BT Tech Stiffening Plate does not improve ride

John in LB · Jun 1, 2007

After reading so much about the BT Tech Stiffening Plate... I decided to get my hands on one and to test it out. I have been driving around with it on the car for a couple of weeks. I have had the car for 9 months with 20,000 miles... so I definitely know the ride of my Prius without a plate.

My conclusion is the plate makes absolutely no difference in the car's ride or handling. I mean zero. This is from a personal driving point of view (the feel - as many of you call it) and from a measurement point of view.

In terms of how the car feels, both my wife and I have been driving the car and neither one of us can sense any difference. We drive the car on hilly roads as well as freeways and neither of one of us is a timid driver.

In terms of measurement: I jacked up the car and supported it on 3 out of 4 points; leaving the rear left wheel completely unsupported. I then had my wife (weighing in at 125 lbs) sit in the rear passenger seat (on top of the unsupported point). I had her jump up and down and observed whether there was any deflection / distortion of the chassis around the area where the BT Plate was mounted. There was absolutely NONE - not even the slightest amount. The whole car flexed an inch or so... but not at the location of the BT Plate mounting.

Below is a photo of the BT plate taken from the passenger side of the car. If you look carefully, the 2 bolts on the driver side of the BT plate are flush with the plate - as they are tightened down. In comparison, the 2 bolts on the passenger side (closest to you in the photo) protrude about 3/8" of an inch... and they are not supporting the BT plate at all. As you can see, there is ZERO gap between the plate and the body of the car. If the plate was helping make the car stiffer, I would have expected a gap towards the rear of the plate. Although you can't tell from the photo - when my wife was jumping up and down on the seat, there was no movement between the plate and body... further proving no bending of the frame at the specific location of the BT Plate.

[attachmentid=8443]

As a side note: the plate is very nicely machined and is definitely stiffer than the original plate (only in terms of a bending moment - the original plate is just as good in tension). However, it just does not affect the car's performance in any way at all.

Finally: I am really surprised of the outcome, given how adamant some of the other chat members were about the benefits of this plate. Given the absolute testimonials that were being provided - I would have thought some degree of benefit would have been evident.

priussoris · Jun 1, 2007

John, you just opened a very large can of worms LOL :lol:

I did not buy the plate as I did not think it would do anything.
I am glad to hear another honest opinion.

Rangerdavid · Jun 1, 2007

Interesting point about the flush bolts. I'm gonna have to go out when it stops raining and look under my Prius. As opposed to John, who's opinion I entirely respect, I must respectfully disagree. I can tell a real difference in the ride before and after. The picture of the bolts make me wonder if yours is installed correctly...?

Regardless, you could probably sell your plate if you don't want it....

IsrAmeriPrius · Jun 1, 2007

Here we go, again.

Swanny1172 · Jun 1, 2007

Has anyone ever done a truly objective test of the BT Tech Stiffening Plate? I'm not talking about "seat of your pants" feel, but real hard data. Test the same car with it and without it on a skid pad and let us know what the results are. That is the only way that this debate will ever truly be over. Until then, it is just opinions, and you know what they say about opinions...

kdk84 · Jun 1, 2007

I don't have the plate and have never ridden in a car with the plate, however from this honest post and another where the user setup a blind test on his wife... both outcomes resulted in no "real" difference. However, everyone who has bought one has realized a "perceived" difference in that they feel that the ride has improved do to the $165 upgrade to their car. Perhaps a kind of compensation to make the money spent worth it. I believe that in itself may be enough for those who have purchased the plate. For the rest of us, it is probably best to just put that money towards a different upgrade.

that's my 2 cents.

Platypus · Jun 1, 2007

<div class='quotetop'>QUOTE(Rangerdavid @ Jun 1 2007, 05:35 PM) [snapback]453657[/snapback]</div>

Interesting point about the flush bolts. I'm gonna have to go out when it stops raining and look under my Prius. As opposed to John, who's opinion I entirely respect, I must respectfully disagree. I can tell a real difference in the ride before and after. The picture of the bolts make me wonder if yours is installed correctly...?

Regardless, you could probably sell your plate if you don't want it....
[/b]
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Rangerdavid I believe you missed the point of the loose bolts. He intentionally left that end of the plate unsupported while his spouse jumped up and down inside the vehicle in an attempt to cause deflection that the stiffening plate supposedly fixes. What that picture is proving if all other parameters are as stated is that the plate is playing no role whatsoever in stiffening up "chassis flex."

Expensive bit of kit.

John - never underestimate how strong the powers of a shiny placebo are - hope you brought a flame suit along with the testing and pictures!

