i'm installing my exhaust this weekend..it's 2.5" all the way through.

but, is that 2.5" OD or ID? how do they measure pipe? everything I buy just says 2.5", never specifies ID or OD.

so, when I buy the flanges, the guy asks me ID or OD .. which one do I want??

thanks

 

measure the pipe. You can measure the outside with a micrometer, inside with a vernier caliper. Which ever measures 2.5" thats what it's based it on. Theres probably only one way that its measure by, but i don't know, so its an option

 

i don't have the pipe, but i need to order the flanges so i can install everything at once....i'm assuming inside diameter? idk, what is the "standard" if it isn't specified?
the cat i bought said it had a 2.5" inlet and outlet. is that 2.5" ID? i guess i could call magnaflow and ask if nobody knows. but that would mean waiting until tomorrow..

 

i guess technically speaking it would make more sense to set the measures at I.D.

 

Im thinking its O.D., i'm not sure though.

 

ID is used for 99.999% of exhausts. I've never heard of it measured OD.

 

well on most pipes it will have both measurements but some just have one.