Exhaust Control Valve
 

quick question, hopefully someone can answer it. So i have a isis 3" exhaust at has an inside diameter of about 76mm and i want to buy a apexi ECV which is 80mm. So my question is, since the 80mm is supposed to be for 3" exhaust will it fit or will i have to get the circuit sports one which come in 76mm?

The difference is minimal, it should work. I'm running an ECV on my 4" dual tip ISIS blast pipes.

is this thing worth running.

when running a NA Ka there is no noticeable adverse power decreases right?

You dont leave it closed, you pull/close it only when you need to quieten the exhaust some when let's say, you're driving next to a cop. You want it popped open since it chokes up the exhaust. It makes a big difference on my RB25 with ISIS blast pipes. Didn't make much difference on my SR20 with Buddy Club IIs. With it closed, the car is slow and feels like dog shit.