I have a tC on order. I would like to have the TRD lowering springs on it, I like the clean look, not too low but enough to be noticable with an improved performance, right?

Anyway, I am new to car parts etc...can someone explain to me the difference between Strut tie bars and Sway bars? Also, why do some people only get a rear sway or a front tie, and not both? If I were to get the TRD springs and both the front strut bar and rear sway boar would this thing handle like it was on rails? I plan on making the car faster, but with no s/c yet, I want it to corner great for now.

Thanks for the education in advance....

 

Well, first off, I don't currently own a Scion, so I can give any real specifics. But I do a good deal of road racing, so I've been up and down the suspension mod path many, many times.

Regarding the difference between a strut tower bar and a sway bar. On old "wet noodle" chassis cars, like mustangs for example, under hard cornering the front and rear end of the car could twist and the strut towers could deflect under heavy loads. This isn't nearly as much of a problem anymore nowadays on most cars, especially on cars with the strut towers being right next to the firewall (as on xB). Until you are running 1000 lb springs or a serious race suspension that can exert the sheer force needed to twist the frame, a strut tower bar is virtually worthless for anything other than a good place to rest your hands on when working in the engine bay. Don't waste your money here unless you are going for looks.

Sway bars. Sway bars tie the left and right suspension together. When driving down the road and you hit a dip, both sides of the suspension move up and down at about the same time and the sway bar pivots in it mounts and does nothing. But when cornering, the car leans and one side of the suspension contracts while the other extends. Since the sway bar is connected to both, it gets twisted, much like a torsion bar, and resists the car's desire to lean. Therefore the bigger the sway bar, the less body lean in the corners.

But... by tying the suspension together you will also loose its ability to maintain good tire contact patches on anything but perfectly smooth surfaces. Not what you want on normal street driving. With really big bars, you end up skipping sideways through bumpy corners and will actually handle worse than stock at times. So, you need to find a good balance of the two. Too much bar reduces grip and will change understeer/oversteer tendencies and can get scary. Too little bar and you feel like the car is going to tip over.

Also, since the tC, xB and xA are all FWD cars, you want to be able to put power down while coming out of a corner as early as possible. So you need a front suspension that is much less tied together than a RWD car. So keep in mind what the RWD crowd tells you about sway bars, doesn't exactly translate to the FWD scene. This is why most FWD road racers go with either a very small front sway bar, or no front bar at all, and a larger one in the back. A stiffer bar in the back actually helps keep the front of the car flatter but allows the front suspension to stretch and react to road conditions, without spinning the tires away when getting on the gas.

If it were me, I'd probably look at getting a bigger rear bar first and see how that does. That along with a good set of matched springs/struts and coilovers would probably help dramatically improve this cars overall handling.

Here's a decent article on the subject:
http://www.grmotorsports.com/swaybars.html