If you're still rocking the factory suspension on your 80s rotary, swapping to a decent set of fc rx7 coilovers is basically the first thing you should do to modernize the drive. Let's be honest, the second-generation RX7 is a masterpiece of engineering, but even the best Japanese suspension technology from 1986 can't contend with thirty-plus years of deterioration. Most FCs on the road today are either bouncing on blown-out struts or sitting way too high to get a car that was made to carve through canyons.
The jump from a traditional strut-and-spring combo to a dedicated coilover setup has become the most noticeable change you can make. It isn't just about getting rid of that "monster truck" wheel gap—though that's a massive plus—it's about how the vehicle communicates with you. The FC has an unique rear suspension geometry that can feel a little unpredictable when the bushings are old and the shocks are tired. A good set of coilovers helps settle that nervousness down.
Why the FC Needs a Suspension Refresh
The FC RX7 uses a MacPherson strut front plus a semi-trailing arm rear. One of the quirks of this chassis is the DTSS (Dynamic Tracking Suspension System). Back in the day, this was high-tech stuff; it allowed for a bit of passive rear-wheel steering. However, since the car ages, that system can make the rear end feel like it has a mind from the own, especially under heavy cornering.
When you install fc rx7 coilovers , you're often pairing them with other mods to tighten up the trunk end. Even on their own, coilovers provide a much more linear and predictable response. Instead of the car leaning over and then suddenly "stepping out, " a well-valved coilover set keeps the chassis flat and the tires planted. It makes the car feel half its age.
Finding the Right Spring Rates
This is where a lot of people mess up. It's tempting to think that stiffer is always better, especially if you're planning on doing some drifting or track days. When you're mostly driving your RX7 in the street, going too stiff will make you hate the car. You don't want to feel every single pebble in the road vibrating through your spine.
For a street-driven FC, you'll usually see spring rates around 8k in the front and 6k in the rear. Many people prefer a 7k/5k setup for a bit more compliance. If you're building a dedicated drift missile, you might go up to 10k or 12k, but just know that your interior plastics—which are already brittle—will probably start rattling like crazy. The goal would be to find that "Goldilocks" zone where the car stays flat in the turns but doesn't punish you every time you hit a manhole cover.
The Importance of Damping Adjustment
Most modern fc rx7 coilovers include adjustable damping. This is usually a little clicker on the top of the strut (or the bottom, depending on the design). This is a lifesaver. It allows you to soften things up when you're just cruising to a meet, and then stiffen them back up when you reach the twisty backroads.
I always suggest starting right in the middle of the adjustment range. Drive the car for the week, let the springs settle, and then see how it feels. If it feels "bouncy, " you most likely need more damping. If it feels "harsh" and crashes over bumps, back it off a few clicks. It's all about fine-tuning the setup to fit your specific car as well as your local road conditions.
Independent Height Adjustment
Something you should definitely look for is a "full-tap" or independent height adjustment. Older or cheaper coilover designs used the spring perch to change the height. The problem with that is that while you lower the car, you lose suspension travel. You get bottoming out the shock, which is bad for the car and terrible for your kidneys.
Modern fc rx7 coilovers usually enable you to thread the entire shock body into the lower mount. This means you can drop the car as low as you want without affecting the spring preload or the travel of the piston. You get to maintain the same ride quality whether you're at stock height or "laying frame"—though I wouldn't recommend going quite that low if you actually want to drive fast.
Camber Plates and Alignment
The front from the FC RX7 can be quite straightforward, and most coilover kits will come with integrated camber plates. This can be a huge win for your FC because the factory adjustment is pretty limited. Being able to dial in a little extra negative camber up front will help the car turn in much sharper and reduce understeer.
The rear is trickier. Since it's a semi-trailing arm setup, as you lower the car, you're naturally going to gain some negative camber. If you go really low, you may end up with more camber than you want, which can wear out your tires prematurely. Some guys use individual camber links to fix this, but a good set of coilovers is the foundation you need before you start worrying about those fine-tuned adjustments.
Don't Ignore the Installation
Installing fc rx7 coilovers is a pretty standard weekend job, but since these cars are getting up there in years, you've got to be prepared for some headaches. Those rear mounting bolts love to seize up. I'd highly recommend hitting everything with some penetrating oil a few days before you plan to start the job.
While you have everything apart, it's the perfect time to look at your bushings. If your subframe bushings are shot, your most expensive coilovers in the world won't make the car feel tight. It's a bit of "while I'm in there" syndrome, but it really does really make a difference. Also, make sure you obtain a professional alignment immediately after the install. You'd be surprised how much a tiny bit of toe-out can ruin the handling of an RX7.
Street vs. Track Focus
Have you been building a "canyon carver" or a "track monster"? Your choice in fc rx7 coilovers should reflect that. If you're 90% street, look for something with a bit more "street-friendly" valving. These shocks are designed to handle the high-frequency vibrations of rough pavement.
If you're building a car for the track, you can afford to go with a more aggressive, monotube design. These handle heat better during long sessions, so your damping doesn't fade since the shocks get hot. They might be a bit noisier—you'll hear some "clunking" or "hissing" from the pillow ball mounts—but that's the trade-off for precision.
Keeping Everything Maintained
Once you've got your coilovers installed and the height dialed in, don't just forget about them. Road salt, grime, and brake dust can wreak havoc on the threads. If you live in a place with harsh winters, it's a good idea to coat the threads in some anti-seize or a dedicated protective spray. There's nothing worse than seeking to adjust your ride height a year later learn that the locking collars are welded shut by corrosion.
Give them a quick wipe down whenever you have the wheels off. Check for any signs of leaking oil around the seals. A quality set of fc rx7 coilovers should last you a long time, but they are wear items just like anything else.
Final Thoughts
At the end of the day, upgrading to fc rx7 coilovers is one of the most rewarding things you can do for your S4 or S5. It transforms the car from the soft, aging grand tourer into a sharp, responsive sports car that may still hold its very own against modern machinery.
Remember to be realistic about how exactly you use the car. Don't buy the stiffest springs available just because they sound "hardcore. " Pick a setup that matches your driving style, take the time to dial in the damping, and get a solid alignment. Your FC will thank you for this, and you'll end up taking the long way home every single time you go for a drive.