Stock car parts on a Yaris

[xnamerxx]

Not completely finished but here is a real rear sway bar mounted to my Yaris. Still needs some gusseting and bracing before its done.

Had it around the parking lot a few times and it definitely handles differently than before.

https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-ash4/468783_492404057497209_1992831713_o.jpg

[UberSilver]

So you've got two. I had my rear wanting to brake lose with my WhiteLine on the firm setting. I had to run it on the soft setting in case of rain.

[ilikerice]

Does the exhaust clear that or do you need custom axle back?

[xnamerxx]

The TRD bar is going to come off when this is done since its dead weight at that point. The back end was loose from my test drive, but it was a different kind of loose, you could feel the back end come around but it was doing it slowly although much sooner than normal. It was completely unlike all of the RSB I've driven so far, I don't know if its better or not yet haven't really done any testing, but it was odd to hear the back tires squeal for once, that's something I'm just not used to in this car.

The stock exhaust doesn't clear it. You could probably make it work if you moved the can back an inch or so and rerouted the exhaust pipe up or down. A custom axleback would work and I'm sure some of the OTS stuff would work well too but I don't have any here for fitment.

[ilikerice]

interesting setup. i like it. When you are finished with it and feel that it is a significant improvement and figure out a exhaust setup. Are you willing to piece together something for the rest of us to purchase?

[xnamerxx]

Yeah, its actually surprisingly simple to make. I'll take some final measurements when I'm done to give a good idea how to make it as long as it works LOL.

Gotta love stock car parts ;)

As it sits right now though here are the parts I'm using.

Shopping list:
splined tubular sway bar, 1" OD x .120 wall x 43" length from www.1speedway.com
pair of straight aluminum arms for the above, I think the 30 degree bent steel bars would be easier to work with though.
Sway bar saddle bracket (Energy Suspension #15.12.0.39 or 9.5129 from Suspension.com)
Grade 8 3/8" bolts, nuts, washers (Home Depot)
12"x12" 1/4" 4130 Steel plate cut to fit.

You can think this guy for giving me the idea. https://www.facebook.com/notes/hollis-racing/the-hollis-bar-diy-rear-sway-for-st-hondas/202403919843582

All in I'm about ~$250 in parts and metal with about 4-5 hours invested.

[mr_miles]

Holy bracing, batman! that's intense. Forgive me for likely overlooking something simple here - but wouldn't it have been better from a "less to modify standpoint" to make something similar to the TRD bar, with mounts up to the current area your new one mounts to? or does the box-ish shape from this bolting to the axle play a large role in this?

[xnamerxx]

Holy bracing, batman! that's intense. Forgive me for likely overlooking something simple here - but wouldn't it have been better from a "less to modify standpoint" to make something similar to the TRD bar, with mounts up to the current area your new one mounts to? or does the box-ish shape from this bolting to the axle play a large role in this?

That was a thought at one point but I was talked out of it. From what was explained to me by my chassis engineer buddies, was that adding a bar like a TRD bar was less effective than a bar like the one pictured above because they don't tie into the chassis like a traditional swaybar.

So the reason it looks the way it does it because I couldn't figure out where I could mount the bar along the chassis where the torsion beam sits so I used the stock toe hooks to bolt onto. This method of mounting creates a bit of a problem since everything needs to be nice and long to avoid binding.

[Viperoni]

Like the idea!

I've ditched my tow hooks to clear my exhaust, but this would be an even better use for the tow hook nuts welded into the chassis.

I can't quite make it out, but have you entirely replaced the tow hooks, or just bolted your brackets to them?

[xnamerxx]

Just bolted brackets to them, on the Yaris the brackets are part of the frame so I couldn't get rid of them. I'd have built a much better mount with exhaust clearance if I could unbolt them.

I ditched the TRD bar and ran just the speedway bar tonight, car was much more composed, but I still don't have enough data to say if its better or not. Seat of the pants says its faster but I'll be sure this weekend at the AutoX event.

[Viperoni]

Sweet, too bad on the tow hooks being a part of the frame though.

Given how solid the bar is, I wouldn't be surprised if it helps keep the wheels located better too, longitudially anyhow.
<edit> didn't see the pic properly at work, the bar probably WONT help at all with what I said </edit>

[xnamerxx]

Yeah the small endlinks keep all that from happening.

First test video below. Way more tire deflection than I was expecting on the back tire.


http://www.youtube.com/watch?v=_9mmrulJsSk

[Viperoni]

The tire is deflecting like MADNESS:

Direct link to the vid right about when the deflection happens:
http://www.youtube.com/watch?feature=player_detailpage&v=_9mmrulJsSk#t=29s

Explains why Johnny and I still get outside tire wear on the rear when he's running ~-2* camber (with coilovers + sway bar) and I'm running ~-1.4* camber (soft springs and no sway bar).

What's your alignment like?

[xnamerxx]

I've never seen tire movement like that on the back before so the ARB is doing something. The tire might be a touch under inflated I think its in the 33-35 range which is pretty low for the z2s

On the back its basically stock but on the front I have -4.7.

