Chassis Stiffening Plate

You'll just have to use the good old scientific method of trying it to see what happens. If a theory disagrees with experiment, it's wrong.

It should also be mentioned that tires make a huge difference to handling. The stock 185s are too skinny and too biased towards mileage.

 

Hi Timkf1,

Brian of BT Tech (RIP) got the idea for the Prius brace because some Corvettes (also with large rear hatches) had a similar problem. And he sold many braces for the Corvettes, long before the Prius. He worked at a Corvette speed shop, besides the Telescope shop, where he designed stiff plates for Telescope mounts too.

As you may have read I am convinced the plate is well worthwhile.

The problem with "scientific theory" is that it rarely is considered to the 2nd, 3rd and 4th order complications of a modern engineering problem by people other than the specialist engineers that have trained themselves up for decades (before a car company will trust them to do a car chasis design). To truely understand the flex in a 2nd generation Prius is going to require that specilist engineer background expensive modelling system or mechanical test rack, or both. Getting to the root of the Prius chasis flex is just so uncertain short of that half a million dollar investement.

Or we can just pay the $160 for the BT Tech plate, and give it a try.

Now, if your alignment is flakey, you may not have much improvement. That is the first thing.

The main thing the plate does, is reduce the oscillatory period of the rear of the Prius to something that allows the driver to more accurately control the car. If your used to driving a vehicle with a 1 to 2 second rear end shimmy, well, your probably not going to appreciate the BT Tech plate. But, if you do not want to wait a second for your control inputs to have an effect, well, the BT Tech plate is for you.

 

Correct. The brace would be completely useless if the factory piece worked as well as the brace. I think we can agree on that.

The factory piece does what the factory was trying to fix, the center tunnel cannot flex outward, under tension. The brace adds the ability to not flex the center tunnel inward, under compression.

The question you need to ask, is 'Do I care if the central tunnel flexes inward, under compression?' This is not a question we can answer for you.

 

I have the cheapo ebay plate, it works fine. The real BT plate has hollows between ribs, so may be lighter. (They can't be for cooling)
http://www.gurexdepot.com/image/priusplate/Plate06.jpg
http://www.evnut.com/images/prius/stiffening_plate/stiffening_plate05.jpg

 

If its just a placebo, then the $59 one is probably just fine. :madgrin:

[ducks and runs for cover]

 

It's good to consider the options. Tom's also makes chassis parts for the Prius, including a rear brace. It's quite a bit more expensive, especially since it involves rerouting the exhaust. But it works much better - I've heard it described as 'the BT brace on steroids' (I think that was Presto) So, it all depends on how many bucks you have and how much bang you want.

 

On paper and in pics, the $59 G7 plate appears to be substantially the same as the $165 BT Tech plate -- 6061-T6 aluminum, black anodized finish, stainless steel bolts.

I have the BT Tech plate, am happy with it, and was glad to support Brian in his efforts to improve the Prius.

But with the onset of the Great Recession, in all honestly, if I were to buy a stiffening plate today, I'd try the $59 G7 plate. I just wouldn't be able to ignore the $106 savings for what appears to be substantially the same product.