Falling boost.....ideas on the cause of it?

[suprafanatic]

for some reason the supra doesnt want to hold very much boost. right now it will boost up to 15 pounds and then drop to 10-12 pounds. at one point on the dyno it hit 15 then dropped to 7 pounds.. its a 60-1 turbo. any ideas what could cause this? i'v tighted up all the clamps on the IC piping..:1zhelp: iam also running open down pipe

 

[subjug4tor]

bad wastegate?

 

[suprafanatic]

how would a bad wastegate cause this problem?

 

[subjug4tor]

I've heard of failing wastegates that caused similar problems, but I could be wrong. Seems to me that if it was coming open when it shouldn't it would cause boost to fall.

I would think that if it were a leak of some sort, It wouldn't want to build to full boost at all, rather than get there, then fall back down. Once again, I could be wrong, just my .02 cents

 

[Poodles]

It's pretty normal for what I've seen for the CT-26

What elbow/DP do you have?

 

[suprafanatic]

i have the 60-1 ct26 3in elbow and the megan racing down pipe that is supposidly 3in as well. and after that its wide open..lol another thing i was thinking about.. i have a cheap voodoo MBC would that maybe be leaking boost through to the wastegate causing it to open and letting boost out?