I don’t know if you’re thinking of it but there’s this site called shadowstats which claims to calculate CPI/inflation with the old method and shows totally wild inflation numbers but the way it actually works is that the guy who runs the site takes regular CPI and adds in adjustments to his liking to get inflation numbers that he thinks look right.

My understanding is that you get pretty similar numbers with either methodology.

See more here for example: https://fullstackeconomics.com/no-the-real-inflation-rate-is...