im 16 and i have a ive got a third gen formula, it has the A4 tranny and 2.73 gears, (its not an LS1 i know... sorry) but i really want some 3.73's because with the 2.73's 0-60 sucks and when im on the highway getting on it, im doing about 70 before i shift into 3rd.... i just want it to do better for street and some strip use (not have second gear go on forever)lol.
so if anyone has any advice, id appretiate it....thanks!
I had a 1990RS with the 305TBI and went from 2.73 to 3.73, made a real nice difference in performance and driveability.
You can't go wrong with either 3.42 or 3.73, I think if I had it to do over again I'd have gone with the 3.42's to have a little more top end in 3rd gear.
Highway mileage with exhaust/intake/chip/etc and gears was still in the 22-23mpg range.
I need to know what size of gear ring my 98 TA has
Ive got 4.10's with a 71/2 ring but will they fit ive got some information saying i might have a 7 1/2 or a 7 5/8 ring which is it
currently my gears are factory 2.73's
Higher gear ratio won't help much on the track or strip because the car is going to be running high revs near peak power all the time anyway. Gear ratio doesn't effect power. With a higher gear ratio, you're trading rpm for torque...which means on the street you'll get much better torque across the rpm range (but at lower mph for a given gear and rpm), which will give you better acceleration from 1000rpm to 6000rpm in any given gear...you'll just hit the rev limiter at a lower mph. Higher gear ratio improves the mechanical advantage of the engine over the tires, it's like making a lever longer...you can lift more weight with it, but to lift it the same distance as a short lever you need a longer lever and you need to move it further. Hope that helps.
I have a 1995 camaro 3.8 auto, and it came with 3.42's from the factory, at least im pretty sure. At least that's what this says: http://tech.firebirdv6.com/general.html. Just wanted to point that out, since it stated in the original post that "your A4 did not come with 3.42's)
__________________ Chad
1984 Camaro Z28 H/C SBC Sold
1996 Trans Am 5.7 M6 Sold
1995 Camaro 3.8 A4 R.I.P.
The original post should be "Your V8 A4 did not come with 3.42s I've noticed that smaller motors have more aggressive gearing from the factory. Look at those 4cylinders running 4.56s
i've got a 00 z with a 3400 stall and 3.42's (previous owner installed) but sadly enough those dang m6'ers with 4.10's from a roll are playin the pinks theme song on me......is gears an option i was thinkin bout 3.90's but from what i'm readin i'm not gonna gain much at all if any. most of my races are on the street from a roll, any suggestions for a nay or yay on the gears will be much appreciated.
-typical racecar 
I've noticed that smaller motors have more aggressive gearing from the factory. Look at those 4cylinders running 4.56s 
