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Discussion Starter #1
Has any one checked into aftermarket swaybars for the 2011 sienna?

I havent gotten in under my van yet to see what it has in the way of a rear/front sway bar. It is a base v6. Does the sport edition have a larger/stiffer sway bar then the base model?

Dont expect it to be a sports car but larger sway bars can make a huge difference in cornering and lane changing ability. Plus it would be a fun project :)
 

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Discussion Starter #2
I just sent an email to Addco, a major sway bar manufacturer, to see if it is possible to get a aftermarket sway bar for the sienna.

Is any one interested in purchasing a front or rear sway bar if it is available?

I also recamanded they visit this site to see all the minivan enthusiasts.
 

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Discussion Starter #3
http://www.welderseries.com

the above site makes a sway bar kit that is typicaly used on hot rods and muscle cars but it may be useable on our siennas. I just sent a email to them, they are a company based in breslau, ontario canada. if any one is interested in improveing the handling on there vans send them a email maybe we can get a kit for our sienna.

Craig
 

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Improved sway bars have always been a good idea for handler. When having the rear wheels off putting mud flaps on my 2011, 4 cylinder, I had a good look at the rear suspension. It is impressively sophisticated; not the simple sway bar situation. For the fronts, I didn’t have to remove the wheels and still have not had a very good look at the front suspension.
 

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Discussion Starter #5
havent gotten in under my 2011 v6 yet, planning to put the summer rims and tires on next week so i will have a look then. Maybe i will take some pictures while i am in under it. always keep the winters on for that last may snowstorm that we didnt get this year(northern alberta canada).

How do you like your 4 cylinder van?
 

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This 2011 Sienna is the best larger 4-wheeler I have ever had, especially good for me is it's 4 cylinderness. Check out my posts on this forum and the other one under "2toyotaman"
 

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if you can't find aftermarket bars, maybe you could (at your own risk) look into modifying the oem rear bar, changing the mounting points, or adjustable end links for more adjustability.

IF you go this route, though, i'd suggest doing a bunch of research/reading, making small, incremental changes, and proceeding w/ caution lest you end up with a tail-happy beastie.
 

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Discussion Starter #8
2dents glad your happy with the van!!

Act thats a good point about making it tail happy wouldn want the wife and kids hanging the tail out. havent had a chance to push it into a tight turn(winter studded tires since new) putting the summers on as soon as i get off shift for a few days.
 

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newfie sienna said:
Act thats a good point about making it tail happy wouldn want the wife and kids hanging the tail out. havent had a chance to push it into a tight turn(winter studded tires since new) putting the summers on as soon as i get off shift for a few days.
yup. small changes to bar diameter can have large effects on stiffness. i think the stiffness of the bar is proportional to the diameter, raised to the fourth power (or something like that - it's a large increase in stiffness for a small increase in diameter).

if you're going to mod the bar to try and increase stiffness, that's one way to do it but you'll likely end up with unintended results.

adjustable or multi-position end links or mounting points are probably a better choice since you can always undo any changes easier than trying to un-weld metal from your stock sway bar.

the other thing i taught my wife and son about is the friction circle theory (you can only have 100% of tire traction available). by getting most of your braking done in a straight line on the entry, you leave more available traction for turning later.

my wife doesn't always do this, but my son (he's only seven) uses this theory when racing r/c cars on the track, and found it works. braking/lift throttle DURING the turn causes an almost immediate spinout. braking early and powering out of the turn leads to controllable exit and even a drift, if he wants to.
 

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I assume that the 3rd generation rear suspension is identical in design to the 2nd generation.

Act162this said:
if you can't find aftermarket bars, maybe you could (at your own risk) look into modifying the oem rear bar, changing the mounting points, or adjustable end links for more adjustability.
Yes, but the way the rear bar is mounted, I don't think it has lever arms and links to modify. As I recall, the bar is inside the "U" of the axle beam, anchored directly into the beam assembly at each end so that it twists if the arm-like ends of the beam move differently. The bar isn't even shown in the 2005 technical manual's component diagram or mentioned in the axle replacement procedure; apparently it is considered an integral part of the "Rear Axle Beam Assy".

