Traction Bars

[RPM]

This is not the first time this "traction" discussion has comeup. What seems to happen is that those who "seem" to understand start throwing out terms like "anti-squat, anti-dive , instant center, etc." and I,m guessing for many of us ,our eyes start to glaze over. I, for one, think it would be great if some of you chassis guru's would post ,preferably w/drawings or pics, exactly what "it" is that your trying to convey to those of us
'" less educated" slobs. You know ,simple, if I change "this" it will do "that" maybe I'm expecting to much? In other words, Don't dazzle me w/ brilliance, or baffle me w/ b/s. sorry, had to say this. thanx, dave

Google any of those terms and you will find the answers you are looking for. In the mean time try this link it will help explain the basics for ya.
chassi suspensions

 

[Differen T]

Google any of those terms and you will find the answers you are looking for. In the mean time try this link it will help explain the basics for ya.
chassi suspensions

Thanks RPM for a worthwhile link. Traction and handling are based on the way tires react to the weight placed on them in a given situation. The suspension controls the amount of weight the tires have on them. This constantly changes because of the movement of the springs. Springs adsorb or release weight. When a spring contracts it is adsorbing weight and the tire nearest that spring gets less weight on it than is actually on that corner of the vehicle. This is a dynamic process because the spring is always trying to return to the amount of weight it carries in the static position so as it tries to extend to its original length it makes the tire feel more weight on it than is actually on that corner of the vehicle. The stiffness of a spring determines how quickly it will adsorb weight. The amount of weight a spring can adsorb per inch of contraction is the spring rate. A spring with a high rate adsorbs weight slower then a lower with a lower spring. If two springs have the same rate the longer one will adsorb more weight. A spring adsorbs weight until it can no longer move. (coil springs when the coils touch, leaf springs when the main leaf when it reaches its maximum length). At that point all the stored weight is instantly transferred to the tire and usually the tire looses all traction.

I'm sorry if this makes some people's eyes glaze over, but it took me a long time to understand the concept of how suspensions work. I have seen the improvements in ETs and lap times drop as racers learned the concepts of how suspensions work. For years it was thought the more a car squatted the more weight was pushing down on the tires. Once the concept of how a spring really works was understood we started to design suspensions to take advantage of it. We learned that suspension mounting points control how the chassis reacts to the springs and that if any binding occurs in the suspension bad things happened to the handling of the vehicle. Names for the motions made in the suspension and formulas to predict these motions were developed. We also learned that shock absorbers can be used to control the rate at which a spring stores and releases energy. Two examples of racers who know how to make their suspensions work are pro stock drag racers. They transfer 100% of the vehicle's weight to the rear wheels, the back raises while the front also raises until the front wheels barely touch the ground. By half track the car has returned to its static position. The other group are the NASCAR asphalt modified racers. Going into a corner the whole car drops several inches and coming out of the corner the whole car rises several inches. About the time it settles to its static position it's time to get off the throttle for the next corner.

I visit this site to learn and I hope contribute to the vast store of knowledge that resides here.

Al

 

[Gerry]

new Idea concept from Gerry UK-- please!?

Sorry, cant just conjure them up. They sorta come to me when they want.
G

 

[Ted Brown]

If you notice on the NASCAR cars, watch the ft ground clearance of the cars, it really does not change, even in a corner, you never see lean, that car can lift a front wheel and the body still does not roll or lift per say... why? because they only need to have (per the rules) 1/2" of suspension travel, pretty much like a go kart setup when it is all said and done, same for Grand Prix cars... Those super wide tires do not like leaning over to the side, as stock factory car tires do, too much lose of traction and the lose of cornering ability ... Gotta keep them tires flat on the track...Not much caster either... my 2 cents

 

[Allen]

Thanks RPM for a worthwhile link. Traction and handling are based on the way tires react to the weight placed on them in a given situation. The suspension controls the amount of weight the tires have on them. This constantly changes because of the movement of the springs. Springs adsorb or release weight. When a spring contracts it is adsorbing weight and the tire nearest that spring gets less weight on it than is actually on that corner of the vehicle. This is a dynamic process because the spring is always trying to return to the amount of weight it carries in the static position so as it tries to extend to its original length it makes the tire feel more weight on it than is actually on that corner of the vehicle. The stiffness of a spring determines how quickly it will adsorb weight. The amount of weight a spring can adsorb per inch of contraction is the spring rate. A spring with a high rate adsorbs weight slower then a lower with a lower spring. If two springs have the same rate the longer one will adsorb more weight. A spring adsorbs weight until it can no longer move. (coil springs when the coils touch, leaf springs when the main leaf when it reaches its maximum length). At that point all the stored weight is instantly transferred to the tire and usually the tire looses all traction.

