New Prius Handling Components to be available soon!!

I'VE DONE IT!

Took a little over an hour. This was for both installing Brian's plate and installing the mudguards. I figured as long as I had to jack the back up, might as well take the wheels off and do the mudguards. Plus don't have to pay the service department.

I took the car over to my Dad's house because he had jack stands. Turns out he also had a shop jack and a pneumatic drill with the correct size sockets.

Time saved: Dad's help and tools.

Time wasted: Dad's help and tools.

Time was saved with Dad using the tools to take the wheels off, etc. But wasted with "Stop, you can't jack the car there." "No, that's not the way it goes." "No you don't reuse the old bolts." Etc. I think you get the picture.

What you won't get is pictures of me doing this. Sorry, but no photos of 50 year old woman on a creeper in shorts and a tank top. I'm sure just the mental picture is enough to cause a shudder, you don't need the reality to reinforce the visual.

And my knees are pretty raw. I was the one that had to keep moving around to "spot" the place where the jack was supposed to go. And keep stopping to go back to the owner's manual and point and go "See!" Lots of kneeling in driveway.

Plus there was the resistance from a 75 year old man who had never modified his own car, ever. He didn't understand why I was taking out the stock plate to replace it with Brian's. He just didn't get why I was fixing something that wasn't broken.

He did take the old plate out for me with the pneumatic drill. Great because that's what I was worried about, not being strong enough to get it out with a socket wrench. When he got it out I handed them both to him and said "Which is better". Silence.

"You know how to put that in?" "Why don't you reuse the old bolts?"

The plate went farther forward on the car than I thought. I tried to get under the car from the rear using the creeper. Couldn't do it. Car wasn't high enough for me to creep forward enough to see it. When I located the place and tried from the side, couldn't do it either. Using a creeper is a gender specific thing. In order for me to use it, the car would have needed to be jacked up much higher than it was already. Do I really need to spell anything out more than this? Okay, one word. Rubenesque. Look it up.

So I rolled out some plastic used in offices under chairs that my Mom had saved in the garage and slid on it from each side to mount the plate. Which I did MYSELF! (Dad: "Make sure you put the nubby side down.") I hope I tightened the bolts enough. I made them tight but didn't really push it. I was using one of those Allen sets with multiple sizes, about palm size. (Brian, what happens if they loosen, fall off and the plate falls off?)

The mudguards went pretty smoothly and I want to thank whoever it was that put up step by step procedures with pictures. "No, you have to take those off." "The clips go inside." "I have to change drill bits because the bottom is different." "Because it is." "Because I read the directions and that's what they say."

Yep, what a fun afternoon.

But an hour later I had four mudguards mounted correctly and had put the plate on MYSELF.

I'm sorry, am I gloating?

Now for performance.

There is one turn I'll have to test tomorrow when I pick my Dad up for the drive to L.A. to see the Tut exhibit. It's the off ramp from the freeway to their house. Tight clover to right and uphill. I'll be able to feel how it is on the freeway tomorrow also on our drive to L.A.

But.....I do feel a difference. It may be a "Princess and the Pea" thing, but I do feel a difference. There is one slight uphill "S" curve on my way home that the car appeared not to lean so much as previously. And it may be my imagination, but it also seems slightly quieter. But most of all...bumps. There is one area just before I turn into the alley to my garage that was dug up by city water crews and when they repaired it the asphalt became all lumpy. Large area of lumpiness. In the middle of where you turn the corner. You can't avoid it from either turning or going straight across. Used to be much bouncing when I took that turn. Not so much anymore.

So yes, plate great, installation easy, go for it!

If a 50 year old woman can do it, so can you.

Can't wait for the aerodynamic thingie. *That* I can do by myself.

 

[font=Comic Sans MS:1bdb67d9f7]Congratulations, Godiva! What a great description! I was grinning [/font:1bdb67d9f7]

 

A rubenesque sandwich? The mental image just got much worse. :roll:

 

That's the problem.

Too many sandwiches.

Try looking under "Zaftig".

 

Apparently I completely ignored this stuff earlier.

Just for laughs, could someone explain why the aftermarket plate improves on the one that came with the car? Like, how much less flexing this plate is doing, to make the handling noticeably better? A reference to some performance website would be OK.

Thanks...

 

mikepaul, this thread is an excellent reference for your question. i know its long, but its been answered more than a few times.

another thought, maybe the why's and what for's might be an entry in the KB if this mod takes off

 

Umm, while I see anecdotes of perceived improvements, I didn't see a "why" answer.

