Glassman

iTrader: (1)

I'm about to port my wastegate on my S6 and I'm hoping someone can answer my questions.
The wastegate is in for welding of cracks now and I want to port it using a cnc mill. After it will go in for ceramic coating. I've modified the larger flapper from the other housing to fit the wastegate. The large flapper is 1.45" in diameter. I have 2 questions.

1) What diameter should I open the hole to? How much meat is required per side for the flapper to work? I will want to radius the top of the opening to prevent cracks so if you can account for that.
2) How deep should the hole be milled into the housing? Just the depth of the hole opening or all the way down?

I couldn't find these specific answers when I searched so hopefully others will benifit from this.

Thanks

Speeder165

iTrader: (7)

Try these out.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-port-wastegate-426526/

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/wastegate-porting-observations-726267/

Glassman

iTrader: (1)

That's where I started, I cant find a thread that goes into more detail for milling and land width

Monsterbox

iTrader: (6)

don't focus so much on the hole.

look at the center housing and move the flapper...youll see it only moves a few mm.

GRIND the sh*t out of the flat part on the middle housing and let the flapper open further. I almost doubled the distance....the solenoid arm can extend much further than it currently can.

Speeder165

iTrader: (7)

I am thinking of porting mine. Have a mill here so doing it manually will be fairly easy. Using a boring bar & die grinder, things should materialize quickly. After reading the post of what another member in this forum did, I would say that what he did would suffice. If you want to radius the edges, you are going to lose valuable area of what could have been a larger unradiused hole opening. I would say that you are in uncharted waters so you may have to wing it. I like the idea of a radiused edge, especially with a cast iron housing which is prone to cracks in the arena of what we subject it to. How much of a radius you will need, I don`t know. Maybe an engineer could tell you. I am not one. I plan to open up the hole on mine all the way through. I will allow it to just be undersized enough to make sure the door doesn`t fall through the hole. Going to remove enough material behind the door as the member did in his post, to let the door swing open wider. Should be plenty for stock twins. I may "fuzz the edges" to round them a little with the die grinder. Outside of that, with stock twins, the rest seems overkill. Good luck to you in your project & let us know how it turns out!

Glassman

iTrader: (1)

Did that one already, thanks though

Glassman

iTrader: (1)

The origional flap is 1.335" diameter, the flap I'm using is 1.45" diameter. The other threads suggest a 1.24" diameter hole with origional flap. That leaves 0.045"+ per side, not much at all seeing how the flap has some slop about 0.020". I was thinking about going 1.20" or 1.21", that would leave 0.120" per side less my radius of 0.040" per side gives me 0.080" land for the flap to seal. This seems reasonable to me and I'm still opening the hole 0.200".

So when you do yours you are going to mill as far down the hole as possible?

Thanks

Speeder165

iTrader: (7)

Hmmmm...squeezed in a double post there somehow.

Yeah. I am going to bore the hole all the way or as far as possible & if I run into any "meat" on the other side, I will just contour everything in with the grinder. The grinding & contouring will take longer than the boring operation. Should be fun though.

GoodfellaFD3S

iTrader: (213)

Bryan at BNR welds in a completely new (and larger) wg flapper door, I'd recommend that route rather than deal with the existing wg.