New Prius Handling Components to be available soon!!

Hmmm...it's amazing how much owning a Prius has expanded my horizons for new learning opportunities.

Now, I find myself interested in understanding the mechanics of how changing the stiffener would improve handling. I can imagine why it would help handling characteristics if it does what it is made to do. On the other hand, I can't grasp why it would make the car quieter.

6061-T6 is aluminum. I have essentially zero experience in metallurgy. I know just enough to comprehend that aluminum, much like steel, can be made to be stiff or flexible. I have bicycles made with 6061 and aftermarket bike parts made from 6061...the goal for using it in bicycles is a balance between weight and ride quality (stiff - flexible). Typically, this is a careful tradeoff between diameter (bike things tend to be round) and thickness.

Just from looking at the pics, the aluminum stiffener seems to be 1/2" thick (less where the bolts go through)...and is notched to fit into the well between body halves...it appears to be thickest between the body halves? I think that extra thickness must not contribute? Isn't the flexure limited ultimately by the thinnest measurement?

As to the Toyota factory original part. It looks like stamped steel? So, we have no clue if it is flexible (like a leaf spring) or stiff (like a car frame).

I can see how it might be difficult to quantify any improvement effects on even a single car. You have to control the experiment tightly; temps, speed, exact same course driven over, etc.

On the other hand, it seems like it should be possible for BT Tech to be able to present some lab data comparing the basics:

(1) weight difference
(2) physical measurements
(3) slap those different stiffeners into some official flex measuring device and report back

(a) flexes along the body length x% under "y" load
(B) flexes along the body width a% under "b" load

That is SOP for any firm selling mechanical parts to any other company....you have to some levels of stress analysis, etc. to prove out the durability, reliability, etc.

Look at all the trouble NASA has and they have very specific guidelines for performance for each and every part that goes into the shuttle. This part has no specific data at all.

I don't doubt that the possibility exists this part is indeed stiffer....it's just that some of us folks like to have comparison data.

Just for grins, I wonder what would happen if someone nested to stamped steel parts together, had them welded them along the seams and used longer bolts?

 

I'm doing what they call an FEA (Finite Element Analysis) for Brian on his brace and the stock brace. Yes a thicker part in any given material will be stiffer. But it doesn't necessarily have to be thicker everywhere, just where the stresses are higher preferably. That's why the stock brace, only .080" thick, can get away with the seven large holes. Those hole reduce the stiffness very little but save a lot on weight. Think of the bends you see in the stock plate as a way of getting some apparent thickness and therefore stiffness.

An analysis of both parts should evaluate both stiffness in bending and stiffness in twist or torsion. They should be subjected to similar load and boundary conditions such as fixing one side and twisting the other or applying a load to bend the other. I'm going to do both for Brian and give him comparative data, that is data that he can use to compare the deflections of the two braces. I've already done some preliminary work that suggests his brace is much stiffer but I'll hold off until I run the analysis next week. I'm assuming high strength alloy steel for the stock brace which in fact may be a best case. Look everyone, this really isn't rocket science and Brian has a fair amount of experience designing these braces. From what I can see of his brace with the diagonal ribs, he does know what he's doing. An FEA at this point can show that and Brian can also have me try any changes he was thinking about but didn't have the time or money to prototype.

Stacking both braces of course could be stiffer. But I think when we find out how much stiffer his brace is, it would be a waste of time to increase the stiffness even 5-10% with the addition of the old brace. Give me until later in the week since I'll be getting my brace from Brian on Monday.

 

cool info. even at 100X, its amazing how small the flex range is.

since installing my plate on Monday, i have only driven a few miles. (yesterday, went on a field trip for work so rode a bus most of the day...whee...)