I compared the port size of my new Y8 manifold to an old A6 manifold I have lying around, and the Y8 ports are a good 2-3mm larger than the A6 ports. I assume then I should get a Y8 manifold gasket when I put this on the car. My real question though is whether the Y8 manifold ports are larger than the A6 intake ports on the head? If there is a step there, I'm sure I would lose power overall.

What have you guys done when installing the Y8 manifold on your A6 head? Did you just put it on a stock head or did you match port the head? If you left everything stock, did you feel or dyno any gain in power?

Thanks

 

Well I put the Z6 on my A6 and I went and got a fel pro gasket its a universal that fits the A6, Z6, and the Y8 IM. And they are also better quality than OEM. Even the techs and the Honda dealer said that they were a better gasket than there's.

I couldnt tell you if there was a difference or not cause I put it on before I had even driven the motor it was all done before the motor was put into my car. But there has to be there is quite a bit of difference in the size there. I mean it s not going to be nothing outrageous but there will still be one. As for the port sizes the ports on the A6 head are bigger than the A6 IM to begin with so by putting on the Y8 IM you going to be using more of the space that is there already. I dont know the size difference though with the Y8 one though??

Oh and one other thing with the Y8 IM you have to drill a hole for the intake temp sensor sicne they dont have them on the Y8 IM.

Sorry I couldnt be more help to you.