Okay...I'll be picking up a 10AE before long and one of the first things I'll be doing is adding an exhaust (amongst a few other things)...however, I want to not have to worry about boost creep. So I'll obviously be pulling the turbo and porting the wastegate.

Wastegate is tiny, I know. I have adequate tools to mill it to just about any size I want, so where would the port need to be to be perfectly secure? I was thinking 25mm (approx 1") would be pretty secure, but I could go larger if I needed to...but I don't know exactly where I should go with it. The most I'll EVER push is 1 bar, if that much, but Idon't want to have to worry about it spiking on me.

Also, you people who have ported the housings without disassembling them first, weren't you concerned with debris?

 

Do it once and do it right. Go up to 35 mm wide and get a new flapper welded on there. I ported my wg without disassembling the housings but I used compressed air and blew all the debris out. If you are worried just disassembly them. I have been driving with my wg ported like that for a few months with no problems. Just be thorough with cleaning it out.

 

What did you use as a flapper?

 

I have an s5 and the stock flapper was retained since s4 and s5 wg design is different. If you want pix of an s4 bnr wg ported with bigger flapper let me know. I've read most people have a washer larger than the diameter of your port welded on and then grind it down so the stock flapper has the small amount of play in it so it can seal better.

 

I read somewhere that someone used a honda valve for a flapper..that's what I was leaning toward using so it would be one piece...no welding it together or anything. I could so the washer method, though...

 

I had a local welding shop weld a large ss washer onto my flapper, then they ground the face of it flat. Works great.
-John

 

well when mine comes back from the machine shop I"ll post pics.

 

It's not extremely diffficult to remove the turbine housing. I'd recommend doing it because it's difficult to account for all those metal shards and there will be a LOT of them. I sort of copied NZ and welded a washer on. Actually the washer I used was thin so I used two of them welded together and then welded them onto the stock flapper door. I used a die grinder to make the hole larger and also cut out the side of the housing that the back plate bolts on to. I found that it fit best by keeping the stock flapper and welding the washer over top. I ended up staggering the washer so that it wasn't centered so that it wouldn't hit the side of the housing. (I just found it fit better this way) I then welded the back of the flapper so that it couldn't rotate the washer.

It works quiet well. At the same time I ended up having to make a 3" TID and I swapped a 2.5" Edelbrock muffler in the stock cat location for a 3" Magnaflow cat. The rest of the exhaust is a 2.5" single. Boost is rock solid at 5.5psi and bleeds to 5.0psi at redline in 2nd and 3rd gear (haven't really tried higher).

 

I don't know why everyone always refers to a "Honda" exhaust valve. Any exhaust valve could be used. Note that there is welding involved, since that's how you attach the valve head to the arm.

Personally I think there's no need to use an exhaust valve head anyway. Valves are designed to withstand combustion temps, which are higher than exhaust temps. A mild steel washer works fine for me.

 

People say "honda valve" in specific because if you search for this topic one of the few descrtiptive threads specifically says "honda valve"...so it carries over. I probably won't use anything in specific, just whatever will cover the hole. After looking a bit more into it I learned that if temps were high enough in that area to melt a mild washer, I'd have much larger problems.

But how large would I have to go to make sure that I can always have solid control of my boost? Would it be possible to built a dual port setup (like on that tubo pictured above) on a 10AE housing? How big can it go before you HAVE to mill away the casting around the chamber? 35mm seems to be HUGE, but I don't know...

 

There are way too many variables to be able to answer that question. Every part of the engine from the pod filter to the exhaust tip can affect boost control. I believe you should always go as large as practical, which is basically what I did.

It would be a huge custom fabrication. Why bother when you can just go out and buy one? That's just an S5 turbo.

Not big enough IMO. If you can get the housing to a shop with a milling machine it's a cheap easy mod.

 

Full 3" exhaust, hardpipes nad an FMIC, and an apexi filter...but I see your point...

I knew it was an S5 turbo but I didn't know if there were differences in the castings...I guess if it was as simple as adding another port then more people would be doing it...right?

I have access to a machine shop...they'll be assembling my FMIC and doing most of the milling on the turbo. I'm gonna try to use my own machines just to play with it. I'll be able to tell real fast if the task is bigger than I can handle.

I guess I'll shoot for 35mm...or bigger if I can fit it. Is there any real reason to keet to port round? If I make it an odd shape would it have much effect on anything...

 

It's a totally different casting. The wastegate is completely revised, the A/R ratio is different and the manifold is also very different. It's also a very worthwhile upgrade.

I guess not, but personally I believe the flap should be left "floating" like it is stock, and that means a round flap covering a round hole.