TheAnnoyingOne · Jun 1, 2007

My Voodoo adviser asks the following questions to the OP:
Did you install the plate during full moon?
Did you use a torque wrench?
Did you had the car facing east when installing the plate?

'cause my plate made a difference after I followed the above <_<

robincx · Jun 1, 2007

My wife blindly noticed the difference. I was on curvey roads tonight and really appreciated it. I think it may just depend on how sensitive ones ...umm, butt is. Then again, I did install mine using a zircon encrusted torque wrench under the moon lighty night.

Robin

Allannde · Jun 1, 2007

<div class='quotetop'>QUOTE(Rangerdavid @ Jun 1 2007, 04:35 PM) [snapback]453657[/snapback]</div>

<snip> As opposed to John, who's opinion I entirely respect, I must respectfully disagree. I can tell a real difference in the ride before and after. <snip>.
[/b]
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Hello Ranger David

As you know, the findings by John in LB are similar to those which I reported a while back. I am especially interested in the expereince which you report as you are clearly a substantial citizen.

I have a challenge for you if you can and will take it.

If there is a person whom you trust to touch your car who will remove the BT plate at a time which you will not be aware of, arrange to do that and see if you notice that the BT plate is not present by the change in ride of your car. I have driven extensively with no plate installed on my car with no ill effects so I do not see that as a problem.

If you haven't noticed after a few days, the point has been made and you can put it back.

How about it? This could be your contribution to the well being of truth.

Syclone · Jun 1, 2007

<div class='quotetop'>QUOTE(robincx @ Jun 1 2007, 10:42 PM) [snapback]453735[/snapback]</div>

My wife blindly noticed the difference. I was on curvey roads tonight and really appreciated it. I think it may just depend on how sensitive ones ...umm, butt is. Then again, I did install mine using a zircon encrusted torque wrench under the moon lighty night.

Robin
[/b]
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There you people go! Plagerizing my full moon statement on the other BT plate thread. No Fair!

FloridaWen · Jun 2, 2007

One of my main concerns is that we purchased an '07 Touring with "stiffer" suspension......... if the BT PLATE makes only a "marginal" difference (or if any as some claim) in the NON-Touring Prius, then will we feel little or no effect in the TOURING models ????
It's ironic because I spent the $165 last week (May 23rd) and I'm very anxiously waiting for it to arrive (BTW- "order tracking" sux!!) so I can install it and TRY IT....... actually my Wife does 99.9% of the driving so SHE would be the one to tell if it REALLY WORKS or we wasted our money. Believe it or not, she has gotten very used to the new Prius (although always still learning new tips and techniques) and she is very "aware" of the handling characteristics since she drives the same route, same back roads and highways (almost down to the same lane) every weekday !! Believe me, if it DOESN'T work well "I" will definitely hear about it................. <_<

Swanny1172 · Jun 2, 2007

Like I said above, until someone does a truly objective test and collects some hard data, discussions such as this are simply conjecture. Spending $165 automatically biases your opinion. Who knows, maybe the "improvement" you think you are feeling is actually attributable to your now lighter wallet.

donee · Jun 2, 2007

Hi John in LB,

The test you performed has been hashed over in another thread. If the Prius was a block of wood, and you slapped a plate on, the test would be valid. As the Prius has a roof, and is hollow inside (ie, not a convertable car) the test is not appropriate. The roof is in tension during the test, while during driving the forces can put roof in bending and buckling modes.

Houston · Jun 2, 2007

<div class='quotetop'>QUOTE(priussoris @ Jun 1 2007, 03:39 PM) [snapback]453630[/snapback]</div>

John, you just opened a very large can of worms LOL :lol:

I did not buy the plate as I did not think it would do anything.
I am glad to hear another honest opinion.
[/b]
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It seems odd to me that an outfit like Toyota would negelect to install a $165.00 item that supposedly made such a difference in the handling of their product.

dmckinstry · Jun 2, 2007

<div class='quotetop'>QUOTE(syclone @ Jun 1 2007, 08:32 PM) [snapback]453759[/snapback]</div>

There you people go! Plagerizing my full moon statement on the other BT plate thread. No Fair!
[/b]
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Come on. Quick complaining. Everyone know plagiarism is the sincerest form of flattery.

Dave M.

robincx · Jun 2, 2007

<div class='quotetop'>QUOTE(syclone @ Jun 1 2007, 11:32 PM) [snapback]453759[/snapback]</div>

There you people go! Plagerizing my full moon statement on the other BT plate thread. No Fair!
[/b]
Click to expand...

Actually Syclone, while I admire your full moon statement, it merely served as a trigger for a different source of plagerism, the phrase I unabashedly stole was from Frank Zappa.

