The Miata's tiny engine never gets much credit. Maybe it never really deserved any, either. It's certainly not the MX-5's centerpiece, a vehicle that puts tidy packaging, blissful handling, and classic roadster aesthetics at the fore.
But I've always thought, despite making very little power, the NA Miata's 1.6- and 1.8-liter inline-fours sound good. Not great, but good. We've always forgiven the meek power because Miata mills proved reliable and easily serviceable, even by hack mechanics like myself. Plus there's just enough grunt to break the car loose on rainy days or adjust the car's attitude on-throttle, so long as you keep the revs up.
If you're looking to solve for the Miata's dearth of power, maybe we can point you to a turbo kit from our good friends at Flyin' Miata. However, if you've got a pile of cash hoarding space in a coat closet somewhere, don't care much about making power, but want the best-sounding Miata you've ever heard: ITBs are the answer.
This promo video from Hummelink-modifications, a Dutch tuning company, shows exactly why. You could put the video on blindfolded and get the gist here, but it helps that this minute-long teaser is shot like a Michael Mann chase sequence.
According to the build specs on YouTube, this engine makes 172 horses from 1.6 liters at an 11.3:1 compression ratio. The ITBs were borrowed from Toyota's 4AGE inline-four (another engine that produces no power and a MONSTER soundtrack), and mated to the head via an adapter plate sold by Hummelink-modifications.
It appears that Hummelink are working on a bespoke ITB kit for early Miatas as well, which won't require sourcing 4AGE ITBs and adapting them to the engine, but costs major coin relative to the cost of a nice NA Miata. However, if you've got a stock Miata in the garage just itching to clear its throat, there are far less charismatic ways to bring an inline-four up to speed.
The only member of staff to flip a grain truck on its roof, Kyle Kinard is R&T's senior editor and resident malcontent. He lives near Seattle and enjoys the rain. His column, Kinardi Line, runs when it runs.
