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Description

BMW E46 3 Series True Rear Sedan/Coupe/Touring (98-06) BC Racing ER coilover kit 6/5 kg/mm

The BC Racing ER coilover kit E46 True Rear (part number I-31-ER) is a coilover kit adjustable in height and damping, also simply called a coilover, for the BMW 3 Series E46 Sedan, Coupe and Touring with rear-wheel drive, model years 1998 to 2006, in True Rear version. The spring rate is 6 kg/mm front and 5 kg/mm rear.

This 2-way adjustable kit has external reservoirs, and the rear axle gets a complete strut. The ER series is made for serious track work and competition.

On the original E46, the spring and the damper at the rear are separate from each other. In the True Rear version they become one unit: the spring sits around the damper, just like at the front. As a result, you set the rear height on the damper body and have the same options on both axles. The standard ER without True Rear (I-02) keeps the separate spring and damper at the rear.

Each damper is a monotube with dual piston and an external reservoir. You adjust compression and rebound in 30 clicks each, independently of each other. The tuning is digressive and the oil is fully synthetic with an ultra-high viscosity index. The spring rate is 6/5 kg/mm.

Key benefits

• True Rear: a complete strut at the rear with the spring around the damper.
• Compression and rebound separately: 30 clicks each, for a setup without compromise.
• External reservoirs: more oil volume for stable damping in long sessions.
• Monotube with dual piston: built for heavy track loads.
• Digressive: firm under weight transfer, compliant over fast bumps.
• Synthetic oil: less variation in damping as the temperature rises.
• Camber plates on suitable kits: rubber top mounts optional.
• Spring rate 6/5 kg/mm: matching the True Rear layout.

Suitable for

BMW 3 Series E46 Sedan, Coupe and Touring, model years 1998 to 2006, with rear-wheel drive, in True Rear version (BC Racing part number I-31; not for the M3 and the Convertible)

• Serious track days and circuit competition
• High-level drifting
• Drivers who want to fine-tune per circuit or per session

Technical specifications

• Manufacturer: BC Racing
• Part number: I-31-ER
• Series: ER, 2-way with external reservoir
• Version: True Rear, a complete strut at the rear with the spring around the damper
• Spring rate front/rear: 6/5 kg/mm
• Damper design: monotube with dual piston and external reservoir, digressive
• Damping: 2-way, compression and rebound 30 clicks each, independent
• Ride height: continuously adjustable via the damper body
• Top mounts: camber plates on suitable kits, rubber top mounts optional
• Contents: 4 struts with dampers and springs, lower mounts, top mounts where applicable, adjustment spanners and warranty card with serial number
• Warranty: 1 year on manufacturing defects. With this track-focused series, noise is not covered by the warranty

Fitting and delivery

With this kit, the struts at the front and the separate spring and damper at the rear are replaced, and the reservoirs get a fixed position with the lines clear of moving parts. Please note: BC Racing specifies that the body shell must be reinforced before fitting a True Rear kit. Preferably have the kit fitted by a mechanic with experience in track suspension, and then have a wheel alignment done on the E46. The delivery time is 1 to 2 weeks as long as the manufacturer has stock. If the kit is temporarily out of stock, you can still order and we will keep you informed.

With 2-way damping and a complete strut at the rear, you no longer set up an E46 approximately, but per axle and per session.

Why choose this ER coilover kit E46 True Rear?

On track you want to be able to adjust compression and rebound independently of each other, and not be tied to a separate spring at the rear. This kit solves both points in one go. The reservoirs also provide enough reserve to keep the damping consistent, even after a long session.

BC Racing coilover kits for the BMW E46 Sedan, Coupe and Touring in True Rear version

Overview of the BC Racing series for the BMW E46 Sedan, Coupe and Touring in True Rear version supplied by Race4DriftParts, with the BC Racing part number. Spring rates in kg/mm, front/rear.

For the standard version without True Rear, BC Racing has separate kits for the E46 Sedan, Coupe, Touring and Compact. Their part numbers start with I-02. For the E46 Convertible, BC Racing has its own kit under part number I-90.

Frequently asked questions

What is the difference between the BC Racing ER True Rear and the standard ER for the E46?

The ER coilover kit E46 True Rear (I-31) has a complete strut at the rear with the spring around the damper and 6/5 kg/mm. The standard ER (I-02) keeps a separate spring and separate damper at the rear and has 10/10 kg/mm.

What is the difference between the BC Racing ER and HM for the E46 True Rear?

On the MacPherson struts the HM uses an inverted monotube, whereas the ER has an upright monotube. Both are 2-way with external reservoir.

Is a check valve available for the BC Racing ER coilover kit E46 True Rear?

Yes, BC Racing offers a check valve as an option for the ER series. Contact us for the options with this kit.

Does this BC Racing ER coilover kit E46 True Rear fit an E46 Touring or Convertible?

Yes for the Touring: BC Racing releases this True Rear kit for the rear-wheel drive E46 Sedan, Coupe and Touring, except the M3. For the Convertible, BC Racing has no True Rear kit, but its own standard kit under part number I-90.

What is the delivery time of this BC Racing ER coilover kit?

The delivery time is usually 1 to 2 weeks as long as the manufacturer has stock. If it is out of stock, you can still order and we will let you know when the kit comes in.

Delivery outside the European Union: different shipping costs may apply. Don’t worry: we will email you as soon as possible after your order and agree the shipping with you. You are not committed to anything without your consent.