Just bought a 2021 Toyota Yaris with a good bargain.

After a few rounds of driving, feel that its handling needs to be improved. Especially in high speed driving, it feels kind of "floating".

I'm looking at Ultra Racing now. And there are front strut bar, front lower bar, rear lower bar, mid lower bar, anti-roll. Which one to start with? Or is there any other modifications that is recommended?

Thank you for your advise in advance.



This post has been edited by Janwy: Apr 18 2021, 11:32 AM

Start with front strut bar

wide sticky tyres, rollcage and a gt wing

Always start with the tyres.

Good set of tyres. Lightweight Alloy Wheels.

Sometimes that's all you need.

1 - wider tyre

2- front strut bar & rear strut bar/ stabilizer bar

Which spec did you buy? J? E? G?

Forget the bars for a moment. All cars post-2010 (if I have to put a figure) got chassis of respectable rigidity, as compared to 80s/90s cars. So no point going that direction unless you go gymkhana, rally, track etc.

As bro.amscouzach has suggested, always start with your tyre/rims combo.

I know your Yaris is new, but for some reasons you want 'handling' improved.

Depending on what aspects of handling you want improvement, imo you should start with redo-ing another wheel alignment re-adjusting/altering what comes from factory, which you desire improvment to suit your 'taste'.

Briefly, for faster cornering/turning thrill you want to make 'as is' camber angles more negative.

Besides you can also ask alignment shop to adjust the front toes to be more positive or more negative for two different types of 'handling' you want it 'corrected' .

Typically front caster angles is not adjustable , but it appears to be not quite relevant with your 'problem' .

Rear alignment angles adjustment? Not sure of your rear suspension type and I suspect it is likely to be of no concern imo.

Spending $$$ on hardware currently may likely not achieving/resolving what you desire specifically.

Note: In case you are re-doing another wheel alignment, kindly take a screenshot (or ask for a print out prior to carrying out the job) and share here what is the specification range of Yaris alignment angles according to computer software.

This post has been edited by zeng: Apr 18 2021, 05:09 PM

I used have to UR bars on my Vios.
But not after it makes certain parts of my car fail prematurely.
E.g. lower arm, absorber.
Due the after installing it, it will make your ride kind of rigid.

I removed it not long ago and tbh, I can't tell the difference.
Like other forumners recommended, go with better tires first.

Also consider coils over

First of all, you are buying a new car and it got warranty.
If you add those bar or modify the suspension setting out from original you risk voiding the warranty if you still care about it.
The best option now is still change better brand or suitable tire for your driving pattern like changing to UHP/Sport base tires.

High speed floating? Sounds like you need stiffer suspensions - maybe lowered a little.

What high speed driving area you doing in public roads?... and to mod as if you have reached the limit of the chassis due to your superior driving skills is it?

Rear is torsion beam, nothing to adjust.
Front alignment, I don't think it is safe to do toe-out for street car. The front will be overly twitchy. Generally a little bit of toe-in is good for highway.

Floaty on high speed is common on the urban city car like Vios/City/Myvi/Axia, new Ativa. They all floaty at over 100km/h, they are design for city best 40-60km/h, efficient, light, easy to maneuver with tight turning radius, in traffic jam. Some 80km/h on inter satellite city is fine. Highway should be a couple of time a year, balik kampung use only.

There are very little things can be done without resort to full project car situation. Biggest problem is aerodynamic lift. Any road car has lift, spoiler merely reduce the lift, overall net force still upward (no or negative downforce), but bigger car has more weight and wider body thus less noticeable. Most effective is reducing the ride high, couple cm makes noticeable difference, so lower spring/coil-over helps (no need to be stiffer).

Other suspension mods are useless in the high speed straight line at regular highway. Unless you talking about Nurburgring, talking curb stone at 200km/h, then yes, but even that the mod is longer stroke and softer suspension setup, not firmer. Torsion beam, the beam structure itself is acting as ARB (that's why it is not an independent suspension). Adding rear ARB actually make the rear to slide at lower speed, remember feeling good (less body roll) is not equal to more grip. ARB is a tuning tool to balance front/rear grip (stiffer rear more over steer, stiffer front more understeer). Upgrade to stiffer rear need to come with stiffer front to maintain the balance.

