BT Tech Stiffening plate

I know.... I have been saying 2 weeks now for a few months!! It goes to show you how difficult it truly is to manufacture quality machined parts in relatively small quantities.

At any rate I should have some sample parts ready within the next week or so, possibly earlier. As soon as I have some parts in hand, I will take some pictures and post them. I will probably make a new thread as this one is getting way too large.

Thanks for eveyone's patience!!


<div class='quotetop'>QUOTE(windstrings @ Nov 12 2007, 04:51 PM) [snapback]538540[/snapback]</div>

 

<div class='quotetop'>QUOTE(apriusfan @ Nov 12 2007, 12:43 PM) [snapback]538464[/snapback]</div>

Hi apriusfan,

Was wondering, doesn't your Prius with all the TOM's parts you have on it, already handle like a slot-car, a Mini or a sports car?

 

Zoom, Zoom, Zoom!

<div class='quotetop'>QUOTE(BT Tech @ Nov 12 2007, 06:35 PM) [snapback]538611[/snapback]</div>

Well, we could change the name of this thread to BT STiffining plate/_ _ _ _ _ ! And let the good times roll!

We would have to find BethlehemPrius, since he started the thread.....

 

<div class='quotetop'>QUOTE(Boo @ Nov 12 2007, 04:03 PM) [snapback]538618[/snapback]</div>

Slot-car or MINI. The look (the Wth open mouth combined with a pointing hand) on people's faces in the rear view mirror when I pass them in turns is priceless. I am interested in the skid plate IF it doesn't conflict with the TOM'S front lower suspension brace.

 

Just a heads-up everyone.. Danny is having a holiday sale on our BT Tech stiffening plate for a limited time.

Here is his post:

http://priuschat.com/forums/showthread.php?p=528316#post528316


Our product must be purchased through the Prius Chat online store in order to get this special.

 

Will my warranty still be valid if I switch to the BT plate?

If I install the BT stiffening plate, will this affect my warranty?

 

Science vs. Anecdotes

I don't have the patience to read through 111 pages of posts on the stiffening plate. My car is only 400 miles old and I love the way it drives,
but if it could become more stable (not "Whoom" ing when trucks go by) I would be interested.

However, every comment here is by nature anecdotal, and as people have pointed out in the posts I've read so far, no one is ruling out placebo or the happy coincidence of installing their plate as the weather warmed up.

Has anyone attempted a more scientific analysis of the effect of the plate: asking someone who didn't spend hard-earned money on it to evaluate the effect (ruling out cognitive dissonance)? Has anyone assessed milage effects by comparing it to similar vehicles with similar loads on similar roads in similar conditions?

What if the psychological benefit of the stiffening plate only accrues to gearheads? Might I, not being one -notice little if anything?

I realize I may be holding you all and Prius to a higher standard. On the other hand, I can get a placebo benefit for a lot less than $150!

(( I get alot of spam about stiffening paraphernalia! ))

 

With all of our BT Tech plates installed throughout the USA or world for that matter, I have never heard of a dealer refusing warranty service due to our stiffening plate installed.

 

Back...


to....

topic......

My stiffening plate comes on Friday. I won't have a chance to install, test, or assess it before my wife and I fly to Massachusetts. Expect a happy new year message right alongside a review.

~ dan ~

 

Thanks Dan for your order. We look forward to your review once you get a chance to install your new BT Tech plate!!

 

One of the things I do not like about the Prius is that it sorts feels like it is hydroplaning - particularly at higher speeds. It's like the road is not connected to the steering wheel. And I do like to drive fast!! 70 to 80 mph

So, I installed the BT and here is what I noticed. The car is way more stable at high speeds. Also it is buffetted a bit less by high winds and/or the blast of 18 wheelers.

By the way, this past summer on a 2000 mile trip with average mph of >60 my MPG ran at about 55. Can't complain about that!!

 

Thanks Snappy.... What you described is one of the most common compliments that we receive after installing one of our BT Tech stiffening plates.

Thank you for taking the time to post your impressions!!

 

Excellent, Brian. I'll be discussing the effects some time after I get it installed today.

~ dan ~

 

to follow up on my post about 10 back - if you subtract the posts off this thread that say "I'm really excited to install the plate" or "I just installed the plate yesterday and I think I can feel a difference" - it gets a lot shorter. I can imagine it makes the car more stable. I'd just like some information that is substantiatable and based on more than 50 miles of experience. Thanks.

 

I read through almost all this thread. There are two posts that actually contain data. On is the the BT folks. They had a test driver (maybe more than one) drive a Prius with and without the plate. A noticable difference was claimed.

