Boost is creeping so I'm porting the wastegate, does this look like I've removed enough?

I think I took a pretty big chunk out but i would appreciate opinions.

Also, do people usually port the WG hole itself? Seems like that would be hard to do
Hopefully the images work.. Using the phone

Thanks guys!

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Interested to see what others have to say, I need to port my wastegate as well. AFAIK, you don't want to port the hole itself at all since that would affect the seal with the flapper when closed, and that's not where the restriction is happening.

-Ryan

You can port the hole if you're careful, make sure to deburr it afterwards so it seals right.
Also you'd have to decide whether there's enough room to port it, some are real close, and on some the door is way bigger than the port, allowing you to enlarge the port quite a bit.

As for what you've already done - looks good.

I ended up going a bit farther, and coming in from the wastegate side a bit. I'm pretty happy with it.. Time to bolt things back up.



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I was trying to run about 6psi so take with a grain of salt.

I had 2 housings. One of them I ported similar to yours. Still had creep issues. The other housing, I just opened up the hole so that there was about .150" sealing area for the flapper. That also had creep.

I had to both port as you have done, and open the hole to hold 6 psi with 2554. Either operation on its own didn't to the trick.

Hmm, I'll have to see then. This is a 2560, and I'll be running 12 psi once I get an EBC. I'll have to see if it holds wastegate pressure which is like 7psi.

I think the housing looks much better the second time around. My feeling towards this topic is, if it looks good, do a little more.

I've ported my MSM housing to the point where I can get it to hold less than 10psi to redline no problem. Granted now I can't get it to hold closed over 25psi. But I don't think most will have to worry about that problem.

Mine looks like Kenzo's but a bit narrower and less perfect. 0% boost creep on my t25 at 6, 9, or 11 psi and stays flat to redline. I wouldn't be afraid to do some more from what I see in your pics.

Cool, well I didn't bolt things back up yet. Maybe I'll bring the channel out toward the flange more like kenzo's pic.

Does anyone know what size studs FM uses?
I know theyre M8 1.25, but I'm looking for the A/B thread length.. shoulder size etc.
One of my studs came out, and when I got the nut off it just fucked all the threads. Looking to replace.

Sort of late to the party, but a great trick to use on stuff like this that may or may not be common knowledge in here:

Get a fine point Sharpie, firmly seat the WG flapper, and draw around it. You get a great idea of where you an and cant port. This works wonderfully for gasket matching too.

Also, look at what prevents the door opening farther. Sometimes it's simply the actuator's range of motion. But sometimes its actually the turbine housing itself interfering with the door mechanism. A little notch can give you a few degrees more opening and that can make a difference.

I have never understood why people don't port turbine housings as much as possible. Even if you don't have creep, the more flow you get through the wastegate the more top end you have. Its the seldom-explained benefit of a external WG. You get another ~1.5 inches of ex flow right where you need it most.

^ I was actually going to do something similar, but with spray paint. Just close the flapper and hit it with a shot of paint.

So anyway, I got everything bolted back up and... it still creeps. Not as bad, but it'll still creep to ~11psi from the 7psi on a 3rd gear pull. I'll have to get a log for exact figures.

I'll probably pull it apart again and port it more + do the flapper. I'll also have to look into getting full range of motion from the actuator because it probably only opens 70-80%. I'm not sure how im going to do that though, as the FM WG mount thing doesn't seem to have a lot of movement.

Because they often tend to crack

You can take it down pretty far...

I would also suggest just running like 10-12psi.

https://www.miataturbo.net/attachmen...ine=1405985408

Do you think it would creep less at 10-12 ish? That's my target boost once I get EBC but I'm concerned it'll just creep up to 14+

As erat said, you can go miles further than you have, if you do the port (and I suggest you do) leave a good millimetre or 1.5 around the port for the flapper door to seal against. I have run a GT2876r on an NB8B at under 4 psi this way with a 7psi wastegate actuator, to show how well you can control it this way.

Dann

The more boost you run the less it will creep. If you'r afraid it will creep to 14 psi when running 12 psi, bumping up to running 14psi will mean it wont creep at all.

Cool, and that totally makes sense now that I think about it. I'm gonna go forward and get the EBC solenoid, we'll see if it creeps at 12psi.

dont use this method!!!

The sealing surface is not the perimeter of the flap, take some grease and rub it on the flap, close, and thats where you can port to!