Review & Install Video
Hey, guys, Stephanie with AmericanMuscle.com, here with the Eibach Pro-Kit Lowering Springs for 2015 and up S550 GT Mustangs. The Eibach Pro-Kit lowering springs are going to be a good option for the S550 GT owners out there who are looking for a lowering spring that's going to improve the looks of the GT, but also still has a comfortable ride quality as well. And for those of you that don't mind spending a few dollars more for these qualities. Lowering springs have a big impact on the S550, as they can completely change the looks of the car, but at the same time, a lowering spring isn't always just about lowering a car. Any lowering spring can lower the car, but the Eibach Pro-Kit is designed with handling in mind as well, which makes them a great choice for those that are concerned with improving handling, and keeping as comfortable of a ride quality as possible.
These are progressive-rate springs, which concentrate on providing balance at all times, in order to improve handling, and they're going to lower the car just over one inch in the front, and one inch in the rear. The drop will change slightly, depending on if the car is a coupe or convertible, due to the weight differences between the models. This drop's going to eliminate a lot of the wheel gap that the GT has from factory, and it's doing to leave the car sitting just above the tires. A one inch drop is pretty standard across the board for the S550, and like I said, a one inch drop is pretty significant for these cars. But I wouldn't say that this is a huge drop, so if you're looking for more drop, Eibach does have the Sportline springs that will drop a half inch more, but they will ride differently than the Pro-Kit. They're just a little bit more aggressive spring all the way around. Now I said that the one inch drop with the Pro-Kit is significant for the S550, and I mean significant in both looks and performance changes. This drop will lower the car's center of gravity enough to have handling benefits and some traction benefits. Squat is reduced during acceleration, and so is some of the wheel hop that the car has. The springs are also going to help with body roll in the corners, and nose dive during braking. All of this means that these springs are generally speaking going to tighten up and improve handling in nearly all aspects.
The Pro-Kit's also a great option for the daily drivers out there that aren't going to drop the car so low that it's difficult to drive places, but they are going to drop it enough to improve looks and handling. They're also that progressive spring rate that I mentioned earlier, so they aren't going to have a harsh ride quality, and that's why I consider these one of the best springs for the dailies. I would consider the ride quality nearly equal to the factory ride quality, slightly stiffer, but really nothing to complain about, and I don't have anything negative to say about it. I do want to say that a lot of times when you're shopping for lowering springs, you're also shopping for things like adjustable caster camber plates, and a new set of both shocks and struts. In this case, I wouldn't say that caster camber plates are required. The drop is only just over one inch, so in all reality, the ability to get the alignment within spec is still there with the small drop. If these were the Sportline springs that were dropping you one and a half inches, I might suggest caster camber plates. It never hurts to have a set of adjustable plates though, so if you've got the extra cash, I'd say go ahead. They're just not required in this case.
As far as shocks and struts, this goes back to the drop, too. I would say that you can get away with the factory shocks and struts in this case, due to the relatively drop, the more forgiving progressive spring rate, and also the low mileage of the components. If your shocks and struts had a ton of miles on them, I would replace them. But in this case, since we're talking about relatively new cars here, I don't think it's necessary. When it comes to price, these springs are going to be one of the middle of the road options. They're not the most expensive, but they're not the least expensive, either. They cost just under $250, which is the same price as the Sportline springs. If you're just looking to get your car lower, and you're not concerned with ride quality, there are some on the site that cost a little less, and will get you where you need to be. On the other hand, if you are concerned with keeping a nicer ride quality, then you're shopping in the right place.
So the install here is going to take about four hours, and I'm going to call it a two out of three wrenches on the scale. You will need some knowledge to complete the install, so I would recommend having a knowledgeable helping hand, or taking this to a shop for the install, especially since it's always a good idea to get an alignment after the install anyway. This install can be done on jack stands if you don't have access to a lift, but as usual, a lift would be your best bet here. Going to need a few tools, including a spring compressor, so make sure you have that before you start the install. Going to need to get down to the spring and strut assembly, so everything like the wheels, brakes, ABS lines, will need to be moved out of the way, so you can pull the assemblies out of the car. The spring compressor will help you remove the spring from the strut and install the new front springs, which are compressed and installed the same way. The strut assemblies go back in the same way they came out, and the install is the same for both sides.
The rear is where things are a little different, but nothing crazy here. Essentially, the IRS subframe will be dropped, along with the rear shock mount, so you can slide the rear spring out. Just like the front, the rear springs install the same way they're uninstalled, and no surprises here. The new bump stops slide onto the shock, followed by the factory dust boot. The new springs can be installed, and the IRS subframe can be bolted back up, and that's about all it's going to take. Like I mentioned earlier, a fresh alignment after the install isn't a bad idea.
Wrapping things up here, the Eibach Pro-Kit lowering springs offer a balance between a spring that will leave the car sitting about an inch lower, and with a comfortable ride quality. The springs give what I'd consider an aggressive look to the S550 that is balanced, and will work to improve handling as well. The springs are not difficult to install, they're in the middle of the pack as far as pricing goes, and you can check them out more online right here at AmericanMuscle.com.