Calculating rear end gearing
Thread Starter
Pro
Joined: Mar 2002
Posts: 527
Likes: 0
From: Colchester VT
Calculating rear end gearing
Could some one tell me how to figure out if I have a 2.73 or 3.15 rear end in my 98 A4. Bought car used and doesn't have the usual sticker with options in the glove box. Thanks guys. :seeya
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Re: Calculating rear end gearing (98silverC5)
you can get under th car and look for a tag on the carrier; it would state the ratio on the tag.
Or you can drive the car at a constant 75mph with the automatic transmission in third gear and divide the rpm by 1000.
2.73 = 2730 rpm
3.15 = 3150rpm
[Modified by Mike Mercury, 11:21 PM 7/21/2002]
Or you can drive the car at a constant 75mph with the automatic transmission in third gear and divide the rpm by 1000.
2.73 = 2730 rpm
3.15 = 3150rpm
[Modified by Mike Mercury, 11:21 PM 7/21/2002]
Burning Brakes
Joined: Jun 2002
Posts: 1,202
Likes: 0
From: Clarksburg MD
Re: Calculating rear end gearing (Mike Mercury)
you can get under th car and look for a tag on the carrier; it would state the ratio on the tag.
Or you can drive the car at a constant 75mph with the automatic transmission in third gear and divide the rpm by 1000.
2.73 = 2730 rpm
3.15 = 3150rpm
[Modified by Mike Mercury, 11:21 PM 7/21/2002]
Or you can drive the car at a constant 75mph with the automatic transmission in third gear and divide the rpm by 1000.
2.73 = 2730 rpm
3.15 = 3150rpm
[Modified by Mike Mercury, 11:21 PM 7/21/2002]
Is it 75 mph or 70mph. For some reason I thought it was 70..
:confused:
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
Re: Calculating rear end gearing (98silverC5)
Food for thought on what gears to choose.
Here is my take on gears. If you plan on running the stock sized tire I would go with the following:
4.10:1 -> stock motor to H & C upgrade up to 450rwhp
3.90:1 -> stock motor to H & C upgrade up to 450rwhp with slightly larger tire or tall slick H & C nitrous combo
3.73:1 -> stock motor with H & C or stroker and nitrous with stock size tire
3.42:1 -> stock motor with H & C or stroker and nitrous with slightly smaller tire
Let me know what ya think.
Phillip :boxing
[Modified by Phil97SVT, 5:43 PM 7/24/2002]
Here is my take on gears. If you plan on running the stock sized tire I would go with the following:
4.10:1 -> stock motor to H & C upgrade up to 450rwhp
3.90:1 -> stock motor to H & C upgrade up to 450rwhp with slightly larger tire or tall slick H & C nitrous combo
3.73:1 -> stock motor with H & C or stroker and nitrous with stock size tire
3.42:1 -> stock motor with H & C or stroker and nitrous with slightly smaller tire
Let me know what ya think.
Phillip :boxing
[Modified by Phil97SVT, 5:43 PM 7/24/2002]