BT Stiffening Plate Review

<div class='quotetop'>QUOTE(DaveinOlyWA @ Jul 19 2006, 08:12 AM) [snapback]288674[/snapback]</div>

I would certainly buy it if I didn't have one already.

 

<div class='quotetop'>QUOTE(windstrings @ Jul 19 2006, 08:09 AM) [snapback]288670[/snapback]</div>

An excellent and honest reply.

That's my point, your experience may vary. Nothing more.

My commute is residential, freeway, winding hills and industrial park. I don't feel a sloppy lag now, and the only time in my neck of the woods I've felt a wind gust is when I'm stopped at a light and a truck passes me at 50mph. If the Prius could take a corner before at 40 and with the brace at 60, fine. But if I take normally take it at 35, I won't notice anything. That doesn't mean that the brace is useless, it simply means I won't experience the same effect as someone who takes a corner at 50. I don't drive the Prius agressively and don't plan to. I've found it helps me relax and take life a bit slower.

 

<div class='quotetop'>QUOTE(windstrings @ Jul 19 2006, 08:09 AM) [snapback]288670[/snapback]</div>

Actually, I disagree with you here. I found the plate made a remarkable improvement driving city streets at 25-30 mph. The suspension seems to actually work better -- it almost feels softer because it does its job of soaking up bumps better. I put my plate on at a friend's house (he has his own lift!) and driving the streets away from his house I was thinking "damn, this is nice!"

 

<div class='quotetop'>QUOTE(BT Tech @ Apr 12 2006, 09:20 PM) [snapback]238946[/snapback]</div>

OK, I really don't want to fuel further discussion about personal decisions to purchase or placebo effects. However, since I never got a reasonable reply from Brian on my question about a lack of "clearance" in the "relief" (notched) areas of the plate, I'm going to share some additional thoughts. I believe there is a design/fabrication issue with this plate that may be contributing to the variation in perceived performance. In fact, on my installation, there is no clearance in this notched area and the plate contacts the thickened portion of the unibody frame so that it bridges from the thickened frame at the front edge to the back edge as shown in this exaggerated drawing.
[attachmentid=4208]
I can actually slip a thin wire through the gap between the plate and the frame in front of the forward bolt. As a result, the plate cannot transfer its increased rigidity to the frame as intended. I do not know whether this results from unexpected variations in the unibody frame or inconsistency in the fabrication of the relief notch. I find it interesting that a variety of pictures have been provided showing the plate both without notches and with notches machined after anodizing. It is clear that this notching has been adjusted over a period of time. It would be good if Brian would provide some specifics about the specified dimensions of the relief notch and the design assumptions he made regarding clearance needed for the thickened portion of the unibody frame. I would really like to resolve this question so that I can correct my plate installation and experience for myself its benefits (real or perceived).

 

<div class='quotetop'>QUOTE(jrfaris @ Jul 19 2006, 09:56 AM) [snapback]288752[/snapback]</div>

Oh great! I just ordered mine yesterday. This is how it looks mounted? It it isn't notched out enough for the "bump?" What kind of stiffening will that give if the bolts are doing all the work? I expected it was designed to mount flat against the frame but, looking back at all the pictures now, I see where this little feature was never clearly photographed.

 

<div class='quotetop'>QUOTE(jbarnhart @ Jul 19 2006, 09:56 AM) [snapback]288750[/snapback]</div>

Your're right.. I should have included that consideration... where I drive, I am blessed with reasonable streets without potholes, but I don't have to go into the big city suburbs either.

<div class='quotetop'>QUOTE(jrfaris @ Jul 19 2006, 09:56 AM) [snapback]288752[/snapback]</div>

Did you torque yours down?

I don't seem to have that issue.

 

On some of the very early 2004 production run cars the "bump" in the frame rails varied by as much as -040"!! I adjusted the reliefs to compensate for this variance on our second production run but perhaps your car has a larger variance.

This is a non-issue on the later 2004-2006 production vehicles as they are now within .010" varaiation and our reliefs that have been programmed allow plenty of room for this. If you like I can ship you out a replacement which has a larger relief and ship the other one back.






<div class='quotetop'>QUOTE(jrfaris @ Jul 19 2006, 12:56 PM) [snapback]288752[/snapback]</div>

Bob, you won't have any issues with your new stiffening plate. The very early 2004 production run cars had large variances in the fram rails. All later 2004-2006 MY vehicles do NOT have this issue.



<div class='quotetop'>QUOTE(Alnilam @ Jul 19 2006, 01:07 PM) [snapback]288763[/snapback]</div>

 

my plate has the clearance as well but BOTH edges touch each side of the frame rails so the clearance is uniform and parallel.

 

<div class='quotetop'>QUOTE(BT Tech @ Jul 19 2006, 10:16 AM) [snapback]288773[/snapback]</div>

Thank you for your reply. If you will ship a replacement, I'll return the one I have. I purchased the plate at the end of April 06 using Paypal (9NS5994700657961U) and it was shipped to JR Faris in Menlo Park, CA. If you need additional information, please send me a personal message.

