Yes, the JCW is a tuned version of the S.
If the standard Mini Cooper S is a turbocharged go-kart with seating for four (barely), what do you get when you throw in a few more ponies, a snortinвЂ™ exhaust, a race-ready suspension and Brembo brakes? You end up with the Mini Cooper S John Cooper Works вЂ“ a mouthful of words that puts the вЂњzigвЂќ Cadillac never quite got into the already zig-a-licious standard Cooper S. After a recent spin in the roomier Mini Cooper Clubman S John Cooper Works – that name will really drive the folks at the DMV nuts вЂ“ we decided it was time to check out its shorter, more agile sibling to see if it possessed the same fun-to-drive spirit. A JCW convertible is supposedly coming soon, too.
And puts you in an entirely different class in SCCA solo if you plan to autocross it.
I think the S is D-Stock, wheras the JCW ends up in STX.
It has more power and better handling.