** THIS POST HAS BEEN MOVED TO THE GEN III MODS AREA ** It appears that a version of the Yamaha made "lateral performance dampers" connecting the strut towers on the Lexus CT200h are sold in Japan as "Cox (brand) Body Dampers" and are available specifically for Gen III Prius. One Japanese web-site with information is here: COX BODY DAMPER setting by D'TEC ①｜クラウンハイブリッド/トヨタ｜整備手帳｜Super City｜みんカラ - 車・自動車SNS（ブログ・パーツ・整備・燃費） Although the damping part of these products appears to be the same as the Lexus part, the design of each end of the damper is different. I think one or two versions of these dampers are sold for different car models, with only the connecting end parts varying from one model to the next. The info at the above link definitely is for a Prius, as are the undercarriage photos. The dampers sold for the Prius connect to the lower part of the frame (instead of the strut towers like on my wife's CT200h). Still, they claim very similar benefits as far as NVH reduction. They are VERY pricey (about $700 each in USD). Still, it would be interesting to find a US rep for these parts and determine if (1) they work as claimed and (2) they could be found for a lower price. My quest is to make my Gen III as smooth and quiet as possible. It will never match my wife's CT200h, but the Prius will always be larger and get better mileage (my preference). I replaced the Prius' OEM Goodyear Fuel Max tires at 15k miles with Goodyear Comfortred and the difference was excellent - far quieter and smoother ride. I've also installed a type of durable rubber weather stripping on the metal lip of the leading edge of the rear doors. This seals the vertical gap there (same as on CT200h), reduces wind noise and absolutely looks factory-like. But other than adding insulation to doors, etc., I'm convinced that "body dampers" (if they could be found at a reasonable price) might provide a significant next step in lowering NVH. Fellow Chatters, feel free to chime in with your opinions on this. Hopefully, someone will discover more info on body dampers. And if one of you can read Japanese (!), a translation of the above site (that's better than what Google offers) would be very helpful indeed. Thanks!
Even worse than I thought! Using a on-line Yen-USD conversion calculator shows that each "body damper" is almost $1,200. That's obscene! The "lateral performance dampers" for the CT200h go for about $350 each. Pricey for sure, but much cheaper. Now if one could use the Cusco or Tanabe strut tower bar end brackets (modified?) with the Lexus damper, a more "affordable" solution might be had.
Whilst I can appreciate the effects, I am having troubles getting around the concept of the web page. It seems like they are there to stiffen up the body but with a shock absorber there, how can you say it stiffens it up? Then what if the bar was made of hard-ish rubber like you might see at the end of a rubber hammer to dampen the body but not do much by way of body stiffening. Not sure if any engineers would agree but what if we put a solid bar at those 2 locations with thick rubber washers/gaskets to allow a degree of dampening if the resonance is the cause of some of the noise.
You both realize you are posting in a Prius v forum right? You might have better luck in the GenIII forum since the modification crowd is more mature than that of the mod crowd for the v.
Mac Prius, Sorry... totally my mistake. Do you know if the original post (and threads) can be moved to the Gen III mod area, or will I need to go there and start again? Thanks.
This website COX Body Damper suggests that the car body is a spring. If so, then the idea of a damper makes sense. That is, if something is designed to move, but you want to impose a limit. Stiffening at each end wouldn't appear to do much. Perhaps if the car had experienced a severe frontal or rear-end crash the dampers might be a bit of assurance after the repair. The damper diagram shows a gas pressure of 0.8 - 2.0MPa. Aren't standard gas-filled dampers (shock absorbers) pressurised to 2.0-3.0MPa? If so, why would a body stiffening device have less pressure? The D-Tec website doesn't show the car as a spring at least. It does have a video of a nicely-dressed mechanic and a model that shows how resonance is damped but not why that might be important or beneficial. (I'll try to fashion an translation later.) On the other hand, if it was sold on the promise that it will reduce the squeaks and rattles from the NVW30, then they might be onto a winner.