 

<div class='quotetop'>QUOTE(BT Tech @ Jul 19 2006, 10:16 AM) [snapback]288773[/snapback]</div>

OK. I'll trust you on this. You seem to have a lot of credibility on this site and it looks like it is well earned since you are always around to answer questions. I just looked under my car and imagined it was going to look just like the sketch above. If it is flush with the frame, I'll be happy. Sorry for the panic!

 

No worries Bob.. Only the VERY early 2004 production cars had these large variations in the frame rails which necessitated me to increase the size of the reliefs. There were very few cars that had larger variances and these were manufactured in late 2003 and early 2004.

You will not have anything to worry about as ALL late 2004-2006 vehicles have had perfect fitment with our stiffening plate.



<div class='quotetop'>QUOTE(Alnilam @ Jul 19 2006, 02:35 PM) [snapback]288846[/snapback]</div>

 

Congratulations on the new 06 Prius!! I will ship your stiffening plate out tomorrow along with the rest of the orders that you sent over.

Please let me know when you receive it.





<div class='quotetop'>QUOTE(Danny @ Jul 19 2006, 04:40 PM) [snapback]288912[/snapback]</div>

 

Danny,

I put an order on the July 16th and paid with PayPal. I got the reciept email from PayPal. However my order is not showing up under my "Order History" therefore I can't check the status of my order. I emailed you about it two days ago and havn't heard back from anyone yet. Can you shed any light?

Dennis

 

<div class='quotetop'>QUOTE(Hybridguy @ Jul 18 2006, 10:48 AM) [snapback]288126[/snapback]</div>

My thoughts exactly! No change in handling after installing the plate 1500 miles ago.

 

<div class='quotetop'>QUOTE(BT Tech @ Jul 19 2006, 10:16 AM) [snapback]288773[/snapback]</div>

Brian, I replied to your PM but was not able to include the requested picture. Do you have what you need to ship out a replacement? I included my direct email address in the second response since my outgoing PC mesasages do not seem to be saved. Thanks, JRFaris

 

Your replacement was shipped to you several days ago so you should receive it any day now. Please let me know how you make out with your new plate.





<div class='quotetop'>QUOTE(jrfaris @ Jul 26 2006, 08:43 PM) [snapback]292884[/snapback]</div>

 

<div class='quotetop'>QUOTE(prev93 @ Jul 26 2006, 09:19 AM) [snapback]292595[/snapback]</div>

Sorry you don't notice a difference.. maybe you can sell it to someone else..

When I first got my two prius's, they seem to drive like a dream, until I was on the 205 freeway thats about 2 miles across the columbia river and sometimes the crosswinds are so fierce that 18 wheelers dare to venture.
Most of the time its just a good brisk wind and I noticed that unless I really paid attention I would find myself changing lanes or at least going over into the next lane without intending to.
I'm sure the other drivers just thought I was distracted or maybe had too many!

But after the plate I don't get that.

Also when on a two lane road going about 70 and encountering an 18 wheeler or large surbuban going the opposite direction... that means about 140 mph difference in our speeds!... I would get tossed around... but not after the plate.

The prius is built aerodynamically near perfect for oncoming wind and resistance, but sucks for side swipes.... much of that may have just been the instability of the suspension for side gradients.

Some people are more sensitive than others... especially if there looking for it.

Whether your talking about music and the subtle differences in tones and frequencies to how a roller coaster feels.... most will have differering opinions.

When I first bought the plate. I was a bit unsure for about a week, until I took my car up on the mountains and did some good windy twisty turns about 60mph.


Tom has a brace that is much more expensive and much more invasive as to how much hardware is installed as well as the complexity of installing it all..... even after all that, I have seen reports of dramatic differences in feel and handling, but I'm sure some would not notice that either.

It is nice to "feel" the difference after spending the money...... if your so inclined..... you could take your wife for a spin down a course at a certain speed down one of your windy roads, and then take the brace off and replace it back with the stock plate and try it again?

If you do so, you might let her drive as its easier to feel the road when your driving verses someone else.

If this is all a mass hynosis, I'm enjoying my delusion. :lol:

 

I'm considering getting the BT stiffening plate. With so many great reviews, it seems clear the plate will enhance performance. I'm curious about engineering though. Perhaps I missed it in prior postings, but is there a technical explanation of why the plate works? What is the genesis of the BT plate? For example, was Toyota or an engineering group tasked with making the Prius handle better? Was the BT plate the ideal fix, or just an opportunistic one (ie: chosen because it's easy to do)? Is there a better, but more difficult fix?

My concern is that the plate looks super strong, but the bolts holding it look rather weak. In the same way a chain is only as strong as it's weakest link, is the ability of the plate to stiffen the chassis limited by the strength of the bolts attaching it to the car body? I've heard at least one person say they stripped a bolt while installing the plate. It seems the ideal design to keep the car body stiff would use much stronger bolts that couldn't be stripped with human strength, for example like bolts used on suspension components or tire retaining bolts.