Upgrading from NGK BPR9ES from BPR6ES.

[At-Least-It's-An-Evo]

ya, 9s are crappy unless you're a big baller big power car. I've had to get them before because 8's were out of stock and I had to keep doing pulls to clean 'em up every 20 miles or so... then finally just found some 8s to put in. This was on c16 also, so 7's are probably whats right for you.