I got a ´89 RS with the LO3 engine. Before I start modifying the engine to gain more horsepower I was wondering if I could get the same acceleration in just changing rear gears. My rear end is originally equipped with 2.73 gears. How low could I go? I heard that just changing to 3.08 gears is a dramatic improvement, but I wanna go more radical, since here in Austria top speed isn´t relevant and I mostly care for acceleration from 0-60 or 80. I got some minor bolt on modifications (chip, pulleys, air filter).

What´s the downfall on shorter rear gears besides needing more fuel (which, in my case, is not important since I drive just week-ends just for fun). Could there be other problems?

Thanks for any help!

 

you should see/feel a differance with a change in the rear gears

 

The main difference will be gas milage. If you don't drive very far, I wouldn't worry, but if you drive 100 miles a day, the cost might add up.

Also, wear and tear. Since the engine has to spin more, it will wear out faster, along with anything else in the driveline. Once again, if you don't drive too far, I wouldn't worry.

Also remember as the driveshaft will be spinning faster, if you have an out of balance, it will be more noticeable. A lot of people switch to aluminum driveshafts for this reason.

My GTA comes with 3.42, well below your 2.73. I think you can safely go this low without any worries.

Since I see you only drive weekends, you might even want to go down to the 3.73 range. Just remember if you don't have good tires on the rear, you'll be burning rubber a lot (might be what you want?)

My first car, a 1970 Challenger, had 4.11s. It would kick my buddie's '65 Mustang in the *** whenever we raced. But on the hiway, it would "drone" (vibrate the whole car) at even 55mph. I think the RPM's were 3500 at that speed (no overdrive).

 

Will gears effect HP/TQ if you were to get it dyno'd? If so in what way.

 

Not really because the dyno takes gearing into account.