BT Tech Stiffening plate

<div class='quotetop'>QUOTE(madler @ Apr 22 2007, 10:52 AM) [snapback]427774[/snapback]</div>

Maybe using "no" plate at all and then the stock or the BT... would be a good test for the test! :blink:

 

<div class='quotetop'>QUOTE(daniel @ Apr 22 2007, 05:28 PM) [snapback]427957[/snapback]</div>

There you go being contentious again! :lol:

You must be referring to my post 421 where I started my sentence about engineers in general and started talking about brians test and how to achieve a bulletproof test with sensors doing real time monitoring while going down the road.

If you look at post 401 were sensors are mentioned you will see that my post was not all about Alans test but "any" test... Alans was included in the discussion but it was not exclusive to his.

In post 428 I assumed he had more than measurements alone, but I admitted all the jargon made me dizzy.

Sorry you misunderstood my post.. it wouldn't be the first time.... some we seem to have between each other I guess?
Seems I wasn't as eager to find fault with Brians plate as you were and since the test seemingly showed no measurement differences I didn't try and pick it apart.

 

Actually, showing a Porsche cabriolet is a VERY poor example of a car with a stiff chassis. Did you notice that its entire roof structure is missing??





<div class='quotetop'>QUOTE(Allannde @ Apr 22 2007, 09:20 PM) [snapback]428052[/snapback]</div>

I have read your posts several times and if I am reading them correctly, you state that the stock OEM brace provides greater stifness to the body than ours??? Anyone that has ever seen or held in their hand the stock brace vs ours knows that this is complete BS.

For some unknown reason you have decided to go on a mission to try to disuade people about our stiffening plate. If this product did not work do you really think that they would sell it on Prius Chat? Do you really think that we would have as many happy customers as we do?

I said it once and I will say it again, your "test" measurements show nothing of substance. The problem with conducting the test this way is that it is not repeatable due to the vehicle using springs and shocks that compress. The correct way to truly measure what you are trying to measure would be to attach one end of the vehicle to a solid non-movable object and then measure the amount of deflection at many different points. This is why I have said from day one that providing these numbers is not financially feasable and only something the factories can do.

When you drive a vechicle down a road, the car is subject to many torsional and compressional loads on its body. None that you can measure anywhere close to what you think you are.






<div class='quotetop'>QUOTE(Allannde @ Apr 21 2007, 11:46 PM) [snapback]427606[/snapback]</div>

 

<div class='quotetop'>QUOTE(BT Tech @ Apr 22 2007, 09:23 PM) [snapback]428084[/snapback]</div>

I don't see where Allan's measurements would be affected by springs and shocks. He is measuring to the solid body, and it is supported further up by the jack stand. The shocks are attached to the wheels, no?

 

<div class='quotetop'>QUOTE(Allannde @ Apr 22 2007, 11:19 AM) [snapback]427853[/snapback]</div>

Funny, I didn't think I was making it more confusing. I thought I was making it more clear! If you're doing an A-B test, you have to test A as well as B. I see from your comments though that you were not quoting results to support an A-B test, but rather to test a claim of the manufacturer. That seems a little off the mark to me, as explained below.

As I suspected. So your tests show that for the measured deflections, A - N == 0, and B - N == 0.

The point of my post was simply that if the original plate provides any stiffening at all, then given your confirmation above, your test does not measure that stiffening.

Yes, one important question is whether the BT plate makes the chassis stiffer than the original plate (or no plate at all). Consider though that the chassis has many modes, and your test covered one particular torsional mode. Both plates apparently did nothing for that mode. It is possible that the plate (original or BT) increases the frequency of other modes. It is probably very difficult to test all possible modes, but a finite element analysis of the chassis structure could probably show what mode or modes that plate affects.

The other important question is whether any resultant stiffening improves handling. Some stiffening may have no effect on handling at all.

In my mind, the question is not whether BT's claim of how the thing works is correct or not. The question is does the thing work!

