As I was looking at the single turbo setup on my car, I saw there was a little flange bolted to the exhaust manifold, right next to where the turbo flange to the exhaust manifold. It looks kinda like this

(sorry for the shoddy image, any questions ask me) There are two 13/64" diameter holes in this flange (one hole is flush to the flange, the other hole is on a nipple) Both of these holes seem to allow exhaust to pass out. Does anyone have any ideas what they are for? At WOT, I am making about 6 lbs. of boost; would sealing these holes up jack the boost up significantly? Any help would be appreciated, thanks.

 

That is wierd....but yeah it would effect turbos performance. At least if I understand that diagram correctly..it's kinda hard to see. Sounds like he couldn't afford a wastegate to bolt to that flange..so he just drilled a couple holes to bleed off pressure.

Sealing them up might get you a more boost sure. I would drill and tap them for an 1/8" pipe plug. If you get too much boost..you can always drill a smaller hole in the plug to help adjust.

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Any exhaust leaks between the head and the turbo WILL ADVERSELY AFFECT BOOST. Excessive lag and reduced max boost can result. Weld them damned holes up!

 

I was thinkin some good 'ol JB Weld shoved down into those holes should take care of em. Will JB be ok with the heat of the manifold?

 

No. JB Weld will pop off the first time you hit boost probably.

It'll have to be welded..or drilled and tapped for a plug.