Posted By: Andrewh
track/cornering questions on what suspension does. - 06/14/12 04:47 PM
so on the corners, do the shocks play a very important part?
that is, if they were stiffer in the corners vs the straights would that be better?
is there any reason for shocks to be stiffer in the straights?
if you could alter the ride height in the corners, would it be better for the outside to increase in height or for the inside to decrease in height for ability to corner?
Or is it even possible physics wise to get the inside to lower since it is unloading weight?
or does this angle make no difference?
finally, do they make an alterative to springs and shocks/struts?
torsion bars and shocks?
or are those the only choices in this game?
Posted By: 70Cuda383
Re: track/cornering questions on what suspension does. - 06/14/12 05:02 PM
I'm no pro, but isn't that basically what the sway bar does? it pushes down on the outside tire ("lift) and pulls up on the inside tire ("drop"), as the body rolls when going through the corner?
Posted By: autoxcuda
Re: track/cornering questions on what suspension does. - 06/14/12 05:11 PM
Shock control a few things.
The high frequency small movements of small bumps in the road with high speed dampening. That would be the high speed straights.
How fast/slow weight is transfered low speed dampening.
That's real basics. It's much much more complicated. I'd google on of the aftermarket shock manufactures and see if they have a 1-2 page brief explanation/primer.
Here's a video of the front suspension of my car:
http://youtu.be/je5oeamQ_uw
Posted By: Andrewh
Re: track/cornering questions on what suspension does. - 06/14/12 05:28 PM
maybe if I explain a little more.
so I have seen active suspensions where the car "adjusts" based on what you set it to for track or whatever, but why not take it a step further.
if you know that the car is accelerating in a straight line, would it not be better if the front shocks unloaded or better yet pushed the front up to load the rear?
if you could tell you were in a turn, and adjust the shock to be stiffer less give for the turn or again better yet, push up on the loaded down side to give better weight distribution(assuming this even matters in a turn,) why not?
or does such a system already exist?
my thoughts were, that there is a lot of compromise and the biggest complaint is how great they are in turns but if you hit a bump, it will break your back cause there is no give. but if the suspension was only super stiff in the turn, would that be helpful or a waste of time?
Posted By: 68Plymouths
Re: track/cornering questions on what suspension does. - 06/14/12 05:31 PM
Pick up the latest issue of Circle Track. They have a "Handling 101" article that explains what those parts do.
No there is no alternative to the spring/shock compbination that I have ever heard of.
Posted By: autoxcuda
Re: track/cornering questions on what suspension does. - 06/14/12 05:51 PM
Posted By: Andrewh
Re: track/cornering questions on what suspension does. - 06/14/12 06:21 PM
thanks. I guess I misunderstood the term.
I saw the magnetic fluid shocks and thought, if you could add g load sensors to the system, it would be a cheap way to manipulate when the shockes stiffened up.
then realized, why not use some mechanical means to lift.
I see I am about 25 years behind on my thinking.
Posted By: Andrewh
Re: track/cornering questions on what suspension does. - 06/14/12 07:27 PM
I think those were not for race cars so much as comfortable "performance" cars.
so the list makes sense in that point. high end must have comforatble ride and if I want to lean on it, it won't wallow like a pig.
whereas I was thinking race/performance car that won't kill you to drive normally. so it would know to tighten up in turns and then loosen up in a stright line while not under acceleration.
directional force sensors are so cheap, it seems it would be easy to set that up to do stuff to the suspension.
Posted By: Mattax
Re: track/cornering questions on what suspension does. - 06/14/12 09:04 PM
You will probably really enjoy some of the
the suspension reading list.
Quote:
so on the corners, do the shocks play a very important part?
that is, if they were stiffer in the corners vs the straights would that be better?
is there any reason for shocks to be stiffer in the straights?
Shocks are dampers, which means that the 'stiffness' is primarily a function of the speed the control arms or axle is moving. Think of the times you have tried to open a door that has a spring and damper on it. If you try to slam it open or speed up it's closing, the resistance increases dramatically.
One way to get a handle on this is imagine of the extremes.
If the shock is really mismatched for the weights and springs, the car will continue to oscillate after a bump (no damping) or act like the wheels are mounted right to the chassis (over damping).
In corners, shocks are most important on entry and exit as that is when the chassis is rolling relative to the axles.
Quote:
if you could alter the ride height in the corners, would it be better for the outside to increase in height or for the inside to decrease in height for ability to corner?
Or is it even possible physics wise to get the inside to lower since it is unloading weight?
or does this angle make no difference?
The physics can be directed different ways through geometry. Different suspension systems offer the possibilty to chassis hieght on a corner. Adams's book covers the major ones in a pretty easy to understand way. Puhn's book also covers these IIRC - including a bit on drag race type launching.
Posted By: Viol8r
Re: track/cornering questions on what suspension does. - 06/14/12 09:05 PM
One very important factor in all this is how aero dynamics and overall tire grip play such a huge factor in how modern racing suspension is developed. Unfortunately, for our older chassis, many of the overall packages are not going to work or even be user friendly.
If you look at NASCAR, DTM, etc. the suspension is sealing the cars to the track, taking advantage of every bit of air they can. They do this by using soft front springs, huge sways bars, huge amounts of rebound in the shocks, bumpstops, and multitude of other things.
Not saying we can't take some of this information and run with it, but we must still use mechanical grip as our main focus which in turn limits our options. I will tell you that I do run heavy amounts of rebound in my shocks, a big sway bar, front spoiler, and down as low as I go with out scraping.
Posted By: HUSTLESTUFF
Re: track/cornering questions on what suspension does. - 06/14/12 09:39 PM
I just returned from a visit to Louisiana and drove my brothers new ZL1 Camaro. What a car. It measures yaw, roll wheel spin and adjusts the shocks 1000 times a second. Rolling start in mode 3-active handling and sport mode and almost no tire spin and very fast. Right foot to the floor shifting which impressed him(scared him too) with no getting out of shape. 1-2-3 shifts very fast 4th a longer gear. Was blowing by the MCG office over 110.
I hope Sergio takes a ride in this car and then builds a cuda to match for the same 55,000. He worked hard and got the 4th zl1 for sticker. Now has all 5 gens of camaro. I'd love to take his car on a track and it would probably be better than most of the optima challenge cars because of the electronics out of the box.
Posted By: curleysracecars
Re: track/cornering questions on what suspension does. - 06/14/12 10:43 PM
If I understood the OP's post, I would think it would definitely be possible. It would benefit the car to have shock settings in corners variable. On our drag cars, we run electric shocks, which can be tightened or loosened as the car goes down the track. We run them off of timers, since we are only going straight. For a road course, one would have to write some sort of program that would know where you were on the track in order to know where the shocks should be set at any given time on the course.
Would take some R&D, but would super cool once done.
Posted By: Andrewh
Re: track/cornering questions on what suspension does. - 06/15/12 12:03 AM
my thought was something more simplistic.
the electric shocks give me an idea.
basically you take the cheap g sensors in like cell phones.
you need enough so you can figure out if you are turning, braking or accellerating at each corner, and that would tell the shocks to stiffen up or loosen up for better rides.
I don't do much cornering, so I don't know what you need and though I would ask in general.
it would mostly help to elminate body roll in turns but still allow for a normal ride when just cruising.