slimstajimsta5

I just need some information on the physics of a coilover system for the end of the year project in my physics class. All we have to do is describe the physics of something, and I chose to do mine on adjustable coilover systems. I just need detailed or descriptive information about how they work. I know the basic stuff and I'm familiar with them as i have tokico illumina struts and Ground Control coilovers on my car, but i'm still not sure about what's inside of the shock/strut and how it works.

So on that note, do you all know of any links that describe how they work in detail, such as the valving inside the shock/strut and how it is actually adjusted. Basically, just a know all page/website concerning coilovers.

Thanks for the help

JimBlake

Details of the valving isn't physics, unless you want to get into fluid flow equations. A better physics issue would be the general behavior of the damped oscillations, that's the same whether it's coil-overs or stock suspension.

The differential equation for the motion is simple...
(W/g)*(d^2y/dt^2) + c*(dy/dt) + ky = (forcing function)
(W/g) = mass
c = damping coefficient
k = spring constant
Check your math book for how to get roots for the characteristic equation:
(W/g)*m^2 + c*m + k = 0

Where shocks gets interesting is the damping coefficient 'c'. Often this is a discontinuous funtion where the value of c is different in compression vs. extension of the shock. It gets even better with progressive springs, then k isn't constant either.

Maybe you could google 'damped oscillation' or 'spring-mass-dashpot'...

slimstajimsta5

well i was going to describe how it alters the way the car handles and then go into detail as to how they worked. I'm a senior in highschool, and the project isn't very serious, and the teacher said it was fine to do, so oh well haha

thanks for the help though

JimBlake

What timing! I just went to http://www.howstuffworks.com & there's a blurb about...
Coming Tomorrow: How Car Suspensions Work.

My guess: read about how the car's mass & springs together determine the natural frequency, then the shocks are chosen to get the right damping ratio. So if you get stiffer springs the natural frequency goes up, you need stiffer shocks to get back to proper damping. Soft springs make the car float around like an old-school big car.

From the standpoint of physics, a coilover isn't different than a stock spring/shock. It's just different details of spring perch design, etc.

Check shock manufacturer's websites for valving stuff, but it'll probably be advertising BS. I expect the engineering details will be proprietary.

slimstajimsta5

that's awesome, thanks man.

about it being similar to spring/shock, i know it would practically be the same, but i doubted that my teacher would know what a coilover was so maybe it would pull extra points haha

nonsense

you could throw in some crap about lowering the center of gravity and the effects it has on handling. Also how the adjustments in height will decreases static camber which also increases cornering performance.

slimstajimsta5

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nonsense &raquo;</TD></TR><TR><TD CLASS="quote">you could throw in some crap about lowering the center of gravity and the effects it has on handling. Also how the adjustments in height will decreases static camber which also increases cornering performance. </TD></TR></TABLE>
Yea, i had planned on talking about the center of gravity. I actually haven't heard of "static camber" before, but i'll look it up.

Thanks for the help guys.

.dave

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">Details of the valving isn't physics, unless you want to get into fluid flow equations. A better physics issue would be the general behavior of the damped oscillations, that's the same whether it's coil-overs or stock suspension.

The differential equation for the motion is simple...
(W/g)*(d^2y/dt^2) + c*(dy/dt) + ky = (forcing function)
(W/g) = mass
c = damping coefficient
k = spring constant
Check your math book for how to get roots for the characteristic equation:
(W/g)*m^2 + c*m + k = 0

Where shocks gets interesting is the damping coefficient 'c'. Often this is a discontinuous funtion where the value of c is different in compression vs. extension of the shock. It gets even better with progressive springs, then k isn't constant either.

Maybe you could google 'damped oscillation' or 'spring-mass-dashpot'...</TD></TR></TABLE>

I'd be surprised if that was taught in a high school physics or math class.

JimBlake

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 cam &raquo;</TD></TR><TR><TD CLASS="quote">I'd be surprised if that was taught in a high school physics or math class. </TD></TR></TABLE>Yeah, OK. I should've looked how old he was or something like that. Thinking back, we barely touched that in my highschool calculus class & my HS only had non-calc physics class.

AutoXer

Just go to http://www.howstuffworks.com. I'm sure the info there will be more than enough for basic physics. Spring rebounds, shock dampens, blah, blah, blah. There's probably some good graphics on there as well.