Often medicine gives you drugs and along with them they provide some lame explanation for how the drug works (because many patients expect an explanation). In fact very often no one has any idea how the drug works. But it does. It is possible that the BT plate works, and that the manufacturer's explanation of how it works is incorrect.

So according to Toyota, there is some other mode that the plate is for. It might or might not affect handling, but your tests of the original and BT plates didn't measure that stiffening.

I read in one of the posts that there was in fact a double-blind test in which drivers could reliably distinguish between the BT and original plates. Was that test conducted by BT or some independent organization, and is the testing protocol and data published and available?

If a reliable double blind test was positive, then we would be left with the mystery of how. The science of structures however is much simpler than that of drugs, so it should be a solvable problem.

 

<div class='quotetop'>QUOTE(madler @ Apr 22 2007, 07:25 PM) [snapback]428131[/snapback]</div>

Hi Madler

While we are approaching the question from a slightly different point of reference, I agree with your basic thinking. I do not conclude that the BT plate has no use. On the contrary, it clearly is useful to many quite without regard to any provable function. That is perfectly legitimate. On top of that, the only issue I dealt with was the claim that it stiffened the chassis. I asked Brian to demonstrate how it might accomplish its purpose in some other way on line and he chose not to respond for reasons known only to him. As you say, there could be some basis for its function which is either unknown or has not been identified.

But, as you also say, this should be a solvable problem. That, also was an assumption of mine. That is why I went to some difficulty to try to find an answer in a low tech way. It would have been much more difficult if the BT plate had shown a little increase in chassis stiffness. But it showed essentially none. This does not say that the BT plate is lacking in structural qualities. It could be that it is located where structural properties are not relevent.

The chassis is the chassis. There is only one. I was measuring the stiffness of that chassis by a documented method. As I have said, it is clear to me that the OEM plate has NOTHING to do with chassis stiffness. It is simply not a factor in this situation. What ever forces which the car faces, it will face them with its chassis stiffness either moving or at rest. There is nothing magic about moving except the freqency of rhythmic motions. The same stiffness meets any force.

What ever function the OEM plate has, I am confident that Toyota designed it to be adequate. I have only speculation beyond what I reported for what that is.

I gave the BT plate a fair test. I did all of the things which were suggested that I do. To me, the BT plate was not satisfactory. I can't understand why some are insulted when others question their opinion. I think it is healthy to question opinions - any opinion.

The bottom line to me is that the vendor needs to demonstrate his product. If he chooses not to OR if there is nothing to demonstrate, then the market place needs to act in an informed way. That is the reason for information exchanges such as this. It is the normal action of the market place.

Historically, products which are without merit rely on testimonials. Is this one of those products?

Let the vendor demonstrate his product. It is clearly not hard to do if it has merit.

 

I appreciate the enthusiasm for this modification. I want to believe and to agree but I just don't understand how any replacement plate can make the frame notably stiffer. Same 4 bolts, same footprint. I appreciate the BT material may be stiffer but it just cannot make that much of a difference with the geometry of the plate regardless of the material differences. I want to belive but common sense basic engineering is trashing my enthusiasm.

<div class='quotetop'>QUOTE(BT Tech @ Mar 6 2007, 11:52 AM) [snapback]401018[/snapback]</div>

 

For those who know it works, they will not give any merit to a test that shows it does not.
Nor will they read every dot and title that seemingly proves so because they already know different.

Back to my original question.... does anybody out here really think any test that proves it does not work will convince anybody that already knows it does to the contrary?

Thats like trying to read a test that proves you don't love your mother! :huh:

I could see new poteintial buyers, but not veterans.

Alans arguement is that the burden is on brian because its so easy to prove if it has any merit?
Statements like these again insult those who know different.
Are we supposed to be convinced against what we already know from some test that some stranger did with negative inclinations in the first place?... I'm not quite that weak minded to give up my convictions on such evidence, sorry!

And Alan, its not quite fair to do a test and make statements as if you "proved" anything?
Again, to me, it appears you are grasping for straws.... I would ask you... Did you even try driving the car with the plate on?.. but I won't, because as I stated much earlier, your words are no longer credible since you have clearly stated that your agenda was to disprove the plate.... of which "at the time" you didn't even own yet, but you somehow deemed appropriate to have already judged.

