sway bar(s) for prius

[font=Comic Sans MS:992f2b6fd0]Hi Tiffany. I'd realy like you to reconsider your decision on tires before you modify the suspension. The OEM Integtity tires just do not handle.

I put on Goodyear ComforTred tires and the difference is amazing.[/font:992f2b6fd0]

 

Tiffany you are worrying me - $70 sway bars? What planet, better yet, decade, are you living in?

OK seriously, I wish someone made a good set of sway bars for our cars, I would buy them too. I posted a thread long ago about the poor handling of our cars.

The biggest improvement, for me, came in replacing the stock wheel/tire package with a set of new take-offs from a Scion. They are 17" wheels with a low profile, wider tires that made a big improvement.

I am also awaiting one of the frame stiffener plates, for $150 I thought that was actually pretty damn cheap. I have seen a similar designed part on one of the Japanese sites for almost $300 and it did not look as solid or nice.

But, you need to be prepared to spend some money if you want to make real changes to your car; nothing is cheap.

 

There is someone who is selling a reinforced brace to replace the existing one that makes the chassis stiffer.

 

<div class='quotetop'>QUOTE(cairo94507\";p=\"103081)</div>

Most aftermarket sway bars I see are around $250 to $375 for front AND rear, or $125-$187 each. $70 isn't that far from $125, I could believe someone sells them that cheap. All they are is a round steel bar bent into a shape plus some mounting brackets and if you're lucky, some fancy powder coating and colored urethane bushings.

 

Well just off the top of head I am going to guess that the difference from $70 to $125 is about 80% give or take. So I think that is a considerable difference IMO.

 

I'm very surprised that no one has brought up the least expensive way to get the car to roll less while turning-in, and that is to replace the stock sway bar bushings (doughnuts, rubbers, whatever you want to call them) with polyurethane bushings. This will commonly get rid of most (if not all) of the mush you are experiencing.

I have used these type of bushings since 1980 to upgrade the suspension on my cars and it is the single cheapest way to get better handling. (The only other thing you can do that is "inexpensive" is to select better tires when its time to upgrade them anyway; however, this approach has never actually been inexpensive for me since I have always opted for significantly more expensive tires to get the best performance and safety that I could).

Poly bushings are a type of plastic that is not rock hard, yet not soft and mushy like the stock rubber bushings. They allow you to get more "action" from the existing sway bar because the poly bushings don't get all squished up every time you turn. The effect is to get less body roll and sharper feeling steering.

These parts are far more inexpensive than a tire or sway bar change (somewhere around $50 for the whole car, if you have front and rear sway bars, or else it's half that).

I did start calling suspension component manufacturers last year to see if I could get an upgraded sway bar kit for my Prius, but unfortunately none of them saw the Prius coming so they put zero development effort into producing a product for us. After months of frustration I decided to let it go for now, but seeing this post reminded me that we can just upgrade the bushing to polyurethane and get nice improvement for very little cash.

Here is a link to a manufacturer that has been around a few years so you can see the kits. These guys don't sell direct so you have to get them from your local auto parts or speed shop. If you are handy enough to work on a car, this is a very simple upgrade (most of the time anyone who can handle a wrench or ratchet can do it, I just haven't looked under my Prius to take a peek yet).

If there are any experienced racers out there, please post your results (and keep in mind that we are looking for a streetable effect for average users, we don't expect our Prius to handle like a C-6 Corvette, OK so maybe some of us do what that, but we are reasonable enough not to expect it.)

http://www.energysuspension.com/pages/swaybb.html

 

I think this is what you are looking for:

http://newtoyotaparts.com/model/struct.php..._id=43&cat_id=7

Bob

 

Gen2,

if you end up doing your simple modification, could you please post your solution for us (parts and methods)?

Thanks!!!

 

No problem, however I am so nusy nowadays that it will be months before I can think about it. It is so simole an upgrade that you really do it yourself if you are handy around a car. Just ask any mechanic friends.

 

Gen2, what's your experience with noise and these polyurethane bushings? I have heard others express some noise from some of them. I have not really looked at the Prius but my RX7 bushing required a press to remove them so it might not be a simple replacement. But if there's lots of compliance there it should help all the sway we get on corners and maybe even impove the tracking accuracy and make the car wander less easily. I'm still searching for the magic bullet there....which probably doesn't exist!

