BMW E30 E36 E46 Roll-Center / Bump street / Angle-kit, MRT Engineering

Roll-Center / Bump Steer / Angle Kit for BMW Models

Compatible with: BMW E30, E36, E36 M3, Z3, Z3M, E46, E46 M3, Z4, Z4M (Excludes E30 M3, E30 iX, E46 xi/xd models).

Latest Gen 3.5 Kit – Main Features:

• 30mm roll-center correction
• 30mm bump steer correction
• 30% quicker steering ratio (approximately 1 fewer turn on the steering wheel)
• All-new one-piece fasteners and billet castle nuts with PVD coating
• Increased steering angle
• Original Ackermann angle for multi-purpose use (proven for street, circuit, rally, autocross, drifting)
• Compatible with original tie rods (thread cutting may be required for sufficient toe-in adjustment and knuckle clearance*)
• Control arm bore requires tapping for bearing retainer inserts on E30 M3 “Dorman” and E46 M3 control arms (thread tool included**)
• Steering rack stops recommended
• Comes with mounting hardware and MRT Engineering decals
• Note: Control arms and tie rods shown in pictures are not included

Why Do You Need This Kit?

When lowering your BMW (E30, E36, or E46), the front-end geometry can become misaligned. This kit addresses these issues by correcting roll-center, camber curve, and bump steer. The steering adapter adjusts the vertical pivot point of the control arm by 30mm, correcting the roll-center and camber curve. Additionally, the tie rod end pivot point is moved vertically by 30mm and closer to the control arm pivot, improving the lever ratio for a quicker steering response and increased steering angle.

Compatibility:

The kit works with most E30, E36, and E46 control arms, spindles/knuckles, and tie rods. See available variations below:

Type 1 = (E30 non-M / E36 M3 / Z3M, 41mm)
Type 2 = (E36 / Z3 non-M, 48.5mm)
Type 3 = (E46 / Z4 non-M / Z4M, 48.5mm)
Type 5 = (E30 non-M / E36 M3 / Z3M with E46 LCA, 48.5mm)
Type 7 = (E36 / Z3 non-M with E46 LCA, 48.5mm)
Type 9 = (E46 M3, 33mm)
Type 10 = (E30 non-M / E36 M3 / Z3M with alloy LCA, 32mm)
Type 11 = (E36 / Z3 non-M with alloy LCA, 32mm)

 

• Outer Joint Sizes:
  • 32mm (E30 M3 “Dorman” – thread tool included**)
  • 41mm (E30 non-M, E36 M3, Z3M)
  • 48.5mm (E36/Z3 non-M, E46/Z4 non-M aftermarket, E46 M-Sport/Z4M)
  • 33mm (E46 M3 – thread tool included**)
• Spindle/Knuckle Compatibility:
  • E30 non-M*
  • E36/Z3 non-M
  • E36 M3 3.0*
  • E36 M3 3.2 / Z3M*
  • E46/Z4 non-M / Z4M
  • E46 M3

Ease of Installation:

The kit includes detailed instructions and assembly drawings (PDF). If you can replace a control arm or outer joint, installing this kit will be straightforward. A press is required for removing and installing outer joints, but no other special tools are needed. Contact us if you need further assistance!

Durability and Service:

• Proven performance in street and track applications by hundreds of satisfied customers.
• Maintenance-free bearings for over 20,000 km in daily use, tested without signs of excessive wear.
• Bearing replacements are easy to source globally from automotive and industrial suppliers.
• Spare parts available directly from MRT Engineering.

Upgrade your BMW’s handling and performance with this essential roll-center and bump steer correction kit. Feel the difference on the street or track!

---

Additional info and downloads:

MRT Roll-center, Bump Steer Angle Kit E30-E36-E46 Instructions (PDF)

MRT Roll-center, Bump Steer Angle Kit E30-E36-E46 Technical drawing (PDF)