control arms

[wireweld]

What are the advantages of using the tubular control arms compared to stock arms? And will I notice any difference on the street? I have a 72 swinger and I have notice this while looking at the internet and I am wondering if they are worth the money on a street cruiser, no strip time.

 

[10secondart]

In fact that condition is wher you would see the most benefit. Our cars were designed with a maxium of 1 degree of caster if you have a good set of stampings. The fact is once you put any kind of tire under the car the attitude angle of the car changes putting you in a negative caster hense the reason why when you drive down the road you feel like you are always steering back and forth. the other common condition is you hit a slight pot hole and the car "darts" to one side or the other. In ALL cases the tubular arms correct those conditions by giving you 3 degree of caster that are adjustable to 7 degree if you buy the CAP Auto Products arms.

www.capautoproducts.com

Thanks,

Ray

 

[USCG CHARGER]

I have a 68 Dart. I also have some upper and lower control arms, strut rods, spindles, etc from a 73 Swinger for a disc brake conversion. I wanted to pruchase ur products but don know if I need them. I basicly want my car to handle better, so would you suggest buyin ur lower control arm and strut rods then keepin upper a arms but replacing the busings?

Jason

 

[autoxcuda]

My car is level front to rear. It's not jacked up in the rear with tall tires and skinny fronts.

If you can get to 3 degrees positive caster and .75 to 1 deg negative camber without the tubular arms you won't really feel any difference. You should be able to do that with Moog 7103 upper bushings installed for more caster.

I got 4.5 degress positive caster and 1 deg negative camber with 73 front end with moog 7103 bushings installed for more caster. That's with shaved 3/16 off the inner poly strut rod bushings. I found the poly strut rod bushing thicker than stock. A thick inner strut rod bushing reduces caster. So I cut the inner front poly strut rod bushing down to stock size thickness. Remember to cut the sleeve the same amount.

Matt Grubel illustrates what I did and he also did here:
http://users.erols.com/mathewg/bushings.html

Street setup:

toe: 1/16" toe in
camber: 1.0 to 1.5 deg negetive 1.5 being more cornering agressive for handling, but you will loose caster with that.
caster: 3+ positive degrees

I'd set the rear eccentric all the way back and the front all the way foward at home to make sure someone spends the effort to do it. Don't assume the alignment guy will do it.

Tell the alignment guy ahead what you want to do. if they try to charge you more or act totally hassled by the car being out of spec GO SOMEWHERE ELSE!!

See for yourself...

These are the rough results without fine tuning and toe setting. This is the caster I got with 7103 bushing and only .8 to 1.0 negative camber. I went more racey on the camber setting to 1.5 negative and ended up with 3.5 deg positive caster.

 

[375inStroke]

Why don't we want more than 3 deg. pos. caster? The more caster you have, the greater the camber change is in turns. This is good, but what are the other effects that I don't know about?

 

[wireweld]

bump

 

[autoxcuda]

Why don't we want more than 3 deg. pos. caster? The more caster you have, the greater the camber change is in turns. This is good, but what are the other effects that I don't know about?

You could run more. In my case I though thte .5 of camber would be more beneficial to higher cornering speeds that an addional 1.5 deg of caster.

For going straight on a dragstrip 4-6 degrees is desired.

Caster inherently creates tire scrub. That why it has it's self centering effect on the tire when going straight.

Caster effect occurs when the imaginary line between the upper ball joint center and the lower ball joint centerline (steering axis) touches the ground in front of the center of the tire contact patch. That results in postive caster.

The force on the tire as it goes down the road self aligns the tire contact patch like a huge tail rudder in the wind.

As you turn the tire around the steering axis, the contact patch is scrubbed around the axis point. Too much is not desirded.

But another feature of caster is that is gains you camber when turning. But in a racing sense, you would just run more static camber to match you tire temperature generated in the corners.

Also, that caster effect will change the corner weights on a car when the the tire turns. The tire lifts or lowers the front end on that side of the car when the tire turns. You can see it on a car placed on digital scale pads. Not a that big deal at 3-6 degrees. But you get more it becomes more of a deal.

There are lots of compromises in Suspension Design.