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Old 03-07-2017, 02:37 AM   #19
Kaotic Lazagna
 
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Always wondered how racers stayed cool in those HOT cabins during a race. Thanks for the info on what it is.



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I'm only 35 lbs under weight. Fuel and tire should do it.

I'm not running the rear ARB because it's not part of the kit.
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I don't run SS lines in either of my racecars. I do run a high temp brake fluid, but I'm not that picky about brand. There isn't all that much braking in a B-Spec.
So I'm assuming in that class, the rear sway bar would be illegal since it didn't come in the TRD package???

Ah, didn't know not much braking is involved in that class.
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Old 03-07-2017, 12:11 PM   #20
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So I'm assuming in that class, the rear sway bar would be illegal since it didn't come in the TRD package???.
Each B-Spec build has specific components and the ARB isn't one of those. That's the simple answer. How one designs a kit and then modifies it probably involves discussions with the SCCA. Hopefully Jason will enlighten us...
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Old 03-07-2017, 01:23 PM   #21
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Each B-Spec build has specific components and the ARB isn't one of those. That's the simple answer. How one designs a kit and then modifies it probably involves discussions with the SCCA. Hopefully Jason will enlighten us...
Toyota had no official interest in supporting B-Spec when the class first came on line - still don't - it gets the same level of support as an other Club Racing class.

Because we were already working with Yaris marketing team we were asked to work with SCCA on the B-Spec program. But with no support, or interest from TMS, there was little to do. Originally the car was going to run in BS nearly stock. We suggested tossing in the already available TRD springs and shocks just to try and lower the car a little, making it less prone to a roll. We did not ask for the rear bar because adding a torsion bar to a stick axle is kind of pointless. You can call it a swaybar if you want, its not, and does not function as such, just cost money and adds weight.

If you take a look at most of the other BS kits they are all adopting the Mazda/CorkSport "rear bar", which is also not a swaybar, its tube with tie rod ends they use to bend the axle to adjust toe. You can accomplish the same thing with shims on the rear axle.

Recently a new BS committee was formed, the previous one was made up of manufacturer reps, the new one is racers. The new committee wants to speed the class up, so they started opening up the restrictor plates on the fast cars (Honda, Kia, Mini, Chevy), and giving things like a CAI to the slower cars. The Mazda2 also got a header. All of these changes are just leaving the Yaris further behind due to the lack of an ECU reflash - and they wont allow a piggyback.

At the 2011 Runoffs they invited all of the manufacturers that had built BS cars to bring them for a demo race. We shipped out one of the cars we had used for a Sony Play Station program (built to BS trim), we were very disappointed to find out the "demo race" was five laps behind a pace car. We spent the money to ship the car and expected it to race, so we started looking at other options... Since BS was not yet a class, we could only field the car in H Prod or Showroom Stock C. We found an SSC driver that had engine problems in qual, and let him run the Yaris - giving us the first BS car to compete at the Runoffs.

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Old 03-07-2017, 01:35 PM   #22
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So many weird guidelines.

I felt that the RSB was the only bar that actually made a difference (was surprised cuz I was thinking the same you were about the torsion beam). But I don't race my cars, and only have on and off ramps to base any suspension changes effects off of. LOL.
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Old 03-07-2017, 01:48 PM   #23
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To clarify, you guys are saying the TRD, Whiteline, or some other flavor of quote/unquote rear sway bar, has no impact? Only costs money and adds weight?
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Old 03-07-2017, 01:56 PM   #24
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To clarify, you guys are saying the TRD, Whiteline, or some other flavor of quote/unquote rear sway bar, has no impact? Only costs money and adds weight?
That is what I am saying. There is no interface between the bar and the chassis, there is no way for it to counter roll. Without some type of connection from the suspension to the chassis the bar can not do its job. All it does is stiffen up the rear beam, that is not what a swaybar does. This is a supplement for soft rear springs, nothing more. Put in the right spring and shock package and you can ditch that piece of steel.

I have only seen one attempt to build and install a proper rear swaybar (speedway style bar attached to the chassis and the axle) on a Yaris, and I think he ended up removing it.

But a lot of people like to believe it transforms the car... There are also a lot of people that think a front strut tower brace makes a huge difference. The front strut towers are inches away from the firewall, and the tops of the struts are mounted in 2" think rubber donuts, no way that bar does a thing. And then there are grounding kit fanbois. When it comes to bolt on accessories it seems like if someone will build it, someone will buy it.
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Old 03-07-2017, 02:23 PM   #25
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That is what I am saying. There is no interface between the bar and the chassis, there is no way for it to counter roll. Without some type of connection from the suspension to the chassis the bar can not do its job. All it does is stiffen up the rear beam, that is not what a swaybar does. This is a supplement for soft rear springs, nothing more. Put in the right spring and shock package and you can ditch that piece of steel.

