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HighlanderGeneral discussion forum for the Toyota Highlander and Highlander Hybrid.
This is a discussion thread titled "Improve handling with tube steps Toyota PTS06-48010-13", within the Highlander forum, part of the SUV Forums category.
ahh ok..as an engineer myself i know exactly what your talking about ...thanks for clarifying...
Kevin
Quote:
Originally Posted by carnutz
Well Kevin, let me try to clarify a little. I am a structural engineer and design steel structures for a living (and post on forums for fun ) but my structures do not move. I was just trying to point out that people were talking about attaching steel tubes to the HL "frame" which is a misnomer since the HL is a unibody structure and the body curves and bends and stiffening elements are the "frame" so there is no seperate frame like in a 4Run'r.
You are correct that boxing a truck frame will add to the stiffness and strength and placing an X member between the frame rails will add stiffness and strength in the plane of the frame rails, but in the vertical plane the increase will be much smaller. If you add the step tube to a truck frame and only connect at the end of the step, the extra stiffness will be limited by the ability of the step tube to resist bending moments in the frame rails where they are connected. However if there is a web between the step tube and the frame rail which is welded continuously between the two, then the frame stiffness (moment of inertia) will be increased. (Same effect as boxing a channel) Torsional stiffness is not much improved by boxing a channel truck frame and adding cross members unless they include a lot of diagonal members to tie the 2 longitudinal members together.
To accomplish this stiffening in a unibody, you would have to gut the interior and add a lot of tubes and make the HL look like a World Rally Car. Welding the doors shut would also help.
I guess my main point was that bolting a thin wall tube to some attachment points on a HL will not improve the flatness of the cornering.
I am a structural engineer and design steel structures for a living (and post on forums for fun ) but my structures do not move.
Doesn't even take an engineer to call BS on this line! Everything moves, it is a matter of how much.
Unibody or Frame, cross member(s) from side to side (driver to passenger) WILL help/assist in cornering. How much is determined by numerous items including placement, size, material, etc.
Unibody or Frame, cross member(s) from front to back (hood to trunk) will have NO impact on cornering.
Enough said.
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1996 T100, 180,000 and counting
One other point about stiffness I was going to make. If the original body was so poorly made that the addition of a little tube to the side so markedly increased the stiffness, the doors would have popped open due to body flex in a turn.
The other thing is, I wanted to apologize if I came off as condesending with the Structural Engineer tag I threw out. I re-read my post and I seemed kind of full of myself and I have only about 2 serious bones in my body. I do like a good technical discussion and have been called a storehouse of worthless information a few times.
bah...i know so many pompous people that one more doesn't make a difference
Kevin
Quote:
Originally Posted by carnutz
One other point about stiffness I was going to make. If the original body was so poorly made that the addition of a little tube to the side so markedly increased the stiffness, the doors would have popped open due to body flex in a turn.
The other thing is, I wanted to apologize if I came off as condesending with the Structural Engineer tag I threw out. I re-read my post and I seemed kind of full of myself and I have only about 2 serious bones in my body. I do like a good technical discussion and have been called a storehouse of worthless information a few times.
am i the only one who thinks this post is insane?
what in the heck are we talking about here? steps, tube type bolt-on steps?
the only way in the world that steps would help road performance would be if they stiffened up the frame from flexing but does a highlander even have a frame? if not then you are stiffing up the unibody? this seems like a crazy notion -to bolt bars on the side of the unibody and have it help the truck handle, i mean what am i missing?
I total agree with you. It made more sense if you find a passager has same weight as the driver. That will have batter balance than 40 lbs step bar.
The $75k straight out of school seems way too high, unless maybe you have a PHd degree. It also depends on the industry you are in. Try www.gostructural.com and do a search on salary survey. This magazine does an annual survey of Structural Engineers pay vs many factors such as amount of experience.
If I could fill up a 50,000 seat stadium with fans cheering while I design a Transmission Tower on the big jumbotron, maybe I could buy my own jet like the pro golfers, baseball players, and basketball players do.
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i suppose it could enhance the rigidity of the frame but do a very minimal effect(i hope )..the supra's frame flexes a lot when the top is off the car as any supra driver who has cornered hard or gone over train tracks will tell u if they are honest and dont have X braces and so forth under the car...this was an issue with older lexus' as well...the GS300 comes to mind...
not saying the original poster is incorrect in his assessment of the handling in his truck...i dont see it, but i also havent tried it...
Kevin
not to get off the subject, but i noticed my 88 alltrac celica used to flex in the corners alot. it didnt have much of a frame, just stamped metal. i didnt like the feeling and sold it.
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MODS: TRD urban package - tint, stereo, jack-in-the box antennae ball, my middle finger.
...And as a matter of fact, i cant spell.
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Green V6 2wd highlander
(alarm,wheel locks,vin number on windows options)
Manik Full Front Guard
Manik Rear Guard
Manik Side steps
Velvet seat covers
Chrome Exhaust Tip
Hyper White xenon bulbs
Tint 20% rear, 30% front
alltrac, huh?...i nearly bought one to make it very fast....glad i didn't now i opted for a BMW M3/4 and modded it instead...xbrace too...rigid piece of machinery.... ...it seems many toys have/had this issue...we did have a celica ST but that thing would top out at about 116MPH in a straight line downhill ...after being totally massacred by a porsche boxster S i decided to remedy the problem and purchase the M3....
Kevin
Quote:
Originally Posted by 42GAMI
not to get off the subject, but i noticed my 88 alltrac celica used to flex in the corners alot. it didnt have much of a frame, just stamped metal. i didnt like the feeling and sold it.
...thanks for clarifying...
Huh? 
, but for once I actually disagreed with a post like this instead of create it.