Ultra Racing 23mm Rear Stabilizer Bar

[Loren]

Installed one of these bad boys this evening. Big thanks to Garm at Micro Image for sourcing these for us and offering them at a reasonable price! Nice part, but I'd recommend not trying to install it by sliding under the car with a couple wrenches between runs at an autocross when you're working from the middle and can't really see either end. I tried that Saturday, didn't work.

I'm feeling a little scatterbrained and disorganized this week, so this review will follow suit. Bear with me.

First, there has been some confusion about whether the TRD rear bar is 19mm or 22mm. I've seen a few references here on the forum that hint at it being 22mm, so I want to clearly state for the record that the TRD rear bar is 19mm. Might be 22mm for some other Toyota, but not for the Yaris. 19mm, I just measured it, trust me.

Now, myself and others have told tales of installing the TRD bar by just sliding under the car and bolting it on. No muss, no fuss, no jacking up the car, no taking off the wheels, just bolt it on. And that's a fact. But, I've learned something... if you have wider wheels (especially with proper offset), it's a little tight getting that TRD bar in and out. I was still able to do it with my 15x7 41mm offset wheels, but it wasn't as easy as it was with stock wheels.

The new 23mm bar, was even tighter of a fit between the wheels, which is partly why I couldn't fit it Saturday with the car on the ground. The other reason I couldn't get it installed Saturday was that I thought it was made wrong somehow because it didn't seem to fit. Here's the deal: The TRD bars are made a bit loose. That is, the ends are a little bit wider than the points they mount to on the car. Makes for a really easy slip fit. The 23mm bar is a much tighter fit, in fact, it LOOKS like it won't fit at all (especially when compared side-by-side with the TRD bar that is made wider), but if you hook one end and push the other end outward, sure enough it will fit!

So, I put the car up on stands today and went back to it. Ended up removing one wheel just to make it easier. Once stretched into place, bolting the bar on is a snap. I reused the bolts that I already had on the car from the TRD installation.

Initial driving impression: After setting the rear shocks to near full soft, I went for a drive and found that I had most of the steering response and front grip that I had with the rear shocks set almost full stiff at the autocross Saturday... but without the "feel every crack in the pavement" harshness that comes with having the shocks set that stiff. Nice. That's just what I was after.

I'll have to live with it for a while and get some autocross time with it to have a better idea of how well it works, but it seems like a step in the right direction for me and anyone else who is interested in less understeer and is confident in their ability to handle oversteer should it occur.

BTW, I now have a TRD bar (just like this one) for sale, PM me if you're interested. This bar comes with a few scratches, some dirt, a racing pedigree, and no bolts.

Here's a couple crappy photos for your viewing pleasure. You can see that this bar doesn't fit into the slot in the beam axle like the TRD bar does. It hangs a bit lower, but no lower than the fuel tank or exhaust or anything else, so it doesn't matter. I think I need to paint it black.

Oooh, let's ramble a little bit more. This first photo allows you to visualize a little bit how the rear sway bar works (something that a lot of people just don't "get"). Look at the picture. Visualize making a right turn. Weight shifts to the left. In the rear, the beam axle should twist a bit allowing the right rear tire to stay in contact with the road in all but the most extreme turns. What does the swaybar do? It resists that twist, it makes that inside rear tire want to lift. But, if the inside rear tire is lifting... where is that weight going? It's got to go somewhere. The answer is that it transfers diagonally across the car to the opposite side front tire. THAT is what a rear swaybar does for you, it transfers weight to the outside front tire in a turn.

On a FWD car, it's the outside front tire that is being asked to do the most work and it's the one that causes understeer when it loses grip. Putting more weight on it at the time that it needs it most allows it to grip more. Good stuff. There is also a secondary effect, though. Some of that transferred weight also ends up on the INSIDE front tire (think about it, you've made the car a tripod at this point, both front tires are sharing more than their usual share of the weight), which reduces inside wheelspin if you're trying to accelerate out of the turn and actually allows you to do so. Cool, huh?