ND Miata Short Shifter
The ND already has one of the best factory shifters of any modern car, so a short shifter is a refinement mod, not a fix. What it changes is throw length: it moves the pivot so the same gate motion at the gearbox needs less hand travel at the knob. You trade a little mechanical advantage for a quicker, tighter gate. Done right it feels great. Done cheaply it gets notchy and loud.
How a short shifter actually works
Section titled “How a short shifter actually works”The ND six-speed shifter is a lever pivoting in a turret on top of the transmission. There are two ways to shorten the throw:
- Raise the pivot (spacer-style). A spacer lifts the pivot point so the lower arm gets longer relative to the upper arm. Most “bolt-on” kits work this way and reuse the factory lever or swap in a similar one. Throw reduction is modest to moderate.
- Replace the lever entirely. A one-piece lever changes the upper/lower arm ratio directly and usually deletes the factory rubber isolation bushing. This gets the biggest throw reduction but transmits the most noise and vibration.
The factory lever is wrapped in a thick rubber-like damping sleeve and rides on an isolation bushing. That’s why stock feels smooth and quiet. Every bit of throw you remove tends to cost you some of that isolation, so the right kit for you depends on whether the car sees daily commuting or track weekends.
Throw reduction by brand
Section titled “Throw reduction by brand”Manufacturer-claimed figures, roughly shortest to longest throw remaining:
| Brand / kit | Approx. throw reduction | Design |
|---|---|---|
| IL Motorsport | ~45% (claimed) | Full lever replacement, isolation bushing deleted |
| CravenSpeed | ~30% | Spacer-style, includes weighted knob |
| JBR (James Barone Racing) | ~25% | Spacer-style |
| Autoexe Quick Shift | ~24% | Spacer-style, fits 1.5L and 2.0L |
| CorkSport | ~14%, adjustable pre-load | Solid upper cup with shims, aluminum/steel internals |
A few honest caveats. These are vendor numbers measured different ways, so treat them as a rough ranking rather than lab-grade specs. The percentages also describe how much shorter the throw is, not how much better it feels — past a point, less throw just means a stiffer, busier gate. COOLERWORX makes a higher-end ND lever aimed at track use as well; it sits in the same full-replacement category as the IL Motorsport unit.
The general rule from owners: spacer-style kits in the 15–30% range keep the car pleasant to daily drive. The 40%+ full-replacement levers feel fantastic when you’re driving hard and noticeably busier and louder when you’re not.
Feel and NVH tradeoff
Section titled “Feel and NVH tradeoff”The thing people underestimate is noise, vibration, and harshness. Delete the factory isolation bushing and you’ll hear and feel more of the gearbox through the knob — a faint whir or buzz in certain gears, more so when the transmission is cold. IL Motorsport is upfront that its kit, derived from racing, can transmit transmission noise because it omits a rubber bearing. Owners report it calms down after a break-in period and that the result is genuinely enjoyable, but it’s louder than stock and always will be.
CorkSport went the other direction: it replaces the sprung upper cup with a solid one and uses thin shims to set pre-load, so you can dial resistance from light to firm. It only takes out about 14% of throw, but owners describe the feel as more mechanical and connected (closer to the old NA/NB shifters) without trading away much refinement. If your priority is feel over the headline percentage, that’s the design philosophy to look for.
A weighted knob is a separate but related lever. Adding mass to the top of the shifter smooths out the motion and reduces the perceived effort independent of throw length, which is why several kits bundle one.
Install difficulty
Section titled “Install difficulty”This is an afternoon job, not a build. The whole thing is done from inside the car with all four wheels on the ground, and most people finish in one to two hours with hand tools.
The sequence is roughly: pull the shift knob, remove the boot and trim, unbolt the shifter housing, and pull the lever assembly. For spacer-style kits you then drop the spacer in and reassemble; for full-lever kits you swap the lever.
The one genuinely annoying step is breaking the shifter turret/housing loose from the transmission, because it’s held down with gasket sealer and doesn’t want to let go. Pry it carefully, clean the old sealer off the mating surface, and re-seal on reassembly so you don’t get a gear-oil weep. Don’t overtighten the housing bolts into the aluminum case. If you’ve never had the boot apart, set aside two hours, not one.
Autocross and track legality
Section titled “Autocross and track legality”If you compete, the shifter is a classing decision, not just a feel decision:
- SCCA Solo Street category: short shifters are not on the list of allowed modifications, and in Solo if it isn’t explicitly allowed it’s prohibited. Bolting one on bumps you out of Street. (The known carve-out is for cars that offered a short shifter as a factory option, which the ND did not.)
- Street Touring (e.g. STR) and Prepared categories: far more shifter freedom, so a short shifter is generally fine there. Always confirm against the current-year SCCA Solo Rules before an event, since classing wording changes.
For HPDE and track days there’s no rulebook issue — run whatever you like. If you’re chasing lap times, the shifter mostly helps consistency on quick 2-3-2 transitions; it won’t show up as free seconds the way tires or alignment will. See autocross classing for the bigger picture on where mods put you.
Recommendation
Section titled “Recommendation”- Daily-driven car, want a crisper feel without drama: CorkSport (adjustable, refined) or a 25–30% spacer kit like CravenSpeed or JBR.
- Track/weekend toy, want the most direct gate and don’t mind the noise: a full-replacement lever like IL Motorsport or COOLERWORX.
- You autocross in Street: leave it stock until you’re ready to move up to STR.
The honest take is that the ND shifter is good enough that this mod is about taste. There’s no wrong answer between the kits above — just pick the throw-versus-refinement balance that matches how the car gets used.