V8Cobrakid · Jun 2, 2007

Hmm... yeah.. can of worms

On the 04 prius (mine).... the change is obvious. on an 06 model it's obvious... but less detectable.

it would be much easier to just change out the rear shocks.. and springs.. they are too bouncy anyways. the front end follows pretty well.. but the rear hatch gives no support and twist with the bouncy rear end.

btw.. try tightening those bolts. they all go flush.. you just need to tighten them... *sigh*

IsrAmeriPrius · Jun 2, 2007

<div class='quotetop'>QUOTE(donee @ Jun 2 2007, 08:12 AM) [snapback]453892[/snapback]</div>

The test you performed has been hashed over in another thread.[/b]
Click to expand...

These are the relevant posts:

<div class='quotetop'>QUOTE(Ken Stewart @ Apr 24 2007, 09:53 AM) [snapback]429069[/snapback]</div>

I have been reading these BT plate discussions for close to a year now and although I have responded to a number of posts I feel it is time that I put my mechanical engineering degree that I earned back in the 60's to good use.

I worked for a company in Michigan that specialized in designing high strength steel and structural components for all of the big 3 automakers (back then at least) One of our jobs at the time was to measure the strength of the frame of a certain Ford vehicle, (which one I don't remember.) The methodology used at that time was for us to take this frame to a company that specialized in taking these measurements and that is all they did. This company had a special fixture for attaching the frame to a Rota table concrete structure and then measuring the deflection of the frame at over 240 points along the frame. We would then make our modifications and the test would repeat, often taking 6-8 hrs per test In this time, the frame would be rotated at different angles to simulate loading. It was imperative that the frame was mounted in this fashion. At all of the measuring points, we were able to measure the results in .0001"! These tests were often very expensive and even the auto manufacturers often balked at the bills they got for executing these tests.

I have read Alan's data and although I give him a lot of credit for going through all of this to conduct his own tests, I am sorry to have to say but the methodology is completely wrong and subject to many errors and inconsistent results. When you are measuring a chassis, frame or a uni-body structure, you can not have the wheels or any other compression type devices coming in contact with the ground to achieve accurate results. This is why when we tested the frames we had to bring the car to the facility and the cars actual frame/body was bolted to the concrete barriers. This was done so that there were no outside forces like the tires, springs, shocks and struts that compress and expand making any measurements suspect at best. In addition, the testing should be done on 3 axis that can induce loads to the structure, none of this was done in Alans test.

It is my opinion that Toyota added the brace in that location because they knew there was significant flex occurring in the latter portion of the vehicle's structure. To say it was there because there was a battery sitting on top of it is horse manure.

The company I worked for later went on to do testing for race car sponsors and it was imperative that they had the best/stiffest chassis so that the cars of that day could withstand the 1+ G turns of that era. In order to test these chassis' with a degree of precision, we built a device that we called a twist fixture and would attach this to the chassis but again we would attach the fixture to concrete and the actual fixture would suspend the chassis in order to get accurate measurements. What was great about this fixture is that we could simply lower one side using a type of tie-rod end to lower or raise the chassis with great precision and measure the deflection at number of points along the chassis. The fixture was also able to be rotated so that additional forces could be placed during the measurement process and documented.

To sum all of what I have just written here are my findings:

The test by Allan although well meaning was conducted incorrectly and the results in his own admission showed inconsistencies. He also conducted no tests of the effect of compression while measuring the amount of deflection anywhere on the body under amy type of load. The methods used for measuring were not proven to be scienfiically accurate and the person (Alan) in this case is not known to be proficient in using scientific meausring tools (un-calibrated) with an unknown degree of accuracy.

A vehicle in motion is also affected by outside forces such as road surfaces, gravitational loads (g-forces) and aerodynamic forces which put additional loads, (sometime great amounts) on the vehicles body. Having a part that stiffens the body would counteract these effects to an extent. The more stiffening the part provides, the greater the result will enhance the differences the driver feels.

I never claimed to be a race car driver but there is no doubt in my scientific mind that the BT plate is providing a stiffening effect on the body of the car. This would explain why the car feels more stable to me when driving it. What is in question is the amount of stiffening that the BT plate provides and I personally do not have the inclination or financial ability to dive into that.

Best,

Ken Stewart [/b]
Click to expand...

<div class='quotetop'>QUOTE(Ken Stewart @ Apr 24 2007, 05:33 PM) [snapback]429398[/snapback]</div>

I earned my M.E. degree in 1966 and went on to work for more companies than I care to remember. The company where I designed strucural reinforcements was the same one where we did the tests on vehicle structures. I worked there from 1978-1989 so we worked on everything from full frames to unibody structured automobiles. While at this company we had many major corporate customers includng the Big 3, Honda, Nissan and Porsche to name a few.

