corksport downpipe

[blackmica08]

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.

 

[lestat13]

I've got a corksport downpipe and I was spiking BIG.... like 22psi on stock turbo, no tune, no mbc before settling back down to 16. Recently I changed out to a greddy rs in recirc and haven't been seeing boost spike but my know-how tells me that can't be why.

So with the stock turbo, what do you suggest doing to ease this problem??

 

[blackmica08]

I've got a corksport downpipe and I was spiking BIG.... like 22psi on stock turbo, no tune, no mbc before settling back down to 16. Recently I changed out to a greddy rs in recirc and haven't been seeing boost spike but my know-how tells me that can't be why.

So with the stock turbo, what do you suggest doing to ease this problem??

you have to try to grind down the part of the downpipe that in my case was not letting the flapper open up, all the air was going back into the turbine making it spike up that high. the flapper should be able to open at least to a 90 degree angle.

 

[logik816]

have you tried contacted CS on this?