New front strut brace bar

[Dobey]

A new front strut brace for those having trouble with BT Tech front strut tower bars: go to sigmaauto dot com, look under Prius, then Performance section, and scroll to the bottom, "Sports Tower Bar".

Looks like this one from C-one solves all the problems of access to the different components in the engine bay - it sticks out more than any of the other bars on offer. The rear tower bar is strange though, it goes in the cargo space and looks like it blocks access to the spare wheel compartment.

[Boo]

Thanks Dobey for the heads up.

Toyota Prius 2004 ~ 2009 NHW20 Performance, Handling & Electronic Accessories :: Sigma Automotive

I have the BT Tech Strut Tower Brace, and I don't have a clearance/fit issue so I'm not interested in the new Front Sports Tower Bar

But the new Rear Sports Tower Bar sounds interesting.

Curious as to what I can expect from installing that Rear Sports Tower Bar versus installing a beefed up rear stabilizer bar (either the Touring Edition rear stabilizer bar or one of the beefed up rear stabilizer bars made for the Corolla/Matrix by Progressive, TRD Sportivo or Hotchkis).

[Dobey]

Originally Posted by Boo

Curious as to what I can expect from installing that Rear Sports Tower Bar versus installing a beefed up rear stabilizer bar (either the Touring Edition rear stabilizer bar or one of the beefed up rear stabilizer bars made for the Corolla/Matrix by Progressive, TRD Sportivo or Hotchkis).

I'm curious as well, it doesn't seem like the rear cargo frame at that lip would affect the suspension struts at all when the car goes through bumps/turns... I would have thought that the stiffening would need to be between where the rear struts are (i.e. where the Tom's rear brace attach to, and/or the rear sway bar). Pity the C-one site is in Japanese, I can't see any pointers to any tech notes, and the translation by Google doesn't help much!

[Rokeby]

Dobey, Boo,

The three of us seem to be thinking along the same lines. With luck,
we won't think ourselves into a corner.

The rear strut tower brace is interesting, in concept at least. In that
the brace is ostensibly intended to reduce body flex/distortion due the
large rear hatch opening, I wonder about its effectiveness being
mounted low down, at the rearmost end of the hatch. (At the front, the
brace has the same purpose, is mounted directly to the top of the strut
tower, and body flex is already mitigated by the nearness of the
firewall.)

So, if body flex in the rear starts with uneven forces acting on the rear
shock towers, I would think that a direct connection between the
towers would be the most effective -- I suspect that it would be at
about the same height/location as the tonneau cover bar.

From a vehicle use/convenience point of view, such a location would
occasionally be an issue as it would cut the rear sill to back of front
seat distance roughly in half and prohibit loading large objects.

Still, I can see them being fitted with permanent attachments to the
strut tower tops, and a removable center piece, the actual brace, with
single bolt attachments at the ends a-la the BT front tower brace. --
Note: this would also require some cutting away of the plastic side
pieces aft of the rear seat... with a pattern, no biggie.

It seems like a simple concept, I wonder what I'm missing.

As I understand it, a sway bar and a strut tower brace address two
different issues: the sway bar addresses whole body lean, the tower
brace addresses body flex. Upgrading/adding both of them would then
not be redundant.

Do I have that right?

[Dobey]

Originally Posted by Rokeby

As I understand it, a sway bar and a strut tower brace address two
different issues: the sway bar addresses whole body lean, the tower
brace addresses body flex. Upgrading/adding both of them would then not be redundant.

Hi Rokeby

I think your last statement that the tower brace and sway bar address different issues is correct. My understanding is that the main effect of a strut tower brace is to prevent the strut mounts (and hence the struts) from flexing relative to each other, so that in turning, the wheels tend to stay perpendicular to the ground, and reduces understeer (i.e contact patch and pressure of both wheels with the ground stays the same). I think a strut tower brace also improves slight wheel turn response (e.g. lane changes) for the same reason.

I believe a sway bar effectively stiffens the equivalent spring rate of one wheel, so that in turning, the force contracting the outer wheel spring is transmitted (via torsion of the sway bar) to the inner wheel's spring, so that the inside wheel's spring is also trying to counteract the turning force. This is why the stiffer the sway bar, the more of the torque is transmitted to the inner wheel spring, and the less lean the car experiences. Of course the effect on under- and over-steer are different depending on whether the front or rear struts are concerned.

I think the tower brace and sway bar have common side effects though, like the firmer ride when going through asymmetric bumps.

I don't know enough of the Prius frame to guess whether firming up the hatch entry lip will firm up the body enough to affect the chassis and suspension, it just didn't seem straightforward how a bar across the hatch lower lip would do that in the case of the C-One rear sports bar.

The C-One front strut bar looks pretty good though, it also looks like it won't have to be removed for any engine bay component access except the strut mounts themselves.

[Dobey]

sigmaauto.com has new stiffeners from C-One - these are interesting. The Performance braces consist of front, center and rear - the latter look like they mimic the Tom's center and rear braces, but the front looks like it attaches to the front frame instead of any of the suspension components. Wonder if it actually does anything noticeable.

The website also sells C-One front and rear swaybars that are thicker than the Touring versions:

Toyota Prius 2004 ~ 2009 NHW20 Performance, Handling & Electronic Accessories :: Sigma Automotive

No vested interest in C-One or sigmaauto.com, just a curious browser...

[thomatt12]

The front strut brace bar looks really interesting. I wonde if it can really improve the handling of the Prius. You're right the rear tower bar looks quites strange indeed for a Prius.

__________________
GMC Accessories

[Boo]

Originally Posted by Dobey

sigmaauto.com has new stiffeners from C-One - these are interesting. The Performance braces consist of front, center and rear - the latter look like they mimic the Tom's center and rear braces, but the front looks like it attaches to the front frame instead of any of the suspension components. Wonder if it actually does anything noticeable.

The website also sells C-One front and rear swaybars that are thicker than the Touring versions:

Toyota Prius 2004 ~ 2009 NHW20 Performance, Handling & Electronic Accessories :: Sigma Automotive

No vested interest in C-One or sigmaauto.com, just a curious browser...

Whoa, I found the beefed up front and rear swaybars much more interesting than the new front, center and rear braces.

These are the first beefed up front and rear swaybars made specifically for the Prius, and the first beefed up front swaybar that will even fit on the Prius.