The TX12 is rated to 11,000rpm continuous and 14,000rpm intermittent. I am running a 147mm crank pulley (up from 127mm stock) and 92mm SC pulley (down from 100mm). At 8600RPM crank speed the supercharger 13,741RPM. I don't intend sitting on 8600RPM, infact I like to keep under 8k even with the new cams and springs which I'll get to later. The TX12 with the standard setup (127mm crank, 100mm sc) would spin at 10,900 at 8600RPM crank speed.The ogura supercharger can only spin to 11.5k rpm a 3.8 inch pulley already spins that dangerously close to the 11.5k
You want to make more power? Put a bigger inlet on the supercharger to allow the air to feed in.
Also that shim on the pulley shaft is a in a bind trick, I would never rely on it to last before the pulley started to develop a wobble.
Sweet as, Happy to helpReally glad to see an update on this! When I eventually get around to starting my blitz SC build (I stare at the box on my living room floor every day) I will likely be bothering you often. Very curious how that smaller pulley works out for you.
If this pulley ratio does give the ability to overdrive the SC beyond it's limit, one can always just lower the engine rev limit a bit. I'd say couple more PSI through the whole rev range is well worth losing 300-500rpm off the top end.
Stock bottom end, I’m feeling okay with that as 11-12 psi is unlikely to harm it on its own, it’ll be detonation/lean conditions that kill my ring lands or put a hole in my piston and I have plans in place to avoid thatDo you yank your drivetrain out twice a week or what? Also, have you done anything to the bottom end of this engine? I don't recall reading if you did. 0.8bar might be kinda hard on a stock bottom end.