Comparing the new plate to the old one, I see a huge thickness difference, but I'd have to assume that the old plate flexed a lot more to accept that the thicker plate helped. However, if I look during my next oil change and don't see much evidence of my existing plate flexing and possibly cracking, it'll remain an assumption.

Not being much of a S-curve guy, I do find my car can take a circular highway on-ramp at a constant 45MPH without a lot of hassle, so if I ever do get this mod I'd expect a lot less hassle to justify the money...

 

it would appear that this mod is not for you

it is for people who feel that their Prius needs to be more stable at high speeds or during situations of crosswinds or while negotiating curves

 

I grimaced when another person was told this, and now that it's directed at me I'm more annoyed, like I'm some dolt.

The car is quite stable at any street-legal high speed. It negotiates curves quite well. Crosswinds (the major source of any high-speed instability I've experienced) being fixed by one piece of metal implies the rest of the car's aerodynamics are meaningless.

Like I say, if the current plate shows signs of flexing when I look at it, I'll believe a thicker one could do some good. But if the current plate is unflexed, then perhaps any post-mod perceived change is imagined to justify the $160 spent on the part?...

 

You are being inconsistent. You take offense when someone suggest that this modification is not for you and then proceed to explain why it is not for you.

Some of us are used to cars that are more stable at high speeds. The few posters who have installed the stiffening plates report an improvement in that department.

The Prius aerodynamics are designed to minimized head on air resistance, not crosswinds, as those rarely affect fuel economy. The car has a rather high side profile in proportion to its width. That causes it to be particularly susceptive to crosswind interference. Hence the instability.

As far as I am concerned, $160.00 is a pretty small investment in improving what I perceive to be a problem when compared to what I paid for the car, including tax and license.

 

For the existing plate to exibit signs of "too much flexure" or torsion, it would have to be flexed beyond the yield stress limit of the material. It could be "flexing" or rotating too much and still not be permanently deformed (stressed beyong the yield stress). How much is too much is a very good question and I don't have an answer for the. I'm going to be doing a stress analysis (FEA) for Brian on his part and the stock part to at least determine how much better his newer part is. I think the kind of proof you're expecting will only come from an investment in time and money that few besides Toyota have the resources to provide.

Brian's contention, and I agree with him, is that the Prius doesn't really exhibit what you would call excellent stability on the freeway. Or put another way, it doesn't track very well. I think Toyota must recognize this as well. I read an announcement for the 2006 Prius in Australia (I assume Europe too) the chassis has been made stiffer (more torsion rigidity), has an added shock tower brace, and recalibrated dynamics for the power steering. I would not be surprised if there's a new beefier brace that's part of this. And Europe already has a stiffer suspension and wider tires with 16" wheels.

So Brian is taking a two pronged approach by looking at the cars rigidity and the aerodynamics. What he is offering doesn't reflect all the different things he has tried so far, just what he feels really worked the best at improving the handling for those of us who feel it needs to be improved. I don't want to be crass and say ignorance is bliss but to those that believe the car is great, I sort of envy you!! I just have to drive my wife's Acura RSX to be reminded what a joy a car that tracks well can be to drive on freeway. It's like night and day and I'd like to move my Prius more in the direction of tracking if I can. The factory has been no help to date and they're only offering these improvements outside the US since they don't think we American drivers know the difference I guess. And generally speaking they might be correct.

 

<div class='quotetop'>QUOTE(mikepaul\";p=\"115307)</div>

With all due respect, please refrain from this type of broad generalization. If you state that as your opinion, that's fine with me. In my case, I don't find the car stable at "any street-legal high speed." I find that (please note the use of the word I), at speeds in excess of 50-55mph, my car has a strong tendency to wander and requires a lot of attention to keep it on track.

BTW, I don't think Brian ever represented that the plate would help the tracking. I think his new spoiler mod will be directed more towards that problem.

 

mikepaul, what is it you want???

there is 6 pages of posts talking about the mod and you want more information. i told you why i would do it. take it or leave it.

or better yet, take the car to Florida and have it inspected, test driven, and then have the tester provide you with a 10 page report on why you should not do it

 

I think mikepaul wants some hard evidence that either there is a problem with the original plate or hard proof that there is improvement. The people who are reporting back are the people who already believe there is something to be improved and have risked $160 on it and probably want to believe it helped. The reports are anecdotal possibily with a bit of bias (no offense, I'm just trying to be objective here). Since Toyota hasn't been actively trying to fix the problem in Prius already out in the wild, the problem is probably minor, a more finishing touch issue than major problem.

