Is it time to replace your race suit? Let’s get you track-ready. 
This is the BC Racing Coilovers BMW M3m4 Competition kit, built to the standard strut and shock dimensions so it bolts straight to the factory mounting points. Chassis code G80/G82. Fits 21+ cars. Default spring rates are front 6.5 kg/mm / rear 14 kg/mm.
Ride height is set on the lower bracket rather than by compressing the spring. That keeps spring preload and ride height as two separate adjustments, which is the main practical reason people move off budget coilovers.
BC Racing Coilovers BMW M3m4 Competition specification
| Vehicle | BMW M3/M4 Competition (AWD) (21+) |
|---|---|
| Chassis code | G80/G82 |
| Manufacturer | BMW |
| Brand | BC Racing |
| Default spring rates | Front: 6.5 kg/mm / Rear: 14 kg/mm |
| SKU | BCR-I-109 |
Available kit configurations
Each configuration is the same damper and spring package with a different top mount arrangement. The kit code is the BC Racing part number for that build.
| Configuration | Kit code | Top mount |
|---|---|---|
| BR Series – RA: Pillowball front / rubber rear | I-109-BR-RA | a pillowball top mount at the front and rubber at the rear |
| RM Series – MA: Inverted front / rubber rear | I-109-RM-MA | as listed |
| ER Series – 2-way adjustable, external reservoir | I-109-ER | as listed |
| ZX Series | I-109-ZX | as listed |
Which series for the BMW M3/M4 Competition (AWD)?
- BR Series gives you 30-way rebound adjustment and full height adjustment independent of spring preload.
- RM Series gives you a race-oriented build with inverted damper bodies.
- ER Series gives you external reservoirs for more consistent damping under sustained load.
- ZX Series gives you raised ride height for soft-road and overland use.
Spring rates and what is in the box
This kit ships at 6.5 kg/mm front and 14 kg/mm rear. The stiffer rear is normal on this layout and helps the car rotate on turn-in instead of pushing wide. Rates are chosen by BC Racing per application, so they suit a fast road and occasional track car as supplied. If the car is built for something more specific, a track weapon or a car carrying a lot of aero, the rates can be changed without replacing the dampers.
The kit covers all four corners and includes the dampers, springs, lower brackets, locking collars and the adjuster spanners. Top mounts depend on the configuration you pick from the table above. Anything that is worn on the car already, drop links, bushes, top mount bearings, is worth checking while the suspension is apart.
Fitting and setting up BC Racing Coilovers BMW M3m4 Competition
Work on a flat floor, set the height on the lower brackets, then roll the car forward and back to settle everything before you take a final measurement. Alignment comes after the height is set, not before.
Start with the damping adjusters in the middle of their range and work from there. Wind towards firm for track work and back off for road use, changing one end of the car at a time so you can feel what each change did.
These are serviceable units. Spring rates can be swapped and the dampers rebuilt, so the kit can be re-specced as the car changes rather than replaced.
Worth reading if you are new to this: how a coilover works and why height and preload are separate adjustments.
BC Racing Coilovers BMW M3m4 Competition questions
Will BC Racing Coilovers BMW M3m4 Competition fit without modification?
The kit is cut to the BMW M3/M4 Competition (AWD) damper and strut dimensions and uses the standard mounting points on the G80/G82 chassis. No cutting or welding is needed for a standard car.
How low will the BMW M3/M4 Competition (AWD) go on these?
Height is adjustable across the full range of the lower bracket. How low you can usefully run depends on your wheel and tyre size and how the car is used, so set it to suit how the car is actually used.
What spring rates do BC Racing Coilovers BMW M3m4 Competition come with?
Front: 6.5 kg/mm / Rear: 14 kg/mm as standard. The springs are a standard ID, so rates can be changed later without replacing the dampers.
Do I need an alignment afterwards?
Yes. Camber and toe both move as the car comes down, so book the alignment once the ride height is set and the suspension has settled.
Are these road legal?
Adjustable suspension is legal for road use in the UK. Keep the ride height sensible, make sure nothing fouls at full lock or full compression, and tell your insurer the car has been modified.
Give us a call or drop us the registration if you want the BC Racing Coilovers BMW M3m4 Competition configuration checked against your car before ordering.
More from this range: BC Racing coilovers. Other BMW kits: BMW X3 AWD, BMW M2 Competition (Rear Integrated) RWD, BMW M5 RWD.
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