1990 Mazda Miata NA 1.6 Updated and Upgraded

1990 Mazda MX-5 Miata Additional Info:

1990 Mazda Miata

I bought the car November, 2013 from the original owner, who took delivery of it July 26, 1989. The idea for all my modifications was a track day/autocross/pure sports car suitable for daily use, which it gets weather permitting. I removed all the weight I could, adding only heat shielding/sound deadening to the floor pan. The interior theme is 60’s British. I did virtually all the work myself, I was an ASE certified mechanic for 17 years. The engine is original.

Engine Mod’s:

Engine internals are stock, dyno’d w/ stock header, cat & flywheel at 107+hp (Underground Autosports, Hoffman Estates IL)

Jackson Racing cold air intake

Balanced fuel injectors (Treasure Coast Miata)

Magnacore spark plug wires

Long reach spark plugs

Jackson Racing header

Magnaflow catalytic converter

Cobalt cat-back exhaust

Fidanza lightweight flywheel

Mazda racing engine mounts

Power steering delete inc. rack sleeve ring

Air conditioning delete

Transmission

Used ’97 trans (from Redline) with 93k on it installed October 15, 2023, front & rear trans seals replaced. At the same time we replaced the clutch, pressure plate, throwout bearing, pilot bearing (all Exedy), and rear main seal.

Short-shifter with Bronze Shifter Bushing by 5X Racing.

PPF frame brace bar

Transmission tunnel brace

Differential tunnel brace

Final drive

Since I’ve had it I’ve replaced the drive shaft, both half shafts, all four wheel hub/bearings, and lower ball joints.

Suspension Mod’s

Polyurethane bushings all around inc. differential wings (Good-Win-Racing)

Street Flex-Z Coilover Kits by Tein, fully adjustable

Adjustable sway bars by Eibach

Corner balanced and ride height adjusted for 185 lb driver

Lightweight (10 lbs) Advanti wheels w/ Federal 595 RS-R tires, 195/50 R 15

Includes original 14” rims w/ Toyo all-season 185/60 R 14

Brakes

Replaced pads & rotors all-around September 2023, plus new front caliper pistons, O-rings & dust boots, with new front caliper pin rubbers assembled with silicone paste lubricant, brake & clutch fluid flush

Interior Mod’s

Removed: radio, speakers, center console, arm rests

Remade & covered door cards and radio fascia plate

Ultrashield Racing seat 15 1/2” (inc. original seat, matches passenger seat)

Body repairs

Full repaint in original color 3 years ago.

New canvas top 3 years ago.

Both lower door sill panels replaced with I Sell Miata Parts (Kenosha WI) replacements.

I treat the undercarriage 4 times per year with ACF-50 protectant

Includes car cover, various tools, parts and books pictured.

Problems

I had the antenna hole filled, came out great.

The windshield washer fills didn’t come out as well as I’d have liked, but decent. A rust spot on the driver’s rear quarter needs repairing and repainting. I Sell Miata Parts has a rear quarter for $85, and Art’s Body Shop in Aurora IL quoted $750.

I installed a parallel circuit with a 30 amp relay & 30 amp fuse to the solenoid to fix a common problem - a compromised amp feed to the solenoid. Works great.