The other obvious things like tires and sway bars have been mentioned but the overall stiffness of the entire structure is another. Several testers have mentioned that the Prius is somewhat wimpy and not very stif at all. That's where some of the stiffeners found at the Carson Toyota sight from Japan might help. Anyone have any experience with them???

I have tried the tires, Michelin Hydroedge. While the traction cornering is improved, they are not the answer to all the sway in my opinion. I've tried various pressures up to 42/40. I'm back at 35/33 because I'm managed to loosen everthing in my dash from harshness of the higher pressures. I now have a severe dash rattle between the main dash section and the display in addition to all the sqeaks. The dealer has tried to fix it with some black flexible putty that I can see through the display....a big mess now and very unprofessional. And the poorly constructed home link auto dimming mirror buzzed a lot more with the stiffer tire pressures too. There's no fix for that according to the dealer except what I do now...grab the mirror when it start resonating. I have to remind myself next time to never ever buy something the first year it comes out. As an engineer I know there are always many tweaks to the process, fit, etc that are occur during the first production runs.

 

Fred:

I also don't understand this desire for a bone jarring rock hard ride to gain at most 1-3 MPG. I think most of the folks who do this will turn their Prius into rattletraps.

The Prius rides stiff enough, I might be in the minority but I would love to soften the ride.

Oh, I have just found out that even a simple mod like moving the front chin spoilers - in front of the front tires - from their stock location to the front of the car makes a BIG difference. I'm now shopping for a good front spoiler.

Jay

 

<div class='quotetop'>QUOTE(jayman\";p=\"103720)</div>

Yeah the ride is sort of hard to figur out really. It doesn't really soak up large bumps (damping maybe) very well and is harsh in that respect. But it seems soft traveling down the freeway and it can pitch from left to right like a very soft suspension or one with a lot of play in it. And it's extremely easy to gets lots of sway out of it or tilt so you're left with this lack of feel for the road that above average cars give you. The above average cars can be amazing in this road feel and I've had a few of those.

I have tried the spoiler move and have even made an almost full length spoiler of my own which I'm experimenting with some. I wish I had some feedback from the Japanese market about how the various frt air dams affect the handling or any other of the suspension parts for that matter. I felt the moved frt dams were not the magic bullet for me and maybe nothing will be at this point. If something doesn't really jump out and make the car wander less then I'm afraid for me it's probably the placebo effect working, lol. These minor improvement are so hard to determine without some measureable test to determine if they're real. I could easily find myself with another $2K into the car and the same below average road feedback and handling.

Sometimes I wish Toyota or even TRD was more helpful but I guess you can't expect Toyota to admit the car's faults. But I've got a collection of quotes from about 12 sources....magazines and professional testers that confirm my feelings about the car's vague/imprecise sort of handling so I'm sure even Toyota knows we're right. Still it ticks me off to have the SoCal Toyota Engineer/Rep act surprised when some in our club here said that there car's have a tendency to wander around on the freeways when asking what Toyota knew about it....his denial was almost funny if it were not such an insult. So we're all stick guessing as to what might improve it and spending money and time.

 

Fred:

Right mine isn't "cured" by a long shot. Much better but not ideal.

When I have ready access to what many would consider a "land barge" - a 2003 Buick LeSabre Celebration Edition that belongs to my parents - the difference in *stability* is remarkable.

When folks ask us about this issue, I think what we're really talking about is overall stability and tracking, especially on grooved pavement and/or crosswind.

Driving my parent's LeSabre is a very relaxing and comfortable feeling. It really doesn't seem to care about what the wind is doing or how grooved the road is. A 3-6 hour drive in that baby you step out fairly relaxed and ready to eat.

I recently had a chance to drive a 2003 Lincoln Town Car, as friends of my parents needed a ride to the airport. On the way back, I headed out to the Perimeter and took the Long Way back to their condo, so I had a chance to drive that huge car in gusty winds and bumpy frost-heaved Trans Canada road conditions.

That huge thing is also a breeze to drive, and it seems fairly immune to winds or transport trucks passing. I sure got to like that airbag suspension too, didn't feel the bumps at all. So no squeaks or rattles in that car either. Horrible seats though, no support at all.

I don't want or need a car that will slice through mountain curves or go squealing around a race track. I want something that is average and competent, and the Prius usually is all that, especially in city commuting with the speeds under 80 km/h.

On the Trans Canada at 100 km/h it's a different beast.

A local hot rod shop is willing to make a custom spoiler for $385 painted or $300 black. I may try this next, though I know I'd have to take it off for winter.