 

<div class='quotetop'>QUOTE(Tyrin @ Apr 22 2007, 09:50 PM) [snapback]428108[/snapback]</div>

Indirectly they are Tyrin, if you were to "remove" the shock and the springs you would be transformed to a near stagecoach ride, with the exception of what cushion the rubber of the wheels gave you and a few other accessory suspension bars etc.

As long as they are not "maxed" or near maxed, they are quite efficient at removing bumps, shocks etc.. but they are attached to the chassis!
If the chassis is not stable on all points, that shock that is missed will be transferred into that same chassis for the driver to feel.
And even when they 'are not'' maxed, the full forces are still shared among the chassis and the wheel, with the shocks and springs only being a buffer.. in other words... the shock and the spring cannot take that energy and simple make it go away.. it still gets transferred... just in a much smoother manner... similiar to the difference of being jolted in an elevator vs. a smooth ride you cannot feel.

Having a stable chassis is the foundation of all the rest... just as the frame of a house is for everything else that is placed.

If I take measurements or put sensors on the top of a door to measure its movement or stress when opening, it will show nothing as the stress is on the hinges... even so in this test of the prius, it is crucial we know where the stress points are.

The sensation of the smoother ride we feel.. or should I say "more stable" is not easily measured by a ruler and pencil with car jacks..... Brian did say he did similiar on a hill and got results by measuring the car door gaps to prove there had been movement with and without the plate, but this test Alan did appears to have been done on a flat surface and not moving down the road under stresses.

As fun and interesting as this test was, it was my no means definitive to prove anything at all, other than that the test itself was a test of something.... but it apparenly was not a test of the plate.

It didn't even challenge the car enough to show a difference with and without the stock plate?

So either we just proved the stock plate also does nothing at all and it should be tossed or the test was lacking in respect to show the results of the stiffening plate.

I see it as fun and notable to test, but this particular test is not the all in all as it was negative in all respects to finding results for any plate... regardless of whether it was stock or the BT Plate.

We need to continue to explore other ways to test if people need to prove this in any other fashion than just driving the car.

I don't recall if "driving the car" was included in this test at all?

 

<div class='quotetop'>QUOTE(Dave Santa Barbara @ Apr 23 2007, 01:33 AM) [snapback]428209[/snapback]</div>

Dave, I don't know how much you've read about this plate, but the basic idea is that the stock plate holds the two sides of the "horseshoe" shape of the cars body from pulling a part similiar to a string or strong wire, and since its metal, it also prevents it from flexing "together". But since the stock plate is so flimsy in that you can even bend it in your hands, it does nothing for the up and down flex differences encoutered by each side of the car as it negotiates pot holes, turns, wind gust and the like.

That has been the only reasonalble explaination I have seen as to how and why it really works.. I don't know if thats in fact the real case.. all I know is I feel like it works as do most folks.
I don't see why someone couldn't just bolt a thick plate of steel to the bottom to test, but by the time your done with the hassle of cutting or having it cut and filed down so it fits flush, I expect one would have wished he would have bought the plate since the metal one will rust etc unless you paint it well.

For me.. I may be riding the happy trail, but I'm only out 165.00 bucks at worst and I really do feel like it makes a difference.

I've spent far more on other things that I have felt weren't really worth it later, I have as of yet no such feelings for the two plates I have bought for both of my cars.

 

<div class='quotetop'>QUOTE(windstrings @ Apr 23 2007, 05:22 AM) [snapback]428234[/snapback]</div>

Not directly, but here's a couple of quotes from the same post as the test...

I immediately installed it according to instructions and left on a 1200 mile trip which included curvy mountain roads, freeways, and high speed driving which I did as vigorously as I dared.

<big snip>

Oh, by the way, the car handled fine with the BT plate installed. It handled fine before, too. There was no noticeable change.

