Cusco Center Power Brace and Strut Brace

You guys are making me a bit envious. I told myself I would not do anything aftermarket to my Prius, but just like the Civic I had - when I threw on my strut tower brace on the Civic (even without any swaybar/suspension/bushing mods), the steering & front handling was like night and day. It seems that any car is helped by that mod.

 

For me, I have a simple rule: I have to be able to put on any mod by myself. If I have to go to a shop or mechanic because I can`t learn or figure it out or buy the right tools necessary (aside from just being plain lazy) to install my mods, then it`s going too far for me. But one thing I learned here on PC, and that is we can do almost anything, This car of ours has taken me to such a level of involvement that I enjoy my car that much more. The car just gets better and better with each little bit...

 

Hello everybody. I read carefully your posts, as well as of others here in this forum with the same subject (body stiffening) but still have my doubts for the real or imaginary positive results. I am not an engineer and I am slow to grasp the idea. We have here a parallelogram (under-part of the car) and a parallelepipedon (car body). The under-part of the car looks quite stiff to me, at least on the horizontal level. It will not distort on the left or right direction. It can suffer from bending moments only (one corner up the other down, etc). To eliminate the torsion of the car body you need more than one DIAGONAL bars or a very stiff cage IN the cabin. None of the after-market products of Tanabe or Cusco are close to a diagonal or cage. Can someone, more savvy in technical matters, clear the issue to me? Are any published results of a laboratory or whatever else in favor of these modifications? Thanks.

 

While it is true that the lower front body of the car does not deflect much, the issue that the front strut tower brace resolves is the deflection of the tops of the strut towers in cornering. The deflection of the tops of the struts changes the front end alignment while in the turn in a configuration that propagates under steer. And the deflection occurs more on one side of the car than the other, and in different directions. By locking the tops of the strut towers in place, and against one another, the outside deflection has to also deflect the inside strut, and the tension cancels out most of the affect (like a sway bar does in the vertical plane.)

 

I am no engineer, but the stiffening plate and front underbody brace have made a substantial improvement in the way my Prius handles in everyday driving, cornering, and driving in cross winds. Wish I could give you a more technical answer.

 

UPDATE: Just installed the Tanabe Strut Tower Brace

Will post a picture up tomorrow as I have to head out.

Took a few minutes driving around earlier and initial impressions are that the front end feels tighter; I can definitely feel something different. Will have to run it thru it's paces to see if I had adjusted it properly.

 

So, is anybody going to splurge and get the Cusco anti-roll bars?

 

Tanabe just came out with the strut tower brace for the Gen 3, I just got mine last week, installed in about an hour with not too much blood on my hands from trying to get the back nuts off and on. It is designed for LHD, so does not interfere with master cylinder, but it does interfere with fuse panel lid. I unhooked the back of the lid, and only connected front, and it seems to be fine, still closed from the elements.

 

Creaky and JACoH, any updates, photos or discussion of the ease of install on the Tanabe strut tower brace? I've got one on order (with the lower 2-point underbrace as well) but am being told they are backordered until mid-October. Just curious how easy/difficult the install was (what other parts had to be pulled) and whether you're happy with the purchase? The price point is so much lower and it appears the configuration is better than the Cusco STB, I figured this was the way to go, but I was disappointed to hear about the long backorder time. So give us your thoughts and opinions. Thanks.

 

Yeah, I've seen the photos of both. If the price of the Cusco were lower and the brake reservoir issue were fixed, I'd have gone that way, but it seems the Tanabe is more Plug-n-Play from what I have read so far. Creaky and JACoH are the most recent that have done the installs themselves, so I was wondering how it went for the do-it-yourselfers...

 

Sorry I haven't gotten around to posting pics. It pretty much looks like the picture @ the Tanabe website 'cept the car is silver. (Life just got in the way... )

To answer your question, Just as long as you give yourself ample time and not rush it, it's really easy to install both products.

