ring gear will be about 20-24" but thats diameter not circumference, the gear would need to be 1/24th the circumference for the right rpm.
Errr....
Circumference is a derivative of diameter. The pulley will need to be 1/24th of whatever dimension you choose to measure on the flywheel.
Either way, the small pulley will only be about an inch across.
140,000 rpm at 7000rpm is pointless - you need to achieve max boost lower down the rev range or it will be a topend screaming monster that is nigh on undriveable.