changing gear ratios?
 

is it possible to add a final short gear in an a6 4.2?

My car is a 2000 a6 4.2l and i'm looking into changing the gear ratio. I heard adding a final short gear could help boost acceleration but only at the expense of higher top speed. I'm not too concerned about top speed as much as i want better initial acceleration but i'm wondering if doing it will cause any other complication as well. any help would be great.

Thanks.

You would have to change both the front and rear differentials. You would have to find another Audi that came with shorter gears AND that will fit the 4.2! Good luck on that one! I think you are stuck with what you have. If you want better acceleration, get a nitrous system.

Bob

AWWW --- BOB -- everyone knows that the easiest way to increase acceleration is to decrease the weight. I sugest the Southbeach Diet becuase it includes girl watching.

I did find a cf hood and trunk for the car so that should take care of most of my weight decrease. I just thought i'd see if it was possible to mess with the gear ratios. thanks though.

Our hoods are aluminum and already pretty light, so I'm not sure if a carbon fiber hood would give you the weight loss you are looking for.

what do you suggest for better weight reduction?

Being as our cars are luxury family sedans/wagons, there is not a lot you can do. The aftermarket world doesn't see the A6 as a modders car as much as they do a 3 series.

Get lighter wheels
Remove your seats, their extremely heavy and get some aftermarket ones.
Your carpet weights a lot more than you would think.

Your biggest problem is Audi designed this car to be a safe, quite, luxurious family cruiser. So they put in tons of sound deadening (which is heavy), thick sheet metal (heavy), leather, cloth covered everything, and thick window glass.

The car was not designed to be a nimble, quick car. Doesn't mean you can't make it lighter and quicker, but it would be better to start with a car designed more with your goals in mind. A 3/5 series, an A3/4, ....... you get the idea.

You can probably have one custom done at a place that does transmissions and rear ends. I know a few guys who had their diffs rebuilt and had much shorter gears put in. Id say your best bet with the 4.2 would be to mod the engine and nothing else. Once you start ripping stuff out to lighten it and changing panels to cf its no longer a comfortable car.

For the same price that the custom gearing stuff would cost you, you could probably get a ecu chip, tip chip, exhaust and air box and make the same difference, or save up for a bit and just go for the supercharger.

thanks for all the suggestions guys! i have been considering the PES supercharger but i don't have $7000 just yet. I did take my car to a shop that did ecu upgrades, and the guy (suprisingly) told me that it wasn't worth it in this car because you only get extra hp at a certain rpm and that it wasn't constant. How much gain could i get from an exhaust system and how much does a tip chip upgrade cost?

thanks again.

ya it will surely increase the acceleration..it should always be upgraded