Sway Bars.....opinions??

[Tim B.]

I don't see too much about sways on here. I see RD sport has some for $425....seems like an inexpensive way to improve handling/roll. Any thoughts???
Thanks,
Tim

[IND-Distribution]

Tim, I've found that adding sways to the E9x M3 goes a long way toward improving turn in response, and eliminating body roll. One interesting thing to consider is the possibility of running a more compliant spring for better overall traction, while still maintaining good roll control to eliminate excessive geometry change.

The RD Sport sways in particular are also interesting because they not only allow you to adjust the effective spring rate of the bar at each end, but the holes are also staggered to allow for adjustment of the rate of change of the effective spring rate. Basically this means that you can have a bar that rapidly increases in stiffness, or one that increases gradually in spring rate, which gives a whole new option to tuning the handling of the car.

Look at these graphs to see what I mean:

[klammer]

some good info, thx dude

[FrenchBoy]

Interesting indeed.

Isn't sway bars install a fairly big job where a bunch of things need to be removed on the E9X M3?

I had UUC sway barbarians on my E46 and it was fairly simple to install. Does not seem simple when looking at the E9X M3 undercarriage.

[BimmerRob08]

I've heard and read that installing the front sway bars is pretty simple and I'm guessing from what I can see under mine is just the strike pan, removeale of attachments and such. But the rear required the entire rear sub-fram to come down. Which requires disconnecting th two intermediate short brake lines, disconnecting the rear suspension, etc. Big job and one would for sure need a lift.

My question is, since I'm not sure I'm ever going to go with the Dinan stage 2 or 3, how would this car handle, or would it benefit, from just installing the RD sway bars only? I don't have the competition package. Any thoughts?

Cheers,

[cole328]

My only insight is that I recently had the Dinan Stage 2 installed, and it made an enormous difference in the handling of the car. Mine is a DD, but the overall ride is much more compliant, no body roll, better turn in, etc. PLus, to boot, the minimal drop in height makes the car look sweet.

[TMR]

Are sway bars from a 335 different. I have a H&R front bar i took off of my 335. Does anyone know if this will work?

[1cleanm6]

i should have gotten them when i got my coils

how much does install on these sways run?

[jml]

Originally Posted by Tim B.

I don't see too much about sways on here. I see RD sport has some for $425....seems like an inexpensive way to improve handling/roll. Any thoughts???
Thanks,
Tim

Read this thread

http://www.m3post.com/forums/showthr...highlight=sway

My take away is that the E90 chassis does not respond well to swaybar upgrades if you are looking for better handling performance. You may experience less roll, but you'll get some understeer in exchange.

[rzm3]

1. The stiffness of a sway bar/spring is the SLOPE of a force vs. displacement (deflection) graph. If the graph is linear, the slope is constant, therefore the stiffness is CONSTANT.

2. Front sway is easy to install. Probably 1-1.5 hrs max. Rear involves lowering the sub-frame, which involves removing the exhaust, disconnecting brake lines, and perhaps even disconnecting the propeller shaft from the rear diff. That's a few hour's job.

3. The 335's bars should be compatible, but it's likely that an aftermarket sway bar for a 335 isn't a hole lot of stiffer vs. M3's. The RD bars are pretty good price and they are adjustable. You could also try M3 vert's bar which is 28mm vs 26.5mm front, 23.6mm vs 20mm rear.

[cole328]

I have an OEM 2011 'vert sway bar that I'd be willing to sell if interested. Name me a fair price

[MNm3]

So the general consensus is...?

Is there a significant enough difference to justify the expense and apparent pain in the @$$ install for the rears?

[mastek]

I don't think this chassis has a critical need for lateral roll stiffness in the rear. Upgraded springs did the trick for me in the back.
Most front engine, rear drive race cars run softer springs or no rear sway bar in the back to get the rear whees to hook up acclerating out of turns.
I do however believe this car (and mostly any front engine car) needs help with the front end.
The trick is to get it right, ....you might run a stiffer spring setup with faster valved shocks and then soften up the sway bar to dial out the understeer ... so the front bar with the most adjustabiity wins.

[Tim B.]

Yeah, and from what i hear about the rear install i think i'll stay away from that........might just do front sway.

[persian54]

On my e93 335i, the car was very flimsy

once I installed front H&R sways, the body roll was pretty much eliminated and handling significantly improved

A month or so later I installed the rear and honestly didn't feel much of a difference.

I couldn't sense any more body roll, but I could sense a bitttt of understeer.

But I do know that the front sway definitely helped.

is it similar with the m3?

would a vert m3 benefit from RD sways? or are the RD sways based more for a couple (which stock for stock has smaller sways than a vert)

[Omerta]

The car is heavy, is there a possibility of over stressing the suspension and all of the components that are associated with it by upgrading the sway bars? If not why wouldn't the M division guys do that in the first place? I understand that they set it up with some amount of under steer for safety reasons but can the stock setup take the extra stress the aftermarket bars will create.

[Dntlvet]

Stock is pretty nice IMHO

[Raptor251]

I just did the Dinan stage 3 and the new swaybar made a huge difference. The car has almost no roll yet still rides really nice on the street. Im super stoked on the dinan stuff to say the least.