Well, I searched and couldn't really find anything that answered my question. Most threads I found dealt with gms1, and not the same problem I am experiencing. Anyways, on to the question. I have been tuned now since July of this year and haven't been experiencing any problems at all (knock on wood), except for lack of traction, but last night I went to pass someone doing 55 in 4th the and got on it, around 65 I floored it and it hit full boost (23psi), but flutter then ensued as it peaked. Is this simply due to the fact that I am still on the stock bpv? Mods are k&n sri, zzp lower charge pipe, cia catless downpipe, and hptune. Just for reference.

Thanks! (Hopefully )

 

your running stock hotside piping..

 

i got the stock bpv on 22psi and im just fine.

 

I am having a simular issue. I have pretty much the same setup you have as far as mods. It almost sounds like the stock bpv won't hold (fluttering sound). My will do it if I am in 5th at about 65 and roll into the throttle. The car runs fine it just makes a fluttering sound. At WOT in the higher RPM ranges it seems ok (no flutter sound). I wonder if the stock MAP sensor and boost guage are limited to 22.7 PSI; and maybe we are hit a higher boost pressure than is displayed and the stock BPV won't hold the boost? I am going to look into it soon, weather permitting, and I will let you know if I find anything. Maybe someone else has experience with this issue and will be kind enough to guide us in the right direction.

 

This is why lol. You are utting to much load on the turbo with lack of rpm so therefore causing the flutter you hear. When rpms raise it has the oppritunity to release the air pressure quicker so therefore not surge. This is the main reason!!

 

ding ding ding. you should never go full throttle below 3500-4000 rpm unless you are in 1st or 2nd, just downshift...

 

I figured it was something like that. My scan guage didn't show anything unusual and when I put my stock ecm back in (lower boost), the problem went away. I guess if I log it with HPtuners I probably won't see any problems either.
Thanks for the input.

 

What if you're getting flutter in first and second, but not the higher gears?

 

I only get flutter in higher gears with a high boost. In lower gears (higher rpm) it is fine. Chevycobaltss3 said the turbo is flowing more air than the engine can deal with at lower rpm and that is why it is fluttering. This makes sense to me. I will tweak the tune and see if it goes away.

 

Well this answers my question. I'm getting flutter WOT in 4th gear, but when I go to third gear and WOT (3000k+) then to 4th (after nearly redlining 3rd) there's no flutter in 4th. So I just need to stop WOT in 4th!

Loving the search button!

 

exactly ^^ definitely dont go wot in a high gear when the engine is bogged down and hit full boost cuz it will flutter at low rpm

 

Yeah, I haven't gotten the problem since the night I posted this, which is why I forgot about this thread but the weird part was that I was getting it even when I did higher RPM pulls. It stopped now though. It may have just been conditions that night or something like that. If it happens again I'll come back here again.

 

Not to bring back a dead thread but I have the flutter at all times. It sounds like a Hyena, or a baby horse (laugh away. lol.), low rpms in 1-3 and you can still kinda hear it at high rpms in any gear. A friend with an LNF said it sounded like Compressor Surge but from reading different threads on here the problems with that sound nothing like mine. I thought it was just a normal sound until he said it sounded different from his. It flutters through any normal shifting (I shift at 3 around town) all the way into 5th, higher rpms (interstate) it just makes one noise, no flutter.

I have GMS1, Injen Upper piping and CAI, factory lower pipe and a HAHN intercooler. Is it normal or should I start looking at my BPV? A few people have said to pull the BPV and check the rubber to make sure it's not torn.