In response to your post, you are never going to see a deflection of 1/2-1"! A 1" deflection is huge and would be indicitive of either a very poorly designed body or something that was in the process of structural fatique/failure.

Often at times when we made changes to a cars frame/body the associated change would show a deflection differential of less than .02" which sounds like a very minor amount but when measured at the contact patch of where the tire meets, this improvement can translate to a tremdous increase in overall TR! This is why I mentioned earlier that not only does the structure have to be secured in such a way but the accuracy of the measurements must be calibrated to a known standard and the person taking such measurements must be qualified to do so.

Things have changed drastically in the automotive world and manufacturers typically rely upon resonant frequency measurements where the vehicle structure is placed in anechoic chamber and the point at which the structure begins to resonate is a definitive test to know the actual stiffness of the product they are testing. The higher the resonant frequency the stiffer the body and vice versa. These tests can also be conducted on high speed computers using complex software where it can detect to a great deal of precision what the resonant frequency of the structure will be. Often times the manufacturers will still test the structure for confirmation but computers have saved engineers a vast amount of time and at the same time money.

As I mentioned previously I think it is great that someone went through the effort to conduct this test however I feel it is my duty as a M.E. to point out the flaws on how the test was performed and that the results whether they were positive for the BT plate or negative against it serves no real purpose other than to say that someone actually did a test.

What I can appreciate about the plate is its simplicity and overall quality. The machining of this part is first rate and I am honestly suprised that they are able to offer it as inexpensively as they do.

In response to Allans post inviting me to do further testing, I will leave that to you younger guys. I really do not feel the need to test something that I already know works as I have a lot more important things to do like relaxing out by my pool.

Best

Ken Stewart[/b]
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BT Tech · Jun 2, 2007

Hello John,

It appears that you were sent the wrong sized stainless washers with your plate that prevents the two bolts that are not flush from making proper contact with the body. All of the bolts should be flush with the plate in order for the plate to make a correct mechanical connection with the body of the car.

Please PM me with your shipping info and I will ship you out the correct replacement stainless steel washers right away.

<div class='quotetop'>QUOTE(John in LB @ Jun 1 2007, 05:54 PM) [snapback]453562[/snapback]</div>

After reading so much about the BT Tech Stiffening Plate... I decided to get my hands on one and to test it out. I have been driving around with it on the car for a couple of weeks. I have had the car for 9 months with 20,000 miles... so I definitely know the ride of my Prius without a plate.

My conclusion is the plate makes absolutely no difference in the car's ride or handling. I mean zero. This is from a personal driving point of view (the feel - as many of you call it) and from a measurement point of view.

In terms of how the car feels, both my wife and I have been driving the car and neither one of us can sense any difference. We drive the car on hilly roads as well as freeways and neither of one of us is a timid driver.

In terms of measurement: I jacked up the car and supported it on 3 out of 4 points; leaving the rear left wheel completely unsupported. I then had my wife (weighing in at 125 lbs) sit in the rear passenger seat (on top of the unsupported point). I had her jump up and down and observed whether there was any deflection / distortion of the chassis around the area where the BT Plate was mounted. There was absolutely NONE - not even the slightest amount. The whole car flexed an inch or so... but not at the location of the BT Plate mounting.

Below is a photo of the BT plate taken from the passenger side of the car. If you look carefully, the 2 bolts on the driver side of the BT plate are flush with the plate - as they are tightened down. In comparison, the 2 bolts on the passenger side (closest to you in the photo) protrude about 3/8" of an inch... and they are not supporting the BT plate at all. As you can see, there is ZERO gap between the plate and the body of the car. If the plate was helping make the car stiffer, I would have expected a gap towards the rear of the plate. Although you can't tell from the photo - when my wife was jumping up and down on the seat, there was no movement between the plate and body... further proving no bending of the frame at the specific location of the BT Plate.

[attachmentid=8443]

As a side note: the plate is very nicely machined and is definitely stiffer than the original plate (only in terms of a bending moment - the original plate is just as good in tension). However, it just does not affect the car's performance in any way at all.

Finally: I am really surprised of the outcome, given how adamant some of the other chat members were about the benefits of this plate. Given the absolute testimonials that were being provided - I would have thought some degree of benefit would have been evident.
[/b]
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BT Tech Stiffening Plate does not improve ride

John in LB Life is good

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BT Tech Stiffening Plate does not improve ride

John in LB Life is good

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