[size=+2]BC Racing BR Type Coilovers - Mazda 5 (Review and Install)[/size] Import Auto Performance: BC Racing Coilover Kit 05+ Mazda 5 A big thanks goes out to Import Auto Performance for making the deal with me on these coilovers. The price is fixed by BC Racing at $1000 shipped a set, but the friendly customer service and quick response times from IAP on my many questions made all the difference between them and another vendor. ---------- Information copied straight from BC Racing NA's web site: Features: - Mono-tube shock design - 30 levels of damping force adjustment, adjust compression/rebound - Pillowball mounts and adjustable camber plates included (where applicable) - Separate full length height adjustable - One year warranty - Rebuildable Technical: - Coilovers use 46mm pistons and 53mm shock housings, the enlarged shock cartridges with specially designed pistons and rods provide a wide range of damping force. - Valves are constructed of special spring steel, which outperforms stainless steels and produces longer valve life. Valve stacks use a patented deflective system to provide more precise control. - Patented concave lower locking ring, to prevent unseating. - Springs are made of SAE9254 high strength, durable steel. Compression tested at over 500,000 tires with less than 5% deformation. - T6061 Aluminum utilized in spring locks and seats for high strength and lightweight. - Iron lower brackets on MacPherson struts to ensure rigidity. - Piston rods are constructed of highly polished steel to lengthen oil seal life and prevent leaking. - High pressure inner rod guide seals ensure a perfect fit for consistent fade resistant damping and long shock life. - 2 step coating process utilizing nickel and chromium plating to prevent corrosion. - Newly developed lubricant oil in shock cartridges minimizes aeration and cavitation. - An additional bearing beneath each pillowball mount provides the smoothest action and prolongs the lifetime of the pillowball itself. Application Guide Link ---------- Related threads: BC Coilovers Unboxing Mazdas247 HondaSwap Brake Fluid Reservoir Relocation ---------- Ride impressions: At the stock settings out of the box (8/30 all around, 1 is stiffest), the ride is actually very smooth. The damping and rebound is firm but not harsh. All the float at highway speeds is gone- on a large rise/dip the car just has one nice smooth oscillation and then it's settled again. No bounce like the stock suspension. The balance feels very neutral. The delay that you feel with the stock suspension after cranking the wheel really fast (like doing an emergency lane change) is pretty much gone- you crank the wheel and the rear of the car follows the front almost without delay. I do have the Mazdaspeed3 rear sway bar though, so keep that in mind- it's a good bit stiffer than the stock bar and increases turning response. I do get a little inside wheel spin when going around really tight corners and mashing the gas, but this really only happens if I add up the rare combo of turning 90 degrees (right turn from stoplight) with my foot on the floor. I can't say that this didn't happen with the stock suspension since I didn't trust it to run corners at high speed- but I do know that most front wheel drive cars will lose traction on an inner front wheel on a quick 90 under power. No LSD kinda sucks. This is the only situation where this happens, so it's not really a big deal. On all other types of driving- rolling through the twisties, zipping through traffic, and even just long distance highway trips- the car is much more planted than it ever was with the stock suspension. I do feel the contours of the road a LOT more than stock, but it's never harsh (with 235/45-17 tires). U-turns going under freeway overpasses are a piece of cake at 60mph, and bombing down canyon roads in the Texas hill country is actually quite fun. The limits are high enough now that you're solidly in "oh crap I'm going to get a HUGE ticket" before you get anywhere near losing control of the car. Now I need more power and more brakes... With the setup now (coilovers, rear sway bar upgrade, 235 tires) it's possible to get the rear end of the car to step out in a tight corner, but it's very easy to control and catch. Even with a fairly aggressive alignment (for this car), it's not twitchy. If I let go of the steering wheel on the highway the car will drift slightly to one side or another, but it's not what I would consider a handful. Keep in mind that the alignment has a HUGE role in how a car feels going off center, and that I typically run settings on my cars that are right at the edge or outside of manufacturer recommendations, so you can dial out whatever twitchiness you want when you get your car lined up. My wife and I prefer cars that respond like go-karts, so I set all my cars to my own specifications. Empty vs loaded: Driving solo, the car encourages