Looking for both speed and consistency? Rear end feeling a little unstable when you’d rather it not? A rear wing might be the answer you seek.
While we still use our Triple Threat Miata project as a time trials weapon and take it out for weekend country drives, it’s primarily become our tire testing mule, a role for which consistency is …
Looking for both speed and consistency? Rear end feeling a little unstable when you’d rather it not? A rear wing might be the answer you seek.
While we still use our Triple Threat Miata project as a time trials weapon and take it out for weekend country drives, it’s primarily become our tire testing mule, a role for which consistency is crucial to obtaining good, comparative tire data.
Harris Hill Raceway, our usual tire test facility, has become bumpier as of late. A recent move to an effective yet inexpensive coil-over kit from RedShift helped, but one thing still troubled us, sometimes causing an off or spin during testing: high-speed corner entry instability around the 90 to 100 mph mark. Fore-aft weight transfer wasn’t the primary culprit, as there was little braking going on–just a minor lift or slight squeeze.
Similarly, in heavy braking zones at the end of the straights, the car would get nervous under trail braking, throwing consistency out the window. In this case, heavy weight transfer to the front caused the rear to get light and lose traction.
Could we add some rear stability at higher speeds without compromising our neutral mid-corner balance in the slower stuff? What devices increase grip as speeds increase? Aero! Specifically, a rear wing.
Not wanting to fully go down the big-aero rabbit hole, or at least not yet, a mild wing seemed like the answer. Enter Nine Lives Racing’s Street Wang. These wings, already developed for the first three generations of the Miata, combat the car’s inherent high-speed, rear-lift tendency, especially when lowered. Nine Lives’ engineering partner Morlind Engineering did a CFD study to establish this fact, coming up with the right amount of wing needed to neutralize the lift without creating a major aero imbalance.
These Street Wangs mount via end pylons that attach to the trunk drip rail, so the trunk itself remains functional. This is key to its streetability, which matches our use case perfectly.
And if the wing needs to temporarily come off, removal takes just six bolts. Something else to love: The new ND version requires no trimming of the trunk lid since the thickness of the uprights measures less than the trunk gap.
What new ND version? After months of pleading, we drove our car all the way to Atlanta to have Nine Lives build a prototype for our ND. That also gave us a first-person view of how wing making happens there. It’s a fascinating combination of technology, art and cleverness.
Step 1
The rear end of the car needs to be digitized to establish mounting points and angles for the vertical pylons. The latter features two bends that must fit correctly. Spray chalk is applied on the car to dull the surface, improving the resolution. A digitizing wand then scans the area, and the results are transmitted to a nearby laptop.
Step 2
Software is used to transform that positional data into continuous meshes within a 3D space. Suddenly, the rear of our Miata appears on screen.
Step 3
Nine Lives founder Johnny Cichowski then digitally adds the vertical pylons and wing element. This is the art and cleverness bit, guided by a whole bunch of hands-on experience. Still, it takes a couple of iterations in real metal to satisfy everyone when it comes to height, angle and trunk lid clearance.
Step 4
The digital representations of the uprights are then converted to machining instructions used to drive a computer-controlled router that cuts them out of flat metal sheet and perfectly drills mounting holes. The two bends are done by hand using a huge press brake. Johnny does so many of these that he knows exactly how to line up everything to consistently get correct angles. To smooth out any rough edges and to provide a textured surface for better coating adherence, the uprights spend some time in a rock tumbler, which is nothing more than a 55-gallon drum rotating with a bunch of wet rocks in it. It is loud.
Step 5
The prepped parts are then powder-coated, baked and laser-etched with the Nine Lives Racing logo.
Step 6
The wing element itself is the easy bit. Nine Lives Racing buys wing-shaped aluminum extrusions in bulk from a supplier that makes them using a proprietary die. Those extrusions also contain the unthreaded bolt holes. A band saw converts that bulk stock into a wing element, while a tap bit on a drill adds threads for the end plate mounting.
Step 7
From there, it’s measure twice, drill once into our Miata’s drip rail.
Step 8
The whole prototyping process took the better part of a day and several iterations, but in the end we drove back home with a new wing on the car. That highway experience was useful in identifying on-the-road visibility characteristics, and we ended up making one more iteration to modify the height of the wing for less rearview mirror blockage. Retail price for the production piece? Starts around $680. All that remained was to see if it performed on track as expected.
Does the Wing Work?
Test day dawned hot and humid with only a slight breeze. Looking for session consistency despite the 90-degree ambients, we mounted some leftover 245/40R17 Yokohama Advan A055 R-comps on Flyin’ Miata Kōgeki wheels.
In previous tests, these tires needed only a single lap to turn on and showed no falloff thereafter. We did a quick 15-minute session to warm up the driver and also get the drivetrain nicely heat-soaked so power delivery wouldn’t change over the entirety of our comparisons. Summer testing can be tricky.
With the lap timer now running, we first hit the track without the wing. The handling was familiar and playful as ever, putting down three laps all within a couple hundredths. The challenging areas still remained, but over time we simply learned how to drive around them.
After quickly bolting on the wing, we headed right back out. The effect was immediately noticeable: High-speed stability was dramatically improved, and we started to explore just how quickly we could enter those fast sweepers and how far we could trail brake into the heavy braking zones.
We even noticed an improvement in corner-exit throttle-up in two slower turns where we normally had to work the steering wheel to keep the car pointed straight. That was a pleasant surprise. Lap times were a bit less consistent with the lack of familiarity, but all were quicker than before. Best improvement was four-tenths.
We took a break and went back out, this time taking more chances in the two big high-speed entries. The quicker we went, the more grip we found. Aero is such magic.
It takes a lot of confidence to simply turn into a corner at 100 mph without lifting, but our new wing made it possible. By this point, we were lapping a full second faster than without the wing. Happy with our results, we rolled up the windows, turned on the a/c and took the back roads home.
Our AiM Solo 2 DL backed up our butt dyno’s subjective impressions, showing higher speeds with just the wing (blue trace) and major time gains in the two big sweepers. You can also see the smoother trail braking in those heavy braking zones. And finally, the improved slow-speed corner exits paid dividends all the way down the ensuing straights. With our high-speed stability challenges now sussed, we can look forward to our upcoming tire testing.
Bonus: We’ll also run this wing at some NASA Time Trial events, where its use on our ND is essentially free in the power-to-weight formula for our TT5 class. How’s that? Our Club model came from the factory already sporting some aero bits, so according to the rules, it’s still the same car as before.