Jay

 

Jayman...I tried a piece of about 3 inch baseboard material. It's pretty wimpy but it's a bit better when curved around the bumper and very cheap to try. But I'm sure it blows back a lot at 65 mph. I put a curved band of 1/2" steel in back of it today to improve it's shape and strength some, so we'll see how that goes. I think I should have brought it around to the outside edges of the bumper but I stopped short by about a foot on both sides. But since it's so low, hitting a parking curb with it is no big deal. I'm going to make another one soon anyway that's a bit stiffer.

You and have talking about this thing called "tracking" before. A car does not have to be heavy to track. My wife's RSX at 2700 lbs tracks very well and my 2700+ lb 1993 RX7 was about the best tracking car I've ever driven...it tracked like it was "on rails" as they used to say years ago. The Prius meanders rather than tracks. It responds to inputs too easily...slight turn of the wheel, gusts of side wind, passing trucks/vans, disturbances in the road like road grooves or cracks. It's got a mind of it's own and it doesn't communicate until it's too late, lol.

 

<div class='quotetop'>QUOTE(FredWB\";p=\"103717)</div>

FredWB,

I have not had any noticeable increase in noise or hardness when I used poly bushings in the past (including one Toyota, a Corolla SR5), however there are scattered reports over the years of a few owners complaining that they can tell that certain, but not all road bumps get transmitted through to the passengers a bit more harshly.

My suspicion is that you are more sensitive to it, or that your Prius had a few loose components in it to begin with. My tire pressure has never been below 42/40 and has sometimes been higher over the past year in an attempt to discover by trial and error what my sweet spot is. There are no rattles in the car whatsoever and no one that rides in it notices that I have raised the tire pressure. Its all a matter of perspective I suppose.

As for the use of any kind of stiffeners in the car, this is no different from going to firmer bushings, stiffer shocks, etc. There is an improvement because the vehicle is stiffer, or more resistant to unwanted motion. The trade-off for this resistance is a possible increase in the amount of harshness that is noticeable. I say that this is possible because everyone experiences the ride differently. If you were to measure these modifications scientifically, you would find that there is no doubt that there is more harshness getting through, its just a matter of individual taste if it bothers you or if its worth it.

The original vehicle manufacturer designs each car with an NVH envelope in mind (Noise Vibration Harshness). To improve ride, handling, response, sway, etc. involves compromises in NVH. IMO Toyota must have chosen to have what we perceive to be a slightly flexible car in order to compromise something in the NVH envelope. Somehow they got the message that the car was a bit too flexible for some of us and they improved the car's stiffness recently. (See other posts for the few details that were released.) Since this was essentially a mid-production run change, we cannot tell which ones of us have the upgraded chassis and who doesn't. We don't even know if this change made it to all markets. I mention this for those who think that they don't like the handling but are resistant to stiffening their vehicle, if Toyota thought it was enough of a problem to make a design change and publicly tell us about it then the car must be a bit too flexible (IMHO).

If your car is rattle prone, I would leave it alone since any more changes could aggravate the situation. If I were you, I would complain to Toyota because we are not getting a deluge of complaints that the cars become rattle-traps just by raising the tire pressure a bit; this leads me to believe that yours just has a few loose components in the dash. I would also complain to Toyota that the dash repair was not professionally done and that you see no way that Toyota would condone sub-standard warranty work. That might get their attention.

As for tires, although they have an extraordinarily large contribution to ride and handling, they has less of an impact on sway (I'm not saying that there is no impact, just that its not as great as other parameters). They do have a large contribution to the initial turn-in which is commonly thought of as part of sway. The Michelin HydroEdge, while being an excellent tire, is hardly a high performance tire, but there is another issue to consider, LRR.

The big issue in dealing with tires is that the Prius is something of a special purpose vehicle (like a sports car is something of a special purpose vehicle) . Its great claim to fame is its fuel economy (I'm not agreeing or denying that, I'm just stating the public perception). When you talk about tires and a car that has a reputation for fuel economy then I usually bring up rolling resistance (I have brought this up on other posts if you would like more details).

The lower the tire's rolling resistance, the better the fuel economy (easier to roll the tires). Increasing the tire pressure also improves rolling resistance (we get to double dip on raising tire pressure, MPG and handling).