I have only seen one attempt to build and install a proper rear swaybar (speedway style bar attached to the chassis and the axle) on a Yaris, and I think he ended up removing it.

But a lot of people like to believe it transforms the car... There are also a lot of people that think a front strut tower brace makes a huge difference. The front strut towers are inches away from the firewall, and the tops of the struts are mounted in 2" think rubber donuts, no way that bar does a thing. And then there are grounding kit fanbois. When it comes to bolt on accessories it seems like if someone will build it, someone will buy it.
The front sway bar, and those under body chassis bars didn't really do anything for me, mainly just aesthetics. The NST light weight pulley didn't do anything either for me.

Grounding kits? Like for those with big audio systems?
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Old 03-07-2017, 02:28 PM   #26
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In theory a solid rear axle (which the twist beam would qualify as) stays parallel with the road surface, the body of the car rolls as the suspension loads. You can combat the roll with springs, shocks or bars. But for any of them to work they have to interface with the chassis and suspension. You can bolt all the stuff to the axle you want, unless you attach the other end to the chassis so it can control the body all you are doing is making it stiffer and heavier.

Here is a very basic 1st gen CRX rear bar.



Even the minivan guys have figured this out.



Or you can bolt multiple bars to the beam like this guy, it still not a swaybar, its still not controlling roll. #carshowpoints

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Old 03-07-2017, 03:45 PM   #27
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Well, they could always reduce the weight of the Yaris to make it more competitive. How do we petition such a change?
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Old 03-07-2017, 03:58 PM   #28
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Well, they could always reduce the weight of the Yaris to make it more competitive. How do we petition such a change?
Just submit a letter: www.crbscca.com

Keep in mind letters submitted without any data (race results) don't get much attention, they want to see the cars run in the current spec before they typically offer changes.
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Old 03-08-2017, 12:25 PM   #29
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Man, thank you, Jason. Not only was that an interesting lesson, but I feel like I owe you a percentage of the $200 dollars I would have wasted on a part I was planning on buying.

Scratching that off the list!
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Old 03-08-2017, 01:29 PM   #30
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Man, thank you, Jason. Not only was that an interesting lesson, but I feel like I owe you a percentage of the $200 dollars I would have wasted on a part I was planning on buying.

Scratching that off the list!
A good set of coil overs will do so much more for the car.
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Old 03-08-2017, 03:31 PM   #31
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Agreed with Jason that the RSW doesn't connect to the suspension so it is not a true sway bar and therefore all it does is stiffen up the rear torsion beam.

That said, I opted for the rsw and coils (and eventually sport shocks/struts) because it was much cheaper then to run a good set of coil overs. A good quality set of CO's will run you over a grand and would be very much worth it had I been planning on using this car for the track. But for a DD and potential autoX car there was no sense in dropping that amount of money when I could do it for less.

The TRD rsw definitely makes a difference and allowed me to run softer springs in the rear so the ride isn't too harsh and control the amount of understeer the soft rear springs cause relative to the front.

If you have the cash and need to adjustment, definitely go with CO's, but if you want a DD and don't need to adjustment or plan or spending bits here and there then the rsw may be a better fit. All comes down to the use of the car
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Old 03-10-2017, 11:01 PM   #32
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Don't want to hijack this thread re rear "sway bar" but...

Yes it is true that this is not a true sway bar, it is essentially a brace to stiffen up the rear axle. But I must take exception with the statement that it "doesn't do anything". I had my car for 6 months before I installed a TRD rear sway bar so I think I had a good feel for how it drove. After I installed it the difference in handling was immediately apparent. Now I'm not saying it suddenly felt like I was driving a Porsche, but the car definitely felt more stable in the corners and seemed less twitchy all around.

No I do not have any data to back up those claims, I don't have any telemetry showing g-forces in corners or improved speed thru the twisties, only my subjective experience. And understand that I am not on a track, just the public roads, on stock suspension, but for those applications I feel the RSW "works" and is the best money I spent on this car.

Could it simply be the placebo effect? Possible but I don't think so. Over the years I have convinced my self on numerous occasions that this or that new product would be so much better than the current version that I owned. Rarely if ever was that true. I have spent many thousands of dollars in pursuit of better (mostly on musical and audio gear) only to realize after the fact that I should have saved my money. My point is I recognize the placebo effect and find it rarely applicable in my case.

Long story short, I'm keeping my TRD rear sway bar.
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Old 03-11-2017, 12:06 AM   #33
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The only reason I'm running the rsb is because I couldn't find any off the shelf springs with stiff rates. I wanted my car to rotate more, and what better way to do that than to prevent the torsion beam from twisting. At least that's what makes sense in my mind.

I recently ordered my coilovers with 7kg/5kg rates mainly because it's my daily, so the rsb might have to stay as 5kg still isn't stiff lol.
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