Mazda 3 BK.
The coilover guide.
Shop the coiloversA daily hatchback and a turbocharged MPS ask different things of their suspension. Start with the first-generation BK application, then choose the damping controls you will use.
From family hatchback to turbocharged MPS.
The first Mazda3 arrived in Britain in 2003 as a hatchback and saloon. The MPS followed in 2006 with a 2.3-litre turbo engine, front-wheel drive and its own suspension tuning. Those differences belong in the buying discussion, particularly on a car with wider wheels or more power.
The current N-03 listing offers BC Racing BR, RM, ER and ZX configurations for the recorded 2004-08 BK application. BR provides one coupled damping adjustment; RM changes the front damper construction, while ER and ZX add separate damping controls. Match the chosen configuration to the exact car before ordering.
Mazda showed the first Mazda3 at Frankfurt in 2003 and began UK sales that autumn. Japan knew it as Axela. Hatchback and saloon bodies replaced the earlier 323/Familia range, with petrol and diesel engines serving quite different owners. Mazda records 67,731 UK sales for the first generation.
The MPS joined the UK range in October 2006. Its 260 PS turbo engine drove the front wheels through a limited-slip differential. Mazda also changed the body reinforcement, springs, dampers and anti-roll bars. A suspension choice for an MPS should account for that starting point, as well as any later engine or tyre changes.
A lower stance and a different wheel package can be the first changes on an ordinary BK. A track-day car brings different questions about tyres, heat and adjustment. Check the condition of the existing suspension before deciding which route suits the car; worn bushes and damaged mounts still need attention alongside new dampers.
Model history: Mazda original Axela historyMazda UK twenty-year historyMazda original MPS launchMazda USA 2007 MAZDASPEED3 press kit.
Start with your 3 BK.
Confirm the chassis, year and existing suspension before choosing your setup.
BK hatchback: the N-03 reference
The listed N-03 application is first-generation Mazda3 FWD, recorded as 2004-08 with BK3P/BK14 labels. Supply the chassis, engine and build details when confirming the kit. Mazda’s wider production history includes other dates; registration year alone cannot extend this product’s application.
View the BK configurations
First-generation Mazda3 MPS
BC’s N-03 regional application explicitly includes Mazda3 MPS BK3P. Confirm the chosen BR, RM, ER or ZX package for the 2.3-litre turbo car, including springs and mounts. Keep the later BL MPS separate; the shared MPS badge does not establish interchangeable parts.
View the BK MPS reference
Saloon, other engines and imports
Identify the body and original market before choosing parts. Axela names cover several generations, and an engine label can be more useful than a registration date. For a saloon, diesel or import, send the full chassis details so the supplier can confirm the exact N-03 configuration.
Check my Mazda3 application
Changed hubs or a developed track car
Record any replacement knuckles, altered mounts or suspension conversions. Add the running weight and tyre specification for a track build. The original BK identity remains useful, but the kit must also match the hardware now fitted to the car.
Discuss my modified BKWhat do you want
from the car?
Road miles, circuit weekends or a car built around the lap. Start with how you drive.
Start with a usable height and one damping control.
Read the buying advice
BR RA is the starting N-03 configuration for a confirmed road application. Its adjuster changes compression and rebound together. The current listing names pillowball front and rubber rear mounts; discuss transmitted noise and the supplied spring rates with the installer. Leave enough movement for passengers, luggage and the roads you use.
- Coupled damping adjustment
- Confirm front and rear mounting parts
- Allow movement for normal road loads
Consider the inverted front construction, then develop the setup.
Read the buying advice
The N-03 RM MA option specifies an inverted front damper and rubber rear mounts. It gives a construction alternative for a car doing regular circuit work. Agree the spring specification around the tyres and operating weight, and keep a record of alignment and damping changes. BR can still suit occasional track days; RM is worth considering when its construction serves the build.
- Inverted front damper construction
- Match springs to tyres and use
- Record alignment and damping changes
Use separate compression and rebound controls with a setup plan.
Read the buying advice
The N-03 ER option adds external reservoirs and independent compression and rebound adjustment. That gives a developed track car more specific settings to work through. Plan reservoir attachment and hose clearance with the fitter, then agree springs and service requirements. The listed ZX option adds three-way damping control if the programme needs separate low- and high-speed compression adjustment.
- Independent compression and rebound
- Plan reservoir and hose clearance
- Agree springs, servicing and test time
A separate rear spring and damper.
On a standard Mazda 3 BK, the rear spring and damper are mounted separately.
Component layout only. Mounts, dimensions and adjusters vary by kit.The BK uses front MacPherson struts and a multi-link rear suspension. At the rear, the coil spring has its own seat on the suspension arm, separate from the damper. The first-generation MPS keeps the same broad front and rear suspension types, with Mazda-specific tuning and reinforcement.
A coilover kit can therefore have complete spring-and-damper assemblies at the front and separate components at the rear. Confirm the rear spring seats, height adjusters and damper mounting parts in the selected package. Follow its installation instructions when setting rear ride height and damper length; changing the spring seat is not the same adjustment as altering a damper body.
Understand rear height and spring preload
Measure the wheel clearance before setting the stance.
Bring the actual wheel width, offset, tyre size and spacers to the fitting discussion. Check inside the front tyre beside the strut and spring platform, then check the outer arch through steering and suspension movement. A clear gap while parked does not establish clearance with passengers or on a bump.
