WIND!

These past couple of weeks we've had some serious gusts out here in SOCAL. I concur, the Prius is not the best choice vehicle to sustain high winds. I was tossed around on the freeway by 40mi per hour winds. It's scary when you have a couple of semi trucks next to you. I'm thinking of adding the BT Stiffening plate and upgrading my tires.

 

<div class='quotetop'>QUOTE(qbee42 @ Apr 7 2007, 04:12 PM) [snapback]419473[/snapback]</div>

Hi Tom,

I agree. That is why I did the tests with out any steering at all. Until one realizes how long the time-constants are on an unmodified Prius, one can easily induce the PIO (pilot induced oscillation).

 

<div class='quotetop'>QUOTE(donee @ Apr 7 2007, 05:24 PM) [snapback]419539[/snapback]</div>

I know PIO. I bounced nearly the length of a fairly long runway one time doing exactly that. I should have gone around, but pride made me fight it out. It was on of my first times solo in a 172, and I wasn't used to the very light wing loading. I carried a bit too much speed into the landing, bounced, and then over controled my way down the strip: bounce, bounce, bounce (insert bits of profanity between bounces.)

Tom

 

Hi Adam1991,

Well, I am an highly trained engineer. And the only time my engineering work has been overseen by a lawyer is when making patent applications. Actually, its been more like me overseeing the work of the lawyer. to be sure what the lawyer put on paper is accurate.

Yes cars are designed as systems. And as far as handling goes some companies do it better than others. Honda, VW and Porshe have good reputations for handling, but I am not sure if there is any real testing of cross wind resistance done. Even if somebody was the "cross-wind handling engineer" how could he/she test the results of his system design? Are there even any wind tunnels that can turn the car sideways while the car runs on large diameter rollers (so the car is not held on-course) ? Are there even any automotive wind tunnels that can gust? Not all effects can be statically determined. I mean there are allot of various rubber pieces between the road and the chasis. And when which one deflects can effect the outcome. Its a long way from Japan to a midwest USA springtime highway. Are there any interstates in Mongolia for so they might test closer to home? What if that year there were not any of these 40 mph gusty conditions. Does not happen every year, or neccasarily during daytime, without rain.

 

I've got the BT plate and it did cut down on the buffeting.

I also bought the BT tech spoiler. The first time I put it on it started to lift on the edges. I took it off, completely cleaned it and Brian sent me a kit to re-apply it, but I haven't had a chance since. It's either been too cold or I've been busy. I haven't had the problems significantly enough to make the time. And to tell the truth, I'm not sure I'm looking forward to having to take then thing off again if this second kit fails to sufficiently adhere the spoiler to the rear glass.

I highly recommend the BT plate.

But for the $150.00 it cost me, I consider the spoiler a waste of money. I haven't read any threads about it recently so either its effectiveness isn't as significant as the plate or Brian never ironed out the kinks of getting it to stick and its not being sold anymore.

 

<div class='quotetop'>QUOTE(Godiva @ Apr 7 2007, 04:01 PM) [snapback]419583[/snapback]</div>

I had pretty much the same experience you did. I would also recommend the BT Plate. I thought the spoiler did work and it seemed to provide some stability when trucks went by. Unfortunately mine came unglued too and the kit Brian sent to restick it didn't work either. I contacted Brian some time ago and he said he was working on getting some better adhesive. I hope he does because I would like to try it again.

 

Yeah, that's the last I heard, but I haven't head anything since. I figured I'd skip the second kit and wait for the third fix. Then wait for someone else to try it and see if it worked any better than the first two.

 

<div class='quotetop'>QUOTE(Godiva @ Apr 7 2007, 07:01 PM) [snapback]419583[/snapback]</div>

I also bought the spoiler when I bought my first BT Plate. When I read about the troubles re sticking I never installed the thing. Are you expecting another adhesive from Brian ??
Love the plate. Have it on both the new cars.
Carl

 

I don't know. I sent him an e-mail asking if there was a better fix.