The Prius ships with special LRR (Low Rolling Resistance) tires that are designed to improve fuel economy (AKA Green Tires, Fuel Saver Tires). In case you think that the difference is negligible, Michelin claims a 5% increase in fuel savings with their Energy tire vs. a non-LRR tire. (Michelin invented LRR tires in 1992 when they released the Energy series of tires.) Every car manufacturer that sells cars in the US tends to ship them with LRR ties from the factory. That many of these tires are not available on the after-market (or that they handle very poorly) is just something they don't care about.

So now we have an interesting situation when talking about handling in a high fuel economy car when we want to change the tires. Do we select LRR tires, do we go for some ultra-high performance tires, or do we stick with a nice middle of the road tire like the Hydroedge?

In the past I have always opted for the highest performance tires I could get on the car (for handling and safety reasons). There was always a compromise, of course, but I did try for the best. My research in LRR ties leads me to believe that there is not enough demand for LRR tires in the US from car owners because tire shops have never heard of LRR tires (or they downplay its importance).

This leads to a situation where its nearly impossible to find the proper replacement tires for the average consumer. This issue is gaining a lot of ground with the release of the Green Seal report on LRR tires, US Senator Charles E. Schumer (NY) published his own research and the great State of California has passed legislation that requires after market tire manufacturers to provide LRR information starting in 2008 (thus forcing them to actually provide more LRR tire choices to us, see the report for details: California Senate Bill 1170 (Sher, Chapter 912, Statutes of 2001), the California Energy Commission (Energy Commission)).

In the US, tire shops will look at you like you're nuts of ask and insist upon getting an LRR tire. They do carry the Michelin Energy MXV4 Plus (an excellent tire, though not ultra-high performance), Bridgestone B381 Ecopia (a wimpy tire that the Hondas got saddled with) and the Goodyear Integrity which we all know and love, no wait a minute, we can't stand that tire. Other than the Michelin Energy, this is not much of a choice.

In Europe, the LRR situation is better with Nokia (yes, that Nokia) offering the superb Nokian Hakkapeliitta NRT2 (no, I did not make that name up, really), Continental Eco-Contact 3, Continental ContiTouring Contact CH95, Michelin Energy MXV4 Plus and Arctic AlpineXL. In Japan they get the Yokohama ES 100, Bridgestone B381 Ecopia, Bridgestone Potenza RE92 (Prius Gen 1 has these) and the Sumitomo HTR200. The Toyo Proxis TPT was claimed to be an LRR tire by the manufacturer but I have a sneaking suspicion that whomever I spoke to did not know what I was asking about, but I'll list them in case I am mistaken.

Of all these tires the only one that a manufacturer told me (via phone, I actually called the HQ of every tire company I could think of last year) could be considered a high performance LRR tire was the Yokohama ES100. I don't know about the Nokian since I could not get a phone number for them, but they have an excellent reputation. Yokohama does make some excellent ultra high performance tire (I have used them to great success in my sports cars), but I have no experience with the ES100, nor was the person I spoke to able to get me the RRC (rolling resistance coefficient -how easy does it roll) number for the ES100 (I called US HQ but the engineers were somewhere in Japan).

Michelin was something of a pain. They pioneered the LRR or "Green" tire, but I spent months with them trying to get information about their LRR tires. They called me back at home numerous times, but never with any actual information. All they would "officially" state was that all their tires were designed with LRR in mind, and it would be improved whenever it could be. Unofficially I got the feeling from all the phone calls that their Energy series still was noticeably better than the rest. But then, I can't prove that.

So where does that put us until 2008? (I am sure that whatever information we gain from the the California LRR legislation, we will share it with everyone at that time.) We are still on our own as far as I can tell. Personally, I will be looking at the Yokohama ES100, Nokian Hakkapeliitta NRT2, Michelin MXV4 Energy Plus and Hydroedge and Continental Eco-Contact3 to see if I can find something that significantly improves the handling but doesn't lose too much or no fuel economy. It shall be interesting.

The last thing that came to mind is that low profile tires have shorter sidewalls and therefore tend to squiggle around less. By switching to lower profile tires than the Prius came with, we could potentially get rid of a bit of sway that is induced by the flexing of the tire. This may or may not be a noticeable effect, so it might not be worth it. Done properly the steering response should improve and if the highway instability that some Prius owners have complained about is due to the tires, this could get rid of all or most of it. Keep in mind the NVH effect, if we make the car stiffer (stiffer tires) then the ride could get noticeably harsher. In order to do a proper upgrade to significantly lower sidewalls, you would have to increase the diameter of the wheels so please factor that not so insignificant cost into the equation.

