B-Spec build Norcal #86

[Jason@SportsCar]

Originally Posted by ysar

The max camber I could get was -2.5. The K&N intake isn't CARB legal, so I can't (honestly) use it in California. So basically my non-competitive B-Spec just got a little less competitive.

Would take you about 10 min at the track to install it.

If you use two sets of SPC bolts (top and bottom hole) you should be able to get -3. This is what I am using, sitting at -3 with more available.

http://www.spcalignment.com/componen...AFrom&to=USATo

[ysar]

Originally Posted by Jason@SportsCar

Would take you about 10 min at the track to install it.

If you use two sets of SPC bolts (top and bottom hole) you should be able to get -3. This is what I am using, sitting at -3 with more available.

http://www.spcalignment.com/componen...AFrom&to=USATo

Thanks Jason. -3 will help tire wear. This year I'm more concerned with learning how to drive FWD. Next year I'll probably focus on performance and upgrade the intake and suspension. Maybe get a fresher motor. I feel like my motor stats are pretty good, but I don't know what a B-Spec Yaris is supposed to make.

[Dabuu]

Awesome info Jason!

Now, where to find off the shelf 500lbs lowering springs for the Yaris lol. I'm currently looking for a new suspension set up.

[Kaotic Lazagna]

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.

[ern-diz]

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?

[Jason@SportsCar]

Originally Posted by ern-diz

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.

[Kaotic Lazagna]

Originally Posted by Jason@SportsCar

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?

[Jason@SportsCar]

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

[ysar]

Well, they could always reduce the weight of the Yaris to make it more competitive. How do we petition such a change?

[Jason@SportsCar]

Originally Posted by ysar

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.

[ern-diz]

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!

[Jason@SportsCar]

Originally Posted by ern-diz

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.

[tmontague]

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

[NYC-SE]

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.

[Dabuu]

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.