If You Lower a 2011-2014 Mustang, do You Need Caster Camber Plates?
Mustang Front Suspension Geometry
When you install lowering springs, you change more than just the ride height; you also change some of the suspension geometry. This is extremely important to understand when making modifications to the ride height. All current Mustangs utilize an independent MacPherson-strut front suspension, which has its own unique properties just like the panhard bar setup which is used to control the solid axle in the rear. With the MacPherson-strut setup, as you lower the front end, the top of the wheel wants to arc inside of the wheel well and angle towards the center of the motor, and at the same time, it is pushing the bottom of the wheel outwards, this angled “up and in” condition is an abnormal amount of negative camber.
Mustang Lowering and Alignment Issues
I had recently checked the alignment on my car and everything was “within spec.” So, after the suspension work was completed, I headed straight back to the shop to recheck the alignment, the entire time I'm praying that I don't have to order caster camber plates, and more importantly, un-install, and then re-install the entire front suspension. The bad news, the alignment rack said my toe was off (angled in). The good news was that my camber readings were just within the factory specifications for tolerance. As far as alignment adjustments that can be made to a 2010+ Mustang’s suspension without aftermarket parts, there is only one, luckily for me that is the toe on the front end. I was easily able to adjust the toe measurement back to factory specification and at the same time make certain the camber reading didn't move out of specification during the process. Could I gain back some camber that was lost with caster camber plates? Absolutely.
In the picture below, the left and right strut towers are connected by the strut tower brace. In the middle of the strut towers you can see the top of the strut, If the top of the strut is coming through the towers angled towards the brace, that would be a visual indication of too much negative camber.
Below is a close-up how the strut looks coming up through the tower. As you can see, here it is pointed away from the brace, if my car was lowered to the point where it needed caster camber plates, the strut would more than likely be coming up through the tower angled more towards the brace. In this picture it is also very easy to see that the stock upper mount does not provide any adjustment, which is where the aftermarket caster camber plates come into play.
Does a Mustang Need Caster Camber Plates? How Low Can You Go
The main question you have to ask yourself is, How low do you want to go with your Mustang? If you're only dropping the car a small amount (less than an inch or so), you can possibly get away without using caster camber plates (asking when you go in for an alignment can reveal your need for caster camber plates). If, however, you plan to install a set of lowering springs that do drop your Mustang quite a bit and eliminate the 4x4 stance from the factory, you'll definitely want to invest in caster camber plates. Not only to correct alignment issues and poor tire wear, but they will allow you to more accurately dial in your suspension in the future.
Mustang Camber Bolts
While discussing options on resolving camber issues, I also want to touch base on camber bolts, while they may initially allow the user to adjust the camber, they should not be thought of as a long term replacement to caster camber plates. Unfortunately, due to their placement at the lower section of the strut assembly, they lack the same range of adjustments and you are also changing out a vital fastening component that is repeatedly subjected to extreme forces. This moves the camber bolts off of the list when compared to a quality set of aftermarket caster/camber plates that have been designed and tested to exceed the conditions a normal street car will ever undergo.
I must say, I wish my car was a little lower from an aesthetic standpoint, but for my driving style , habits, and locations frequented, this setup is leaps and bounds better than stock, especially when the road I'm driving on starts to curve. More importantly, I'm able to enjoy my car every day, without worrying about increased tire wear or other unwanted side effects from excessive negative camber caused by lowering springs.