Giving our Miata the aero edge that it really deserves

We’d tripled our Miata’s OEM horsepower via an LFX swap, and this fact sent chills down our spine: We’ve raced this car at Daytona, and even with only 200 horsepower, it was no fun at higher speeds.

Early Miatas like ours make boatloads of aerodynamic lift in stock form, and that makes them both harder to drive and slower around a track–not exactly great attributes for a race car.

[How to increase downforce using CFD | Against the wind: Part 1]

Fortunately, we can fix it: Since we’ll be running this car in series like Lucky Dog, AER and WRL, we’re allowed to add aerodynamic elements to the car. That led to the question: “What should we add?”

Simple: A Medium Downforce Kit from Nine Lives Racing.

We tested one on a past Lemons build and came away impressed as the kit includes a wing, air dam, splitter, and the proper mounts and hardware to bolt it on the car. So it only made sense to give our LFX Miata the same treatment. (The Nine Lives Racing site contains a price calculator, with this kit starting around $860–but figure closer to $1500 for something like our setup.)

First up, the wing. Nine Lives Racing supplies a 64-inch-wide aluminum wing in its Medium Downforce Kits, which bolts to the trunk rain gutters via custom-made aluminum uprights.

It’s worth mentioning that even though this wing is aluminum vs. carbon-fiber, it’s actually lighter than most of the other kits on the market: Nine Lives Racing uses a more durable aluminum for the wing uprights, which allows them to be thinner and lighter than some other options.

Installation involves drilling four holes and shaving down the edges of our trunk lid with an angle grinder. Then, we set the wing’s angle of attack using a straight edge and a digital level. We’ll start at zero degrees, then fine tune at the track.

We then moved to the front of the car, where we had much more work to do: We needed to install the splitter, air dam and radiator ducting, but each part is designed for a stock Miata.

All this meant the Nine Lives Racing kit didn’t quite bolt on, but fixing it wasn’t too hard: We simply removed the clever quick-release system that anchors the rear of the splitter and replaced it with two bolts that thread into tabs we welded to our V8 Roadsters subframe.

A little cutting and grinding let the quick-release front splitter mounts, dubbed “Sturdy Bois,” attach around our oversized radiator, which left radiator ducting: We had cooling issues with the factory front bumper, so knew we couldn’t afford to leave anything on the table in this department.

We weren’t able to use Nine Lives Racing’s radiator duct, and instead bent up a piece of aluminum to create a clear path for air to flow through the radiator. And, spoiler alert, our own testing would later show that this kit made downforce AND improved radiator cooling.

Next, we made a pair of support cables to strengthen the outside edges of the splitter. These are easy to put together with cable and eye bolts from the local home improvement store. 

All that was left was the air dam, which installed in a few minutes with the included rivets. After a few hours in the shop, we’d transformed our Miata into a downforce monster. Now we needed to race it.