Engine & Gearbox Best size exhaust?

Discussion in 'Honda F/H-Series' started by rick_I_S, Saturday 6th Oct, 2012.

  1. rick_I_S Senior Member ★ ★ ☆ ☆ ☆

    looking into getting a new exhaust as mine is going to pieces. Which size is the best for the h22a7 as i been told a 3" system would be best but then someone else has been saying 2.5" would be better. also seen a system at 2.75"

    Think i will be going for 2.5 as its an easy off the shelf system and its proving hard to find a decat to fit from 2.5 to join onto anything bigger as i have a Civic so can't use accord decat unless i get a different flange put on.

    Any help is great thanks

  2. scottray Club Member ★ ☆ ☆ ☆ ☆

    If you plan on leaving the motor naturally asperated the go with the 2.5" for the simple fact that back pressure is needed to reach maximum proformace. Anything bigger than that is really only made for turbo systems which require as little back pressure as possible and more free flowing being it is forced to breathe better hints a larger exhaust....so i deff wouldn't go any bigger than 2.5" even a tad smaller would be fine also
  3. rick_I_S Senior Member ★ ★ ☆ ☆ ☆

    thanks for the help hopefully be getting mine made end of January =]