Table of Contents
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
- 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.
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.
Constraints and Limitations
- 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.
Engine Block (draft)
- 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
- Manley Intake Valves (Back-Cut)
- CatCams followers
- CatCams Springs
- 6mm Lash Caps
- Tomei Cams, why?