[Viperoni]

So -0.5* camber at MAX on the rear... that'll enable some deflection.
I don't have any vids of the rear tire deflection, but I do have a rough one of the front, not quite as bad on similar tires (can't remember the brand, but it has two sipes and is a slick otherwise like yours).

[xnamerxx]

You can see some tire deflection on my previous rear suspension vid. No where near as bad as it is in the current video.

http://www.youtube.com/watch?v=504PlSYzTVg&feature=player_detailpage#t=7s

[ilikerice]

so how does it feel? Butt dyno

[Jason@SportsCar]

Yeah the small endlinks keep all that from happening.

First test video below. Way more tire deflection than I was expecting on the back tire.


http://www.youtube.com/watch?v=_9mmrulJsSk

That is a lot of angle on the bar, can you flip the endlinks and get the bar flat at rest?

[xnamerxx]

so how does it feel? Butt dyno

So far very good. A lot of the things that have been annoying me seemed to have gone away. I haven't been able to get the inside to spin on the areas I normally see it, the backend also doesn't seem to step out as easily which I don't understand quite why yet but I'll have better understanding of how it behaves at the limit this weekend.

hat is a lot of angle on the bar, can you flip the endlinks and get the bar flat at rest?

That was the way I initially planned it, but once everything was mocked up there was interference with the shock under compression.
So the options I had were to move the link outboard and use a longer bolt for the shock, which makes it longer and still single shear on the same semi thin bolt.
Move the arms as you can see above, it makes them go at a extreme angle so the forces are uneven side to side IE you transfer more force to one side over the other under twist. This setup isn't ideal but it helps me get a better understanding of how this kind of bar works over just utilizing the torsion beam alone. I could have milled the aluminum down and used a ball joint to get some extra space, but given the interference and the axle play I didn't want to risk it.

The third option is the one I'm planning on doing later, is to get 30 degree arms so they sit parallel to the ground using the bottom link.

[Jason@SportsCar]

The third option is the one I'm planning on doing later, is to get 30 degree arms so they sit parallel to the ground using the bottom link.

Option four, droop limiters in the rear shocks and drop 30lbs of unneeded swaybar. :laugh:

[xnamerxx]

Option four, droop limiters in the rear shocks and drop 30lbs of unneeded swaybar. :laugh:

Its closer to 15lbs :tongue:

[justjesus]

Thank you Namer for further pushing the development on the Yaris. :)

You still need a CAI, though!

[TOUGEghost]

Wow, finally, someone who realizes how a real sway bar works! Nice job. :thumbsup:

[xnamerxx]

Thank you Namer for further pushing the development on the Yaris. :)

You still need a CAI, though!

Gotta make sure I can get power down before I turn power up :wink:

Getting the car ready for the race this weekend, will have a better idea on how it works when everything is said and done.

[xnamerxx]

First test is in...and I don't know how to drive the car now.

Biggest thing that comes away from this to me is I can trail brake now, the car doesn't want to get loose on liftoff, so it doesn't rotate all that well. Not a bad thing but something I kept finding myself anticipating but never happening.

Overall it behaves like driving a RWD mcstrut car, on lift off or braking it doesn't want to turn but power down it turns in really really nicely, I think part of that is springs but I don't know what else to attribute it too. I can mat it wherever I want now, the inside tire will not spin on anything aside from a clutch dump. Its going to take some relearning of the car but I think its working exactly like I wanted it too. I need to play with the springs again but the rates I was running were fairly close to what would be a good match.(Thanks again Jason)

The suspension video is really cool to watch and a touch disappointing as well since I don't have wide enough rims.

RSB Video
http://www.youtube.com/watch?v=whM3faIv29w&feature=youtu.be

Fast Run
http://www.youtube.com/watch?v=kItBgm8kuJs

[malibuguy]

id be worried about all the deflection using the tow hooks as mounts. In your videos they move around ALOT...not designed for side loads. I would attempt to build strong brackets that bolt to the frame.

I have damn near on command lift-off oversteer with my Yaris sedan with the UR 23? mm RSB...but i also have more weight to fling about, so that gives me leverage.

I like your idea, I just think it needs refinement. Good work!

[xnamerxx]

I need to stick a tape measure up there to verify but I think some of what looks like deflection is the gopro flexing on the bumper.

There really isn't that much load going through the toe hooks it really shouldn't exceed 500 lbs which 2 stamped 1/8 pieces of steel should be okay.

Lift Off oversteer is mostly bad in my situation, controlled rotation is good but not being able to get confidence the car isn't going to spin is bad. Of the fast STC guys who've driven my car, that was the one major complaint they had was that with the 19mm TRD bar, the car wanted to rotate too much.


As a double check I pulled one mount of the swaybar and pulled the bar like a breaker bar. The energy bushing and my mount deflect and I wasn't really able to get the toehooks to move. Those toehooks must be designed to pick the car up individually, they seem way overkill for a 2400 lb car.