Hey all, few things here. I'm having huge boost drop off lately and I'm trying to figure out what's causing it. Just last week I was having a slight over boost issue me and my tuner were still working on after we were tuning for e47. Then lately in the past few days or so I haven't had any over boost. It goes straight to 22 then quickly declines to about 15-16 psi. Me and my tuner have tried EVERYTHING to get boost to hold and nothing will make peak boost go over 22 and it won't hold, the boost drop is consistent and never varies. Could a boost leak be consistent like that? Would a bad map sensor cause this? It's not in the tune. We reverted back to my e47 tune we started with and it was the exact same result, no matter what tables we messed with boost stayed exactly the same, I figured even if it was a boost leak it changing the tune would cause some sort of change but it didnt.

 

I'm assuming you're on the stock turbo? I know they fall on their face, but I don't recall the actually psi it normally drops to

 

This is bay far from normal. Before I was peaking 24 and it held 22-23 till about 6k then it dropped to roughly 18, I then switched to e47 and I was peaking roughly 22-23 and it would drop to about 17, would occasionally over boost 24pounds. Now it's hitting 21 and falls from 4k all the way down to 15-16psi. It's worse then before and cannot be tuned out. We tried..

 

Starting with a boost leak test would never hurt

 

That's what I'm thinking, weird part is I had a vacuum line on my lower charge pipe pop off. And I just noticed it when we were tuning and I plugged it back and there were no changes in the boost at all. Why would that be, I fixed a leak (small but still there) and boost literally didn't change 1 psi.