Dolphin

Ordered new FW Drive RX350.... my one complaint, which I hope to solve is the excessive body roll the car has. The F Sport was much nicer in this regard, but for multiple reasons, I elected NOT to order the FSport.

Is there an after market product that can be installed to reduce body roll in the RX350? TYIA

Clutchless

Having just bought a used 2010 I too am interested in this issue. I have not seen any aftermarket sway bars for the RX350. Having modified the suspensions of many cars over the years I see a few possibilities.

You could replace the body to frame rubber bushings with firmer polyurethane bushings. You need to measure the sway bars diameter, front and rear. There are a few internet providers of poly bushings, you just need the measurements. However, they usually need to be greased every couple of years, some brands have grease fittings on the mounts.

I plan to measure them and see if the Highlander sway bars are any thicker. They should fit as it is the same platform with the same track width. The Venza may also be a candidate for thicker sway bars that could fit. I plan to investigate.

You could get the Sport Suspension pieces, firmer springs, front struts and rear shocks or struts ( I have not looked underneath the rear suspension yet) and I think it has a firmer (larger) front sway bar.

When they become available as separate parts you could get the F-Sport sway bars. I think sway bars do the most to reduce body roll. Leaving the soft springs and struts/shocks alone but adding the F-Sport sway bars may preserve most of the ride and reduce body roll improving handling dynamics substantially.

I still have my 1995 Explorer 4 wheel drive (will sell in the Spring) and replaced the sway bars with very stiff aftermarket bars right after I got it in 2000. They transformed the handling, greatly reducing body roll and the ride was not much worse. It is only on single wheel bumps that you really notice stiffer sway bars. The Bilstein shocks I added later also made a big improvement while maintaining the ride quality.

I have not even seen any aftermarket stiffer shocks for this vehicle.
There are some stiffer lowering springs available from Japan that have been posted about on this forum. They are a little difficult to find.

Dolphin

Great response....

My fear was, adding sway bars would come with a stiff penalty on a plush ride like the RX.... body roll is part of the reason the ride is so plush....

However, after driving the RX FSport, I felt Lexus did a good job stiffening up the ride and radically reducing the body roll, which is what motivated me to look for alternatives. But the F has a smart system involved which prob. eliminates many of the negatives u refer to above. I am surprised there is no after market products for this, as their is a ton of RX's on the road.... my guess is, people who drive this car are not sensitive to body roll. My Land Cruiser has much less body roll, and its a good 11" higher...

Dolphin

From Daizen site.... not sure if they have anything for the 2013 model year.....

The RX-series chassis reacts very favorably to simple sway bar bushing upgrades - this easy upgrade significantly improves handling and high speed stability, and along with our other chassis bushings, transforms your RX into the sure-footed SUV that it was designed to be. Applications available soon for all RX models.

Clutchless

Energy suspension makes some that probably fit, one needs to measure the sway bar and identify the type of bracket that matches the factory bracket.
http://www.energysuspension.com/univ...-bushings.html

cossie1600

You might want to be careful with changing bushings, the NVH will go straight into your body!

Tropicsun

[QUOTE=Dolphin;7598974]Great response....

My fear was, adding sway bars would come with a stiff penalty on a plush ride like the RX.... body roll is part of the reason the ride is so plush....

I have to ask, what size wheels do you have? 18" or 19". I have never had the "Plush" ride you mentioned and am looking for the reason why. I have 19" and some suggest tha 18" have the better ride.

GrandSedanFan

iTrader: (1)

18s will have a much better ride. I have a 2010 Lux. Pkg. RX350 and every time I get a loaner RX it has 18s on it. I personally like the 19s too much along with the better steering feel to swap down.

Clutchless

I have 18s and plan to get 19s when it is time for new tires. I am actively searching for a deal on a set of used 19s.

I measured the rear sway bar at 21 mm (a 21 mm wrench fit tight over it) and the front one at about 28.5 mm. I ordered some Prothane greaseable polyurethane sway bar bushings in those sizes (also ordered a 1 1/8 inch one to cover my possible measuring goof on the front bar as none of my wrenches was large enough to fit over it) I will provide an update after they are installed and tested.

Dolphin

Clutchless.... are you suggesting to decrease body roll, changing out bushings will accomplish this? The Bushing has such little play in it, I don't understand how that would help? Can you explain?

Regardless, I really look forward to your experience with your bushing change-out.... it would be great if something this simple and low cost can create the improvement we are looking for....thx for your contributions.... keep us posted!

Clutchless

Yes. Those soft rubber bar to body bushings deflect a lot under the dynamic forces and large amount of weight pushed thru a small area. I have swapped sway bars on many cars and most aftermarket bars come with poly bushings. I have even filled trailing arm bushings holes and motor mounts holes with 3M Window Weld polyurethane to make them stiffer with little or no decrease in ride quality or NVH.

The only time I had a problem was on my 1997 Mazda MX6 when I replaced the front control arm bushings with poly bushings. That let in so much vibration that I swapped them out after a week for the stock rubber ones.

Of course this is my wife's car and the RX350 is all about cushiness, quietness and road isolation so I have to be carefull in my mods so she does not notice too much difference yet it is more engaging for me to drive and has less body roll and more direct steering. She did have an ES350 before and that was really quiet and smooth.

Dolphin

Very interesting information.... body roll reduction has always been a bit of a mystery.... specially with a top heavy vehicle, it seems physics will always win-out....

So if I understand your post...its the bushing that takes the "hit" when you the car body rolls into a turn.... the stiffer the bushing, the harder it is to compress, the less body roll ?

If this is the case, why replace the sway bar itself.... which I see offered for many cars.... I assume new sway bars offer better leverage and usually offer a larger bushing as well vs. factory sway bar / busings? In which case, on the RX, your position is.... a slight upgrade to stiffer bushings would offer a slight improvement in body roll without compromising much on the plush ride of the RX, which is part of the cars appeal.... do I have this right?

TYIA

Clutchless

Yep. A stiffer bar will offer more body roll control and more handling improvement but will make the ride a bit worse. You may not even notice. The poly bushings are an inexpensive slight upgrade. I will try to install this week.

Here is a link to a thread last Summer about lowering springs: It states Zoom Bane in Japan makes lowering springs and apparently Luis at Carson Toyota ( I think in CA ) can order them for you.

https://www.clublexus.com/forums/rx-...r-the-car.html

Dolphin

Interesting link, thx.... after this thread, and reading up on the issue, I think u have the most sensible approach.... a possible slight body roll reduction is the most we can ask for, assuming we still want a somewhat plush Lexus ride...

It's the mix of a high center of gravity, combined with a plush suspension which makes the RX prone to body roll.... fix the body roll, u loose plush ride. It's all about compromises. Hopefully your bushing upgrade will be the happy medium... if so, I will soon follow your lead once my RX comes in.

this comment from the referenced link says it all...

> after cutting the springs you can forget about a smooth ride, you'll bounce all over the road.'

This is one advantage of a car vs. a Crossover, or SUV.... cars have lower COG so can have a better mix of plush ride with less body roll. My LandCruiser has a unique suspension system...one between the frame and the wheels, and another between the frame and the body.... its works incredibly well, as the body roll is SIGNIFICANTLY less than any SUV of its size and height. An incredible engineering achievement ....

thx for sharing your insights and knowledge.....

brendan999

I've asked a body shop about solving body roll problem on my RX450 (w/ 18s) and he suggested installing dampers (Lexus original part available). Sorry for my ignorance but this is different to sway bar correct?
If so, has anyone tried installing these? (I believe this is what's standard on the F-Sport models).