Cusco Rear Chassis Brace, 952492REN.

Just the bar is included, instead of the uni-body railings ends taking the torsion stresses it it ties the 2 ends together and makes it undergo the tension horizontally.

 

Bill that being said, crumple zones are meant to absorb energy, kind of like how concrete can take compression but not tension.... That's why there's rebar put inplace.

 

JJ,
Very true, yet somehow I feel a little safer having that chunk of steel back there at the aft end of the aft crumple zone. Plus I get all the real benefits of having a receiver hitch !

That pretty piece of aluminum does not do anything,,,,,, IMHO.

 

I guess that's your opinion then, but from my hand's on- road racing experiences with other simlar(but faster) compact vehicles built of similarly (uni-body) (without being 100% steel), and dealing with this stuff at school, and at work (In the Aerospace/Aviation industry)-- (Applied Mechanics (X and Y axial)- [Dynamics and Static loads]- it seems to me it will help a marginal amount, how much I'm not sure (I could mount a Vbox and find out).....

As far as the trailer hitch, I'm not sure how 2 end plates being mounted to the rear aft end of the frame rails and being quite a distance away from the subframe floor would work as well.

 

Well now that you show it like that, maybe both are equally flexy.
Don't both of these use the same existing mounting holes on the car?
So, we need to use Science !
Is a 'Vbox' a strain gauge type of data gatherer?
You could test loads and flexing on both of these 'stiffeners'.

I too am in the Aerospace/Aviation industry and have had lots of experience with high-end vintage race cars, both maintaining them and repairing sheet metal monocoque frames. One was Mario's car for a season !!! But now a rich guy plays with it,,, and breaks it !

No, forget it. Your brace is cool. My trailer hitch is cool. They both have multiple purposes, some similar, some not.

 

There are 2 on the other side as well (for the towhook)

 

Both do use the same mounting points, just the rear tie bar is closer to the sparetire tub reducing the flexture of the tub chassis.
Vbox is a velocity meter that can measure track times and cornering loads.

 

Nothing personal, but has anyone seen all the chassis stiffeners offered by Brand C for a lot of different cars?
Holy Moly ! Some of them don't even tie the sides of the car together.
Does Brand C have any documentation on the measurable results of throwing thousands of dollars at the underside of a car?
All chassis flex starts at the suspension attach points, correct?

I suspect it is mainly for ALL SHOW, NO GO.
Do these Racer Boys have Get Togethers with mirrored tiles on the ground and stand around looking at each other's Bottoms??

 

BigPete,
You're my Buddy. You pointed out the cheapest place to get TRD springs and rear sway bar, dang it.
You started me down the road to having a better performing Prius, dang it.

The rear sway bar is the most important and noticeable suspension upgrade.
You saved if for last and bought a bunch of stiffeners that really can't be quantified???

A 45 minute install of the rear sway bar and take the car back out onto a skid pad and Bob's Your Uncle!
You now are pulling way more lateral G's.
Springs, coil-overs, every Blue Gee-Gaa you can bolt on to the underside of your car will not make this much of a difference.
Add some sticky, wide, low-profile tires and you now have a FUN Prius.

Don't get me wrong... I will be adding a front stiffener between the front suspension area.
That's where all the biggest loads come into the chassis, right?
Only I'll be adding it last. And I hope to hell I can feel a difference with it......
and remember, there are feelings and there are measurements.

 

If you have the thin "hourglass" brace right now, you will find a marked improvement in stiffness.

However, if you cave the "tubular" OEM brace, the improvement in stiffness will be less.

The part of the Cusco brace that takes the stress, both twisting and bending or folding will be the center section of the crossbar between the welds of the trailing members.

The "trailing" bars effectively does very little to stabilize the car, since the rails are free to move in a "scissors-like" action.

The JDM model shown here,

2012 2013 Toyota Prius ZVW30 ZVW35 Door Under Floor Support Bar JDM VIP Japan | eBay

does the same thing without the "trailing arms." The stress on the beam is spread over its entire length, while, in the Cusco 4 point is spread over the shorter section just 1/3 the length.

Like it or not, these are the facts. The Cusco just looks nice.

 

I must say this is NOT a boring thread!!! A good deal of useful information, pros and cons, truths and untruths, enough to help those considering this mod to make a decision either way. I myself read this tread minutes after installation.

Yes, the under tray is a challenge. I spent the majority of my time (on my back) figuring out how to remove the three center fasteners on the tray...BTW they don't come off, you simply turn counter-clockwise to free the tray lol. I ended up NOT removing the drivers side most forward fastener and was able to easily move the tray with adequate room for the install. Rather than cutting a notch out of the tray, I simply made two cuts and allowed the tray to rest against the brace.

This is my third chassis mod. I first installed the Prius Plus rear sway bar, then the Tanabe strut tower bar (w/revised drivers mounting plate), and now the Cusco rear under brace. I have both the Cusco mid power brace and the front lower arm brace on order. I also have Tanabae DF210 springs and KYB Exel-G shocks and struts on order, shocks and struts to be proactive (bought my Prius a month ago with 174K miles).

All the mods that I am completing are for show, although I do push through corners and windy roads a bit more aggressively! Is it no surprise that I also work in aeronautics =)

 

Hi BigPete,
The Cusco rear bar is a quality piece. Super strong/stiff. I have one and did the install. I believe you will feel the difference. I did. You do have to notch the big plastic cover for it to fit back on properly and looking correctly. I eyed mine five times or more to notch the plastic and cut the small piece out as is shown in the instructions/diagram and it looks like a factory install. Take it slow. Review the diagram in the instructions closely. The cutting the plastic bit out "to perfection" was the fun part. Get it. Install it. We're waiting for your review!

 

I have this brace, too, on my Prius v. It is made of steel, not aluminum. It does weigh a lot less that the trailer hitch that I also have. Occasionally, I install the trailer hitch when I need it. Most of the time, I have the CUSCO installed.

 

Why would it not be OK to use such a brace on a vehicle used on public highways -- point two under "Attention"??

 

Would be just fine. That's only a legal disclaimer, because it has not been tested by regulating government or industry regulating authorities as the Department of Transportation or the Society of Automotive Engineers.

A lot of aftermarket items have this legal disclaimer. LED bulbs are a common item not certified and as such "recommended for off road use only." They work just fine and are a lot better than incandescent bulbs that they replace.

 

"Feelings. Nothing more than Feelings."

This brace is 3 ft. away from the rear wheels and suspension components. How can it do anything?

Measurements, so much more that Feelings.