MX5 Performance Tuning tips

"The Fantastic MX5 Eunos or Miata "

The Mazda MX5 (also badged Eunos and Miata) is what every small roadster should be.

They are superb at handling thanks in part to the great chassis design and the cars light weight.

It was an instant hit, when it was introduced in the late 80's/early 90's and each model revision sees improvements.

Its back to basics approach captured the spirit of a fun roadster and won the car many fans.

One criticism thrown at the MX5 is the lack of power. Originally provided with just 2 engine options, a rather revvy and sporty sounding 1.6 and the slightly more powerful 1.8. The first task then is to uprate the power. Thankfully Mazda have provided a good block which has substantial scope for improvement.

Internal modifications should include a fast road cam, ported and polished head with a 3 angle valve job. If budget allows then blueprinting and balancing the engine and fitting a low ratio gearbox will futher increase the cars appeal. A lighter flywheel will make the car rev more easily and it appears that the MX5 becomes quite a different beast with a slightly lighter 10lbs flywheel. (NB: If the flywheel is too light then the car will be hard to drive in stop start traffic.)

The clutch is a different story and should be the primary upgrade before any other MX5 engine tuning is attempted especially if the mileage is getting up there.

One popular mod on the MX5 is the addition of forced induction. Whilst turbos can be added it seems slightly easier and makes economic sense to fit a supercharger. We find that turbo engines need quite a few extra parts namely an exhaust manifold, intake piping and ideally stronger lower compression pistons and a diverter valve wheras a supercharger is pretty much a bolt on and remap upgrade. 

There is still a lot of debate or arguments between the MX5 turbo owners and supercharged owners as to which is the most cost effective, and which suits the car the most.

Dyno results are generally fairly similar but the power delivery is very much down to personal tastes. The supercharger has a linear smooth delivery and the turbo gives a fun wallop in the back part way up the rev range. When this is properly setup you can hit power figures in the order of 200 to 300bhp or around 150 bhp on stock internals.

The stock engine will also benefit from some basic tuning modifications. Most owners will add an induction kit although the benefits of this are questionable unless you also add a cold air feed pipe. A sports exhaust and sports catalyst will free up a few more horsepower on the NASP versions and even more if you have added forced induction with a bolt on turbo or supercharger kit.

Handling is already very keen but adding some uprated suspension can dramatically improve the handling. All older models will benefit from the fitment new rubber bushes (bushings) as these tighten up the suspension especially when there is old worn out soggy suspension components. It should be noted that some owners reported worse handling with polyeurothane bushes as these cut out the passive rear steer effect which makes these cars so much fun.

Having made the car go faster and handle better you really should look at uprating the brakes. Fitting better pads will improve things but for the best effect you should really get a big brake disc conversion and 4,6 or 8 pot calipers.

Stick with 16 inch alloys for best performance although 17 inch alloys might look marginally better it will stuff the handling and performance, smaller wheels are better from a performance point of view.

A strut brace will keep the alignment of the chassis and help to prevent flexing. Fitting a rear anti roll bar is not an option as the MX5 comes with a good anti roll bar. To join us in our friendly tuning forum and meet other MX5 owners and swap tips hints and tuning ideas click here.