Inspect the suspension arm bushes, joints and mounting areas while the old parts are accessible. On an MPS, include existing power and tyre changes when agreeing the setup. Set the running height before the final alignment, and keep the measured results so later adjustments have a useful reference.
Wheel width and offset
A wheel that fills the arch can also put the inner tyre close to the front strut. Measure both sides of the wheel package and include spacers. Check brake hoses and any reservoir lines through steering and suspension movement.
MPS power and tyre changes
Give the installer the current engine specification and tyres. The MPS began with different suspension tuning from the ordinary Mazda3, and a later power increase does not tell you which spring rate or damper setting the car now needs.
Rear springs and adjusters
Identify the supplied rear spring seats and any retained rubber parts before fitting. Agree how the chosen kit sets rear height and damper length. Keep the spring seated through the permitted movement and follow the kit maker’s instructions.
Bushes, joints and alignment
Deal with worn or damaged suspension parts before judging the new kit. Measure alignment at the final running height and note the settings. For circuit work, record changes alongside the tyres and operating conditions.
The current 3 BK range.
See the controls and hardware in the listed kit.
N-03 currently offers BR RA, RM MA, ER and ZX. The listing records a 6 kg/mm front and 4.5 kg/mm rear default, while BC’s Australian BR application shows a different rear spring code. Confirm the springs supplied for the exact configuration and order. RM MA names inverted front construction; ER and ZX add separate damping controls.
View BC Racing 3 BK kitsFind your 3 BK coilovers.
Prices include UK VAT. Choose an application and brand, then open a kit for its current options and availability.
1 listing
Match the engine, body style and axle-load limits on the product page before ordering.
![BC Racing Coilovers - Mazda Mazda 3 (04-08) [BK3P/BK14]](/images/09cf8cd191b679-480.webp)
BC Racing · BCR-N-03
BC Racing Coilovers - Mazda Mazda 3 (04-08) [BK3P/BK14]
BK hatchback: the N-03 reference / First-generation Mazda3 MPS
All 3 BK kit links and part numbers
Before you order.
Identify your car
Identify the generation, body and engine. Keep the BK MPS separate from the later BL, and include the original market for an import.
Match the kit
Match N-03 and its exact configuration. Confirm the car application, mounts and springs before choosing BR, RM, ER or ZX.
Check what’s included
Confirm the rear components. Check spring seats, height adjusters and damper attachments against the kit’s fitting instructions.
Check your modifications
Measure wheels and changed hardware. Include offset, tyres, spacers and any altered hubs, mounts or suspension parts.
Plan fitting
Plan fitting and alignment. Inspect the mounting areas, agree usable height and keep the final measured setup.
See what the adjustments do.
Choosing coilovers for road and track
Compare the kit against your roads, tyres and setup plans before counting adjusters.
Ride height and spring preload
Understand the two adjustments before choosing a lowering range.
What spring rate tells you
Compare force and movement, read the units and choose a spring with the damper in mind.
Spring rates and top mounts
Read the front/rear figures and check which mounts come with your kit.
Questions about Mazda 3 BK coilovers.
Check the details before choosing your kit.
Which coilovers are currently listed for the Mazda3 BK?
The current BC Racing N-03 listing offers BR RA, RM MA, ER and ZX configurations for the recorded 2004-08 BK application. Confirm the exact body, engine and selected configuration. The product page provides current prices and order options.
Does the N-03 application include the first Mazda3 MPS?
BC’s regional N-03 application explicitly names Mazda3 and MPS BK3P. Confirm the selected package for the first-generation 2.3-litre turbo car, including springs and mounts. The later BL MPS is a separate application.
Are the Mazda3 BK rear spring and damper separate?
Yes. The standard BK rear suspension has a coil spring on its own suspension-arm seat and a separate damper. A kit can retain this layout while providing front coilover assemblies. Confirm its rear spring seats, adjusters and damper mounting parts.
What changes between BR, RM, ER and ZX?
BR has coupled compression and rebound adjustment. The listed RM MA configuration specifies inverted front construction. ER adds external reservoirs and independent compression and rebound controls. ZX provides three-way damping adjustment, separating low- and high-speed compression from rebound. Match those features to the actual build and available setup support.
Which spring rates will my N-03 kit have?
The current listing records 6 kg/mm front and 4.5 kg/mm rear as its default. A regional BC BR specification uses a different rear spring code, so confirm the delivered springs for your chosen configuration and car. Do not assume every series or market uses identical rates.
Can I choose a kit from a Mazda3 or Axela badge alone?
Confirm the generation, chassis, engine and body first. Axela and Mazda3 names cover several generations. A saloon, diesel or import needs its exact application checked; a shared badge or similar registration date cannot establish fitment.
Do occasional track days require an ER or ZX kit?
BR can suit road and occasional track-day use. Choose around the actual tyres, springs and intended use, then develop the alignment and damping setup. ER and ZX offer more separate controls for a build with the time and support to use them.
Will wider wheels fit after lowering?
Check the actual wheel width, offset, tyres and spacers at the intended height. The fitter needs to inspect inner strut clearance and outer arch clearance through steering and suspension movement, with allowance for road loads. Measure alignment after setting the height.
Let’s talk suspension.
Tell us whether you have a BK hatchback, MPS or saloon, and include the engine and any wheel or suspension changes. We can help check the N-03 application and the configuration that suits your plans.