TheGreenZ28

Hey guys!

Recently my father and I took the Z28 to Autofab speedshop to have them fully convert my cars gear ratio from a 2.73 to a 3.42. We were able to pick it up last night and man is it a world of difference!

First off, let me explain why we did this. We had to replace the rear because the clutches were worn in the limited-slip rear we had (the 2.73). We knew this because any time we would do a burn out, only the right tire would actually do the burn out. The left tire didn't even seem like it was supplying any power. (We know it was a limited-slip rear and not an open rear because of the option code). We got this 3.42 from a guy who had a T/A but sold it. It had about 50k miles on it, so it was practically brand new compared to the 180k miles on the 2.73 we had .

So, we got it replaced, and I notice two major things:

One, obviously higher RPMs. BUT it is nowhere near as bad as I thought it would be. I could cruise at 70 at about 2k RPMs with my 2.73, and now I can cruise at 70 at about 2.3k RPMs. It's not as bad as I thought it would be.. I doubt I will see too much difference in the amount of gas burnt (besides the fact that now I will be having a bit more fun in the car ).

Two, it is like night and day with the acceleration. The 2.73 is good for if you're really trying to squeeze as much gas mileage out of the car as possible or it's just a daily driver, but man is this 3.42 touchy in comparison. It gets me to the speed limit (and then some) very quickly compared to the 2.73. I really enjoy this car, even more-so now because this gear swap gave it a bit more pep in its step. Besides that, who the hell buys a V8 Camaro for good gas mileage anyways .

Having an A4 transmission I was a bit worried the ratio would be too short for it, but I can now say that it's perfect for the car, at least for me. It gives the car a little more get-up, and doesn't raise the RPMs too much, so it's a "best of both worlds" deal. If anyone is thinking of changing the rear end ratio of their car (or at least the 4L60E cars) I wouldn't look past putting a 3.42 in the rear.

Thanks!

Nick

Injuneer

All V8 4th Gens left the factory with a limited slip differential, so there is no question your car would have had it.

RPM increase is a simple mathematical calculation:

3.42 / 2.73 = 1.253

If your 70 MPH cruise was 2,000 RPM with the 2.73's, you should now be at 2,505 RPM at the same speed, with the 3.42's. Are you sure the gears are not 3.23? Did you count the teeth on the ring and pinon? Was the car it came out of a an M6 manual trans? They are the only V8 4th Gens that got the 3.42 gears, and only starting in 1994 model year. The 3.23:1 rear axle was supplied with the A4 transmission cars that had the "performance rear axle" option (GU5).

The change in torque at the rear wheels follows the same mathematical relationship... it should feel like you added 25% more torque at the rear wheels.

FirstYrLS1Z

was the computer corrected for the gear change ?

3.42s' too short for a A4 ?,NO,I ran 4.56s' with my A4 for 4 years including 4 trips from Ohio to Florida.

Your MPG(freeway) will surprise you. Real world MPGs' would be 2.73-25.9,3.23-24.5,3.42-24.0.

Kevin Blown 95 TA

I did the 3.42 gear from the original 2.73 and cruising about 70 mph the dash tach says ~2400, so he is pretty close there.