al503

First of all, I'm no expert on the topic of swaybars but I've seen some info in this forum regarding aftermarket swaybars that may not give the entire story/effect of using them.

Most people will look to swaybars to reduce body roll in turns. Stiffer swaybars will definitely help with the body roll. However, as with the majority of (if not all) aftermarket parts, there are tradeoffs.

The stiffer the swaybar, the less 'independent' the suspension becomes. An independent suspension allows each tire to react to the road surface, which is usually a good thing. When you decrease that independence, road imperfections will have a greater negative effect. More importantly, you may also lose overall lateral grip.

If you're looking for increased roll stiffness, the best way to achieve it would be stiffer springs/coilovers. You'll get increased roll stiffness without decreasing the benefits of an 'independent' suspension. The arguably proper use of aftermarket anti-roll bar is to fine tune the general under/oversteer characteristics of that particular car. However, if you just want the increased roll stiffness and don't plan on probing the limits of adhesion, changing the roll bars are actually decent means to get there.

ndk83

interesting... What if i want alot less body roll but i dont want to loose any later grip. I have to tein s. tech springs and all in all honesty the change in body roll wasnt that much. I know that this is a lexus and i know our suspension is not the best platform for performance driving, but thats not gonna stop me from trying to change that.

Whats the best move? upgrading to coils? or putting on the sway bars? Do they really decrease the levels of grip alot?

Im not tracking the car, but i do alot of very aggressive driving. We have big roads in dubai and alot of wide, curved on/off ramps that you can enter at high speeds.

RX Renesis

a side note to remember for anyone looking into swaybars... upgrade both the front and rear sway bars at the same time... also get similar sized sway bars to get neutral handling, if too big of a sway bar is fitted up front, the car will tend to understeer, if too big of a sway bar is fitted in the rear, the car will oversteer easily... choose wisely...

Kurtz

iTrader: (1)

While it's true the car will over/under steer if one of the bars is "too big" I wouldn't say one should always use the same size front and back... it depends on the way the car handles otherwise and the rest of the suspension.

My last car for example required a 1.25" bar up front and a 1.5" bar in back (which are pretty big bars) to achieve neutral handling.

Gernby

iTrader: (1)

The stock rear bar on the 2IS is tiny compared to the front bar. If we were to replace the rear bar with one that was as big as the front bar, it would have WAY too much oversteer. Personally, I would like to replace the rear bar only with an adjustable version.

ba-b4

^ I ordered the F sport sways which just shipped. Those come with front and rear sway's as a set. I hope they'll be okay. They're not adjustable I don't think but i'm assuming since they've been designed by Lexus it wont make the car "dangerous" with oversteer.

al503

I would bet that it might take a little understeer away but there is no way an OEM manufacturer is going to put out a product that will lead to an oversteer tendency.

lobuxracer

iTrader: (2)

^^I'd bet the cost of the bars you are correct.

RX Renesis

i'm sorry... i guess what i was trying to say was if u upgrade the bars, dont go too over sized on one or the either... like if the front was a 10mm and u put in a 12 mm, thats a +2 diff... and then in the back u put in a +8mm, thats probably not a good idea.

Gernby

iTrader: (1)

It's also important to note that bar stiffness goes up exponentially with diameter, and hollow bars aren't that much softer than solid ones.

KeepGoing

iTrader: (4)

Since we're here talking about sway bars. Just got done installing a set of Hotchkis. The car had a little body lean with the factory. After installing the Hotchkis, there is virtually no lean. Steering is very responsive.

Installation was real easy. Took less than an hour for both front and rear. The stock size indicated are off a 350. I don't know if the 250 are the same.

The bars are a perfect fit. The only problem I encountered is on the front bar. Apparently the hole for the vehicle height sensor is too small. I just took a drill bit and enlarged it.



Hotchkis front size 32mm, stock 27mm





Hotchkis rear size 19mm, stock 15mm

Kurtz

iTrader: (1)

Anybody know the size of the F-sport bars to compare? Also I'd read the Hotckis ones are adjustable in the rear, which setting did you use? Any change in the ride since in theory it makes your suspension slight less "independent"?

KeepGoing

iTrader: (4)

I used the soft setting which they state is about around 70% stiffer than stock. I'm not sure but I think the car rides a little stiffer. Like I can feel the bumps and groove on the road more.

Gernby

iTrader: (1)

The difference in ride that you describe is the downside of larger sway bars, so it would be nice to know if they also provide a good upside (better balance). Does your car still have massive understeer?

2slow

iTrader: (5)

I'm no expert, but one of my friends told me that if the sway bars are stiffer, it's easier to spin out?