All I wanted to do was tinker with the racecar…

I’d been racing in the Spec Miata class for a couple years at this point and I was getting tired of straightaways feeling soooooo long. Once I started looking for animal shapes within the cloud formations during an active race, I realized I wasn’t having enough fun. Racing is a ton of work for a tiny reward, so if I’m going to put as much energy into the sport as I am, I want to go faster.

So that was my goal. The Miata already existed, so buying a different car didn’t seem economical. I entertained the idea of a few different engine swaps, but in the end, that would probably be even less economical. I’d already hacked off the windshield and thrown away as much extra weight as possible. The only left to do was upgrade the stock engine. Now I know, turbo is cheap, easy, and powerful, but I can’t live without that NA exhaust note and driving character. So, as far as I’m concerned, one NA horsepower > one turbocharged horsepower, so I’m willing to live with a lower peak HP number.

But it wasn’t an easy choice. Like I said, I want to go faster, way faster. What if I end up wanting a turbo in the future? I don’t want to paint myself into a corner. I like having options. With this lack of decisiveness and feeble sense of naturally-aspirated purity, the Tri-Speed Intake System was born.

An ITB intake system that can accept a turbo

At the inception of this project, all I was trying to design was a removable air filter for the DIY ITB setups I’d already seen only for the NB. The tracks I frequent are dusty, and open velocity stacks are not a good idea. There were few options in the market, and at prices higher than I was willing to spend. The “I can TOTALLY make that myself” thought is a blessing and a curse sometimes. So, I thought to cap the whole system and bring it through one opening to filter the air more easily. The byproduct was then being able to use MAF tuning since all the air is now going through a shared opening instead of four separate ones. On top of that, the engine can utilize forced induction (if the 3D-printed plenum can stand up to the task).

There were a few novel concepts I wanted to experiment with in this design. Check out the video below to see more.