I just completed this mod and did a nice 30 mile drive. I first read the forums for the 335I and 135I guys, I do not know what they are thinking that if you plug the vacuum line that it will open the valve. I don't own a 335I but on the X635I the vacuum pressure is what opens the valve. So if you plug it the valve will never open. I did keep it open by wrapping a wire around it and pulling it open and then securing the wire. It won't melt like a zip tie and it is easy to take off. I can say it does sound better. Not quite as much as a $3,000 exhaust system. But for free its worth every penny. I did not notice any loss of low end torque which is common with free flow exhausts, and I do feel the car ran better. One other note is on my loop which I do daily to work, my MPG was up...still to early to tell on that for sure.
|