Lowering Upper Control Arms on '65-'68 Mustangs
I'm sure this has been covered before, but I was thinking of lowering my upper control arms 1".
Where can I get a template to do this? And is there anything else that needs to be done other
than drilling new holes and moving it?
You'll find a template and instructions here, on Dennis Begley's excellent Shelby Site
After the arms are lowered, what alignment specs to use? I would guess Shelby specs are a
good place to start but how does wheel offset affect the specs? Tire width? Seems to me wider
tires would require a different camber, wouldn't different wheel offset also affect that? Factory
settings have a certain amount of vagueness and understeer built in. When you put on a bigger
front sway bar and add a rear sway bar in an effort to see handling improvements, how should
the alignment change to maximize the improvements?
I took a look at the link and it says to change the settings for different applications.
So, how does changing the specs affect the handling? What effect will changing the toe-in have?
What effect will changing the caster have? What effect will changing the camber have? Also, if I
use a wider tire, then the edge of the tire will have more pressure on it than the same edge on a
thinner tire. It seems to me as you widen the tire, the camber would have to change. The specs
given are for what size tire? As you widen the tire would all the specs have to be adjusted? Is
there a site that helps explain suspension tuning? If you have understeer, what to do? If you
have oversteer, what to do? Years ago I read in Hot Rod magazine, I believe, about a couple of
road racers, Herb Adams and Dick Gulstrand, who had two different philosophies about
handling. One said to use stiff springs and strong shocks to control them to control body lean
and use relativly light sway bars. The other says to use lighter springs and shocks but use
heavier sway bars to control body lean. Any thoughts on that? My Special Service (cop car) Fox
chassis LTD uses poly bushings in the suspension and it feels very controllable but it does let
you know about every bump and crack in the pavement. 'course it does have stiffer springs and
struts and shocks than a regular car. I'm not sure I would use the poly bushings in my '66. I
want it to handle better but I don't want to harsh ride poly gives you. What effect does a posi
have on cornering? In my 4X4 the posi tends to cause understeer. Turn the wheel and it wants to
go straight. We can use the Shelby cars as examples to set up our cars but what has been
learned in the last 35 years that we can use to improve on them?
Rande, first thing is that trying to find a perfect suspension set-up for the vintage Mustang is
impossible. There are no two people that would have the same requirements or driving habits. If
money would be no object, just look at any new performance car, how many of them have leaf
springs, how many have the same type of front suspension and steering as a 65-66, absolutely
none of them. We are dealing with an antique suspension that was designed long before anyone
thought about radial tires. Each person will have their own ideas on what makes it handle better,
it is up to you to sort out the BS and do what works for you. I could tell you the tricks or
changes I've made to my coupe, but they might not work for you. One thing I can tell you is that
if you use the set up numbers that Shelby used on lowered control arms on you street car, your
tires will wear very quickly.
You're right about the tire wear, it's definitely a consideration. But if your main interest is
handling, lowering the upper A-arm works. Note that there are some aftermarket springs that
should NOT be used with lowered A-arms.
I see you found Dennis's site; I'd forgotten he has the front end dope on-line. If your springs are
tired install some new ones while you're in there, and a set of Gabriel adjustable shocks on all 4
corners (set in the middle) wouldn't be a bad idea.
Yikes, George, you say there are some aftermarket springs that should NOT be used with
lowered A arms. Can you explain?
My car is 12,000 miles away getting a paint job (while I freeze my nuts off in England), and
since the engine is coming out, I asked my mechanic to lower the A arms and find some
suitable new front springs. What kind of disaster am I looking at if he chooses the wrong
springs? (As you may know, I'm looking at popping in a 429, but for the time being, they only
have to handle a 351W.)
I realize that I will have to do some experimenting to get the ride and handling I am looking for.
kcode's point is understood. I am not looking for someone to give me a set of magic numbers.
What I am looking for is some guidelines to work with. My question about tire width and camber
settings for instance. Seems to me a wider tire needs a different camber setting than a narrow
tire. Perhaps front alignment isn't as critical as I may be thinking it is? Perhaps on a street car,
basic settings are just fine. Lots of time spent experimenting would not show much improvement
in the real world although on a dedicated track car it would. What do you guys think? What is it
about the Shelby settings that causes the accellerated tire wear? Is there a solution for that?
The Shelby specs are for hard road course driving, hard lefts and hard rights. If this is the
purpose of the car use the specs. When I made this change about 5 years ago, the alignment
mechanic laughed at the caster/camber specs. What he set mine at was zero degree on both.
After about 20,000 miles with 15 x 7 inch rims and 215-65 radial tires, the inside tread is
showing some wear. But, the car handles perfectly on the street and interstate highway and the
Kentucky backroads. George won't agree with this, but, I'm also running the 620 front springs
and 1 1/8 sway bar and KYB gas shocks. The ride is very firm almost stiff, but thats what I
wanted. One other suggestion, make the rear suspension match the front. If you put poly
bushings up front, do the same to the rear. Good luck.....
Hey Kcode, run what you brung. If you like to rattle your fillings, go for it! I'm not sure what sized
sway bar or spring rate my '67 Shelby 350GT has, but it's a little mushy compared with my ex C
type Jag, Lotus 11, and '73 911 Targa.
I just finished installing my suspension kit from Mustangs Unlimited, 620's and 1" sway bar on
front and 4 1/2" leafs with the 3/4" bar in back. In the front I used all urethane except for the lower
control arms and strut rods, rubber in the rear springs, urethane for the sway bar. Boy, what a
night and day improvement that is. The parts all fit well and look good. Anyway, my alignment
specs are the way I wanted .3 degree - camber 2.5 degrees + camber and 1/16 inch toe in.
I used - camber so the tires don't "roll under" in the corners.
As an 8 year alignment man I don't agree with the 0 0 settings. Sure the car will track straight and
the tires are bound to wear with these settings, but how about in the corners? I would think it
would be prone to bump steer, and, at the least, the toe out in turns will cause problems. Take
some of the german cars made for the autobahn. They can run as much as 4-5 degrees of caster
to a point. A Saab has this engineered into its design. (look at how the strut is angled)
Yes, the wider the tire the more tire wear you will get. With camber and toe, the wider the tire, the
less you will want. I don't recomed 0 toe or camber, though. You need some toe in to make up
for the natural pull out of the tires when driving. Same goes for camber under acceleration or
heavy braking. These angels will change dramaticly.
The last consideration is driver weight. I have seen cars that I had to set the align to PULL to
make up for a very heavy driver. If one side is weighted down, the effect is like having a broken
spring; one side will shift to the negative and the other side will shift to the positive. This is
in case of major weight transfer. With new springs, a 260 pound driver shouldn't have any problems
with this. (thats why I changed all mine to the 620's. lol)
Well, I'll stop now.
To add one more thing, don't forget about air pressure. This will have a big effect on wear and
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