MRT E46 WTCC/STW style Modular reinforced lightweight knuckle for E46, Z4

RACE modular spindle for BMW E46 / E46 M3 / Z4 / Z4M models (excluding E46 xi/xd models)

Our latest and greatest RACE modular spindle is finally here! This listing is for limited quantity PRE-ORDER, lead time 4-5 weeks, estimated shipping on February 2025.

Geometry is based on E30 Gr.A DTM and E36 STW era parts which were optimized for pure racing applications:

• ~30mm base roll-center correction, adjustable via spacers in 10mm steps up to 60mm (see comparison here)

• ~30mm base bump steer correction, adjustable via spacers in 10mm steps up to 60mm

• 15% quicker steering ratio to approximately match BMW Motorsport steering rack ratios

• Designed for higher caster range

  • E30 Gr.A DTM style steering arm 9-11 degrees

  • E36 STW style steering arm 7-9 degrees

• Reduced caster trail

• Reduced KPI

  • Adjustable ±1° via shims

• Reduced Ackermann angle for high speed maneuvering

Benefits over original BMW Motorsport parts:

• Cost and serviceability

• Modularity

• Use of standard BMW parts:

  • E90 / E60 / F8X wheel hubs and bearings

  • E36 / E46 brake options

  • E30 / E36 / E46 strut mounting

  • E30 / E36 / E46 control arms with MRT spherical bearings
    (or MRT RACE front control arms)

• Versatile ABS options:

  • Mk60 ABS compatible as standard (with E8X/E9X sensors BMW part no. 34526762465 or 34526760424 or 34526870075 or 34522283045 or 34527853586)

  • E30 ABS sensor adapters available

  • E36 / E46 ABS sensor adapters available

• Stronger and lighter (see weight comparison here):

  • CNC machined AW-7075 T6 aluminum

  • FEM optimized design

  • Improved mounting on steering arms

• E36 / E46 requires minimum 7 degrees of caster

  • Compatible with M3 spec top mounts (and control arms)

  • For more adjustability please check our caster adjustable top mounts

• Slight increase in track width due to KPI change (wheel backspacing requirement)

• Must be used with tie rods with M14 size rod ends or E30 Gr.A DTM tie rod assembly

• Please refer to wheel fitment chart (for diameter and backspacing) and check compatibility with your combination

• Steering rack stops recommended

• Sold as pair (includes parts for both left + right side)

• Hardware sold separately

  • The kit includes base spindles with chosen steering arm, strut mounting and brake caliper adapter option only

  • Matching control arms and/or control arm outer joints are sold separately

  • Matching tie rods are sold separately

  • Wheel bearing units are sold separately

  • ABS sensor adapters are sold separately
     

• Comes with all necessary bolts, nuts, spacers, mounting studs and of course MRT Engineering decals

Why do you need one?

Have you found the limits of stock or modified stock spindles? Look no further, we've got you an ultimate solution to gain more speed and reliability.

Only aftermarket purpose made front spindle for RACE applications without compromises. Thanks to modularity this can perfectly suit your car and parts combination without the struggle to source extremely rare and expensive BMW Motorsport parts.

Does it fit my car?

The kit can be fitted on most E30/E36/E46 models, not compatible with iX/xi/xd models. See available variations:

Steering arm type:

• E30 M3 Gr.A DTM -style

• E36 STW -style (different product)

Strut mounting type:

• E30 non-M / Universal (weld on brackets)

• E36

• E46 (clamp mounting)

Brake caliper adapters:

• None

• E36 / E46
   

Is it easy to install?

The kit requires specific combination of standard BMW parts to be used, but it's basically a bolt-on replacement and does not require excessive modifications on your car.

If you need any further info please contact us!

How about the lifetime and service of the kit?

The kits have been proven on street and track applications by hundreds of our customers. We're constantly doing R&D to make the kits even better, all improvements are based on customer feedback which is very important to us.
Any of the spare parts can be bought separately from us.

We want to keep our customers 100% happy thus we're only using the best materials and manufacturing processes available. All parts are CNC machined: aluminum parts are aerospace grade AW-7075 with hard anodized finish (silver and black), mounting studs are made of highest quality CrMo tool steel and all hardware meets European quality standards.

Required extra parts can be found here: https://www.motorsportparts.nl/revisie-diff-versnellingsbak-motor-en-koppeling/mrt-engineering/modulaire-spindel-benodigtheden/