Slow Boring No Torque Miata (Spring <del>22</del>23)

• Mazda BP6D Block with 10.0:1 Pistons
• Oliver Conrods
• ARP Main Studs
• ARP Head Studs
• Boundary Stage 2 Oil Pump
• Oil Pan Baffles
• Hastings Rings | 30 Euro
• ACL Main Bearings | 100 Euro
• ACL Rod Bearings | 60 Euro
• Head Gasket | 30 Euro
• Honbürste | 80 Euro

• Mazda BP6D VVT Head
• Porting
• Adjustable Chinese Exhaust Cam Gear
• CatCams Valve Springs | 170 Euro
• Valve Stem Seals MAZDA!! | 200 Euro

In the current state, the car has around 230250whp and is, at least to this point, reliable even under heavy use. Octane requirement is 95102 RON / 9195 AKI, this seems reasonable for 9.5:1 and 0.60.82 bar (912 psi). The intake air temperature is only 10 K above ambient temperature which leads to the conclusion that the current setup is somewhat efficient.

The goal for the next stage should be a significant gain in power while maintaining reliability and practicability.

Related:

• https://www.miataturbo.net/supercharger-discussion-38/searching-holy-rotrex-grail-106890/
• https://mx-5.de/forum/showthread.php?324195-C30-94-Kompressorumbau
• Previous Consultation (camshaft choice)

As one can see, the airflow of the supercharger at reasonable efficiency (~0.65) is around 0.36kg/s.

In theory, this should lead to at least 360whp. Previous archivements were 302whp @ 6.74krpm by bigb5031, 93krpm @ supercharger. Supportive mods were I/H/E and mild head work, stock 9.5:1 compression, 98 RON / 93 AKI.

315whp @ 7.317krpm by trackdogracing, 100krpm @ supercharger, I/H/E, E85.

324whp @ ~7.3krpm by kraftwerks, 100krpm @ supercharger, mods unknown.

• Torque output should be under 250lb/ft / 340nm (at the wheels)
• Octane requirement must be ordinary 98 RON or lower. 100 / 102 / E85 is not an option. fuck it
• Engine should not be knock limited, even under harsh conditions (45 C ambient / track use)

• Target RPM
  • 105mm sc: 8500
  • 100mm sc: 8100 - 161 mph / 259 kmh ←- current state
  • 95mm sc: 7700 (101 Euro + S&H) - 153 mph / 246 kmh
  • 90mm sc: 7300 (81 Euro + S&H)

95mm would be “optimal” but would limit rpm to 7700.

Smaller pulley would lead to more belt slip probability.

• Pistons: Wiseco K590M84 84mm 10.0:1 OR Mazda NB2 83mm 10.0:1 used with new hastings (2C4651) rings - cost: 30 Euro
• Conrods: Oliver A-Beam

• Head Studs: ARP
• Main Studs: ARP
• Rod Bearings: ACL Race
• Main Bearings: ACL Race
• Thrust Bearing: Mazda
• Oil Pump: Boundary Stage 2

• VVT
• Manley Intake Valves (Back-Cut)
• CatCams followers
• CatCams Springs
• 6mm Lash Caps
• Tomei Cams, why?