SkidNation MX-5 NA Thermal Stability Foundation

The B6 and BP engines in the NA MX-5 are virtually unkillable – provided they don’t get hot. The factory cooling system was designed for a 115 hp street car, and its biggest flaw is the “dead-end” coolant flow that leaves cylinder number four running significantly hotter than the rest. If you are driving hard, using a high-flow radiator alone isn’t enough to fix the inherent design flaw of the original plumbing.

The NA Thermal Stability Foundation is the ultimate cooling overhaul. By physically relocating the thermostat to the rear of the head and pairing it with a massive 50 mm radiator and high-draw fans, we fix the factory’s design compromise. This kit doesn’t just keep the car cool; it ensures the engine operates at a uniform temperature from front to back.

SkidNation MX-5 NA Thermal Stability Foundation

What’s inside the kit:

• Premium Cooling Reroute Kit – The most critical upgrade for engine longevity.
  • Balanced Flow: Reroutes the coolant to exit from the back of the cylinder head (like the original Mazda 323 engine design), ensuring cylinder #4 is properly cooled.
  • Model Specific: The 1.6 version includes a threaded blanking plate for the water temp sensor, while the 1.8 version is tailored for the later head casting.
  • Customization: Choose from 9 silicone hose colors to match your engine bay theme (Black, Red, Blue, Green, Purple, Pink, Yellow, White, or Grey).

• 50 mm Aluminum Radiator – A massive increase in fluid volume and surface area.
  • All-Aluminum Construction: Eliminates the brittle plastic end-tanks of the OEM unit that are prone to cracking with age.
  • Natural Silver Finish: Uncoated aluminum offers the best raw thermal dissipation and a classic motorsport look.
  • Pro Tip: The 50 mm core provides a huge thermal “buffer,” giving you more time to react if conditions get extreme.

• Dual 120W Fan Shroud Kit – High-velocity airflow on demand.
  • Aluminum Shroud: Covers the entire core to ensure the fans pull air through every square centimeter of the radiator, not just the area directly behind the blades.
  • 240W Total Power: Dual high-output fans move significantly more air than the aged factory units, critical for sitting in traffic after a hard track session.

• Silicone Cooling Hoses – Heavy-duty plumbing for the entire system.
  • Multi-Layer Silicone: Engineered to handle the increased pressures of a high-performance cooling system without ballooning or leaking.
  • Color Matched: These will be supplied in the same color as your reroute kit for a cohesive, professional look.

• 82°C High-flow Thermostat – Lowering the “floor” of your operating temperature.
  • Earlier Activation: Opens sooner than the factory 88°C unit, allowing the system to start managing heat before it builds up in the block.
  • Why it’s here: It works in tandem with the 50 mm radiator to keep the engine in the “sweet spot” during spirited driving.

Key benefits

• Equalized Head Temperatures: Protects the head gasket and prevents localized hotspots in the rear cylinders.
• Massive Cooling Overhead: Whether you’re on a track in mid-summer or stuck in stationary traffic, the system stays ahead of the heat.
• Modernized Reliability: Replaces every “weak link” in the 30-year-old cooling system with motorsport-grade components.
• Consistent Power: Cooler intake temperatures and stable block temps mean the ECU won’t pull ignition timing due to heat soak.
• Bulletproof Aesthetics: High-quality aluminum and colorful silicone transform the appearance of the engine bay.

This kit is for you if:

• You use your MX-5 for track days, autocross, or spirited mountain driving.
• You are planning to add a turbocharger or supercharger in the future (this is the mandatory foundation).
• You live in a hot climate and find the factory temp gauge “creeping” upward during use.
• You want the “Gold Standard” of MX-5 cooling and never want to worry about overheating again.

This kit is NOT for you if:

• You only use the car for gentle grocery runs: For low-load street use, our “Owner Confidence” refresh is likely sufficient.

Fits all 1989-1997 models – NA (Mk1).

Shipping worldwide.