At the same time, if you don't have a stability issue with the car, I can see why people are saying this part isn't for you. It seems dismissive, but it is also true. This stiffening plate is to fix a perceived problem with the rigidity of the Prius. If you don't perceive the problem, then it wasn't worrying you before the plate came out and probably shouldn't worry you now that the plate is out.

I have yet to crawl under my Prius to see what the existing plate looks like. I can visualize this new plate making a more rigid connection between the two sides of the car, but personally I'm still on the fence about the my own need for it..

If someone with a late 2005 Prius could post a picture of the new, stiffer Toyota plate that I've heard about (but have not seen any hard evidence of), I would appreciate it. I think that would add Toyota's support to the idea that the chassis needs to be stiffened and also useful to compare old Toyota plate, new Toyota plate, and BT Tech plate. It would also be interesting to know if you can buy the new stiffening plate from Toyota (sorry, Bryan, I don't mean to be diverting business away from you, but it's always good to know all the options available).

 

OK, I'm going to look into this as soon as I can. But as far as I know, the new stiffer plate from Toyota is also anecdotal. If there was some improvement no one in the marketing department of Toyota was told about it or they would have been bragging. Yes the European versions of the Prius are getting improvements to the cars torsional rigidity, a strut tower brace to reduce flex there and improved PS. These improvement may in fact include a stiffer brace. The fact that the Toyota has announced this is confirmation to me that they know the car can stand some improvement in this area and they have in fact been working on the problem inspite of the dealers or US Toyota always saying "that's the first I've heard about that".

Like I said before, Brian probably doesn't have Toyota's money or resources and is not going to be able to provide anyone with the proof that this works. He and others can only say what they've experienced with this and yes some of it might in fact be from the placebo effect. But Brian is taking a good approach to what numerous experienced road testers have noted. The Prius is surprisingly not very stiff in torsional department. Therefore any reduction in the chassis compliance could help. I say could because again like you've pointed out, we don't know how much is lacking or exactly where. All we can do is try it and evaluate it. Personally I'm willing to spend much more than $160. if there's any improvement that I can feel. That's how disappointed I am in how the car behaves and how sure I am that Toyota is not going to help me out with stiffening kit.

 

I wanted to add my thoughts here as well. I ordered the plate, installed it the other day and am happy with the result - it works as Brian says it does. I too was an automotive engineer and worked on Corvette program as well, but back in the day for the 1984 redesign. I then left Motown for a career in the Aerospace industry – Flight Airborne structures and mechanisms working on such projects as Shuttle, and Titan IV Launch Vehicle to name just a few. I can tell you that this is a quality product, and what came off the car went straight to the trash.

 

I think there's a third and possibly rather large group for people like me, as I don't fit in either of your groups. I like my Prius as is, feel that no improvement is necessary (it is a wonderful car as is), but feel improvement is always good (no product is perfect), enjoy making improvements to my car (I have done a few minor modifications/customizations to my Prius), and would like to make my Prius more enjoyable to drive. I think a lot of the people who waited for reviews of this product are in this group, and I think there may be a lot of us.

I don't know if I'd appreciate a stiffer chassis b/c I have no reference for comparison (I've never driven any performance car). My last car was a Ford Tempo and the Prius handles much better than that, but maybe there's a world of driving I'm missing out on.

I think asking about:
1) the rumored stiffer Toyota brace,
2) if someone with the BT Tech brace is willing to try a double blind test to see if someone can really tell the difference, and
3) if there is some difference that is measurable
is fair. However, due to the amount of effort to do the double-blind test and the scarcity of people with the BT Tech brace, I don't know if it'll really happen. I have no expertise in automobile engineering, but since we have two professed experts (MHR and blkc5) in the field in this thread, I think that either/both of you should be able to come up with a quantitative test of this upgrade. If not, setting up a double-blind test shouldn't be hard (but maybe a bit time-consuming) for anyone who has the BT Tech brace, since it's such an easy install. Maybe several of us who are interested in a double-blind test could chip in to buy a test plate for one of the resident/trusted Prius gurus to do a double-blind test with.

Another thought Brian, is maybe you wouldn't mind some sort of trial period for this product. I wouldn't mind losing $20 in roundtrip shipping to try out this, just for the comfort of mind that I won't be out $160 if I don't like it.

Anyhow, the two groups thing reminded me of a joke. There's 10 kinds of people in the world. Those who understand binary and those who don't.