Straight water is pretty much useless. Water/meth (boost juice) is safe for 15lbs.
Thing is you can’t really tune meth properly without getting intake temps.
I’ve made made just shy of 500hp on pump fuel, non intercooled. The bike had a stand alone ecu, and aem progressive system on it. It’s been running for years now, and raced regularly.
Again the sky’s the limit, just need the right tools to tune meth properly.