Hey all, recently took possession of a lovely CS. It has an aftermarket exhaust with a valve switch remote. I've already found the relevant stock exhaust components...but just wondering how the stock exhaust valve system works. Is it purely mechanical? ie; if I swap the stock system in, will they open at the correct revs? Or is some computer work required to control it? Cheers!
Stock CS has the two bypass valves opened by the ECU via the vacuum switch. Some after market system has their own user controllable valves and they normally require a wireless controller tapped into the middle of the vacuum circuit. If you have that, then you have to remove the additional board, get the hoses back to original, and swap the valves back to stock.
Theoretically, if the mechanic Just dropped the exhaust components in, without connecting the hose or removing the board, what would happen? Valves stay shut?
I am unsure. It depends on the brand of exhaust you are removing. Some valves are normally closed, and some normally open.
But surely the aftermarket valves would come out with the exhaust? So now I'd have the stock ones but not connected? Are they open or closed by default?
Stock ones are normally closed, and open under vacuum. Some after market ones are normally open and closed under vacuum, and I have never understood why. All I am saying is if you put it back, make sure you rip out all the extra after market accessories.