Shelby-Arning drop question

other_shoe

Member
May 4, 2007
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I was talking to a friend of mine this afternoon about doing the drop on my 67, and he tried to persuade me that the same benefits could be achieved with lowering springs. As I understand it from looking at sites like DazeCars, using a lowering spring would achieve only one of the effects of the upper control arm drop, a modest lowering of the center of gravity, but it would not give you the same benefits in terms of reducing body roll or improving the camber curve, which are arguably the more significant benefits.

Do I have this right? Is there something I'm missing?
 
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I think I have to side with you on this one. When Ford did the testing to improve the handling on the Falcon prior to the Mustang's introduction, I'm sure they would have gone the spring route vice the control arm drop if the results were equal.
 
Lowering is a side effect of the drop, due to the angle of the upper arm being changed. The geometry change of the alteration moves the roll center of the suspension, causing the 'rolling' to go more against the leverage of the arms. The result is the car is much more resistant to rolling, as if you put a stronger sway bar in. Of course, if you also add a 1" bar, the effect is increased. Another aspect is that when the car does roll, the tire is kept more square with the road surface, which is good because you are no doubt using modern belted radial tires, so you have, effectively, "radial tuned" the suspension. The original geometry was designed for narrow, non-belted, bias-ply tires. Below is a photo of a 64 Mustang with original size bias-ply tires. Here's more info on the "drop".

Arning/Shelby Suspension Drop

FRG112003-9.JPG