Even if one determined to remove factory spoiler, replace it with a proper calculated wing (not ah beng ricer decoration). Let's assume 300kg of downforce, that's 4 adults weight. It is enough to change the pitch angle of the car, front nose will point 2-5 degrees up. (Remember modern car with HID/LED needs headlight adjustment also need compensate passengers load that influence to pitch angle) Then, in turn front become floaty, have to add front splitter to balance the car back. Bla bla bla... become fix A, break B, then C, a lot of effort + money, in the end overall drag increase, bad fuel economy as well.

In conclusion, my advice is always want/need a fast car, then buy a fast car. Frequent highway use at least C-segment. No budget either get used or delay gratification (live with what one have, then work harder for a couple more years). B-segment is best for city use.

u corner limit how much now.
simple diy mod is tyre pressure

bar is final touch up. bukan 1st choice

if u dunno corner limit how much. then u wanna improve how much.
no guide line tu

1. lowered
2. wider rims
3. bars

A good set of coilovers and good tires.

Just get better UHP tires first, like Michelin PS3/4, that's the easiest and more effective way of improving handling without voiding your new car warranty. Other things that mod suspension and chassis can be used as excuses to void your warranty. But if you don't care about warranty then besides tires, get a set of sport springs and stiffer dampers, or adjustables if got budget. Those will make much more noticeable improvements than those bars cuz most of those bars are only chassis stiffening which only takes effect if you drive like a racer, but for most people they just add weights. The only bars that you may consider for street use if you drive hard enough are antiroll bars to tune your handling behaviour whether you want more understeer or oversteer.

Huge salute for even replying in thorough to a non solution that's being provided.
But I think he recently discovered the wonders of alignment and apparently have a "sub forum" for it

1)Anyways few pointers: Proton Iriz/Persona definitely not floaty above 100, maybe above 150
2) Typically you'd need to stiffen a lowered height at the suspension require compensation on shorter stroke travels.
3) a suspension can be very soft yet very firm or even harsh (86 BRZ twin is a damn good example)
Key is in damping rate and rebound rate. However that's another rabbit hole that's not within this thread topic.
Very good pointer on the less roll does not necessarily mean more grip
4) yeap the bottomless/money pit of modding. Modding a mod or workaround is not uncommon especially to new enthusiasts
5) totally agreed, even if it's painful on the wait (eg: starting out with a hand me down econo box)

Janwy take note former Inspira owner
A Proton (maybe you want to exit from Proton brand?) Iriz Persona Is actually a more suitable car than a Yaris if handling/suspension performance is important
However yes comfort wise, Yaris handles potholes and bumps a bit better.
Yes I've test driven all 3 - Yaris/Iriz/Persona

Lowered sport springs, lighweight alloys, wider sticky tyres

If got more money adjustable coilovers, bigger ARB, strut bars.

Beyond this going to take alot more money for the smallest improvements, starts becoming pointless imo.

This post has been edited by kdr93: Apr 20 2021, 05:08 PM

Yes, thanks for topping up the details.
1) see I never list Proton hehehe
2) true also, otherwise it will hit the fender to an extreme
3) yes, soft enough not to send the car flying over the curb, but enough rebounce to maximize the tire contact

Me too, started with an 13 years old corolla from father which he bought used.
In exchange I paid for my sister college living allowance until she graduated. That's over 30% of my fresh grad gross pay.

is it even worth it to do all these modifications and void your warranty?

Lower the car, upgrade coilovers, better tires. That's it, can call it a day.
UR racing bars are a waste of money. Better use the $$$ for the coilovers and tires.

In the end, it's a Toyota, well known for floaty rides. Unkers love Toyotas for a reason, this is one of it.
Save $$$ for better cars in future.

Thank you for clarifying that Yaris Rear is a non-adjustable Torsion Beam.

Assuming after-market parts are not available for Rear adjustment in this torsion beam, in your assessment can locally made eccentric bolts and/or shims (by local specialised machining shops) be resorted to by those mati-mati mod kakis, to achieve say zero thrust angle at Rear?? Just curious.

Unaware that TS did mention about highway driving and floating phenomenon in the OP, and your mentioning of desirability of toe in at Front , this is exactly what TS can do to alleviate (if not fully resolve) his 'problem' at hand.
Add: By making TS as is (factory set) toe angles more positive aka more toe-in.

Imo, anti roll bars or its replacement/mod has no role in whatever form in the TS current problem of floating at highway straight ahead driving.

