corksport downpipe

[blackmica08]

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i was having big time boost spike and boost creep problems on my gt2871r turbo so finally i followed christian from cobb advice to port the wastegate, as we pulled the wastegate out we notice that the housing was cracked all around and also the turbine was missing some pieces. i made the arrangements and send the turbo back to atp turbo for inspection, at the same time i ordered a gt3071r and i just paid the difference. we put the turbo back in the car and what do you know same boost problems as before. so we pulled the turbo back out and as we were checking things around david my tech noticed that the flapper from the wastegate was hitting the downpipe not letting the dp open not even in a 45 degree angle. finally we ported the wastegate and the mani too and fixed the dp problem and now the flapper opens a full 90 degrees. i might not be the only one with this problem so i strongly advice all of you with boost problems to check your downpipe and flapper to check if the dp is letting the flapper open as its supposed to. we even checked on a stock k04 turbo an it also happened

[Darksun280]

kinda a known issue but glad you figured things out

[CraigHJr]

Si!!! been there ported that! How much material did you remove to make that open a full 90 degrees. I would have to say that mine isn't that ported but I am on a stock turbo still.

[LBV]

The part about the flapper hitting the DP is not a known issue afaik, so thx for posting that. How's the 3071 performing?

[Darksun280]

Originally Posted by LBV The part about the flapper hitting the DP is not a known issue afaik, so thx for posting that. How's the 3071 performing?

Well your one guy I knew when Crigh told me. Figured many other people had to have run into that by now.

[CraigHJr]

I don't think anyone knows it but it does. The stock turbo flapper open right over the wg dump pipe. I don't know how I am the only guy over boosting and spiking so bad on a stock turbo who wanted to fix it.

[blackmica08]

Originally Posted by LBV The part about the flapper hitting the DP is not a known issue afaik, so thx for posting that. How's the 3071 performing?

im not done putting the car back together, i will be done by tomorrow. hopefully all the porting will take care of the problems.

[CraigHJr]

Looking into the 4 bolt flange you need to clean that huge hump out of the turbine housing. You can also open up the wastegate oriface a bit as long as the door still has some meat to seal on.