First Timer Building a Track Miata

A friend and his dad are just getting into track driving, and building up their NA8 Miata for that purpose. It got me to thinking, if I was in that situation, knowing what I know now… what would I do, and in what order?

My wife next to my first Miata, California 2012. Also the first hardtop I built.

Phase 1: Track Ready

The first thing is a car that’s track-legal, and safe. It’s also never too early to start collecting data.

  • 4-point Rollbar – Most tracks and HPDE organizations require this.
  • Brakes – StopTech 309 pads and high temp brake fluid. The StopTechs don’t have a lot of bite, but are great on the street, and handle track temps OK. Their big selling point is price, sometimes I find them for less than $40.
  • Tow straps – Baby teeth are fine, but if you removed them, you need something to attach a tow hook to, front and rear.
  • Data – If you’re just getting started, a phone app is fine. You’ll want to add a 10 hz bluetooth antenna eventually, or better yet, get an Aim Solo or similar device made for motorsports.

Phase 2: Mechanical Grip

Drive the car like that for a few events. Resist the urge to put on sticky tires; All-season tires and stock suspension are learning aids. But once you can slide the car through every corner, it’s time to get more mechanical grip. This is a big step, and requires several things at once.

  • Tires – A Miata on sticky tires is what momentum driving is all about. I like Hankook RS4s for their predictability and durability, but they aren’t super sticky. At the other end of the spectrum are take-off Hoosiers and Toyos from Spec Miata racers, which is an economical way to go fast. And there are a lot of 100-200 TW tires in between, the tradeoff is always between grip and longevity.
  • Wheels – The stock wheels will hold you back. A 15×8 +35 wheel and 205 tire will fit with no modifications. If you roll the fenders, you can use 15x9s and run 225s, which is the current go-fast formula.
  • Hubs – Sticky tires break stock hubs. The fronts are usually the ones to go, but my race car broke at the rear. I have BroFab hubs on my street car and Miatahubs on my race car. There are other options, and some people simply throw out the OEM hubs every year.
  • Suspension – Shocks with stiffer springs and NB top hats. Coilovers so you can corner balance. Stiffer front sway bar and a bracket so you don’t tear the mount. If your car has a lot of miles, it might need new suspension bushings. Ugh.
  • Alignment – You’ll probably need extended lower ball joints to get enough front camber, otherwise you’re going to wear the tires out. Get a proper track alignment.
  • Seat and belts – At this point you’re going to be thrown side to side more, and a race seat is nice. You might also want a 5-7 point harness, and with that comes the requirement of a Hans device.

Phase 3: Hurt Machine

Bolt-on power and areo are next on the list.

  • The usual suspects – A cold-air intake, header, and cat-back exhaust will each unlock about 5% power, which is still doable on the stock ECU. You might bump the timing a few degrees and do other minor tuning tricks if you haven’t already.
  • Maintenance items – Some performance gains can be had if you’re replacing parts. If you need a clutch or throwout bearing, then do a lightweight flywheel at the same time. A 10-lb reduction in flywheel is worth about 7 hp in 1st gear, 3 hp in 2nd gear, and 1.5 hp in 3rd gear. If you need to pull the head for any reason, deck it .040″. That’ll cost about $60 and you’ll have to use Premium gas, but it’s the best bang for the buck. A high-flow catalytic converter will get 1-2 hp, but you can sell your OEM cat for almost the same price.
  • Front aero – Airdam, undertray, ducted radiator, and hood vents. You have to do all of these at the same time because they are related. Brake ducts are optional, but easier to do that now than later.
  • Rear aero – For a car that does more street than track, I like the looks of a spoiler. It needs to be at least 4″ high, preferably 7-8″. For a dedicated track car, use a 9 Lives Racing wing and add a splitter to the undertray.
  • Misc aero – Fender vents, side skirts, flat bottom, diffuser, etc., are all worthwhile. Just say no to vortex generators.

At this point the car is the Trackable Miata build many people aspire to, and it’s a damn fast car. The engine is still basically stock, and you can beat on it all day. You can also beat on average drivers in Porsches, BMWs, etc. This is a machine that can hurt a lot of feelings.

But if you want to run with a well-driven Porsche, Corvette, or whatever, you need more power. This is the point where you decide if you’re going to NA tune the engine on a standalone, swap the engine, or go forced induction. Those decisions are like diets, religion, and politics: you don’t bring them up in pleasant company. And so I’ll leave my opinion out of it, except to say that anyone tuning a normally-aspirated 1.6 deserves their beatings.

2 thoughts on “First Timer Building a Track Miata”

  1. This is almost exactly the path that I took to get here, except that I’m a glutton and went with expensive GLoc pads and haven’t done the hood vents yet (although I have some in a box somewhere). And it is fun running down Boxters and the like in mixed-talent groups. I’m now in an almost daily debate with myself between caging this car and going for ST6 and either keeping or selling it to someone who’d appreciate it as an ideal currently street-legal cold-A/C HPDE car.

    As a random aside, if you start with an NB you get slightly better aero and the ability to run 15x9s without a roll or removing any fender liners – and I was able to validate that the liners add ~3mph to top speed on my NB presumably by not opening up those big holes into the fenders.

    Like

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