Originally Posted by CJ421
Ok. Suspension/drivetrain is something you want to do right the first time. I would advise doing a lot more research before you proceed with any of this, based on the questions you're asking.
The standard sport suspension in the 3-series is decent; I would not modify it for the sake of modifying it. If your goal is to simply adjust the height of the car and make the ride firmer/more complaint, then coilovers are a good bet. Search here to see what people are using ..... KW V1 is popular, I have no experience with them however.
i used to own an e46 m3 and i want it that firm with no rebound just like that car. this car is too squishy for me...the kw v1 is gonna probably be my choice as the price is good as long as they are pretty firm.
as for diff i am set on wavetrac as i will be doing very minimal track so clutch type is too expensive for the little gain i will see vs wavetrac. and ive done some reasearch and it seems that wavetrac and quaife are about the same in the performance area even though some people claim that they feel that quaife puts down power better. but i dont see how this is really all that possible since the 2 are about the same disign and about the same size and material.
most likely ill be sticking with the 3.08 final drive as the 2.56 does seem a bit tall even though i could get 2nd gear all the way to about 85 mph =) compared to about 71 in 3.08