NA MX-5 LSD differential upgrade

OPEN DIFFS | Mechanic Meme on ME.ME

Introduction

The Mazda MX-5 is a great but not powerful car. It can take corners at high speed without any issue thanks to its low weight and good suspension. Nevertheless, you have to accelerate after that turn to keep up with your opponent. This is where you can improve your car without even increasing your power. In fact, it’s all about how your power is given to the wheels. I am not talking about grippy tires and light wheels which are the first things to think about. I am talking about your differential that gives power to your wheels.

So… What’s an LSD?

Wikipedia: “A limited-slip differential (LSD) is a type of differential that allows its two output shafts to rotate at different speeds but limits the maximum difference between the two shafts “.

Let’s take an example: You may have been stuck on a road with one wheel on snow and the other one on ice. Your standard differential was not able to bring power to the only wheel with grip because it was not limiting the difference between the two wheels. Your wheel stuck on ice was spinning and receiving all the power while your other wheel was waiting for power.

Cusco LSD Type RS 1.5 Way Limited Slip Differential Front Subaru Impreza  93-00 - Part-Box.com – High Performance & Tuning Car Parts Online

While accelerating to leave a corner, it is possible to see the same situation. The inside wheel will spin, dumping power that could be given to the outside wheel.

In this situation, an LSD would have reached its maximum difference to finally give equal power to both wheel.

My LSD differential preparation & install

Because I love when it’s too complicated for me, I decided not to buy a completely OEM LSD differential from an other MX-5. In fact, even if I hated my differential because it was not an LSD, I loved its lightness and the fact that it was the shortest ratio available. Taking this into consideration, there was two alternatives left : An aftermarket Kaaz LSD unit or a rare Mazdaspeed LSD unit that you have to put in your own standard differential. After a few months waiting for the best deal, I finally found a used Mazdaspeed unit from a spec miata car in the US.

A few weeks later, it was time to put this unit in.

Disassembly

After having removed the differential from the car, here are the steps:

  • Remove the stub axles with a hammer
  • Remove the 12mm head bolts
  • Remove the carrier

Now, you can see the differential unit. Here are the next steps:

  • WORK IN PROGRESS