This post has been edited by zeng: Apr 21 2021, 11:18 AM

Seriously I don't know, at least I never seen one. But I never search hard, I'm not their target customer anyways. I'm sure you know eccentric bolt can make McPherson struct a little bit of camber adjustment. Another example is Ferrari 488, the front double wishbone is not designed to be adjustable (I think), but since the pivot of arms are just bolted to the chassis, people simply add washer to change the camber.

Torsion Beam the wheel bearing is on structure itself, not sure (someone mentioned it can be bent, in other topic). But from my experience of the limited cars I own/owned, the limitation is space if we were to add structure. Also even multilink, double wishbone, not all are created equally.

1) This is Elantra Sport multilink. The non sport version has torsion beam and full size spare tires, while the Sport have space saver because the multilink taken more space.
This is typical multilink on the econobox chassis adapted to sport sedan, 4 arms (1 of them is trailing arm). Civic has same design. Again, not all multilinks are created equal, this of course has less degree of freedom vs the 5 fully adjustable links on a pure sport car

As you can see only arm 1 and arm 2 are adjustable. They both affect toe and camber. So this depends of the experiences of the tire shop to balance the 2 arms.
Arm 4 is blocked in this view, and non adjustable. But you may in theory replace it with an aftermarket adjustable rod. Same for double wishbone, the A shape arm can be replaced with 2 adjustable rod (in modern BMW, the A of lower arm has become 2 separated arms). I don't know torsion beam has the luxury, or is it even possible?


2) This is Volvo S60. It is common design for all the SPA platform, SUVs have same design.
As you can see, only arm 1 is adjustable. It is primary for toe, but inevitable it would affect camber slightly.
Arm 2 is kinda like lower arm of double wishbone, but as one giant flat structure (imagine you fill in space of a char A) for aerodynamic, and it is also the same arm air suspension sitting on for model with air suspension. You can in theory, replace this with 2 adjustable rods, with some CNC machining needed for mounting structure.
Then arm 3 is one of the support arm and also the spring itself. The called is transverse leaf composite spring, because it is single spring the across the chassis. This save a lot of space for flat wide trunk.
Arm 4 can be replaced with adjustable rod.


3) 488 Front upper arm of the double wishbone, bottom have same design. You can see the whole pivot structure is bolted, adding washer will move it away from the chassis, thus changing the camber, so it is matter number of washer at upper vs lower. Most passenger cars, the pivot points are part of the chassis, we can not do the same hack.
P/S: Borrowing this idea, how is the wheel bearing mounted on the torsion beam. Any potential to add washer? I don't know, hahaha



This post has been edited by constant_weight: Apr 21 2021, 01:07 PM

I think in bold pretty much summarizes your message LOL!
Still, really salute your efforts in replies

on the last part, Iswara uses washers to adjust rear trailing arm/torsion beam (more trailing arm since it isn't a solid one beam piece, as there are pivots on the middle and both sides of the arms)
The wheel bearing is separated within the wheel hub itself not related to the arms.

Aiya, better than just telling people "you stupid, this is impossible" right?

At least share something constructive, then you corrected some part of my comment, I also learned something along the way.

Win-win loh

very well said! really love your positivity!

wider tyre should help..stock size is 185 55 16? maybe can upgrade to 195 50 16 or even 205 4516 but then original rim widht may not suit the upgraded tyre width.

This may sound harsh, but it sound like u bought the wrong car, appreciate the yaris for what it is, a comfortable cruiser, with good f.c.

The car is based on old gen vios chassis, albeit with some additional strengthening. Not sure on 2021 model, but on my 2020 model, the front ARB is still connected to lower arm using satay bush just like on old 1.3 & 1.5 wira. So dont expect much from its suspension system.

Dont even bother to change to lowered spring if u want to pair it to stock absorber, as the stock absorber is very soft. U will end up bottoming your suspension.

Ok that explains the awesome roll when I push the car a little bit harder on the braking and then sharp L turn playing some tire music and SA protesting

Yes the absorbers/dampers are really soft. But thankfully it is compliant on road irregularities, as opposed to shit P2, soft and just straight out surrenders itself on any and every road irregularities. :x:

can start with set of Absorber, Spring set. Take the all-in package, not Spring aftermarket but plug into current absorber.

this alone improves sampan feeling at the highway etc, floating.

Thanks for your reply.

The body-roll during highspeed makes me feel unsecure. Just a normal driving on KV highway (below 100km/h), and a wide turn, the body-roll is very obvious. Afraid that it will goes oversteer anytime, or it just me overthink?

