The Crapcan Miata — Once More Unto the Junkyard

For many car enthusiasts overcoming adversary is a skill employed nearly every time they open the tool box. Overcoming tragedy is a skill that some will require, and the way they approach it differs from person to person. This is the build thread/story of how I have been making the best of a bad situation by completely changing my outlook and letting a part of myself free. A crazy (well, crazier than the rest) part of me that is still firmly rooted in the car-modifying mindset of Need for Speed Most Wanted is at war with the part of me that enjoys the pure experience of things, and the result is my 1991 Mazda Miata.


As I bought it the car was a case of Crouching Deal Hidden Shitbox. I gave $1000 and my salvage-title bought-for-$500 Honda Civic for the Miata which soon had a myriad problems stemming from some fairly obvious front-end damage. After fixing it up a little with the intention of “restoring” it and enjoying the purest form of a 25-year-old Japanese roadster, I had a bit of an incident.


Here is a quick list of things Miatas should not have:

  • Positive camber on the front passenger wheel
  • Positive camber on the rear passenger wheel
  • Scrapes on the passenger door
  • A huge-ass dent in the rear quarter panel

Some new ball joints, control arms, and a mismatched $50 salvage door later and the car was back in half-decent condition, but after the financial outlay of fixing all of these issues I decided to throw caution to the wind and make the car mine, ‘pure’ be damned. Everything I had ever wanted in a car would happen to this unsuspecting Miata. While it was in the shop I bought a replacement, a 2005 Ford Mustang, and later my ’97 Buick Riviera, so the Miata was no longer required to schlep me to and from my nine-to-five. At this point there were a few mods done to the car:

  • Switchback LED front turn signals
  • H4 headlight conversion
  • H4 LED headlights
  • Rockford Fosgate door speakers
  • Passenger seat reupholstered
  • Replacement OEM catback, ebay-bought longtube header

As well as general maintenence stuff like

  • Synthetic 0w30 oil
  • Air/Oil/Fuel filters
  • NGK spark plugs
  • NGK wires

The seat reupholstery was replacing the awful cloth seats with some fake leather replacements from the internet.

The stockers were in good condition, but Miatas have old soft tops, and old soft tops leak, and cloth absorbs water which then finds its way onto my waiting bottom. The result here is an unhappy Jake and wet pants.


A few hours of wrestling with hog-ring pliers and cutting dykes resulted in this. Far more comfortable. The leather’s tendency to not stretch helped reinforce the aged collapsed foam in the bolsters, an unexpected bonus. Not bad for $155 from Amazon. Thank you to Sierra Auto Tops & Seats for making a quality product. I actually purchased a soft top from the same company which, as of this writing, still sits in its box due to Kansas weather being uncharacteristically cold and rainy.


Once I finally got the Miata repaired after its wreck and drivable I took it for a spin and was appalled at how slow it seemed after daily driving the Mustang and Buick. Those two are no track monsters, but they might as well have been compared to my lowly 1.6 liter Miata. The sudden appearance of a free Mitsubishi turbocharger and my lack of dependence on the Miata for transportation made up my mind to wring a couple more ponies out of the anemic mill with forced induction on a budget so tight I can’t even afford the shoestring.

So I hacked up my ebay headers, bought some stainless steel bends and tees, and welded the whole mess directly to my exhaust housing. Hey, one-piece turbo manifold/exhaust housings work for Koenigsegg, so they work for me. Some random hose spotted sitting in a junk pile in the shop and some fittings bought off the interwebz got me an oil feed and return line, and I bolted the mess into my car.


Wow that’s a tiny snail. This is the stock turbocharger from a Mitsubishi 3000GT VR-4. In that car two of these would be feeding a 3 liter V6, leaving each turbo with 1.5 liters of displacement to feed. The Miata being a 1.6, and the turbo being designed by an OEM for that size, I figured I would get quick spool times and calculated roughly 7PSI peak and roughly 170 horsepower out of the little Miata engine with this setup. Just getting to this point took so long that I slapped the vane airflow meter onto the car and drove it around for some time naturally aspirated, with the turbo spinning happily attached to the manifold just blowing air around the engine bay making choo choo noises.


As of this writing, that is the state of my powertrain. I took the manifold off and wrapped it in fiberglass insulation in order to avoid cooking my oil lines, and replaced the toasted ill-fitting gasket that came with my Chinese headers.


The nice thing about exhaust wrap is that you can’t see my terrible welds and I can almost pass this crap off as “professional”.

Next up on the saga of Crapcan Miata: I get distracted.


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