[fnckr]

I know and understand all of the common answers like the car handles better, accelerates and brakes quicker, etc. I also know that less mass means the suspension can move up and down quicker because it now overcomes less intertia.

So, my question, and speaking in terms of the stock sport suspension on my 2006 330i, or really, in general, all suspension components remaining equal what affect do lighter wheels have on suspension behavior?

Put differently, will the ride be bouncy (under-damped) because lighter wheels require more damping since the spring is now free to over-power the stock damping as it no longer is burdened by the extra inertia of heavy wheels?

In my mind that seems likely and must be counteracted with stiffer damping, but I'm sure I'm missing something because everyone raves about their new tires or wheel/tire combos instead of RFTs.

[SV Concepts III]

Lighter wheels, if built properly (meaning they are not weak) should not have an effect on ride quality. Your car will be more nimble and have better acceleration because of the decrease in unsprung weight.

[fnckr]

So lighter wheels wouldn't allow the spring to overpower the damping?

[GeekinE90]

For me, it changed the acoustic characteristics. After going from stock wheels to forged 18's the brakes tend to give out a higher pitch squeal when cold compared to a duller grunt when cold. After putting in the bigger/heavier discs, and calipers, it changed back to the original duller sound. Also road noise seems to have gone down and car seems slightly more comfy. However, its also feels more lazy and less nimble. Sigh.

[Orb]

Originally Posted by fnckr

I know and understand all of the common answers like the car handles better, accelerates and brakes quicker, etc. I also know that less mass means the suspension can move up and down quicker because it now overcomes less intertia.

So, my question, and speaking in terms of the stock sport suspension on my 2006 330i, or really, in general, all suspension components remaining equal what affect do lighter wheels have on suspension behavior?

Put differently, will the ride be bouncy (under-damped) because lighter wheels require more damping since the spring is now free to over-power the stock damping as it no longer is burdened by the extra inertia of heavy wheels?

In my mind that seems likely and must be counteracted with stiffer damping, but I'm sure I'm missing something because everyone raves about their new tires or wheel/tire combos instead of RFTs.

Your suspension frequency will increase slightly which means better suspension response. Your dampening is a function of the suspension frequency so you have the right idea and it may require a small increase in dampening stiffness.

Orb

[fnckr]

Originally Posted by Orb

Your suspension frequency will increase slightly which means better suspension response. Your dampening is a function of the suspension frequency so you have the right idea and it may require a small increase in dampening stiffness.

Orb

Just the person I was waiting for! I figured as much. Obviously it can't be that bad since many people have eliminated RFTs and moved to lighter wheels while keeping stock suspension and they still love the handling of their cars.

I have no interest in lowering the car from stock sport height, but just like on my motorcycle, I notice and like the adjustment ability of compression and damping. I figure a set of KW V3s are just what I would need as a spirited street driver; and perhaps some future occasional track usage. Would a rear sway be beneficial in any way?

BTW, when I say "spirited" I mean I'll drive for a few hours over nearly 250-300 miles of the same upstate NY and NJ roads I used to ride my motorcycle on, trying to recreate the experience. Obviously that is dialed down a little bit from a track pace.