An auto with 2.73s. What kind of gains would it see. Thanks.

 

I went from 13.24@106.45, 2.05 60' with 2.73s to a 12.96@108.35, 2.03 60' with 3.73s in my 98 A4.

It was about 15* cooler between times, but it still made a huge SOTP difference, and I personally think was worth .2/10 and maybe 1mph in the traps

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1998 BG Chameleon Firebird Formula A4 - ATI P-1SC, 3.73s, cutout, BMR suspension
314 rwhp, 328 rwtq(lid, cutout, filter)
12.96@108.36, full weight and a 2.03 60'(CAI, cutout, 3.73s)
No times or dyno with the boost...

President & Webmaster, Central Ohio F-Body Association: www.cofba.org

 

Thanks!

 

Did you start with the 2.73's or the 3.23's?

 

he said 2.73's in his quote that you quoted. I would tend to agree with him.. You may lose a mph but you will ET faster. Gears are good to have.

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Psycho Cabbage
2002 Camaro Z28
(6 sp) Bone stock
Webmaster for RaceHer.com
Check out the current polls and vote!
by the prìcking of my thumb, something wicked this way comes

-Traded in- 1995 Camaro Z28 (A4 (#6 I might add!),ES tranny mount and torque arm bushing,SLP CAI,ASP 34% Underdrive,Strange 3.73's (shredded Auburn),1LE alum driveshaft & intake elbow,Yokohamas AVS Intermediates,160-stat,MAF screen removed, HPP+(for shift points only),Borla Y-pipe, Flowmaster Force-II catback, Gutted Cat, Airlift Airbag, !TB Bypass, J&M LCA's, Bosch Platinums, Moroso BlueMax Wires, Free RamAir, Meziere Electric H2O pump, MAC 3point STB, BMR Panhard, SCR SFC's
Just installed:Nu-tek Heads (mild port) and Comp Cams 1.6RR's! New track and dyno #'s to follow!
best 13.44 @103.26
0-60ft 1.96
270 RWHP/296 RWTQ
0-60MPH 4.8sec
1987 Porsche 944S (waiting on LT1 mod)

 

So, how much faster is going from 2:73 to 3:23? One tenth of a sec. for the 1/4 mile?

 

3.23's might get you a tenth quicker, but I wouldn't waste my money getting 3.23's --- "go big or go home" --- get 3.73's and be done with it. With the 4-speed auto, you've got overdrive for the highway which will help maintain your gas mileage, but you'll feel one hell of a difference. I've got 2.73's, and I'm planning on getting 3.73's next year. HTH.


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2002 Z28 - A4, 2.73's, Blk/blk, leather, T-tops, sport appearance package - just bought on June 26, 2002! - Pics

1981 Z28 - 383, TH350 trans., 3.42 posi - sold August, 2000 - Pics

1973 Camaro - Dad's & my project in the works - to be built: 355 Chevy, 11.5:1 pop-ups, "camel hump" heads (w/2.02 valves), solid cam, 4-speed.....it should be quick! - Pics

 

On my auto I had 3.73's and I wouldnt of wanted it any other way.. They really wake up the car.. Make you feel the torque and power.

As for gas mileage, I stop worring about that once I start power mods.. At that point, I am concentrating on making the most power the car can within a set guideline.. Gas mileage is secondary if I am going a bit faster.
hehe

 

First off, go to 3.73s. Excellent all-around geat for the A4. Good for acceleration and power handling, but not too steep that you'll max out soon. I've seen 150+ with 3.73s, so the top end doesn't suffer that much.

I also have a blower. As long as I keep my foot out of it(yeah, right ), I still retain good driveability and decent gas milage. Stock with 2.73s, I used to average 320 miles per tank. Now I average out to about 270 on a good day with the occasional boost run thrown in....with 3.73s.

Do 3.73s, they're an excellent gear and you'll never wanna go wider(numerically lower)

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1998 BG Chameleon Firebird Formula A4 - ATI P-1SC, 3.73s, cutout, BMR suspension
314 rwhp, 328 rwtq(lid, cutout, filter)
12.96@108.36, full weight and a 2.03 60'(CAI, cutout, 3.73s)
No times or dyno with the boost...

President & Webmaster, Central Ohio F-Body Association: www.cofba.org

[This message has been edited by Bone Maro (edited August 30, 2002).]

 

How close are you getting to the critical speed of the driveshaft with 3.73's going 150+? For all I know its not even close but it is definately something I would want to find out before I tried it. I think 3.73's will be one of my next mods.

 

The critical speed of the LS1 DS is said to be 200mph.

However, I have the 1LE racing DS on my car, said to be rated at 278mph

But, I rarely exceed 120mph, let alone drive the car

[This message has been edited by Bone Maro (edited August 30, 2002).]

 

I'm looking at this DS myself!

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=1855460344

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"GillZ28" 2002 Camaro Z/28 LS1 A4 (2.73's)
Sunset Orange Metallic
Fernco, SLP Airlid, K&N Filter, 17" SS 10 Spokes
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1995 Ford Aspire M5
!Torque & !Power, 40+MPG!!!

 

The critical speed changes with gear changes, because deeper gearss mean your DS is spinning faster at a given RPM

I have heard 155 MPH in a stock 6 speed, which would be 3.42 gears

If the MPH is right that would make the critical speeds for gears..

2.73 - 195 (which coresponds with the speed given)
3.23 - 165
3.42 - 155
3.73 - 143
4.10 - 130

of course these are approximates, give or take a MPH or two but it should give you an idea

[This message has been edited by Freak (edited August 30, 2002).]