Installing Strut Tower Brace Questions?

I ordered the Tanabe STB(strut tower brace) for my '07 Prius Touring. I'm hoping this is a pretty simple install? Couple questions..

1. Does the car have to be raised to get the weight of the suspension? Or just level on the ground?

2. I see it is adjustable for "width"?? When I install it, do I need to tension the bar in any direction, or just make it fit?

3. Anyone do this to their 2nd gen Prius? What all needs to come off if anything? I see the gen 3 guys had to remove the cowel?

Here is the link from Amazon which is where I purchased from. I'm a "Prime" member so it was a no brainer... http://www.amazon.com/gp/product/B004QO12NU/ref=oh_details_o00_s00_i00

also, I bought the Tanabe rear under brace. Anyone do this modification?
http://www.amazon.com/gp/product/B004QNW320/ref=oh_details_o00_s01_i00

you shouldn't need to raise it, you want the struts loaded. no instructions in the box? i don't think you want to pre-load the brace, unless the instructions tell you to. i would think you want the brace pushing the struts outward rather than pulling them inward, but there's got to be instructions either in the box or online at the manufacturers site

The instructions are laughable! I'm attaching below. The rear under brace instructions are even worse.. ALL in Japanese!!!

After the rain stopped, I went and looked under the hood... sure enough, I'm going to have to remove the wiper assy and cowl to get to the strut towers.. oh well.

The brace is to keep the two strut mounts from moving independently. Do all the work with the car on the ground. I could point you to some good instructions for a Gen III install but I don't know if they apply to a Gen II. Most of the work on a Gen III is to get the windshield wipers & tray out so the strut tower tops are accessible.

After you install the mounts on the strut towers, you'll have to adjust the ends of the bar so that it spans the two mount points' attachment points and stands vertical when unloaded. I'd suggest not tightening the strut tower mount nuts until you've installed the bar, then tighten the nuts. After installing the brace, (assuming it's like mine), hand-tighten (load) the bar by rotating it up and back. Mine rotated about 45 degrees. Go have fun!

I don't own a Pris Generation IO or any of the components that you mention, except what Amazon calls a Tanabe "Sustec" "rear" underbrace. I've been working extensively on both front and mid-chassis braces for the Prius "v," which has the same underpinnings as the Generation III.

The Tanabe brace is really a "front brace" My experience with the Tanabe "Sustec" brace is that I could do better and less expensive. I'm NOT one to brag, but I achieved much better design and implementation reusults of onle a 3 ounce addition weight than the Tanabe bar. Just read the comments in the thread that I started and the descussion that followed;

http://priuschat.com/forums/prius-v...icer-version-tub153f-2-point-front-brace.html

As far as the BT Tech mid chassis plate goes, I developed a simpler design that imparts greater stiffiness than the BT. The BT by its designed structure, while stiffer, sill had a great deal of flex. Here's the discussion thread on the improved box beam chassis stiffener;

http://priuschat.com/forums/gen-iii...chassis-stiffening-brace-center-box-beam.html

As for the strut tower brace, I decided to to tackle its complicated install and its obtrusive limiting factor that hinders access to the servicing of the components under the hood.

The most important upgrade must be the mid-chassis beam. The front chassis brace is an additional plus. I found the hard to install "strut tower brace" to be unnecessary, after installing the two chassis braces. Eventually, I will write a conclusive report based on my findings.

Mike500

I've linked the MS word file from the following post at the bottom:

http://priuschat.com/forums/gen-ii-...-strut-tower-brace-install-pictures-text.html

From Lee Gadget Dad's Installation instructions. The braces are different, but the install is the same.

Attached Files: BT Tech Strut Tower Brace Install - By GadgetDad (Lee) v2.doc

It was an easy install, it just took about an hour for me to install my tanabe-clone sabre-sport strut tower brace.

I used a piece of cardboard to keep track of which bolts go where. I pushed the bolts though the cardboard, and labeled what part the bolts came from. You have to remove the wiper assembly, cowl, lower cowl, to get to the strut towers. it all comes apart easily, and goes back together just the same. but there are more than a few bolts to keep track of.

I would also recommend purchasing the G7 Chassis Brace from eBay if you already haven't already gotten a brace for the rear, it took me 10 minutes to install and for less than $100 why not!? Here is a link to an available auction:
http://www.ebay.com/itm/G7-Performa...Parts_Accessories&hash=item1c234b8b69&vxp=mtr

Mike500... very nice work you have! Wish I would of seen this before I purchased the G7 plate(installed and made a nice improvement), and the Tanabe chassis brace. I'll keep track of your builds and when you come out with a better ?????, I'll be a guinea pig

Dave09prius... thanks for the links! I've got the wiper assy and cowl out. Taking a break and going to tackle the STB instal now.

And yes, I already purchased the G7 and it's installed. Noticing the improvement is what prompted me to get the STB and chassis brace.

BTW, the Tanabe chassis brace did not come with hardware. Do you just reuse the OEM chassis bolts?

The G7 is a copy of the BT Plate. I see no advantage to the lightening cuts and black anodizing on the aluminum.

