15 difference in quarter mile times described above.
You'll have to replace either one if you are looking for real performance.
Oh youre wrong about that my friend.
theres a very noticable difference between a 2.73 gear and a 3.42 gear.
Melting Slicks
Joined: Apr 2004
Posts: 3,287
Likes: 7
From: n/a SC
the performance ratio is a must. Having 3.15's (c5) or 3.07 (c4) is like the 6sp's have 3.73's. See manuals always haved to be geared lower (higher number) to make up for it being a 6sp with the pauses in shifting etcetc. So when manual guys upgrade gears they go to 3.73-4.10 and a4's 3.45-3.73.
in a c4 a 3.45 geard 6sp pretty much is like having the 2.59's in the auto.
the 3.07 auto c4 is like a 6sp having 3.73.
you can tell a good bit of difference the 99 I had before my 95 vert had 2.73 and my c4 with 3.07s gets a better track time so it makes a lot of difference.
in a c4 a 3.45 geard 6sp pretty much is like having the 2.59's in the auto.
the 3.07 auto c4 is like a 6sp having 3.73.
you can tell a good bit of difference the 99 I had before my 95 vert had 2.73 and my c4 with 3.07s gets a better track time so it makes a lot of difference.
Team Owner
Joined: Aug 2003
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Originally Posted by I X L R 8
Oh youre wrong about that my friend.
theres a very noticable difference between a 2.73 gear and a 3.42 gear.
theres a very noticable difference between a 2.73 gear and a 3.42 gear.
And I agree with you, that there is a very noticable difference between a 2.73 geared C5 and a 3.42 geared one. Actually the difference is huge. I should know by now. My car has had 3.42s in it since this past spring, upgraded from 2.73s.
Last edited by '06 Quicksilver Z06; Sep 25, 2004 at 01:33 AM.
Pro
Joined: Jun 2004
Posts: 560
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From: Prattville AL
Originally Posted by boatboatboat
I have an auto with the 3:15. I struggle to get the tires to break loose, with 3:15's. I would think that the 2:73's would be even worse.
If you have a choice I would get the 3:15's if possible. From what I have read you only loose about 1-2 mpg.
If you have a choice I would get the 3:15's if possible. From what I have read you only loose about 1-2 mpg.
Hmm.....my 3.15'ed C5 has had traction control/active handling kick in quite a few times while punching it from a roll....much less a stop!
Drifting
Joined: Oct 2000
Posts: 1,396
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From: Sacramento CA
A4 wit 3.15s
I can break my tires loose at will under 35 mph, let alone from a stop. Now I have some mods also. But I like the top end speed of the 3:15's I hit 164mph 3nights ago with the top down. The 30 mpg at 85 mph is really nice to for a long trip. You guys might beat me off the line but lets go play on the freeways sometime (oops sorry that's right no one from this forum would do that)
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
You'll have to replace either one if you are looking for real performance.
But also like you; I also have driven C5 A4s with 2.73, 3.15, and 3.42 and I could tell a difference between them almost instantly.
Give me any C5 A4 (without telling me the rear ratio), and I bet that after two dead-stop launches I could tell you the ratio (without going 75mph in 3rd gear... HE-HE
).Many here aren't into modding... and simply want what's the best the factory has to offer; and I think that was the post originators question.
Obviously the 2.73 to 3.15 is much more noticeable (15 percent change) than the 3.15 to 3.42 route (8.6 percent).
Last edited by Mike Mercury; Sep 25, 2004 at 09:18 PM.