What you say is true. I agree.

I am not taking this car to a gymkhana or street racing, but I just wanna feel more secure and safer on the highway. The body-roll worries me. Below 100km/h, taking a wide turn, the body-roll is obvious to me.

Thank you for confirming that. I heard a lot of people is saying that the Iriz and the Persona have a batter handling performance as well.

By the way, this Yaris is a daily driver for someone close to me.

This post has been edited by Janwy: Apr 29 2021, 07:34 PM

Thank you all for your precious advises. Very much appreciated.

Just get to know that the feel that I felt is a body-roll. Might go for an anti-roll bar, maybe.

Thanks again.

This post has been edited by Janwy: Apr 29 2021, 07:39 PM

Yaris is not for high speed stable ride. Dont modify, high risk.

Wow... thank you very much for the very elaborate and thorough explanation on alignment adjustment on various models of cars/suspension systems.

With body roll as a concern, you have a good basis to look into anti-roll bars option to help out in a turning scenario.

You overthink

Consider this:
- Body roll, so long not excessive, is not necessarily bad
- Less confidence also not a bad thing

Then don't mod.

No need anti roll bar

Thanks again for your advise!

First thing you should do is get performance suspension with lowered spring. Once car is lower, it will be less floaty. Get adjustable absorber so that you can adjust to your preference.

You not performance kaki is it? Ask people do double work get lowered springs and coilovers?

I had read a few time to make sure I didn’t get the wrong info from that. Lol

Maybe my English bad, comprehension bad.

my bad..didn't type properly.

Should be sports spring and sports absorber. Or complete adjustable absorber. Either one is fine.

And yeah, I am not performance kaki.

Then why not you asked that person first if the handling and body roll still OK or too much.

Np
That explains it.

So sports absorbers are typically fixed damping, non adjustable.
If you want adjustment, typically is straight to coilovers (or what most layman call adjustables)

Which also mean, like you said - it typically is either (not both) sports (typically lowered, however not all sport springs are lowered) springs and sports absorbers, or complete coilovers replacements.

Most cheap/entry level coilovers though, I don't care what you say/what most say, comfort is thrown out the window. Especially anything >3kg/mm spring rates per 1 ton vehicles (or 6k : 2 ton, for better illustrative purpose on this example)

That's why I usually don't bother on coilovers unless I know what I want and I'm able to/willing to pay the price (sacrificing comfort vs cost of adjustables vs mechanical grip improvement)

Changing to coilovers definitely consider best bang of bucks to get if you’re going for handling improvements even if the price ain’t cheap for those good/great ones.

P/S: your wife and kids most likely will complain about it once you’ve upgraded from stock absorbers. Which is why my family car is dead stock. My own car is another story 😬😬😬

This post has been edited by cyapd: Apr 30 2021, 08:26 PM

Coilover or lowered spring, I think are overkilled for Janwy case.

Judging from his description, sub 100km/h at highway, I think what he felt was mostly of lateral g-force with just a tad of body roll. It is hard to imagine highway bend that would throw a passenger car at excessive body roll as such speed.

If at the large curves that exit/enter highway, those corners usually have banking that exactly compensate the body roll.

So I agree with Quazacolt, that he overthink and don't really need a mod.

Back then for my old waja, the stock absorber alway kiok right after a year. Warranty for absorber was 6 months. Installed Proride Sport absorber (not adjustable) with their red sport spring. It lower down the car a bit and not that hard as my friend adjustable absorber, forgot it brand.

Went with my friends car, even at Ayer Keroh highway there is some section with kinda rough road, the car end up bumpy, great if u bring gf there.

On Proride it still with comfort level as i believe due to non adjustable types. At least it doesn't fail after a year as stock kayaba

This post has been edited by ayamxxx: May 1 2021, 09:06 AM

Thank you and noted.

Just get a set of eibach pro kit. Not cheap but definitely no sampan feel.

Myvi, rolls like crazy but can cause other cars to turtle. Body roll isn't necessary a bad thing, in other words, it depends on the driver.

First of all, the things we all talk about here is 'vehicle handling', or how it behaves to driver input. It's true, since a car can't drive itself. https://en.wikipedia.org/wiki/Automobile_handling

Or, particularly to your issue, can check out body roll.
https://en.wikipedia.org/wiki/Body_roll



This post has been edited by alexei: May 5 2021, 01:08 AM

floatiness on straight can be fixed with a wing, get a voltex swanneck