Miata slow? please…

SR20 Time Attack MX5 Side View

1990 NA MX5 – Currently running 200WHP. This Miata may not be one of a kind, but it is indeed perfect! With the heart of an SR20 Nissan motor, the perfecty body of the MX5, this Australian MX5 is a weapon!


Now some people, after reading the mods list below will immediately begin to think, why didn’t he do this, this and that. This car is built for the WTAC (Time Attack). They have loads of rules and regulations, as you might read in the original build thread the driver also wanted to remove bit of the windshield to make it more like a race car but sadly the rules state that you must have an OEM windscreen.


  • – NB Fenders and Headlights
  • – Nissan SR20 Engine (PLR Performance)
  • – Engine Stroked to 2.2L with HKS Stroker Kit
  • – Cage, Splitter, Diffuser, Canards, Flares, Wing Mounts (Fabrication 81)
  • – Tune, ECU, Dry Sump, Engine Install (STZ Automotive)
  • – Single Element Wing (Custom copy of Nemo wing by Cawthorne Composites)
  • – Inconnell Exhaust (CES Racing Systems)
  • – Garrett GTX30 Turbo
  • – E85 Fuel
  • – 2200cc injectors
  • – Dry Sump
  • – Nissan Skyline RB25 Gearbox
  • – Custom Clutch
  • – RX7 FC Diff with KAAZ 1.5 LSD
  • – Haltech ECU and digital display
  • – Enkei RPF1 Rims (17 x 9.5 all round)
  • – 255 Wide Semi Slicks all round
  • – MCA Coilovers (Reds)
  • – RX8 Rotors (Front)
  • – RX7 Rotors (Rear)
  • – Wilwood Calipers Front
  • – RX7 Calipers Rear
  • – Datsun 260Z Extra Wide Fender Flares
  • – Custom Chassis Bracing
  • – APR Mirrors
  • – Carbon Trunk
  • – Carbon Doors (To Come)
  • – Dyno Estimate 400+ whp at 20 psi (Still running engine in)




The car is just an evolving hobby and something to have fun with, so I’m not out break records or run ridiculous power in order to win a trophy, dyno shootout, or promote a business. I’ve had it for few years and it gets upgrades as I need to replace or rebuild things such as the engine. If I do eventually go down that path then I’d be looking at a sequential, VET head and 600+whp, but that’s not on the cards… fun and drive ability within a reasonable budget is.



The car is tailored to Open Class rules of world time attack so I can’t run a full flat floor and there are limitations on aero dimensions. Not sure about diffuser effectiveness at this stage, so will test and check data over the coming year. The Nemo wing copy (it’s narrower than Nemo’s and only a single element) came about because I know the guy who built it, got a good price, and can get it trimmed if need be. A twin element Nemo wing is about $5,000. If you want a custom designed one from an aero expert such as Andrew Brilliant, throw on a few grand more as well.



Rubber on the rear is likely to be too narrow at 255 and the plan is to go to 18’s and wider rubber, but wanted a baseline to start with and already had the 9.5 inch rims as well.


Original thread at MX5 Car Talk (direct link)