 

<div class='quotetop'>QUOTE(Bill Merchant @ Apr 6 2007, 10:16 PM) [snapback]419221[/snapback]</div>

<div class='quotetop'>QUOTE(adam1991 @ Apr 7 2007, 05:10 AM) [snapback]419325[/snapback]</div>

<div class='quotetop'>QUOTE(adam1991 @ Apr 7 2007, 08:02 AM) [snapback]419352[/snapback]</div>

<div class='quotetop'>QUOTE(adam1991 @ Apr 7 2007, 11:12 AM) [snapback]419439[/snapback]</div>

Where did I tell anyone to inflate their tires to an incorrect pressure? I mentioned that some members, in fact many, choose a different pressure. The maximum pressure specified by the TIRE MANUFACTURER is far from meaningles.

Adam, you are a jerk.

 

<div class='quotetop'>QUOTE(Bill Merchant @ Apr 8 2007, 03:24 AM) [snapback]419734[/snapback]</div>

Aw, what do they know about tires?

Tom

 

<div class='quotetop'>QUOTE(Bill Merchant @ Apr 8 2007, 09:24 AM) [snapback]419734[/snapback]</div>

I can understand Adam's comments, even if he did not say it very tactfully. The tire manufacturers know the limits of their tires, but cannot know what the effect of a particular tire pressure is on a particular car. So you can assume the tire won't explode, but that does not make it safe.

There's a thread that points out the dangers of not sticking to the pressures recommended for your specific car, as specified on the door sticker. And safercar.gov says this:
Overinflating tires can adversely affect vehicle maneuverability, make the ride harsher, and sometimes lead to loss of control and crashes.

So anyone deciding to follow any advice found on this forum overriding the tire pressure recommended by the sticker on THEIR car (Touring might be different from base, European different from US etc) does so at their own risk. Anyone recommending such a change should realize and mention the possible danger involved.

 

Well I used to have the same problem...
It might be my imagination haha but after I installed the BT plate and the toms upper strut bar it all seemed to even out... If i feel anything its minimal... and i guess the TRD suspension may fix that

 

Posted in wrong thread, sorry.

 

A little over 4K miles on my Pri now and I got my first bout with the wind issue last night. I drove onto the interstate and from the onramp had to merge between two 18 wheelers. I must have been driving about 60mph but felt the Pri swaying back and forth while following that truck. Luckily I had to get off the next exit but having driven many vehicles over the years I can say that this was by far the worst handling under the conditions. Personally, for me it wasn't a safety issue as much of an annoyance.

 

I've had my Prius since Jan. 2006. Everything is stock; tires are at the manufacturer's recommended pressures. I live in New England, where it tends to get windy, and I drive over a suspension bridge to work everyday. I have not found any problems due to the car being unduly buffeted by wind. My last car was a Honda Element, which is a box on wheels, but I have owned a variety of cars and can't say that the Prius is any worse in windy conditions than the others. Maybe I just have good alignment on mine. I might try the BT plate and I will probably upgrade wheels/tires in the interest o improving handling, but so far, no wind problems.

 

<div class='quotetop'>QUOTE(ABQ Prius @ Apr 6 2007, 11:55 PM) [snapback]419208[/snapback]</div>

I have also had my Pri for about 1.5 weeks. I LOVE it thus far. I have noticed that on my trips to work along interstate 380 in the Pocono’s, PA I do feel unstable. I did not try any tactics to help this yet. Just held on to the wheel with 2 hands. I am going to try to correct the air pressure to 42/40. Does everyone ride with that?

 

<div class='quotetop'>QUOTE(Bobby @ Apr 13 2007, 12:02 PM) [snapback]422681[/snapback]</div>

I don't think that there is a single thing that every prius owner does. I have mine at 40/38, but I did drive for 35/33 for months. I'm still running stock everything without any major issues after 15,000 miles. Not sure if I just got a good one or if I'm less sensitive than others. The only time I have been blown around was a night where the winds were so bad that everything else on the road including trucks were having a hard time keeping in a lane.

 

I don't believe that there are "good" Prii (plural, correct?) and "bad" Prii when it comes to this wind issue. They are all built to the same tolerances. It is the shape of the Prius that causes issues from side winds -- head-on or tail winds most likely don't cause much such issues, if any.

I drove my partner's GM truck the other day, and it was buffeted as much as the Prius -- the only difference is that with the Prius, it is very easy to overcompensate because of the high steering sensitivity.

Also, adding tire pressure will actually make your car LESS stable. Lower pressure puts more rubber on the road, giving you wider shoes and increased stability. Higher pressure will actually reduce your footing and give you a stiffer ride. The latter will exacerbate the effects of wind or any other external impacts, as they are more efficiently transmitted to your steering column.