Alignment with FF control arms

[Fern]

What alignment specs are people running with Firm Feel upper control arms?
My lower ball joints are getting replaced and I can't remember what the alignment specs were.

[EMCD]

I used the specs for a 2005-2009 mustang GT. Most shops can only program an alignment based on car type now. They've dumbed it down to this level....

[303 Mopar]

For caster get as much as the adjustment will allow, usually barely 3*.  This is done by turning the front adjusters so the control arm is as far outward as possible & the rear adjuster so the arm is as far inward as possible .  Installing Moogs offset upper bushings opposite the instructions will get you more adjustment range.

For camber you want approx 1/2* negative so the top of the tire is slightly inward , this adjustment is done with the upper control aem cam bolts as well so you may have to back them off slightly to get the camber right .

Toe in should be 1/16" 

If the shop has to input a vehicle, do as @EMCD suggests and use 2005 Mustang GT specs

[Fern]

Thank for the replies.
I believe with the FF upper control arms you can get 4 1/2 caster.
Is that too much?

[HP2]

No.

Ideally, you want a couple more degrees than the spindle axis inclination. So you ideal range would be more like 6-7*

[Fern]

This is what I'm going with, unless someone knows of better specs.

Caster +6-7
Camber -.5
Toe in 1/16".

[cataclysm80]

The factory alignment specs for vintage muscle cars are as outdated as the factory bias ply tires.
If you're running modern radial tires, you should be using modern alignment specs to take advantage of their increased performance capabilities.

Modern alignment specs for 1962-1972 B body & 1970-1974 E body Mopars with radial tires

                    Range
Camber    -.5° to -.9°   equal on both sides
Caster   +2.5° to +8°   equal on both sides
Toe In       .05° to .14°   this is per wheel

Camber   0° produces the least tire wear if you're driving in a straight line. 
Negative camber increases wear on the inside of the tire.
Some negative camber is desirable for cornering.  The consensus is to run at least -.5°.
Run more negative camber for more aggressive driving.
Modern (2015) muscle cars run -.7° to -1° camber from the factory.
Inside tire wear might be noticeable in the -.75° to -1° range, and will be noticeable beyond -1°.
Camber beyond -1° is for a road race course and not suited to regular driving due to tire wear.

Caster   is considered a non tire wearing adjustment, but extreme caster can affect Toe during suspension travel.
Positive caster makes the car track straight and return to straight after cornering.
Run more positive caster for more aggressive driving.
Positive caster also increases steering effort.  This is why the factory spec for manual steering is negative caster.
If you have manual steering, you may not want more than +1° caster.  (tire width & steering wheel size factor into steering effort)  With power steering, you can run way more caster. 
The consensus with factory parts is to aim for +2.5° or the most you can get, but equal on both sides.
With factory parts, you may not be able to get more than +1°
Offset upper control arm bushings or tubular upper control arms can each provide about +3°.
Modern (2015) muscle cars run +5.6° to +8.3° caster from the factory.
+1° or +2° more than the Steering Axis Inclination would be ideal for keeping a large contact patch on the inner tire in a turn, but this would be pretty extreme caster on a vintage Mopar.
The factory spec for Steering Axis Inclination on most muscle car era Mopars is 7.5°  This is engineered into the factory parts and not adjustable.  Installing aftermarket parts can change the Steering Axis Inclination.
Extreme caster will lift the car body on the inside of a turn, transferring body weight to the outer wheel, which is the opposite of what you want to do in a corner.  Even if the tire has an optimum contact patch, the weight transfer isn't good.

Toe In   is the most common cause of tire wear.  It increases wear on the outside of the tire.
1/8 inch Toe In drags the tire sideways 40 feet for every mile driven.
Toe in also results in better high speed stability and less wandering.
Good strut rod bushings are important for keeping your toe adjustment set.
The factory spec for Toe In on most muscle car era Mopars is 3/32 to 5/32 total. (about 1/16 per wheel)
Inch based measurements like that are affected by tire diameter. Toe measurement in degrees is more accurate. 
Toe measurement in degrees is a measurement of the angle between vehicle centerline and tire centerline.
Inch spec to degree spec converter   https://robrobinette.com/ConvertToeInchesToDegrees.htm
Using the factory front tire diameter, the factory Toe In spec per wheel is  .14°  ± .03°.  (.28° total)
Modern (2015) muscle cars run .05° to .10° toe in from the factory.

[cataclysm80]

Thank for the replies.
I believe with the FF upper control arms you can get 4 1/2 caster.
Is that too much?

Firm Feel told me that their tubular upper control arms provide an additional 3 degrees of caster.
So if your caster adjustment originally maxed out around 1.5 degrees (reasonable), then your new maximum should be around 4.5 degrees.

I don't think 4.5 degrees is to much.  It sounds great to me.

[cataclysm80]

This is what I'm going with, unless someone knows of better specs.

Caster +6-7
Camber -.5
Toe in 1/16".

I don't see any problem with those specs.  I think I'd lean towards +6 Caster, and -.6 Camber.


"better specs"  is ENTIRELY  dependent on HOW you will be driving the car.  It's practically a matter of personal preference, and whether the improved performance on the extreme end of things is worth the additional tire wear.
Are you building a strictly race car?
Road & Track?
Occasional Street car?
Daily Driver?
Be honest with yourself about how the car will actually be used.

If you set up an aggressive performance alignment for a twisty race course, but your actually more of an over the road Power Tour driver, then you'll likely just have unnecessary tire wear.  Most street driven cars spend far more time traveling straight ahead than they do taking corners.

[Fern]

Thanks cataclysm,  excellent info