I'm prepping an s4 to use on my 1st gen blow through and was in the process of porting the wastegate. It is much larger at this point but it is still covered by the stock cover. I know on the aron cake site the porting is done to the size where a new cover needs to be welded on. Is that necessary? or is porting to the maximum size allowed by the stock cover good enough?

Thanks in advance.

 

IMO porting to the edge of the stock flap is a waste of time, when for a little more effort to put a bigger flap on you can have far more flow potential. Plenty of people have just done the porting and complained that boost creep still occurred. Here's mine if you're interested...

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/serious-s4-wastegate-porting%85-343788/ (scroll down to post #15 for reposted pics)

 

Thank you. Great reference. I will continue porting.

 

Port as big as possible so you can get better flow.