[chocobo15]

I searched the forums as well as google, and found 2 complete write ups. One from a guy in a different forum: hated it, and another from a member of this forum back in 2009: they seemed to like it.

Nothing else showed up in the search results, and I know this topic has been discussed a lot.

what seems to be the verdict of this swap...

...in terms of 1) handling and 2) ride comfort

I love the comfort of the stock suspension. Dips and speedbumps don't phase me at all it seems. However, the body roll on tight turns is a little nauseating.

Is this swap a good balance of the two? or is the added stiffness completely destroy the everyday ride quality of the stock suspension?

I do not plan to add coilovers, I just want to keep the stock struts and springs.

Any advise is appreciated.

Or if there were any other writeups that I missed, I would highly appreciate a linky link!

Thanks

[Phil325i]

It sounds like you're happy with your current set-up...except for roll. So why not just fit the M3 ARBs?

[cvc 22349a]

The M3 control arms/bushings won't reduce roll; they will reduce suspension and chassis deflection if you've switched to non-rft's. If you're happy with your suspension except for the roll, you're probably best off leaving it alone instead of beginning the path down the slippery slope.

[chocobo15]

thanks for the suggestions.

i switched off rft's a while back, and yes, I am pretty happy with the suspension except the body roll.

I just want to hear some other experiences as well i guess. It's one of those "should i just do it for the heck of it?" kind-of dilemmas

[CJ421]

A stiffer front sway bar is one way to reduce roll. The other way is to upgrade springs ... which would involve upgrading dampers ... this is a slippery slope as cvc said.

Look into the E93 M3 front sway bar.

[Sered]

Isn't most of the roll in the back due to the super tiny rear sway bar? If anything, shouldn't the rear subframe bushings and the rear sway bar be looked at with more suspicion?

[CJ421]

Body roll is a function of weight transfer via lateral forces, it's directly related to the spring rate (and dampers to a lesser degree). The car wouldn't roll at all if you replaced your springs with solid cylinders (ignoring the tire sidewall flex).

The sway bar is basically a spring rate band-aid; it adds to the spring rate by connecting one side of the car to the other. However using a sway bar to increase the spring rate doesn't have the same overall performance benefit as increasing the spring rate itself, since sway bars only come into play in turns (e.g. won't do anything for squat/dive).

That said the excessive body roll of the stock car is due to too-low spring rates. The ideal way to reduce the roll is to increase the spring rate, but this is a slippery slope (see my earlier post) ... sway bars are cheap and compensate from a lack of spring rate to a certain degree. The rear subframe bushings don't have anything to do with the body roll.

[demontwinz]

Originally Posted by CJ421

Body roll is a function of weight transfer via lateral forces, it's directly related to the spring rate (and dampers to a lesser degree). The car wouldn't roll at all if you replaced your springs with solid cylinders (ignoring the tire sidewall flex).

The sway bar is basically a spring rate band-aid; it adds to the spring rate by connecting one side of the car to the other. However using a sway bar to increase the spring rate doesn't have the same overall performance benefit as increasing the spring rate itself, since sway bars only come into play in turns (e.g. won't do anything for squat/dive).

That said the excessive body roll of the stock car is due to too-low spring rates. The ideal way to reduce the roll is to increase the spring rate, but this is a slippery slope (see my earlier post) ... sway bars are cheap and compensate from a lack of spring rate to a certain degree. The rear subframe bushings don't have anything to do with the body roll.

THANKS .. could you please explain the slippery slope of spring rate?
I have 335i e92 and I also dont' like the roll on turns. I was thinking of LSD + sway bar but $$$. I would like to track 5 times a year.

[CJ421]

As I noted:

Originally Posted by CJ421

The other way is to upgrade springs ... which would involve upgrading dampers ...

Can't upgrade the spring rate on these cars without changing the damper to match.
The suspension is a system; the parts work with each other. Our cars are 'balanced' in stock form; the RFT's mate well with the stock suspension and no part stands out as a weak link relative to the others. Upgrade the spring rate and the dampers become the weak link or vice versa. So it is an all or nothing affair; you can't half-ass suspension upgrades. It gets expensive quickly.

[CALWATERBOY]

Originally Posted by chocobo15

I love the comfort of the stock suspension. Dips and speedbumps don't I do not plan to add coilovers, I just want to keep the stock struts and springs.

An '09 will have a resistance to bumps that's diff than '11+ models. The sudden resistance ramp-up of progressive springs & stock dampers leads to pothole explosions.

At a minimum, before suspension arms, you should move to Koni FSD shocks. They're designed for stock springs, but what a difference!

The best first step IMHO. Then, think LSD. You'll thank yourself for that.

M3 parts after. Enhances former quite a bit.

[mave198]

Still debating on upgrading to M3 parts, living in NYC these streets just plain suck in the winter and I don't want the ride to become spine braking with my girl cursing me out about her ass hurting.

Was considering just a LSD and M3 subframe bushings and call it a day.

[Mavus]

Originally Posted by mave198

Still debating on upgrading to M3 parts, living in NYC these streets just plain suck in the winter and I don't want the ride to become spine braking with my girl cursing me out about her ass hurting.

Was considering just a LSD and M3 subframe bushings and call it a day.

Check out OEM PS and if you add LSD and subframe bushings you'll transfrom the car.

As stated above, make sure that the components in your suspension are designed for your car. It is not as simple as take this part from M3 and instal it on E9x whatever. These suspensions are very complex.

GL

[mave198]

Originally Posted by NokTurNaL 330i

Check out OEM PS and if you add LSD and subframe bushings you'll transfrom the car.

As stated above, make sure that the components in your suspension are designed for your car. It is not as simple as take this part from M3 and instal it on E9x whatever. These suspensions are very complex.

GL

Yeah I had the PS installed earlier this summer and it definitely improved handling. Don't want a track monster however, but I hate how the rear is so squirrely when I take off.

[xxwarderxx]

Originally Posted by Sered

Isn't most of the roll in the back due to the super tiny rear sway bar? If anything, shouldn't the rear subframe bushings and the rear sway bar be looked at with more suspicion?

I'm no expert by any means, but just increasing the diameter of the rear sway bar would likely change the driving dynamics and may cause oversteer.

[CALWATERBOY]

Originally Posted by xxwarderxx

I'm no expert by any means, but just increasing the diameter of the rear sway bar would likely change the driving dynamics and may cause oversteer.

Sure will. M3 rear sway needs an LSD to be effective.

Was amazed how wimpy the stock 'sport suspension' sway is.

[CALWATERBOY]

Originally Posted by mave198

Still debating on upgrading to M3 parts, living in NYC these streets just plain suck in the winter and I don't want the ride to become spine braking with my girl cursing me out about her ass hurting.

Was considering just a LSD and M3 subframe bushings and call it a day.

Ok, skip M3 parts, they won't solve the pothole problem.

FSD's will. Hey....

[chocobo15]

thanks for all the advice!