you to do bad things. You really can whip it around like any other compact car that has a decent suspension setup on it. Driving loaded (4 adults, 2 kids + roof box loaded with 100+ pounds of stuff), the suspension still handles fine. You're not going to attempt sliding around a corner or anything for the sake of your passengers, but the response is still plenty good to feel what the car is doing. It doesn't bottom out as far as I can tell, and there's enough damping and rebound on the same settings to keep the car from oscillating over large bumps. BC vs Tein Flex (on my 95 Civic): Honestly, the BCs feel pretty similar to the Tein Flex setup I had on my Civic. They're not nearly as stiff because I had a custom spring setup and the suspension geometry is different (and the Civic was 1100 pounds lighter), but the level of control and confidence gained is right up there with it. BC vs AST 4100 (on my S2000): Sorry, no comparison... but then you're comparing $1000 universal cartridge coilovers vs $3000 custom valved coilovers that were designed specifically for one car. I don't hesitate to take a high speed sweeping turn with bumps at 1G in the S2k, but I might have to think about it with the BCs- not that I would ever be in a position to try that out with the 5 being the family vehicle. Who knows? I might decide to take it to the track one day to screw with newbies who think they're hot in their Corvettes. Either way, the BCs are a hell of a deal for what you pay. Three months and 5k miles later, the BCs are still performing like day 1. They still feel great, and I really like driving the car with the stiffer suspension. It adds a lot to the driving experience, and the value for what you get is excellent. If you have to replace the mounting hardware on your 5 (commonly breaks) and you buy the cheapest shocks you can find new plus lowering springs, you're going to end up right on the price of the BC setup. Pictures after the install: ---------- Build Quality / Design: If you look at my unboxing thread (linked above), the build quality of the coilovers looks very good. The paint did scratch a bit during the installation, but I'm a klutz, and the paint will get worn off at metal to metal interfaces no matter what. The one issue I had with the build was with the studs in the top mount on the front struts. The studs start to spin as you get close to the torque value called out in the factory service manual, so it can be difficult to torque to the right level. The studs don't back out though, and I've had no issues with them after 5k miles, so it doesn't seem to be a real issue- just a minor annoyance on assembly. One issue I have with the design is the double locking ring setup on the front struts. It's nice to say that you have some kind of "Patented concave lower locking ring, to prevent unseating" according to the web site literature, but the locking rings come loose. It only loosened up on the driver's side, but it happened 2-3 times (and extended the length of the strut, raising that corner of the car) before I dumped a ton of blue Loctite down all the threads. Issue solved. The passenger side didn't have the same problem of the shock extended over time (from vibration? turning?), but the adjuster rings were still loose, so I applied Loctite there too. Maybe I just have a one-off because only one side had a real issue, but it's worth mentioning because it can be a pretty big problem if the threaded housing decides to back all the way out while you're driving. If BC just used a non-fancy adjuster ring with a gap and bolt through it that physically cinched down on the threads to keep it from moving (like my ASTs), this would never happen. It's also worth mentioning that this was never an issue on my Tein Flexes, even after 20k miles of driving in MUCH more abusive situations than the 5 will ever see- but those cost over 50% more too. I'm ok with a $5 tube of Loctite- I can still break the threads loose later if I want to change the ride height and then dump another $5 tube in to lock it down. Look for the adjustment section after the installation for more info. ---------- Factory hardware vs BC coilover: Front side by side: Front OEM weight, 16.6 pounds including ABS sensor wire bracket which I did not reinstall: Front BC coilover weight, 11.8 pounds (4.8 pound savings per front corner): Rear side by side: Rear OEM weight, 10.8 pounds: Rear BC coilover weight, 9.4 pounds (1.4 pound savings per rear corner): Overall, 12.4 pounds is lost from the car after this coilover installation. It's not much, but it was something I could measure- so why not document it? If you're wondering about the scale, its measurements are repeatable with the same items every time, no matter what order you weigh in, what times, how many times etc. It's dead nuts accurate down to 0.2 pounds, verified against industrial/calibrated scales that I have access to.