For the most part, Honda's Civic family, both old and new, has typically been blessed with a rather deep aftermarket parts bin. Arguably the most modified vehicle family on the planet, manufacturers know when a Civic model hits the market, there comes with it a flood of amateur and experienced enthusiasts, their heads full of ideas on how it should look, how performance can be increased, and how they can personalize it to separate themselves from the rest of the pack.
Engine performance, aesthetic, or suspension—where do you start? For me, it's typically the area of suspension that I tackle first. The fact that I reached out to Eibach about the Si project and they mentioned needing a Si sedan to R&D some new product definitely helped solidify that decision. The group was one of the first to research and develop springs and sway bars for the 10th generation family, including the Type R, and they've continued development on some other parts to fully cover Honda's latest iteration of the Civic family. Currently they offer a PRO-KIT for the Si that grants a mild drop and a definitive improvement in handling but what I would be testing are their SPORTLINE springs, which offer a more drastic drop and are designed to up the handling ante even further.
In the past, a spring and anti-sway bar install would take an hour or two in your garage with a friend, a few jack stands, and maybe a frosty beverage or two. These days, well, things have become a bit more complicated. And it's not just the current model Civic, but other automakers have made it increasingly difficult to make aftermarket suspension changes. Fortunately for me, Eibach's lift, vast tool assortment, and crew that happen to know EVERYTHING about suspension were on hand to make this as quick and easy as possible. The spring portion of the install can absolutely be done at home with basic hand tools. However, and it pains me to say it, for the average guy, the mid-level sway bar install has been pushed up to "highly experienced" based on the complexity and steps involved in making your way to the stock front bar. If you're going to accept the challenge at home, as always, please consider your safety above all else, get a solid set of dependable jack stands, and secure the car properly before getting started.
Though their PRO-KIT is probably more well known by the masses, Eibach's SPORTLINE springs are what most in our community will typically reach for. Like the PRO-KIT, they use the same progressive spring design that will improve handling and offer a ride that doesn't veer far from the factory comfort of your vehicle, but the SPORTLINE springs do it all at a lower ride height.
While some would opt for a coilover system, the 10th gen. Civic Si's selectable driving modes, normal and sport, which have a significant effect on ride and handling characteristics thanks to the active dampers on board, are something I'd much rather keep in play. Fortunately, Eibach's done their homework and developed their springs to work together perfectly with Honda's selectable damper system.
With the car on the lift and the wheels removed, the first order of business on the spring portion of the install is disconnecting the active damper plug and unbolting the brake line anchor
The axle nut is removed and the knuckle's connection to the shock is unbolted as well as gently tapping on the axle in order to free-up the entire knuckle assembly. The axle is tied up, in this case, using a bungee cord with hook ends to keep it secure and out of the workspace. Some have worked their way around the knuckle removal, but it's dicey and Eibach recommends putting forth the effort in order to avoid any complications.
Under the hood, the shock tower bolts are removed and with everything disconnected in the wheel well, the factory shock and spring assembly can be fully removed. From there it's set into the spring compressor to safely remove the OEM spring and replace it with the SPORTLINE prototype spring.
The process for the front springs is far more complex when compared to say a late-'90s Civic or Integra, but again it's entirely possible at home given that you have a decent amount of wrench time under your belt. The sway bar on the other hand is where things get quite a bit deeper.
Along with the SPORTLINE prototype springs, Eibach supplied their Civic Si front sway bar (29mm) and for the rear, they offer a 22mm Si sway bar upgrade but we opted to go even bigger, with their 25mm Civic Type R version, which you'll see installed a little later.
The Civic's front undertray is removed entirely, along with the downpipe.
Sensors disconnected and freed from their clips along with subframe bolts loosened, but not removed so that the frame doesn't drop from the car completely.
The steering rack needs to come down as well, which requires going inside the cabin and removing the bolt that connects the steering shaft to the rack (I told you it was involved). This allows the rack to be lowered enough to make room for the sway bar removal and replacement. In order to avoid any damage, the tie rod ends are secured using high-strength straps.
Finally, access to the factory bar is granted and the stock sway bar is removed.
Eibach bushing lubricant is applied to the new polyurethane bushings (all included in the kit) and the new sway bar is bolted into its new home. The process of removal is reversed and everything goes back into it original place. The Eibach sway bar does not require any sort of modification to the car in any way.
In the rear, the spring removal and installation couldn't be any simpler, being that they're not connected in any way to the shocks. In this instance, however, we added some additional components to the mix.
The idea of using Eibach's CTR rear sway bar is to further help reduce the amount of unwanted understeer but not to the point that the upgrade would contribute to oversteer—a somewhat delicate balance with FF vehicles and often times testament to the "bigger isn't always better" sentiment. In this car, however, the Eibach staff, having tested so many different variations, assured me this setup would undoubtedly impress me.