I'm sorry if this makes some people's eyes glaze over, but it took me a long time to understand the concept of how suspensions work. I have seen the improvements in ETs and lap times drop as racers learned the concepts of how suspensions work. For years it was thought the more a car squatted the more weight was pushing down on the tires. Once the concept of how a spring really works was understood we started to design suspensions to take advantage of it. We learned that suspension mounting points control how the chassis reacts to the springs and that if any binding occurs in the suspension bad things happened to the handling of the vehicle. Names for the motions made in the suspension and formulas to predict these motions were developed. We also learned that shock absorbers can be used to control the rate at which a spring stores and releases energy. Two examples of racers who know how to make their suspensions work are pro stock drag racers. They transfer 100% of the vehicle's weight to the rear wheels, the back raises while the front also raises until the front wheels barely touch the ground. By half track the car has returned to its static position. The other group are the NASCAR asphalt modified racers. Going into a corner the whole car drops several inches and coming out of the corner the whole car rises several inches. About the time it settles to its static position it's time to get off the throttle for the next corner.

I visit this site to learn and I hope contribute to the vast store of knowledge that resides here.

Al

To Differen T

So, a jag 3 point will it work properly without a rubber grommet?
"You only had one change at me, then I was looking in my rearview mirror"

I was at a cruise night in Visalia, CA.

[media]http://www.mediafire.com/?qal7wbmh2rm9fz1[/media]

 

[Allen]

Try Youtube.com instead of downloading the file to your computer (above).
This may make it easier to view. Sorry about the double post guys!

[media]

 

[Gerry]

very cool Bucket.
Gerry

 

[Differen T]

To Differen T

So, a jag 3 point will it work properly without a rubber grommet?
"You only had one change at me, then I was looking in my rearview mirror"

I was at a cruise night in Visalia, CA.

[media]http://www.mediafire.com/?qal7wbmh2rm9fz1[/media]

On first and second generation JAG IRS units we have a four point locating system for lateral and vertical movement control. A lower control arm with a fixed length and an upper control arm (the Half Shaft) of a fixed length. On first generation units a fore and aft movement is controlled by radius rod which is mounted from the lower control arm to the chassis. If this rod is mounted parallel to the direction of travel no rubber mount should be necessary except to reduce road vibrations. This may be difficult to accomplish on a narrow frame vehicle and the rod may have to angle towards the frame. Depending on the mounting positions on both the lower control arm and the frame if there is any misalignment a rubber bushing will be needed. Of course the bushing will be subject to wear.

On second gen rears Jaguar widened the mounting points on the lower control arm and did not use a radius rod in the direction of travel. They also changed the design of the rear section to frame to reduce the need for a radius rod.

I would hope that after installing the rear, but before installing the coilovers you would check for any binding in the suspension for at least 3 inches of travel above and below ride height. If your mounting points for the radius rod are different lengths and angles than the factory mounts this will also affect the geometry of the rear possibly causing unwanted changes in the wheel base during cornering.

Al

 

[Old Rotor Flap]

Well, that video sure does answer all the design, suspension and chassis dynamics questions I could ever think of.

 

[Allen]

Hi Al, I'm also new here on the forum. The second generation JAG refers to it as the traction arm. Thanks a lot for your input. Good job.

 

[ruggs]

Well, that video sure does answer all the design, suspension and chassis dynamics questions I could ever think of.

ORF.... You have missed the concept of posting 100 posts in 30 days of poo poo.

 

[Allen]

UMMM...... it takes quite a lot of time to put some threads together, however, if you don't want to see me around here for awhile, I'll stop posting. Simple as that. I've only done so, because the forum looks like it's struggling. I'm more than happy to hear other people talk. I thinks it's important to compliment others for what they do. Simple one liners.

ORF.... You have missed the concept of posting 100 posts in 30 days of poo poo.
[/quote]

 

[Allen]

[
On second gen rears Jaguar widened the mounting points on the lower control arm and did not use a radius rod in the direction of travel. They also changed the design of the rear section to frame to reduce the need for a radius rod.

I would hope that after installing the rear, but before installing the coilovers you would check for any binding in the suspension for at least 3 inches of travel above and below ride height. If your mounting points for the radius rod are different lengths and angles than the factory mounts this will also affect the geometry of the rear possibly causing unwanted changes in the wheel base during cornering.

Al
[/quote


Rear radius rods at lower link and hub carrier for a Jag rear.--Single rod for a Roadster is best!!---bushing # C8949 {2} -required- and will not affect the geometry or cornering.