The MX5 NC has a small case differential housing a 7" pinion and the NC MX5 was only available with a limited number of ratios. For many short course racing such as hill climbs, sprints and circuit racing the standard diff ratios might be too long, and you might favour quicker acceleration over maximum top speed.

We can offer the components to swap your differential from the standard MX5 unit to the larger and stronger 8" pinion RX8 diff, which have shorter ratios available, or using a short-ratio gearset to increase acceleration.

Alternatively, we can offer a hybrid gearbox, retaining the lighter MX5 differential (or combining with the RX8 differential), which provides a fairly broad range of options to suit most needs.

Have a play with our speed calc to see what works for you.