WTypeRogerX

Anybody know of any articles on swaybars and why/how they are sized to cars? It seems common knowledge that they reduce body roll by transferring forces from the loaded side to the opposite side. Also that increasing the rear bar decreases understeer, but increasing the front bar increases understeer.

I'm wondering how the auto manufacturers determine what sizes to use on cars. Shouldn't a heavier car have thicker sway bars? Does f/r weight balance and drive wheels affect the size difference between f/r bars?

In considering replacing my WRX wagon stock rear sway bar (17 mm) with the stock sedan sway bar (20 mm), in an effort to reduce body roll, I've heard things such as going even bigger on the rear than the front (20 mm) will make the rear too tail-happy. It seems as though Subaru choose a smaller rear sway bar on the wagon because it is 80 pounds heavier in the rear. WRXs are 400-500 pounds heavier than the Integra, yet have smaller sway bars. All G3 Integras have 2 mm larger front sway bars than the much heavier WRX, however, the weight balance is 62/38 v. 60/40 and FWD v. AWD.

My findings seem to indicate that sway bars have a much bigger effect on body roll than springs & shocks. Is this true? The G3 GS-R seemed to roll like a pig when they softened the springs from the G2 Integra (correct me if I'm wrong, but I don't think they changed the sway bars).

Finally, do you need stiffer springs (and shocks?) if you increase the sway bar size?

uNF$@#!

in a nut shell,

depending on the thickness/size of the swaybar, it will adversely factor into how much that portion of the car "gives" prior to letting go.

a good example is arm wrestling.... lets say you arm wrestle a little peewee. you can easily win.....as you wrestle him, you slowly put his hand down to the table.

now lets say you wrestle someone 2 times stronger than you....as soon as the match starts, you can hold him in place....but then as soon as he gets pumped up, you get tired and he slams your fist into the table.

this example would imply to either a thicker bar in front , or in back.

Sway bars wont reduce "body roll" as you think it would.

instead they will probably cause you to really mess up your balance.

body roll is caused by the suspension accomodating stressful situations, and the piston gives in. to reduce this body roll, you can change the suspension to a shorter travelled shock with a higher spring rate.

this will cause your car not to induce as much body roll.

this is yet another topic that search may do wonders on

good luck with your guestimate!

95 integra

iTrader: (2)

From what I have experienced: I put a GSR rear sway on my LS...only taking it from a 12.1mm to a 14.0mm and I could tell a huge difference in body roll. After I took the GSR back off and put the LS back on it felt like the rear of my car was going to flip *** end over on me(haha...*** end over), anyway, the point being is that with the GSR rear sway(not much bigger) and a GSR front strut bar I could tell considerably less understeer and it performed much better in curves. BTW, Im going to be getting a 22mm sway soon for a gsr .

Chris N

If you are trying to reduce the ridiculous body roll of the WRX wagon/sedan, you are going to need much more than thicker sway bars. Like numnuts said above , you want to look into different shocks/springs in addition to sways. Careful with the sways, they can really change the car's tendencies to oversteer/understeer.

yoshi234

something must be wrong w/ my 26mm mugen rear sway. The dang bar didn't seem to make a diff for me

Chris N

stock springs/shocks?

yoshi234

zeal b6 w/ 10k springs F&R.
tried running on the track w/shocks set at:
2F / 2R
2/ 3
4/ 5

ZygSpeed

How's the lateral grip and strady state/transient response dynamic in cornering situations?
Any oversteer, or (upon lift throttle ...oversteer)?

yoshi234

still understeers. in the corners last weekend, I had to lift and turn the wheel more to get it to over steer. Just lifting alone didn't do anything.

Chris N

spring rates? Would lowering the rear rate, OR raising the front rate fix that problem?

ZygSpeed

I'll be running 12K F/14K R shortly, with Mugen 26 mm bars and tower bars front and rear soon.
Steve tells me the motor is in the car and the exhaust will be fitted this weekend.

Looks like you may still up the rear rate, Yoshi.

Big Phat R

Try http://www.racingarticles.com for starters.

Anti-sway bars make a car lean less by tying the right and left sides of the car together. They basically allow a car with "soft" springs to have a nice ride when running straight but at the same time prevent excessive amounts of body lean when going around corners.

Ideally - you should not count on the anti-roll bars as much as the springs when designing a suspension. Choosing spring rates carefully can allow you to have great performance even WITHOUT anti-roll bars - or reduce the need for a thicker bar. The suspension setups provided by a manufacturer are always a compromise between ride comfort and performance. The more you swing towards the performance end of the scale - the more ride comfort degrades <---big generalization.

Generally heavier cars have bigger antiroll bars because they have bigger springs too. FWD/RWD/AWD and concomitant weight distribution of the engine and drivetrain will also affect the selection.

Sway bars affect the motion of the springs only. Spring rate and weight/height of the vehicle are the main factors in suspension dynamics.

ZygSpeed

Then it looks lile you need to go JDM and put even bigger tires on the front!

yoshi234

RA-1s in 235/40R17 front & 205/40R17 rear

yshi - who was suprised to see the M&M DC5s in jpn running 235's race tyres!

ZygSpeed

How are your alignment settings?
A tad of toe-in up front (1/8" total) goes a long way to aid turn-in.