The STB from Tanabe, you'll have to remove the wiper assembly and the plastic cowling piece underneath to get at the tops of the strut towers. Note, once you get the STB on, don't buckle up the cowl and wiper assembies immediately. Take your car out for a spin to note how it 'feels'. For me, when I installed my brace, I overtightened the brace just a tad too much outward. So if I was hitting a corner real hard, I could sense that it was pushing mild understeer more than it used to. Bringing it in fixed the awkward feel.

Regarding the underbody brace, that's far more simpler. Just get under the car, remove the two bolts already there and install the brace. As I've noted elsewhere, if anything, you'll likely scrape this piece going over speedbumps.

The Prius '10 body is flexy enough that you'll definitely notice the difference in how it feels/drives and how much noise you hear.

 

Creaky, are the steps to remove the wiper assembly and cowling pretty obvious and straightforward?

Can adjustments not be made once the STB is installed? It appears in the photos that the adjustment nuts at either end of the bar would still be accessible any time after install, is that not true?

 

Yes, removing the wiper assembly and cowling is pretty easy. I went in blind. Putting everything back together was even easier as it all was obvious where everything went.

Yes, adjustments can still be made, to answer your second question. It's just that it would be easier with everything off to get it right. And as JACoH said, unlatch the fuse box cover so you can get under it once your STB is installed.

 

This past weekend, I installed a Scion XB (08+) TRD Anti-Sway bar. For all those who are looking to reduce how much our car 'rolls' when taking turns at a good clip. This here is the answer:

Re: Does Prius III has anti-roll bars?

The total sum of all parts which I have added/changed on my car with the final addition being the rear anti-sway bar, I can honestly say I am now driving a completely different handling car from what I had originally purchased over a year ago.

As it stands, here is my mods list in the order with which I acquired each piece:

Kazera KZ-J 17x7.5" Rims w/ Kumho KH16 215/45R-17 Tires
Tanabe Sustec Under Brace -- Toyota Prius (10+)
Cusco Center Power Brace -- Toyota Prius (10+)
Tanabe Sustec Front Strut Tower Brace -- Toyota Prius (10+)
TRD Anti-Sway Bar -- Scion XB (08+)

Without having had to change out my springs or shocks/struts, I must say that the car is now performing at the level that I like. Before I got the anti-sway bar, I characterized the drive experience as being fun. I was wrong. What the car feels like now is a blast.

For everyone who has been looking for a means to decrease the amount of roll in the body when taking turns, the rear anti-sway bar is the way to go.

When the rain clears up here in the North-East, hopefully by tomorrow, I'll take the car out on a few excursions to see how well I can hammer her thru the switch-backs. From what I've already experienced since installing the RASB, I'm in for alot of grins.

 

So which part helps tighten up the chassis and gives less of a wobbly feel the most? Or another way to phrase it, if you had to buy just one part out of all of those, which one would you buy?

 

Currently considering the Cusco Center Power Brace, Cusco Front Lower Arm Bar and the Tanabe Underbody 2-pt Brace. Curious if any of you have recommendations on prioritizing those 3 options, and which of the three will yield the most improvement.

I am inclined to believe that the 2-pt brace by Tanabe that is smack in the center of the vehicle will yield little improvement. My thoughts are that the 4-pt Cusco power center will yield the most improvement, followed by the a-arm. My goals with the braces would be improved straight-line stability.

Thoughts?

 

Tanabe underbrace keeps lower part of strut tower parallel, and reduces steering force. Not to the same extend as STB, but at least 25% improvement with marginally better front traction. Cusco center brace would reduce front-rear flex. Neither would help with straight line stability.

What helps with straight line stability is lowering rear tire pressure. I was running 42 front/40 rear and had issues in crosswinds, dropping to 42/38 alleviated it. Basically at static load you wanna make sure that front/rear tires are flexed similarly, the lack of stability is due to high profile soft tire casting, not b/c of body flex. When wind shakes car, front tire deflects more and pulls car to the side if pressure incorrect good luck.