Custom machined spacers to install SW20 rear brake calipers on an AW11.

The stock brake bias on the Mk1 MR2 is very far forward. This can somewhat be remedied with a proportioning valve in the front brake circuit tuned for full grip conditions, but any reduction of grip and the bias will continue to be suboptimal.

Luckily, an SW20 rear brake caliper bolts on and has a larger piston diameter for more braking force.

You can either use Mk1a (85-86) front rotors with 91-92 turbo or 91-95 NA rear calipers (they’re the same), or Mk1b (87-89) front rotors with 93-95 turbo rear calipers. The smaller version with the NA rear calipers can be done very cheap, whereas 93 turbo calipers are pricey and it may be hard to find somebody willing to separate a complete set.

These spacers go underneath the brake rotor. Your wheels will no longer be hub-centric, so you will need to run wheels that are lug-centric with conical seats. Most stock wheels do not have conical lug seats and should not be used with this upgrade. You will also be pushing your wheel further out which may cause interference issues. We recommend getting extended lug studs, as you will likely be reduced to only a few threads with the stock studs.

Brake Bias

Stock Mk1a - 66.3%

Mk1a front, Mk1a rear with 91-95 NA rear calipers - 60.7%

Stock Mk1b - 65.7%

Mk1b front, Mk1a rear with 91-95 NA rear calipers - 62.2%

Mk1b front, Mk1b rear with 93 turbo rear calipers - 58.8%