To stiffen this type of bar, I think one would need to build a replacement with a larger bar and the same end fittings.

We have a race-prepared Honda CRX with a similar issue (integrated rear swaybar not readily modified) and the aftermarket solution was simply to leave the stock bar in place and add another completely separate - and differently mounted - external bar. It hangs low and adds a bunch of weight, but that's what I could buy.

Act162this said:
IF you go this route, though, i'd suggest doing a bunch of research/reading, making small, incremental changes, and proceeding w/ caution lest you end up with a tail-happy beastie.
Good advice! Undesired oversteer can certainly result from inappropriate roll stiffness balance, although the Sienna - with its long wheelbase - would be less prone to this than our CRX.
 

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brian_bp said:
Yes, but the way the rear bar is mounted, I don't think it has lever arms and links to modify. As I recall, the bar is inside the "U" of the axle beam, anchored directly into the beam assembly at each end so that it twists if the arm-like ends of the beam move differently. The bar isn't even shown in the 2005 technical manual's component diagram or mentioned in the axle replacement procedure; apparently it is considered an integral part of the "Rear Axle Beam Assy".
interesting - so one option would be to actually increase the stiffness/resistance to twisting of the bar through the addition of metal to the stock/oem bar, or another would be to add an auxiliary bar and find another way to mount it like your CRX.

i've seen people sleeve oem bars, or even just weld metal to the oem bar to stiffen it up (since it technically is the "stock" piece, and not an aftermarket bar so they could stay within a "stock" class of auto-x). this is assuming that there is no OEM alternative that was offered as an option to that model (running si bars on an hx civic/crx since they are technically both the same model).

brian_bp said:
To stiffen this type of bar, I think one would need to build a replacement with a larger bar and the same end fittings.
that's another way - use the same end fittings and fit them to a larger bar - the only thing is you'd have to know how much larger to go, and the formula for increasing stiffness to the fourth power of diameter differs from hollow to solid bars. you could very easily go overboard even with a mild increase in diameter on a solid rod (assuming your calculations were based on a hollow bar) and end up with a handful.

i'm not sure what increasing only the rear bar's thickness would do to overall balance as well - perhaps a larger front bar would help as well to balance out the overall handling. keeping the stock springs should result in a nice compromise of comfortable ride vs. increased roll resistance with the thicker bars.
 

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I had a quick look today, and confirmed that (in a 2004) the rear bar is inside the axle beam's "U", but I could not get a photo and without jacking the vehicle up and taking off a wheel I could not see how the ends are anchored.


Act162this said:
... one option would be to actually increase the stiffness/resistance to twisting of the bar through the addition of metal to the stock/oem bar...

i've seen people sleeve oem bars, or even just weld metal to the oem bar to stiffen it up...
That makes sense, but the design concerns me. For any given degree of body roll (and therefore left/right difference in suspension travel) there is a specific twist of the bar. Reinforcing only part of the bar will force the remaining part to twist more, risking excessive strain and failure. Also, how are swaybars heat treated? They are springs, and so my guess is that they should not be weldable after heat treatment.


Act162this said:
that's another way - use the same end fittings and fit them to a larger bar - the only thing is you'd have to know how much larger to go, and the formula for increasing stiffness to the fourth power of diameter differs from hollow to solid bars. you could very easily go overboard even with a mild increase in diameter on a solid rod (assuming your calculations were based on a hollow bar) and end up with a handful.

i'm not sure what increasing only the rear bar's thickness would do to overall balance as well - perhaps a larger front bar would help as well to balance out the overall handling. keeping the stock springs should result in a nice compromise of comfortable ride vs. increased roll resistance with the thicker bars.
I agree.
 

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Discussion Starter #13
I cant see adding material to the stock swaybar being an option for me, too likely to cause problems. Also as noted above i dont think a sway bar should be heated or welded, just my opinion of course.

