abit of a strange question however, can someone please tell me the diameter of a crank pulley off a 1.6 Mazda Mx5 engine? im really struggling to find it out and am working on some mad maths formula to work out what size supercharger pulley i need to put on a charger to create 6 psi of boost on a conversion i have to do for my mate, i wont be seeing him for a couple of weeks so i cant measure his pulley.

I'm in the process of supercharging my MX5 1.8 lump. If you are using the outer pulley (inner one drives altenator) then it's 100mm (Inner pulley is 130mm), pretty sure they are the same for 1.6. I have the Eaton M65 which is the same at the M45, just a different inlet casting. I have fitted the smaller 62mm pulley and am getting 7psi boost on 1st rolling road runs. Should have some more figures later this week. 1st run also gave us 220bhp and 185lbs torque...

HTH

Thankyou,

Sounds impressive what ECU are you running?
We have a M112 charger off a 4.2L jag!!! I plan to run about 6psi of boost as the volumne of air will be massive. The charger is almost as big as the engine!

I have just fitted a CANEMs ECU. Having it dual mapped on a pilots red toggle switch. Approx 190 bhp for normal use and approx 250 bhp (kamikaze mode) for tack use. The ECUcomes with Harness to plug straight into MX5 loom so no wiring involved....simples