Miata/MX5 1.6 to 1.8 Engine Signal Converter
The Mazda Miata, or the MX-5 as it’s called over here in the UK, has been a hugely popular model. As a small sporty little everyday driver through to super modified track car projects it’s widely regarded as a great car. The earlier versions of the Miata/MX5 were supplied with either a 1.6-litre or a 1.8-litre engine. This Engine Signal Converter is designed to simplify an engine swap from a 1.6 to a 1.8 litre.
I’m no Miata/MX5 expert but there are conflicts between the 1.6L and 1.8L variants throttle position sensor (TPS) and the 1.8L idle air control valve runs at a different frequency than the 1.6. This means people attempting to put a 1.8-litre in as a replacement for the 1.6 had to either drill holes into the intake manifold and add an adaptor plate to fit the 1.6-litre throttle to the 1.8-litre, or swap the entire ECU and cabling. Both these options sound complex with the ECU swap being the least invasive but also incredibly complex versus the permanent and “one chance to get it right” manifold drilling approach.
This Engine Signal Converter allows your 1.6-litre engine ECU to talk directly to the 1.8-litre throttle by simply splicing it in with a few wires. It seems to my untrained eye that this saves a lot of rewiring work and means you don’t have to fiddle with getting key transponders to talk to new ECU immobilisers and the like. Of course, using this kit and this approach means that it’s also fully reversible.
Supplied fully assembled this board has a conformal coating so it should be long-lasting and less susceptible to corrosion. There are onboard potentiometers with which you can adjust your engine idle and wide open throttle (WOT) positions and it’s even supplied with a small screwdriver to make these adjustments!