I've been having turbo flutter issues for a little while now that have progessively gotten worse. I thought that the stock bpv might have been the issue so this weekend I replaced it with the forge bpv. For starters it didn't fix the issue, it only seemed worse. But the other thing that surprized me was that the phhhhhshssssshhhhh sound was actually quieter than it was with the stock bpv. I have the K&N SRI so it was already loud, but after installing the forge it only got quieter and I thought that it was supposed to make it even louder. Is this normal, or could I possibly have gotten a faulty bpv?

Thanks for the help all!

 

After I installed mine the psssh definitely got louder, are you sure you don't have a boost leak from the chargepipes or the end caps of the intercooler. Are you tuned? How many psi of boost are you spiking at and maintaining?

 

Swap the old bpv and see what your boosting at, and compare with the new one, also what color spring did you use in the new bpv, the yellow or green one?

 

I have the K&N SRI, GMS1 tune, and now the forge bpv.

Recently I've boosted to 20 psi (after installing the K&N). Before installing the K&N I was at 23 psi (don't really know why). I haven't checked since installing the forge because I threw a CEL and have had terrible turbo flutter and no boost past 3 psi, so I'll have to try it today because it's been doing fine today.

FYI I installed the yellow spring because I have GMS1. Also, the opening sound might be louder but the pssssshhhhhh definitely isn't.

 

That is exactly the experience I got when I put my Forge on when I already had the K+N on.

 

Did you do anything to fix it, or is that pretty standard?

 

I was having the same issue when the stock intake was still on the car and with the sri with the stock bpv and the forge, but try these and see if any of them work, check for any vacuum leaks, make sure your tmap sensors are seated properly and have good, positive connections at the splice point, and try running the green spring, it sounds like the yellow spring is to strong on your car thus causing the valve to close sooner and quicker than it should, aldo I am tuned to 24.5psi and I'm still using the green spring with no issues.
The fix for mine was re-soldering the tmap wires as well as disconnecting and re-seating the charge piping on the intercooler.
Hope that helps.

 

Thanks for the info, that's really good advice. Here's another thing about my GMS1: the lower TMAP sensor that causes issues is installed backwards! And, I can't turn it the right way because the AC Compressor won't let it fit. This tells me that the lower charge pipe is somehow out of place, so maybe you hit on something with the last part of your post.

Anyone have any other ideas?

 

Sorry, i was on my way out the door. I should have been more complete. I don't have any surge. I got a trifecta tune and since then the car have had no surge. You're going to need a tune to get rid of it.

This part, however, is exactly my experience -

 

Are you trifecta tuned with the GMS1 sensors or still the stock? If the issue lies in the spliced connections can the trifecta tuner redo the connections entirely?

 

I'm on stock sensors. Will your tuner resplice your wires for you? That would be between you and your tuner. I guess if they were willing and you paid him/her to do so. Who spliced them in the first place?

 

I bought the car with the GMS1 already on it and I have no idea who installed it. GM has no record of it either which is weird.

 

So, someone put on the sensors and never had it flashed? Well, I'm sure you can get someone to splice them. It's not hard to do.

 

Well it certainly appears that someone flashed it because it boosts at 20 psi and I've boosted to 23 or 24 psi before which shouldn't happen on a stock tune. Also, I periodically get CEL P0236 but I would think that I would have one all the time if the tune wasn't flashed. I wanted to get my GM dealership to check and see what tune it was running but they said they have no clue how to do that.......wow.

 

Why are you saying wow? If it's not a GM tune how would they be able to know who's it is? It's not like someone signed it. I'm guessing that someone bought the sensor, put them on, and got an aftermarket tune, and perhaps not a very good one.

 

To me the stock and forge sound about the same

 

Also check on how the forge divertor is installed there is an opening and it needs to be facing down towards the ground

 

Gaurentee your sensors need to be soldered I had an issue with GMS1 only boosting 4 psi

 

After re-soldering did you get the problem to go away?

 

Did you put the forge bpv in the correct way. The opening of the bpv should be facing down. Also is it fluttering at part throttle let off or WOT let off. When i swapped my green spring to yellow i noticed it wanted to flutter at part throttle. Remember bpv springs should be matched with what vacuum you pull not how much boost you make. If you vacuum isnt sufficient enough to pull on a stiffer spring you will get flutter.

 

Yes I never had the issue again. I was having boost issues as well as a surging feeling while driving. after the 3rd trip to the dealership they soldered the wires and that was it it fixed the issue.

 

I definitely installed it with the opening facing down so I think that's ok. It flutters under any throttle. I can barely touch it and let off and it will flutter. I think I might try and switch to the green spring and then do the vacuum tank delete and see if that works. Somehow though I have a feeling this is related to GMS1.

 

Mine fluttered as well and would only boost to 4-5 PSI.......I think your issue is Soldering the Wires.

 

Yeah I think that might be it. I'm just really confused as to why my lower charge pipe is off location because right now it's completely impossible to install the lower TMAP sensor facing the AC compressor and I'm wondering if the sensor being backwards could be part of the issue as well.

 

The lower TMAP sensor should face away from the fan. You'll need to cut the plastic boss/tab on the TMAP sensor to do this.