Im in the process of porting my s4 wastegate and I am wondering how big a valve everyone else here uses or recommends. Im using a valve from a big block ford... its all I had handy. Its 1 1/2 inches wide(38mm) so I was gonna make my port 1 1/4 inches(31mm) wide. But Im thinking thats to big....as far as the valve having room to function properly. What advice can yall throw my way? Thanks in advance for any help with this.
Jeremy

 

that would be perfect

 

recess the flange that bolts over the back of the hotside to allow it to open more, also squaring off one side of the valve and doing the same for the port would allow for better flow while still allowing you to make the port larger

 

You think so? I was workin on it earlier and it seems like its way to big to work....I dont want the valve to be right next to the wall do I? Im also wondering how I will make the hole centered under the valve correctly...I mean the valve seems so big that I have too offset it from the arm alittle bit and I want to make sure the hole is offset the right distance. am I making sense? LOL.
Jeremy

 

Hmmmm. So just square the side nearest the wall where the arm is? Is that what you are telling me? Ive never heard of anyone using a square port. Not saying you dont know what you are talking about...just wanna make sure I do this right.I cant afford to mess this up...lol.
Jeremy

 

Make it just big enouph to allow sealing of the flap

 

Ya, I knew that much. Just want to make sure the flapper fits.
Jeremy

 

mine was so big i put a washer in and welded it then had to takes some of the sides off for it to open...still got around 7lbs. with a front mount but it never went over that..