BT Stiffening Plate: The Verdict

OK. So I unboxed this, as seen in photos here:

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And the review to follow.

~ dan ~

 

Here is my review:

(I) Purchase
I ordered it online after being reassured by moderator danny that those of us seeking the shock tower support brace would be able to cash in on a retroactive package deal. So I still anxiously await the release of this part.

At a sale price of $145 shipped, I was satisfied with the purchase and the shipping, which overall took nine days from online purchase to delivery; I found that acceptable for free shipping in the holiday season.

(II) Installation
Installation took no more than 10 minutes. I used the reverse camera to inch the rear of the car up on my 10" ramps. I grabbed a 12mm socket on a ratchet, but had to sorta "fake it" for the 8mm Allen wrench.

As the story goes, it took one minute to drop the old bar. And then I wiped down the mating surfaces and brushed out the bolt holes (add one or two more minutes).

One difficult part was explaining to my wife (who was kind enough to stand out in the cold helping me) that the oily substance was supposed to stay on the new screws.

Another difficult part was using three adapters and a socket holding the wrong size Allen driver to torque the new part in. Using an old, large torque wrench, with a 5/8" -> 1/2" adapter, a 1/2" -> 1/4" adapter, then a 1/4" socket, I managed to put a 7/32" Allen driver tip into the socket. It was a pain to torque the screws down to 17 lb-ft, but it worked.

(III) Effects on Performance
The truth of the matter is I can understand exactly why the people who like it say so, and I can understand exactly why the people who don't like it say so.

The change is subtle and not always noticeable, and is about what I expected for a $145 floor-pan brace on a unit-body car. It tames some of the U-shaped flexing the car experiences under strong asymmetric (left-to-right) shocks.

Those of you who think a $145 floorpan upgrade is going to make enormous changes to the car and prevent body roll and prevent it from sliding around corners are going to be soundly disappointed; but those people really don't know what to expect, apparently.

Those of you who notice the difference but can't describe it... Be sure you know there's a difference, and be sure you can AT LEAST qualify it, before you claim it has any effect.

Here's what I notice: there's a bit less flexing through corners, but body roll is unaffected. Also unaffected is the massive understeer I don't like. That bit is one of the smallest changes I notice. Larger and more noticeable are the extra stability any time there are vertical shocks to one side of the car or another (like a gutter area on the side of a road nearer the curb). An easy way to test this is to go over a moderate speed bump with only the tires on one side. It's noticeable in potholes and other such fixtures.

(IV) Conclusion
Though it was about $40 more than I would expect to pay for a similar part, the part does have an impact on performance. As with any single upgrade, it's not a profound effect, but it's there and it's a pleasurable change in a sportier direction for the car. Alone, users will not find it is the panacæa; however it will be an essential component of a performance suspension upgrade, balancing forces against the center of the car and preventing unmatched upward flex. It definitely belongs in its niche and I'm glad I have it; just by itself the subtle changes are nice, and when the car is all done I'm certain it will be necessary rather than just helpful.

~ dan ~

 

Thanks for the comments, folks.

Since I live in the SF Bay Area, it's tough to find a place where there are good gusts of wind except in rare weather conditions. I would imagine that since a gust of wind from the side will translate into a similar asymmetric vertical force, the BT plate will provide extra stability.

Ironically, I'm sitting next to my wife at Chicago O'Hare Airport, waiting for our connection into Providence. I'd like to drive the car in the conditions I see outside.

And yes, on northern California's crappy freeways I do notice more stability and less rear-end trailing; I don't think it's improved in a "major" way (warning: subjective term), but that's more a job for a well matched front-rear anti-sway kit.

I'm interested in hearing about the costs and benefits of the TRD Sportivo system, but I'm also considering going way further -- I'm thinking about getting some pretty exotic parts to put together a tight lowering system. I want a 15-20mm lower center of gravity, so the rear end trails even less, and I need the front to be substantially stiffer to correct the vast understeer problem these cars have stock. I know it will never perform like my Mustang, and maybe I'm just spoiled on that, but the properly balanced oversteer/understeer in that old Ford really makes me feel in total control of the vehicle under every extreme (read: panic) condition.

Hobbit: it sounds like you're describing the saddle shape of a slice of Hyperbolic Halfplane with your arched piece of paper. Do people start to really understand? Because I'll tell you, before I installed the BT plate I never imagined the car "smiled" so easily underneath.

Thanks again for the comments, and I hope you all have a great holiday.

~ dan ~

Review of the Monte Carlo bar as soon as I receive one. I may even video tape some hard cornering without and with, if anyone's interested. There are some good, safe curves that make great testing grounds. Maybe even a comparison between a carefully kitted race car and the Prius' before-and-after.

 

The stock exhaust pipe is tucked nicely up under the car in the tunnel in the absence of a front-to-rear driveline. I was just up under my car a few days ago to install the BT plate and was impressed by the nice placement of the exhaust. If you want to see exhaust that's low to the ground, view this:

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In most places you cannot sweep a trouble light under the car, and the exhaust is so close to the ground a closed fist will not pass under it at the collectors.

I'm hoping to go a bit further than the TRD kit for the handling of the car; I would like strong anti-sway options front and rear, and you'd be surprised that with high-quality (read: ridiculously, stupidly expensive) shock absorbers you can get good, hard shock damping without sacrificing road quality or shaking the car to bits.

But if there's really no other reasonable option than the TRD, I guess I'll have to start there.

~ dan ~

 

I wish I had taken it out for controlled (or better yet, measurable) tests before, without any, and after the brace was installed. At least I could have replicated it.

As a mathematician (though not a physicist or materials engineer, mind you), I expect it to be mostly stretching at that location. But I would expect the stock part to be acceptable as it's reasonably thick and doesn't appear easy to stretch.

I would expect the torsion to be decreased by the new part, but I would expect a sway bar to give me more stability. I think the combination of torsion rigidity (greatly improved by the new part, though not all that important to the general feel of the car) and the complete unwillingness to stretch and allow the car to "smile" (probably not improved as much, but still noticeably so) give the BT Tech brace a huge thumbs-up.

And it moves the "smile" shape from the floorpan to my face. Good place for it!

~ dan ~