The lightening cuts , as I discovered, will reduce weight, at most, of about 2 ounces.

The exhaust heat shields are made of aluminum and not coated. They will last just fine for the life of the car, as it.

A "sheet of aluminum," however thick, add only a limited amount of stiffness to the brace. A tubular box beam is structually strong and stiff. That's how thin aluminum, not more than a few times thicker than paper, can be made into a strong airplane fuselage, a wing or a spacecraft, like the space shuttle. Just think how thin and how little aluminum is ia a soda can. Yet, it is exceptionally rigid and holds a lot of pressure.

While the Tanabe "Sustec" bar uses the OEM bolts, therein lies it's weakness. The 1/16" thick aluminum is fastened in with the washered bolts. The edge of the washer creates a "stress point," whrere the edge of the washer "digs into" the aluminum every thime that the bar is flexed. With only a 3 ounce penalty, my design uses massive billet aluminum components that are under almost NO STRESS with each flexure. The design will outlast the car, effectively having an "infinite" design life.

My findings,

Mike500

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These things are pretty but you are getting about zero handling performance increase from them.

For one thing there's really not any body flex between these points, and if there was it wouldn't matter in the least with a fully rubber mounted suspension that has at least a 1/2" of cumulative mount movement.

If the Prius had 300 hp and you were cornering at 100 mph with a solid mounted suspension you "might" get .050" movement at these points. Eliminating the .050" movement might gain you .0005% increase in skid pad G's.

If you did replace all the rubber mounts with hard urethane or solid mounts and you wanted to lose that .050" movement these braces probably wouldn't do it, especially the top one.

The bends in the top mount make it weak, especially the small black tubing at the ends. The force that it takes to move this chassis .050" at this point is way more than these bends will handle.

The Prius suspension with it's torsion beam rear axle is one step above a tractor. These add on braces are going to give you just as much handling performance as the decal on the window, all they are doing is adding weight. You would be better served finding some urethane suspension bushings/mounts and some stiffer springs and sway bars.

If someone really wanted to improve Prius handling they would come up with a independent rear suspension retrofit.

How did you measure the body flex (or lack thereof) between the strut tower mounts? Did you use a mock bar or dial indicator? I have a hard time believing there is no flex... one can observe quite a bit just jacking up one corner of the car.

So what you're telling me that in no way a strut-tower brace, a stiffer under chassis brace and a rear sway bar will make no difference in the vehicles handling? I hate it when people say this, you obviously haven't tried the mods yourself, because I can tell you that they do make a difference. I drive 130+ miles every day, most of which is fast highway speeds. I have multiple opportunities to 'test' the suspension and vehicle handling everyday. Each mod has slightly increased the vehicle's handling. They may not seem like much, but they do improve the vehicle.

They are way more than just adding weight.

The flex in the exhaust system tunnel, both just behind the engine cradle and at the mid-point of the chassis gives the driver a false sense of instability, when the car is actually very stable.

To me, that is a very very bad feeling of "false feedback."

Starting with the 2012 models on the gen III, including the "v" and subsequently, early this year, Toyota "silently," and without informing anyone, upgraded the chassis of all Prius models, including the "c" with a stiffer chassis to eliminate the "false" feedback.

With the 2012 models, the "L" shaped braces connecting the engine cradle to the outer floor pan stiffing rails and the exhaust tunnel rails were replaced with much stiffer and stronger "triangular" braces.

In the early spring of this year, "ALL" Prius models were fitted with stiffer "composite" welded steel mid-chassis braces.

Effectively, a "front" underchassis brace and a stiffer mid-chassis brace would effectively upgrade the Gen II to the stiffer and better ride quality of the Generation III plus models.

Photos of both the OEM and upgraded mid-chassis brace installed in 2012 production models are attached for the information of Gen II owners.

The issue isn't instability. Toyota wouldn't want to put an unstable car in the hands of the masses.

It's about improving the car's stability, and the driver's perception of the car's stability.

As long as you can jack up one corner of the car, and three wheels remain on the ground, there is still room for improvement.

Everything flexes. It all depends on how much. Even "adamatine rock of ages" flexes.

There is, however, a difference between the fflex in the frame and the boay and the suspension. The suspension is designed to flex. You don't want it not to. If it deesn't your will have a "bone jarring ride."

...except with the prius, the body is the frame. There is no difference. Once you understand this concept, the rest of this thread will make sense.



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Hey what part number is the Tanabe-Sustec under brace? Is that the TUB151F Brace? It looks different than the one on the Tanabe website. can you post pictures of it once you get it installed?

The Tanabe photo is a "generic one."

The photo that alexilic posted is correct. I believe that the part# for the Gen II is correct.

Is that Tanabe underbrace install upfront? or in the rear? I wouldn't mind installing one more brace up front.

It's installed on the front, just behind the engine cradle.

There is an awesome how-to someone on this forum, but I couldn't find it. I have one that fits the GenII that I bought, but never used. It's on ebay right now if anyone is interested. The link is below.
Tanabe Front Strut Tower Bar Toyota Prius 05 09 | eBay