Tire wear with Arning drop?

[classicdoug]

I was going to do the Arning drop on a customer's 66 Coupe, but now he's hearing that on a regular street driven car that the tires will wear bad on the inside and it's basically a race car mod. Correct me if I'm wrong, but isn't that why we have different alignment specs for cars with the drop? My point to him was if the car is aligned correctly, then there should be regular tire wear. Am I wrong?

Doug

 

[tarafied1]

you are right, what the arning drop does is change the UCA geometry so when the car leans, the top of the tire won't pull in. It moves the arc of motion lower so that in effect it won't be shorter as it travels downward. It should actually improve tire wear. I have been driving my car for two years with the arning drop and no noticable tire wear!

 

[Jonk67]

I'm with Craig, they should put the tires flatter to the ground (better wear, more tread to the pavement) than original but you must adjust the alignment to the new specs. or it will drive horrible at the stock settings. Many shops won't align these old cars or any car for that matter to anything other than what their stock manual/computer tells them to.
See the instructions ~3/4 the way down the page from Daze's site, i used his drop templates and am very happy with the results:
http://dazed.home.bresnan.net/drop

Jon

 

[Anonymous]

What others have said, who's spreading this crap? Probably the same people that owned a 63 Mustang with a factory 427 mg

 

[midpack]

Probably the same people that owned a 63 Mustang with a factory 427 mg

Hey, I work with a guy who lived next door to another guy who owned that car!!

 

[AtlantaSteve]

Hey, I work with a guy who lived next door to another guy who owned that car!!

When I was growing up our neighbor had the same kind of car! Exactly the same! Only it was a '68 Firebird.

 

[Gigantopithecus]

And it was vtech and had a turbo...

 

[66gt350]

What others have said, who's spreading this crap? Probably the same people that owned a 63 Mustang with a factory 427 mg

Is that the one that came with either a sunroof or a t-top???

 

[turq66]

I know a guy that has a Mach II.


Hey jonk67, who does your alignment?

 

[Jonk67]

Turq66, sent you a PM.
Jon

 

[FordDude]

i used his drop templates and am very happy with the results:
http://dazed.home.bresnan.net/drop

Jon

OK question about drop templates. Or more about the measurements. I made a template years ago when I was working at my uncles machine shop. Without the internet I could only go by what I read in magazines and books. I drilled my holes one inch down and what I am measuring to be about 1/4 of an inch back. Might be 3/16 of an inch, really just eyeballing it with a tape measure. Is that too much? I drilled holes in an aluminum plate and pressed in "drill rod". I drilled a starter hole and the finish hole in the material, heat treat it and pressed it in. fd

 

[Anonymous]

65-66 = 1" down and 1/8" back

67-70 = 1" down


All holes 17/32"

 

[FordDude]

67-70 = 1" down

Frack :roulette

But I did get the 17/32" right. :doh fd

 

[gt289]

I've never done it, but down an 1" AND back should just increase your positive caster.
(vs just going down an 1")
It'll be an interesting experiment

 

[tarafied1]

this is the template I used (67)

more info from DAZE

What Does The UCA Drop Do?
- Three factors make lowering the UCA an improvement in handling. First, this modification to the suspension lowers the center of gravity on the front of the car; second, body roll is reduced by 7% to 9%; and third, the camber curve is improved.
- The center of gravity is a geometric property that relates to any shape, but to keep things simple and related to the topic of automobiles, it is basically the internal balancing point from all directions of a car. When you do the UCA drop, you moderately lower the overall height of the front of the car, which in turn lowers the center of gravity. Easier understanding the application of the center of gravity and how it plays a role in vehicle stability can be illustrated by looking at the stability changes in a canoe based on passenger position. If you sit down on the floor of a canoe (low center of gravity) then the boat is extremely stable and nearly impossible to overturn. If you rise up and sit on the seats, the canoe becomes noticeably less stable, but still functional. Finally, if you stand up in a canoe (high center of gravity), the boat becomes completely unstable and will most likely overturn. In the same way the lower the center of gravity is on a vehicle, the more stable it will be.

and another good expalination

Shelby Drop Front Suspension Mod.
During hard cornering the Mustang body had a tendency to lift a wheel off the pavement and to plow in to the turn.
Klaus Arning, Ford's own suspension engineer, redesigned the front end of the car by lowering the inner pivot of the upper control arms exactly one inch.
Lowering the body resulted in greater changes in the wheel camber during cornering, keeping the wheels vertical to the ground.
It also lowered the front end's roll center and reduced the body's plowing.
To further stiffen the front end, a 1.00 inch anti-roll bar replaced the stock .84 inch stock GT bar. The live, rear axle was held in place with a 4-leaf, semi-elliptical leaf spring and beefy torque reaction arms sitting on top of the axle and anchored through the floor to the chassis.
These changes made the car handle more quickly and precisely.

and this is the alignment specs I used from DAZE (the Firestone in Clarksville did it for me without any complaints)

Please align to these specs “1967-1970 Mustang, Falcon & Cougar Performance Alignment with or without UCA drop�.

These specifications are in order of importance.

1. NO more than .25 degrees difference between driver’s side and passenger’s side.

2. +2.0 to +3.5 degrees caster.

3. -.5 to 0 degrees camber. No positive camber, please. There is no problem having a slight variation from driver’s side to passenger’s side to account for the crown in the road.

4. 1/16" to 1/8� toe in

 

[Lemmiwinks]

OK question about drop templates. Or more about the measurements. I am measuring to be about 1/4 of an inch back. Might be 3/16 of an inch, really just eyeballing it with a tape measure. Is that too much? fd

What happens if you move more than 1/8" to the rear of the car is that the UCA will get too close to the inner fender housing where the UCA is installed. You can forget about a 90 Degree grease fitting for the UCA bushings, if you even have that much room.

Lem