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From out of no where SURGE!

Schmitty

Schmitty

New Member
Big Nate said:
This sounds like an install error.(sorry) I think if we can take a look at Porky's we will be able to figure it out.

Also did your forge come with a new hose clamp for the large dump pipe?



Not telling your that is the issue but it will fix the small issue you have.

Also The shims go on the top side of the valve. The side that doesn't move to dump pressure. Was there a lot of white grease on the internals of the valve? if not then you could have a sticky mess in there. That can get fixed by doing a valve service and regrease the seals.
Click to expand...
I am almost certain it is install error. LOL.

No, I didn't get new clamps wth my Forge. I replaced the one that attaches to the BPV this morning with a spare I had laying around. It is clamps down much tighter now. Didn't resolve anything. I will try to get to the one on the inlet tonight before Porky's.

The BPV was clean, save for the cap wich did have some grease on it.
 
Schmitty

Schmitty

New Member
Quick update before Porky's-----

Replaced 2nd clamp on hose running from BPV to inlet - Same sound
Yellow + 2 shims - Same sounds but holds boost to 21PSI (love those spikes). Will try one shim for the ride up.

Found a thread on 247 that seems very relevant LINK

Mine sounds like a groundhog bark. Others are having the same sound after installing the Cobb inlet. Different BPV are being used and still have the same sound. It's not surge but seems to be the released pressure hitting the silicone inlet. I'm not for sure what is happening but people running the metal inlets have not report this sound so I believe it has to do with the silicone inlets.
Click to expand...
Although my inlet is not silicone, the connecting pieces are perhaps it just resonates more now?
 
Schmitty

Schmitty

New Member
Uodate for those of you that weren't at Porky's....

Yellow + 1 shim, still surging.
Swapped with a known good Forge BPV, still surging

Will try stock BPV tomorrow.
 
W

WhiteSpy9

Guest
I can't really hear much from your vid Schmitty, but I can attest that I do get a bit of flutter if I run under full throttle but for a short period of time. (shifting around 4k full throttle) Much like what Jay describes below.
My solution is to either run the rpms up a bit more or avoid slamming the throttle if it will be a short lived run through the gear. It is the most noticeable in 3rd for me as well.

Possibly with the added inlet tube and bpv too much air is entering too quickly when the throttle plate is slammed shut. I'm not the most technical, so my theory here could be full of :JD:, but maybe it is time for a cbe/tbe?

edit - if you ever want to hear it sometime to compare, let me know.

dmention7 said:
Well, the same thing can happen when the throttle plate slams shut and the turbo is still spooled and trying to cram air into the motor. It's obviously a much more instantaneous and short-lived phenomenon than the truly dangerous type of surge you described (and Luke illustrated in his first vid), but the phenomenon is the same.

The type of surge you're describing kills turbos. The type of surge that results from an insufficient bypass/dump setup can "merely" increase wear.
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M

Matt D.

Guest
After listening to the video I have to say you are worried about nothing. Welcome to forced induction. :)
 
dmention7

dmention7

Hater
Oh hey there Matt! Thanks for the useful post!




[whisper mode]Don't trust a DSM guy when he says "that's normal". Any time the motor is not spewing oil out a hole in the block is "normal" to them....[/whisper]



<.<





>.>





<.<





:D
 
Schmitty

Schmitty

New Member
patty has some good feed back in the 247 thread

My guess is that the cap o-ring has failed and the upper portion of the valve can't hold enough vacuum to keep the valve open. This is causing the piston to open and close rapidly and making the "turkey" sound.

Perform the "pent-test" in this PDF and let me know what happens.
Click to expand...
He failed to post the link though. :(

For those that can't hear it or think its normal, crank the speakers and pay attention at the 17sec mark.

Once again guys, thanks for all the advice. If an MNMazda mate finds the fix, you will get a six pack on me.
 
dmention7

dmention7

Hater
I did a google search for "pent test" and came up with nothing but the thread you posted. lol

If you wanted to do a quick and dirty test, you could try reinstalling your stock BPV, then attach the Forge part to the vacuum tee that's currently going to your boost gauge and look for abnormal operation when giving the motor a few quick revs.
 
JohnnyT

JohnnyT

New Member
What are your AFR's looking like both at idle and WOT?
Your intake (because it doesn't have an air straightener) tends to create turbulence in your intake. This could be the root cause. Swap intakes with someone at Porky's, and see if that helps.
 
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