 

Anyone know what the traction battery weighs?

If the traction battery weighs as much as a very fat man, you could see how reinforcing the plate could help.

I can image that if the traction battery was heavy enough, the vehicle could flex in the center, sometimes in an upward arc, sometimes downward. Such a scenario could put enough force on the wheels to throw off their vertical alignment for a moment, hence the effect on handling.

Here's another scenario. Perhaps the plate stiffens the floor so that the occupant(s) do not feel the floorboard beneath them bending. In other words, maybe the feeling that the BT plate works is due to the reduction of g-forces directly to the driver's nice person.

 

<div class='quotetop'>QUOTE(Les Gas @ Apr 23 2007, 02:09 PM) [snapback]428528[/snapback]</div>

Just going by memory.. I think its about 98lbs.

 

<div class='quotetop'>QUOTE(windstrings @ Apr 23 2007, 07:19 AM) [snapback]428287[/snapback]</div>

As have I. That's probably true of most of us at some time or other.

Dave M.

 

<div class='quotetop'>QUOTE(windstrings @ Apr 23 2007, 02:24 PM) [snapback]428538[/snapback]</div>

Still quite a bit of weight... enough that Toyota added the plate. If the plate is required for structural support, it seems logical to deduce that handling would be worse without it, and perhaps better with a stronger plate.

Whatever the case, the handling of the Prius in the wind on the highway brings back memories of the Jeep soft tops I've owned. You learn to correct for it, but it feels dangerous to a new driver. I think the handling of the Prius is bad enough to warrant the gamble on the BT plate. I think I'm going to try one.

 

<div class='quotetop'>QUOTE(Les Gas @ Apr 23 2007, 12:01 PM) [snapback]428573[/snapback]</div>

Hi Les

One of the things which I have learned in all of this switching of plates around is that all of them are equipped with stress relief slots on one end (round holes on one end and oblong holes on the other). That together with a relatively small torque specification of 17 foot pounds means a limited strength against the kind of stress which you are visualiziing. The BT plate would not add any strength over the OEM device in this way.

Where the BT plate might add strength would be to a twisting force which the OEM device clearly is not designed to absorb. The traction battery could not possibly impart such a force. My guess is that the Toyota engineers discovered that a COMBINATION of three heavy adults siting in the back seat and the traction battery could cause some problem and installed this OEM device as an after thought. My guess is that the OEM device is plenty adequate to deal with that problem.

I wish all who are interested in this topic well. There are obviously more important things in life. Enjoy!

 

I just purchased a 07 Prius Touring Edition and have put about 200 miles on it. The handling of this car is not great but its not bad either. I did notice when driving on the highway (Approx 65- 75 MPH) the car seems to wander a bit espeically when passing a semi. As for going on and off the ramps I could push it to about 45-50 mph before the stabiltity sensor kicks in, which I think is not bad. Now that I have a pretty good feel for the car with it being stock, I've ordered the BT plate and will be installing it as soon as it gets in and do a comparision. I wil report back with my findings.


Wayne

 

<div class='quotetop'>QUOTE(Les Gas @ Apr 23 2007, 02:01 PM) [snapback]428573[/snapback]</div>

Did you just bring back some memories.. jeep cj's loved em even bought an old 1951 M151A1 Mutt
now that was one terrrible handling pos but went anywhere

 

<div class='quotetop'>QUOTE(Allannde @ Apr 22 2007, 09:15 PM) [snapback]428152[/snapback]</div>

I was thinking of that myself! Good point!

<div class='quotetop'>QUOTE(Dave Santa Barbara @ Apr 22 2007, 11:33 PM) [snapback]428209[/snapback]</div>

I, too, have commented on this, but nobody seems to think it's worth a response: If you want to stiffen a rectangle, you add diagonal braces. You do not add a brace that connects the sides and makes it into two squares. Geometrically, the BT plate would not stiffen anything.

<div class='quotetop'>QUOTE(windstrings @ Apr 23 2007, 03:53 AM) [snapback]428229[/snapback]</div>

Just like religion!