Our Rear Sway Bar Improvement

scottn2retro · 04-11-2010, 11:43 PM

Pic says it all

We decided to try going with no rear sway bar to see if we can keep both rear tires on the ground more.

Dangerlucas · 04-12-2010, 12:07 AM

And? First impressions?

theanhdy · 04-12-2010, 01:36 AM

Did you guys break the skinny rear sway while driving?

larryn · 04-12-2010, 07:30 AM

Sawzall FTW!

Scott, what did you wind up doing for dampers/springs? Last I heard, I think you were looking at some cut 5 series springs.

scottn2retro · 04-12-2010, 11:01 AM

Quote:

Originally Posted by Dangerlucas

And? First impressions?

The first session out at PIR, Ralph did a lap that was 3/4 of a second faster than the track record he had set last year. The car also seemed to be able to run faster laps through the course of a race. Normally we get a couple of real fast laps before the tires start going away (because of the weight), but he seemed to be able to run laps near his best lap time longer.

scottn2retro · 04-12-2010, 11:02 AM

Quote:

Originally Posted by theanhdy

Did you guys break the skinny rear sway while driving?

We didn't break it - we cut it using a grinder with a cutting wheel

scottn2retro · 04-12-2010, 11:06 AM

Quote:

Originally Posted by larryn

Sawzall FTW!

Scott, what did you wind up doing for dampers/springs? Last I heard, I think you were looking at some cut 5 series springs.

Right now, we have the KW Variant 2 kit on all 4 corners, but on the front, we've custom cut the length of the spring (increasing the rate) and we have the OEM spring perches that we knocked off the OEM struts and have them sitting on top of the KW front struts.

We've done some independent spring and shock dyno testing and hopefully soon, I'll be getting some custom stuff made by the guys at Eibach (they are at the 91 and 15 freeway intersection out here in SoCal).

vitig · 04-12-2010, 01:10 PM

I don´t understand all. What do you like more, the driving whiout bar or whit bar?

I have mount the 20mm rear bar and i think more time about is better than 12mm or bad.If you say me that whitout the bar the car is better, i mount the old 12mm bar and take out the 20mm bar to the window of my house.Thanks.

scottn2retro · 04-12-2010, 02:07 PM

Quote:

Originally Posted by vitig

I don´t understand all. What do you like more, the driving whiout bar or whit bar?

I have mount the 20mm rear bar and i think more time about is better than 12mm or bad.If you say me that whitout the bar the car is better, i mount the old 12mm bar and take out the 20mm bar to the window of my house.Thanks.

So far (based on just one event), we think we like it better without. But we'll know more with 2 more events coming by the middle of May.

zsapphire7 · 04-12-2010, 02:35 PM

interesting... i was thinking about running without a front sway... The rear u kinda want cuz the rear motion ratio is horrible so getting higher spring rates in is unreasonable and theres still the issue of too much understeer.

arrutled · 04-12-2010, 03:06 PM

Quote:

Originally Posted by zsapphire7

interesting... i was thinking about running without a front sway... The rear u kinda want cuz the rear motion ratio is horrible so getting higher spring rates in is unreasonable and theres still the issue of too much understeer.

pretty sure thats a terrible Idea. you would need like 10 degrees of camber to combat that body roll.

mshahidz · 04-16-2010, 02:45 PM

Quote:

Originally Posted by TrackRat

Roll is controlled by spring rate so if you remove the swaybars you need to increase the spring rates to control body roll. The trade-off is stiffer springs only work well on smooth tracks. So ultimately you use stiffer springs with light swaybars or soft springs with stiffer swaybars. There's no magic here as this is all known.

By removing the rear swaybar you reduce binding of the rear suspension and lift of the inside wheel which is especially important without an LSD, thus you help the tires stick better to put power down exiting the turn. There are various means to tune the suspension but a lot depends on the smoothness of the track surface. No matter what approach you take it's never perfect. You just try to use the best set-up for the application and track.

