Okai, Guys im a total newbe with honda civics. I just gave up riding and went to cars. So i just got a AEM cool air intake for honda civic, I got it installed im trying to get a bypass valve for it. I'm not sure what size to get, I'm looking on ebay and i see AEM 3" COLD AIR INTAKE BYPASS and AEM 2.75" COLD AIR INTAKE BYPASS and AEM 2.5" COLD AIR INTAKE BYPASS. I really dont no which to buy can anyone help me?

 

measure your intake pipe width

 

i gotta figure out that the 3.0 2.75 2.50 2.25 is becaause it cant be feet because it would be to big also it cant be inches... thats whats confusing me

 

It is inches, diameter of the inside of the pipe (not circumference). Disconnect pipe and measure across the inside of the opening.

 

Wow thanks man, I guess it was just simple math Circumference divided by pi and i got 2.5 inches in diameter. Cant believe i didnt think of it haha

 

well dang, too bad i didn't read this earlier, I could have told you that AEM intakes are 2.5" diameter.