Which Exhaust Bore

[JonnyK]

alrite peeps,

i have a 2.5 inch bore cat back system on my 2.0 hybrid at the mo, but i have heard this is too high a bore and decreasing the bore size would make my car quieter.

what is the best pipe diamter for outright performance?

many thanks

john

 

[haitch]

..2.25" would be a good compromise, any less and you may restrict flow as i found (pending on your other mods of course?) but to get the full benefit performance wise a decat is required, i have a full system @2.5" and its loud but necessary