To avoid excessive camber and to find the right balance of grip and tire wear, Eibach also added their PRO-ALIGNMENT rear camber arm kit, and in order to get to the upper bolts and disconnect them Eibach recommends dropping the rear subframe, which in turn requires removing the exhaust system. Having a lift, exhaust stands, and a good tool selection made things easier.
Like the front, the shock sensors are unfastened and the Si's exhaust is removed. Being that the tubing and muffler is a single unit, an extra set of hands or multiple exhaust stands will come in handy at this point.
The rear calipers are removed and hung securely to relieve stress and avoid any damage to the brake lines and the outer portion of the rear arm is unbolted. In the third photo you can see the inner portion of the arm located further inside and just under the body. It's tough to get to and break loose and even tougher to completely remove, which is why lowering the subframe helps so much.
The shocks are unbolted and their fasteners added to an ever-growing pile of hardware comprised of subframe bolts and assorted bits. The lowered subframe, secured by safety straps on both ends, gives even more access to the factory sway bar end links, which are easily removed to make room for the new Eibach piece.
Eibach's precision end links bolted in place using the supplied spacers for a rock solid fit.
Another new part that Eibach just finished for the 10th generation Civic line is this rear subframe brace. Produced in solid billet aluminum, it adds increased rigidity to the rear and for anyone worried about tearing a subframe when using anything larger than Eibach's CTR rear sway bar, this is additional peace of mind and it's now available on its own or part of Eibach's 10th gen. Civic rear suspension system.
Combine this with the billet aluminum sway bar brackets and polyurethane bushings provided in the sway bar kit and you're ready for business. The brackets even include Zerk fittings so that you can add additional bushing lubricant in the future without having to remove everything.
Eibach's adjustable rear camber arms bolt into place exactly like the factory piece and their threaded end links are to be adjusted once the car is on an alignment rack. As for the springs, they're simply pushed into place using the factory rubber top hats.
With all of the suspension-related nuts and bolts double checked, the subframe and exhaust are reinstalled and the car is ready for a road test.
The final step in the process is loading the car onto Eibach's in-house Hunter alignment rack where crucial adjustments are made and our Si sedan is ready for the road.
I'd been daily driving the Si sedan for a few weeks and spent quite a bit of time on the weekend at our local canyon getting an overall feel for the car and a sense of how hard it can be pushed—safely, of course. As I mentioned in the intro story, the car's handling is exceptional and, with the Si badge attached, it really should be seeing as how it continues a long-line of Civic models that offer an increased fun-factor over their counterparts and are often more capable than their competitors.
Some suspension manufacturers give you the tools to lower your vehicle and in turn, the new center of gravity and usually stiffer spring combination should give you better handling. Like any performance addition, without proper R&D and real world testing, some of these parts can cause more headaches than benefit, and that's exactly why I reached out to Eibach, a group that puts the hours into finding the right formula.
With the car completed and properly aligned, I headed out of Eibach's Corona, Ca, parking lot and hit the street. I left the car in "Normal" mode to get a feel for the new suspension pieces in the setting that I use the majority of the time on my day-to-day routines. Hitting a few bumps and dips on the surface streets surrounding Eibach produced similar results to the factory suspension, though I could feel a little more impact with the car lowered and the stiffer sway bars the difference was minor. After tapping the "Sport" mode and feeling the dampers and steering tighten up, I fully expected greater impact from the rough streets that line Corona's industrial business park grid. What I found was that even with the increased stiffness of the more aggressive driving mode, the Si still carried plenty of travel and the "pucker factor" when aiming for uneven road surfaces diminished after the first few miles. That's not to say that there wasn't more road being felt, it just wasn't nearly as dramatic as I'd imagined, especially having opted for the larger rear sway bar.
The decision on that rear bar proved to be the right one about halfway through the first long, sweeping right-hander that spits you out onto the 91 East. Initial turn in is as sharp as you'd expect from over an inch of drop based on a quality spring set up and those thick bars doing their job. Halfway through the turn, I realized I could have entered at a higher rate of speed without issue in the car's new form, and closing out the action allowed a full throttle romp with the Si sedan planted firmly and prepared for far more than I'd ever introduce on a public road. The confidence-inspiring boost you get from performance springs and sway bars is always eye opening - doing both at the same time will transform your behind-the-wheel experience dramatically
The Si's handing is very, very good in stock form, and it's outstanding now with the new additions, and with new wheels and tires on the way, it will be even better. Any thoughts of adding more horsepower rather than working on the suspension package were tossed aside - this is exactly where the car shines and what area I think deserves to be exploited the most.
Eibach's sway bar options are already available, as are their adjustable rear camber arms and rear subframe brace. After countless hours of testing, including quite a bit of feedback from our Si project, which ran the prototype version of the SPORTLINE springs for a few months now, Eibach will soon release these to the public to accompany their already popular PRO-KIT spring kit option.