Someone else, around the 300th post, put the Prius up on jack stands, removed the rear jack stand, and measured how much the body flexed with and without the plate. The body flexed on the order of 1/8", and difference with and without the plate was insignificant.

It has also been noted that this was an inadequate test, and that something definitive would involve thousands of dollars of testing on very sophisticated equipment.

My own view, in spite of the myriad testimonials, is: unproven. And I have no axe to grind--I have the plate installed.

 

Actually, I've got very good money on there being an easy way to test it. I'm just afraid to do it.

Why not hook up a G-Tech, level it out, and then push the car's every extreme. Many times. Then, install the plate and repeat the test at the next opportunity conditions are the same. If there's a change, it'll have to be read on one of those accelerometers.

~ dan ~

 

That is one idea for a test. I am not sure that the result would be significantly different with the BT plate being on the car or off the car. The number of G's a car can pull is affected more by tire width and suspension factors (negative camber, thicker anti sway bars and spring rates) than chassis stiffening where the BT plate is mounted.

But I would be quite curious as to the results of a skidpad test, however.

Lets get a debate going over the merits of a skidpad test as an objective way to measure the relative merit of the BT Tech stiffening plate - that should be a way to get at least another 100 posts added to the total post count. If we are creative, it might be good for 200 posts.

windstrings - care to weigh in?

 

Hi Doc...,

I am not sure if its in this thread or one of the others on the BT Tech plate, but I consider my test as good as anything else that has been done. But it was just lucky weather conditions that permitted it.

We had very severe gusting winds winds two weeks apart, of identical severity and direction. Without the plate holding steering steady (no control input) I had a 1/2 to 3/4 's of a lane variation in latteral position due to uncontrontrolled yaw by my car during a wind gust. With the plate, and holding steering steady, in the same place on the highway, with a similar gust, the uncontrolled lateral movement was about 6 inches. The impact of the wind gust in both situations was audible, and I estimate it was a 0 to 40 mph change in less than a second. The tires at the time were the GY Integrities running at the door panel pressures. The weather report inidcated 40 mph gusty conditions on both days.

The sensitivity of my car to the wind gusts might be alignment sensative. And not comparable to those who have had their alignments tweaked to positive toe-in. I have not had my car aligned since it purchase date. I do not have alignment records. That said, the car tracks straight in windless conditions at 70 mph on the highway, and does not have any unusual response to a semi-trailer trucks passing at high speeds. Tire wear on the Michelin Hydroedges I have on the car now are tracking identically side to side for 15 K miles.

We have not had such wind conditions since. But there have been windy days. I can feel the front of the car switching back and forth, but there is no dramatic yaw like previously. During this switching action, the car is tracking down the center of the lane within a few inches. This probably means my front tires are close enough to toe-in zero that the force from wind pushes them through zero.

A less scientific test, but a difference I think I notice (anecdotal mode on) is understeer during a left turn over a change in road from banked-with-the-turn to banked-against-the-turn. Specifically, going through a left hand turn lane at about 35 mph, then over the center crest in a 4 lane road, and over onto the reverse camber portion of the road during wet conditions. Stock, the car wil understeer upon entry into the reverse camber portion of the road. With the plate, the car still understeers, but the tires are gripping in the reverse camber area, and the car is easily held on a track into the left lane , versus not even sliding, just steering by itself out to the outside lane without the plate, even though the steering wheel is turned. Now this anectodotal, and subject to the specific steering inputs, which were not documented (in contrast to the cross wind test above). The weight of MG2 and the driver on the left side of the car might have something to do with this.

A static G limit (skid pad) test probably will not show any differences. As the improvement appears to occur around the transistion between directions. A slalom test might show a difference, but is very subjective to the adaptation of the driver to the different vehicle dymanics. A good driver just might be able to make the worse handling car perform to the same level, with preknowledge of the course. If one had a robot that would put in identical steering inputs during the test, that would be telling. But lacking that, the comments of the driver at the ease of holding specific tracks is all one gets. And that has been insufficient for the "placebo" people. Even though we are talking about a mechanical system (including the inner-ear / seat-of-the-pants sensors), not a biochemical-physcological system.

 

Ok ive seen alot of the posts about this plate. Is there an actual "Poll" out there someplace? im not talling about a paragraph of opinions im talking an actual YES/NO poll and the yeahs and neighs. Is this a Placebo effect to the new plate owners. One other question. Why is this plate soooo expensive? Im really not trying to rain on free enterprise here, as a buisness owner i cherish it. However ive had machinists look at the "Stock plate on mine and tell me that they could make the equivelent plate, even from Billet, for about 35-40 bucks. It might not be all pretty but who looks at the bottom of the car anyway?