BillyShope
10-15-2009, 04:07 AM
This is about the only forum (other than eng-tips) where I could post something like this and it will be appreciated. And, you might have a good laugh at my expense.
Now that I'm retired, I get a kick out of helping those interested in suspension design, but who do not have access to all of the fancy fixtures and software available in the industry. So, I considered it another accomplishment when I added Page 28 to my site. With only a floor jack, a set of wheel scales, and a tape measure, I provided a means to determine the roll stiffness distribution. I had it all figured out as to how I would compensate for different fore and aft locations of the jack. The software determined the proper jack placement. So, the user had to input the wheelbase and then locate the jack at the proper distance back from the front wheels.
Then, it hit me. It wouldn't matter if the user was somehow able to place the jack between the front wheels, so that the total weight on the rear wheels was unchanged. The rear roll stiffness would still have the same effect.
So, all of those fancy compensatory equations simplified down to one simple equation and the user is free to put the jack anywhere he likes (fore and aft, anyway).
If any of you guys ever looked at that page and wondered why I asked for the wheelbase and gave you that screwy jack location information, now you know.
Almost forgot: The answers haven't changed. I just went around the barn a couple more times to get there.
http://www.racetec.cc/shope
Now that I'm retired, I get a kick out of helping those interested in suspension design, but who do not have access to all of the fancy fixtures and software available in the industry. So, I considered it another accomplishment when I added Page 28 to my site. With only a floor jack, a set of wheel scales, and a tape measure, I provided a means to determine the roll stiffness distribution. I had it all figured out as to how I would compensate for different fore and aft locations of the jack. The software determined the proper jack placement. So, the user had to input the wheelbase and then locate the jack at the proper distance back from the front wheels.
Then, it hit me. It wouldn't matter if the user was somehow able to place the jack between the front wheels, so that the total weight on the rear wheels was unchanged. The rear roll stiffness would still have the same effect.
So, all of those fancy compensatory equations simplified down to one simple equation and the user is free to put the jack anywhere he likes (fore and aft, anyway).
If any of you guys ever looked at that page and wondered why I asked for the wheelbase and gave you that screwy jack location information, now you know.
Almost forgot: The answers haven't changed. I just went around the barn a couple more times to get there.
http://www.racetec.cc/shope