An additional sway bar mounted outside of the axle beam would be the option i would choose.
 

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I've been driving my new 2011 AWD Sienna for about 2 weeks now. Am I the only one who does think that the body roll is well controlled and the slight understeer is just fine and therefore there is no need for aftermarket sway bars? Maybe I'm just getting old. :)
 

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dmz01 said:
Am I the only one who does think that the body roll is well controlled and the slight understeer is just fine and therefore there is no need for aftermarket sway bars?
No you're not the only one - I have the same opinion - but I understand that other drivers may have different desires, and additional roll stiffness might be appropriate for them. It's just a rare enough desire that the aftermarket isn't likely to offer a solution.

I drive a much smaller car to work every day; I like the Sienna but if I were driving it all of the time I might want to tweak it.
 

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Discussion Starter #16
brian_bp said:
dmz01 said:
Am I the only one who does think that the body roll is well controlled and the slight understeer is just fine and therefore there is no need for aftermarket sway bars?
No you're not the only one - I have the same opinion - but I understand that other drivers may have different desires, and additional roll stiffness might be appropriate for them. It's just a rare enough desire that the aftermarket isn't likely to offer a solution.

I drive a much smaller car to work every day; I like the Sienna but if I were driving it all of the time I might want to tweak it.
Cant say that i have any real problem with the way the sienna handles, but I have seen what a difference adding a sway bar to the rear of a vehicle can have, so im just curious to see what it would do for the sienna. Dont ever expect it to be a sports car but the tighter it handles the better. Plus its just a fun little project. Have sent a couple emails back and forth to the welderseries guys, waiting for a reply regarding getting it fabbed to fit our vans. May never happen though. :'(
 

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I would also like to know if there is anyone that makes a more heavy duty front sway bar and one for the rear as well. It really leans a lot on twisty roads at medium speeds.
 

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perhaps addco might have an application for your particular vehicle, or some company that specializes in towing or heavy-duty applications?
 

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I have an '11 SE (LUV, Luv, Luv) any way my mods to the supension have been poly front Sway bar bushings (energy suspension, red), these eliminate the play in the OEM rubber bushings and make the bar act like 1 size (mm) bigger. Highly recommend. Also, I have put in the air lift bags and since there is not a mod for the rear swaybar I originally hooked up the airlines individually, this increased the roll resistance of the rear.

Really DON"T recommend, while roll resistance was noticeably way up, so was resistance to turn in, the Van was fighting me on initial turn in and holding the corner. This similar to having too large of a rear sway bar, also causes severe understeer when pushed.

After I replumbed the airline so that the 2 bags share 1 line the rear suspension has pretty much the same action as the factory.

I'm sorry I don't know the number of the front swaybar bushings, if you measure your bar you can buy them from autozone. My SE handles more like a sport sedan than a family hauler.

BTW the endlinks are the best you can get, NO FREEPLAY.
 

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...Also, I have put in the air lift bags and since there is not a mod for the rear swaybar I originally hooked up the airlines individually, this increased the roll resistance of the rear.

Really DON"T recommend, while roll resistance was noticeably way up, so was resistance to turn in, the Van was fighting me on initial turn in and holding the corner. This similar to having too large of a rear sway bar, also causes severe understeer when pushed.
This doesn't make any sense to me. Higher rear roll stiffness (in proportion to the front) causes the rear to handle more of the lateral load transfer, causing the rear to have less traction and front more, reducing understeer, not increasing it. Rear-engine cars typically have huge front swaybars (relative to the rear and the axle loads) to ensure understeer at the limit, since they would be prone to oversteer otherwise.

BTW the endlinks are the best you can get, NO FREEPLAY.
I had not noticed the endlink design until the endlinks of the same design on my Focus failed at about 120,000 km, probably due to poor lubrication, sealing, or materials. I thought this was stupidly early for these components to fail, and I looked at our same-year, similar-mileage (now up to 150,000 km) Sienna: same design, much more robust (but it is a much bigger vehicle) and no play / no problems. I agree: this is a good design when properly executed.
 
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