I was pretty sure that it was 2" OD.

Also, a 2.25" pipe has about 25% more cross-section than a 2". That's a pretty significant jump. Also, going too big on a non-turbo car is very easy to do: a 155 cube engine pushing 7k rpm isn't going to develop any real kind of velocity in a much bigger exhaust.

-Philip Maynard '95 Contour [71 STS | Track Whore] '97 Miata [71 ES | Boulevard Pimp] 2006 autocross results