View Single Post
      04-05-2012, 12:56 PM   #11
MA128
Second Lieutenant
MA128's Avatar
United_States
89
Rep
257
Posts

Drives: 2013 128 Coupe 6MT
Join Date: Mar 2009
Location: Boston Suburbs

iTrader: (0)

Garage List
2013 128 Coupe  [0.00]
Quote:
Originally Posted by 1speedbike View Post
The only way I could ever see a sway bar affecting ride quality in the way explained above is MAYBE if you hit a bump with only the passenger side wheels and as a result of the stiffer swaybar linking between the driver and passenger side, the driver feels the bump more than normal. But I don't see this as really being an issue, even if it works that way (which I am honestly not sure about, I'm not that well-versed in this area). It reduces roll by reducing flex, but I don't think that flex reduction really influences the transmission of road shocks from one corner to the other. You hit a road imperfection with your passenger side tire, it extends/compresses then rebounds. It doesn't transmit to the other side... (at least I don't think so. It doesn't make sense to me that it would.. correct me if I'm wrong).

The weight difference between the M3 sway and the 135i sway is negligible because they are both hollow, and even though the M3 one is indeed thicker, since it's hollow you're not really adding much mass to the bar. But even if it wasn't, it really wouldn't matter. The H&R bar is indeed solid and not hollow, and even that one has no detrimental effects to handling.

The only negative effect I can even forsee is if the front is much more stiff than the rear, this can increase understeer. For fixing this, I really like this web page:

http://www.nyracer.com/overunder.htm
As stated above, standard theory holds that a stiffer FSB usually increases understeer (because the front end will slide sooner than before). However, as a reader of many posts over several years on this fine forum, it seems that - up to a point - a stiffer FSB reduces understeer in the 1 series. This is apparently due to the overall softness of our suspensions. If you read to the bottom of the linked page, you'll find: "Stiffer front sway bars will, in many cases, decrease understeer because of reduced body roll and better camber control."
__________________
SOLD: 2013 128 Coupe / 6MT / Premium / M-Sport / Cold / Xenon / HK Audio / CDV Delete / M3 RSFB
SOLD: 2009 128 Coupe / 6MT / Premium / Sport / Cold / Xenon / HK Audio / CDV Delete / M3 Suspension
Appreciate 0