So in that case, would you recommend removing the rear sway for a car on V3's which will see aggressive street driving with a few track days a season?

bradford · 04-16-2010, 04:51 PM

Quote:

Originally Posted by mohammadz

So in that case, would you recommend removing the rear sway for a car on V3's which will see aggressive street driving with a few track days a season?

Definitely not. V3s are sprung very softly. If anything, you want to upgrade to the M3 bars.

larryn · 04-16-2010, 06:51 PM

I wouldn't consider removing the sway bar on my car, unless I had an LSD installed, and have a pretty beefy suspension upgrade.

04-11-2010, 11:43 PM	#1
scottn2retro Major 496 Rep 1,342 Posts Drives: Join Date: Oct 2007 Location: Huntington Beach, Ca. iTrader: (2)	Our Rear Sway Bar Improvement Pic says it all We decided to try going with no rear sway bar to see if we can keep both rear tires on the ground more. __________________ 2015 M4 BMW Club Racer SCTS Racing https://www.facebook.com/sctsraceteam/
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04-12-2010, 12:07 AM	#2
Dangerlucas Captain 30 Rep 621 Posts Drives: BMW 135i Join Date: Jul 2008 Location: Bay Area, CA iTrader: (2) Garage List 2008 135i [5.50]	And? First impressions? __________________ Legal Disclaimer: Anything I or anyone else says about my vehicle on this website(1addicts.com or any affiliated or nonaffiliated sites), pertaining to modifications, is only to gain acceptance from my/our peers, and does not actually represent anything actually existing on my car, and thus, cannot be held against me in any issues, i.e. warranty claims, that may arise.
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04-12-2010, 01:36 AM	#3
theanhdy Major 93 Rep 1,083 Posts Drives: 135i Join Date: Nov 2007 Location: SOCAL SFV iTrader: (7)	Did you guys break the skinny rear sway while driving?
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04-12-2010, 07:30 AM	#4
larryn Lieutenant General 2146 Rep 10,176 Posts Drives: '97 332ti, '21 X5 45e, '16 GT4 Join Date: May 2005 Location: Seattle iTrader: (2)	Sawzall FTW! Scott, what did you wind up doing for dampers/springs? Last I heard, I think you were looking at some cut 5 series springs.
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04-12-2010, 01:10 PM	#8
vitig Private First Class 4 Rep 189 Posts Drives: 135i Join Date: Jun 2009 Location: España iTrader: (0)	I don´t understand all. What do you like more, the driving whiout bar or whit bar? I have mount the 20mm rear bar and i think more time about is better than 12mm or bad.If you say me that whitout the bar the car is better, i mount the old 12mm bar and take out the 20mm bar to the window of my house.Thanks. __________________ 135ijb3, h & r filter, SSK, CDV,clutch stop, klracing fmic,seccond catted ,225-255 michelin ps3, E93F-E92R swaybars.M3 parts front.M3 tension rear.Plates mod(F-2,0º R-1,5º).Bilstein + stock springs.Ps rotors.Subframe bushings.Weichers fstruut.Finally mods sdiff and raceland dp.
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04-12-2010, 02:35 PM	#10
zsapphire7 Colonel 104 Rep 2,368 Posts Drives: 08 e92 M3 Join Date: Oct 2007 Location: SF Bay Area iTrader: (21)	interesting... i was thinking about running without a front sway... The rear u kinda want cuz the rear motion ratio is horrible so getting higher spring rates in is unreasonable and theres still the issue of too much understeer.
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04-16-2010, 06:51 PM	#14
larryn Lieutenant General 2146 Rep 10,176 Posts Drives: '97 332ti, '21 X5 45e, '16 GT4 Join Date: May 2005 Location: Seattle iTrader: (2)	I wouldn't consider removing the sway bar on my car, unless I had an LSD installed, and have a pretty beefy suspension upgrade.
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