Looking at my chart for the Yokohama ES100, I see that it is available in a 205/45ZR17 size that has almost exactly the same number of revolutions per mile as the stock Goodyear Integrity. Oh yeah I can see myself in the tire shop now, checking to see if we can get a 17 inch wheel in there.

 

Great post Gen2. From what I could tell there wasn't any significant difference in gas mileage with the hydrodege. I've driven each one for about 8000 miles with virtually identical results. I even tried the wider 195HR60X 15 for about a month. Those affected the around town results somewhat (1-2 mpg but guessing here) and the highway mileage was about the same.

My comment about the bushings was from what some RX7 owners and others were experiencing.

I think that the bushings and stiffeners may indeed lead to a stiffer feel to the car where the compliance will be more controlled and more isolated to the shock/springs where it belongs. Maybe then the shocks and springs will be all wrong, I don't know.

Has anyone heard Toyota admit to this publically, that the new cars are stiffer. I've looked for documented proof and found none so far. So is it just wishful thinking. I've heard new owners still complain about the handling so I'm very doubtfull anything has been fixed.

As far as the squeaks go, tolerances, tolerances, tolerances is all I can say. Some cars will be at one end, some in the middle and some at the other end. It's part of tweaking the design and I'm sure and I got one that's on the loose end. It sqeaked from the beginning. I do think that the dealer caused my loud rattle when they did the speedo/gas tank fix (not really a fix since I still get 8-8.5 gal to a fill up) so can't blame Toyota for that. As far as getting Toyota involved, my track record with that is pretty bad. They were just not very helpful or concerned when I talked to them about the handling issues.

 

You are welcome FredWB.

Glad to hear that there was not much MPG difference with teh Hydroedge. Michelin did tell me that they continuously improve rolling resistance with each new tire series so it could be that that Hydroedge is as good as the Integrity in MOG (it certainly is better in all other aspects).

The bit about the Prius being stiffer was from a Toyota press release, I do try to be careful about what I post, but unfortunaty I did not bookmark the release. doing a very quick Google that addresses all the issues I read so it will gove you an idea what I was talking about (read about).

http://www.carpages.co.uk/toyota/toyota-pr...on&echo=9900438

As far as the squeaks/rattles go. I agree that there is plenty of room in the declared tolerances for any given car, but you have a problem dude. In theory any goven car that is within the tolerences should not make noise. I am familiar with the theory that the various tolerances of differences culd stack up and work against you, but having had a background in the automotive industry I can tell you that the corollay is also true. If you adjust everything so that it is within tolerence, it shall not squeak rattle or otherwise annoy the occupants. You can bet that the Toyota enginerers know exactly what the worst case stack is in either direction (tight/loose) and have taken that into account.

Do not give up. If you bug Toyota enough, you should find some support. escalate all the way to Japan if you have to. Also try different dealers as their support can vary dramatcally. What you want to do is to escalate the issue until you get a Toyota employee (not a dealer employee) to take a ride in your car. Just ask them: Are all Prius are supposed to sound that bad? and see what they say.

Bushings: you can always find a car that is an exception. Many people considered the RX7 to ride like a quarry truck before any suspension mods, so undoubtably you will find a lot more complaints after any mod whatsoever.

It is easy to change the sway bar bushings in most cars, remove two bolts and the left bushing bracket falls down. Two more bolts and the right hand bracket falls off. Now just one nut for each end link and you can slide all the bushings off then slide the new ones on (with a bit of the proper lube if needed). Its easier to do than to say.

That the RX7 is unusal should not change the odds for us since its not made by Toyota. All the previous Toyotas I modded were this simple. I'll eventually take a look at the Prius to see if its the same.

Ride quality in the Prius should not be noticeably harsher since its really not that harsh to begin with (yes, I saw that post but there are just some people that think that Cadillacs should ride softer, so we cannot account for them).

When we upgrade to poly bushings we usually find that he spring and shock rates "feel" better. I have never heard of anyone feeling that the rates subsequently felt wrong in any way.

I have heard that in some sports cars the owners mixed poly with regulat biushings to get the oversteer/understeer exactly where they wanted it to be. This is not to say that the poly bushings were wrong in any way, this is just a very inexpensive and quick way to tune a suspension. In those cases it is more likely that the spring/shock/sway bar rates were not tothe owner's liking to begin with but they were more willing to take an inexpensive approach than to fix the problem at the source. In that they they are no different in what we are trying to do with the poly bushing upgrade.

Good luck and hang in there, I know you can do it.