Talk to me about sway bars

[adren77]

Here is your chance to shine and share your knowledge with everybody here about sway bars! I know very little on the subject so any information, no matter how trivial it may seem to you, will be very helpful.

[smockers83]

What if I don't want to?

They aren't too big of a mod. I'd only suggest it if you've done other suspension mods.

[Q45tech]

Front sway bars are used to create understeer, rear ones are used to reduce understeer since most modern vehicles use springs whose stiffness is roughly equal to the ratio of fore/aft weight.

Sway bars don't really reduce body sway that much since they are softer than springs and in parallel with springs.

Sways bars are less harsh than springs since they only begin to work when the body has rolled 1/2>1" due to rubber mounts needing compression.

All about balancing traction fore/aft under one exact set of conditions. If you design for warm and dry, the tires will change significantly in cool and wet and there is not easy way to adjust sway bars to reduce their action to comply with the tire and road changes.

With rear traction decreasing by 1/3 to 1/2 or worse stiff rear sway bars can create a nightmare..

Kind of like summer only tires which become worthless at 40F especially in cold rain..

But with adjustable rears you can lighten the stiffness when you swap on all season and again even more when you change to winter tires.

The Big BMW have a rain/cold tire sensing rear sway bar stiffness reduction device which also can be engaged just by turning wipers on...........what a great idea!

[Omegamerc]

Here is your chance to shine and share your knowledge with everybody here about sway bars! I know very little on the subject so any information, no matter how trivial it may seem to you, will be very helpful.

Sway bars for our G's don't do much if any from what I've gathered. the G stock sway bars are beefy enough. If you want to improve cornering and reduce chassis flex look into strut bars. They do a better job.

[telcoman]

Here is your chance to shine and share your knowledge with everybody here about sway bars! I know very little on the subject so any information, no matter how trivial it may seem to you, will be very helpful.

Here in New Jersey you have to be 21 and they check for ID

[tollboothwilley]

Here in New Jersey you have to be 21 and they check for ID

LOL

Please don't go into details about what you do on weekend Telco

[CYO44Baseball32]

Well I know they a pain in the a$$ to install on a G37. Rear one made me disconnect the mufflers and the funny thing is I put it in backwards first time so had to disconnect it again. lol The front took forever to take bottom cover off and get bolts loose ( needed braker bar). I have my G37S stock ones for sale and they appear to be about the same size as the stillen ones.

[Q45tech]

Diameter and the twist arm length are the critical parmeters.

With a 20mm diameter rear bar going 21mm is 22% stiffer

With a 6" twist arm going to a 5" is 20% stiffer

For drill: estimate that a 20% stiffer rear bar will only stiffen the total rear by 7-9% depending on springs.

AS with most things it takes a 10% change to be feelable by average driver.

The problem with stiffness vs traction ratios is many forget that when accelerating that 50%>90% of handling traction goes away [is used to accelerate the vehicle].

So steady state [speed] cornering is very different from accelerating out of the apex. Understeer going in, neutral at apex, slight oversteer coming out of curve with WOT.

You can only make the car perfect at one curve, one speed, one ambient temperature, with one amount of fuel [gasoline weight].

The question is at what fuel load empty, middle or full do you want precise tuning......................Nascar and others use driver adjustable rear sway bars to correct for the differences as fuel is used.

A weight variance of 140 pounds on rear tires is significant full to empty.