How about a simple and inexpensive mid chassis "transmission tunnel" stiffening brace? I read nearly all of the posts on Priuschat and many of the posts on other sites regarding the "mid chasis" stiffening plate for other Prius versions. While nearly all of them are an improvement over the thin and nearly flat "hour glass" shaped sheet metal strap held by four bolts to the bottom of the rails of the transmission tunnel, none of thems seems to be structually design for maximum stiffness and rigidity. That can only be had with a "box beam." My design will be simple and elegant. It will hang down only a lttle over 1.5 inches below the bottom rails of the transmission tunnel. I'll be using a special 6105-T5 aluminum extrusion with rounded corners, which is nearly twice as strong as the run of the mill architechual 6063 with the square corners. Since the mounting holes for the brace are only 78mm apart, I see no need to make the brace as a plate three to four times as wide, as others have done. CNC milling the stiffener out of solid aluminum and anodizing it to a pretty color, while nice to brag about, in may opinion, adds no benefit to the function of the stiffener. The longitudinal axis os the tube is exceptionally strong and stiff as it is and will keep the bottom legs of the transmission tunnel from flexing much better than the OEM separator. I also considered making the tube "torsionally stiff," but it does not appear to be necessary, since the transmission tunnel, itself is a tube and stiff enough, already. Basically, for a mere $40-$50, I believe that I can achieve the same, if not better stiffening as the $120-$200 custom made plate. My box beam stiffener will mount with the original screws. It can be easily adapted to all Prius types by drilling the mounting holes in their appropriate locations. I will keep the folks, here, informed and will post photos of the simple elegant solution as it becomes available.
I'll look forward to being kept informed! Thanks. Sounds like it might be a good DIY challenge for someone with the appropriate skills and equipment? This would be something that I'd consider buying, though, as my metalworking/milling skills and equipment are rudimentary at best. Something made out of wood, however, would be a different story! (I've been thinking of making a wood shift knob - maybe curly maple, or layered maple and cherry, or some exotic that'd polish up nicely - but that's still early in the planning phase...) Anyway, keep me informed. :nod: Andy
I'd also be interested in that. I have the aluminum billet stiffening plate on my 2007 and it definitely made a difference in handling and body roll.
Andy, I'm not interested in making these for commercial sale. I can't see buying a a very expensive CNC plate with multiple lightening cavities milled into it and an expensive anodized finish., when a simple lo cost solution does the same thing. The aluminum I will use will have a 1/8" wall, just like the ones that are extruded and are used in the bumper reinforcement under the bumper cover. There's no need to worry about corrosion. I've had 6061 outside for 20 years with no appreciable corrosion. I'm just looking at the least expensive and easiest to make stiffiener that will do the job. My aim, here, is to provide other's here with ideas on how to make their own. I can see how some users of ther Prius models migh want to adapt my design for thir cars. Like the custom jacking blocks, I might make a few to sell to fellow Priuschat posters, if they are not handy at making their own. I removed the bolts and took off the brace, today. The bolts are M10X1.25x 20mm long. I've heard that they are M8 on the regular Prius. I thought about using channel or an "I" beam, as well as welding angles on the end to recess the tune into the space in the body. The 1.5x3 inch structual tubilg seems to be the simplest solution. The tubing will sit under the rails, create very little aerodynanic drag and still sit higher than the catalytic converter. Anyone can design an expensive, heavy and labor intensive to make stiffening plate. I want to design one that is inexpensive and easy to make and install. I see no need for stainless steel bolts. The OEM ones work just fine. And, I'll use 10mil UPC plumber's direct burial wrapping tape to insulate the aluminum from the metal of the main body rails, although it may not be needed, since the body is painted. Any commercial shops, who are interested in using my ideas, are very welcome to, as I am putting them in the public domain. Regards, Mike
I thought of making just one for myself. On second thought, I have enough material on hand to make four of them. I will probably do it, this weekend. For my own, I might use my hole saw on the drill press to cut a series of lightening holes on the bottom to give it an "aircraft" look. On the botton, it would not affect the stiffness of the brace.
I have been busy for the last couple of days and spent about 10 hours making the "box beam" chassis barce and installed a prototype on my car. The 12 lightening holes on the prototype did not get the result I wanted. It saved not even 5 ounces in weight. The sold "box" beam probably creates almost no turbulence, since the bottom still sits higher than the main engine covers, the gas tank and the rear components. 3 hour on the milling machine were needed to get the alignment of the mountiong holes correct. The "box beam had to be milled for clearance to use the standard bolts and the required 14mm socket and torque wrench. The box beam "preform" weighs about 8 ounces more than the "wimpy" steel OEM brace. The OEM weighs 1 pound 5.3 ounces. My box beam weighs 1 pound 13.5 ounce; maybe a tenth less after final machining. As I stated, there will be only three avalable for those who are interested. They will be finished this weekend. For all the work involved, the $48 that I'm asking for each delivered, I believe is a bargian. I wish I could have bought one for that, myself.
Emailed you a moment ago. I definitely want one of the box beam stiffeners. Will install and share results with the group. Peter
Andy, Please send me a PM, and I'll send you the details. I will send one out, tomorrow. I've got two in "preform" condition left. I can get them finish within a day or two. Thanks for your interest, Mike500
I'm interested in how much improvement in handling you get from this great design. As you're not interested in mass production, perhaps there is another way to crank them out. A guy at Toyota RAV4 Forums : RAV4World.com has set up a CNC plasma cutting table in his garage to make custom parts. From what I've read, it can handle a 4' x 4' sheet of metal up to 5/8" thick. Looks like it could crank these out of sheet aluminum or steel pretty quickly. Here's a video of the same plasma cutter/etcher that he has:
Interesting...... This would be great for a younger man wiho would be interested in starting a "cottage industry" small business. However, I'm retired in my 60's after three successful carreers in three diverse endeavors. I only create innovations to keep my mind sharp and occupied as a hobby. Also, it is very satisfying to pass on my ideas to others who can benefit from them. I've spent and owned several patents for which I spent tens of thousands of dollars, which resulted only in monetary losses and no profit. Although these were monetary losses, they were not failures, since so called "failures" result in the best lessons learned. A lot of good innovations don't make it, because of the 'inertia" of certain industries. Being adopters of hybrids and EV's, we already know that of the majority of the driving public and auto industry. So, although I'm not poor, I'm not rich, either. I'm just happy and comfortable with whatever I'm doing right now. Life is "peace of mind" and realizing you have enough.
Has anyone installed yet? If so, what are your results.... I have yet to install mine and am curious as to others experience so far.
DGH PM'd me, yesterday and said that he bolted right on will no problems. I hope that you have the same result. Yours was made with the same bolt hole spacing.
Great...haven't had the time to install yet. I was wondering if anyone has yet to establish differences in rigidity/performance. Thanks
Thank you, I've noticed some increase in performance in mine. And, I've since discovered that the same strenthening beam will fit the Generation III Prius. A few posters, here, have expressed interest in getting one for their own "v." The trouble is that I cannot order the tubing in a small quantity. Each unit already sent out was custom marked, machined and drilled, which meant that making them was very labor intensive. I know that the tubing will cost more for future units, but I hope to offset the cost by streamlining the process of laying them out and making them, so that I can still offer them for $50 each delivered. I have developed a more accurate way of manufacturing them, especially when it comes to the mounting holes. They will, however, still be custom made and individually finished to a high standard. Anyone interested, please let me know if they are interested. Regards, Mike500
