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Compressor surge fix

12K views 10 replies 6 participants last post by  Roman 
#1 ·
anyone knows how to fix compressor surge or a shop in socal i can go to get it fix? i searched around but in all the threads people had aftermarket bov that was causing the problem and no one said how to fix it i have my stock bov on never had an aftermarket one put on.

my mods are ets test pipe, ets uicp, aem intake, megan downpipe, cnt v3exhaust, cobb AP stage 2 map, stock bov.

i took my car to big bear the beginning of the year and when i was going up the mountain on 5th gear i started to hear a fluttering sound, my friend said he was also hearing the same noise on his and he said that we were over boosting so i didnt use 5th gear on the way up anymore i stayed on 4th. Now its been a couple of weeks and i still hear the same fluttering sound everyday when im at 2500rpm-3000rpm on gear 3-5.

anyone knows how to fix it
 
#3 ·
im actually talking to mike from road race for a tune but i want to fix this problem before getting tuned.
 
#4 · (Edited)
Just to clarify, the stock "BOV" isn't a BOV, it's a DV (diverter valve). A BOV releases pressure/air to the atmosphere, a DV diverts the pressure/air back into the intake system.

Also, that flutter in gears 3 to 5 at those mid-range RPMs...... I don't think that's overboosting, as your friend suggested. Did you have a boost gauge that showed excessive/high boost levels? That sort of flutter is common on the stock DV, and most aftermarket DVs, when under light load and your intake pressure is hovering/oscillating between slight vacuum and slight boost. There are many threads on here about that situation. This is one of them. It's a long read, but a good read, and it covers a lot about flutter and surge:
http://www.evoxforums.com/forums/showthread.php?t=58419&highlight=flutter

And here's a thread where I managed to get rid of my flutter with a Synapse Synchronic DV (like 98% gone). Not relevant to your stock DV, but maybe informative nonetheless:
http://www.evoxforums.com/forums/showthread.php?t=64573&highlight=synapse

In general, most people agree that a little bit of flutter/surge under these conditions is nothing to be concerned about. Bad surge (at high boost) is a concern (be sure to watch some of the videos in that first thread above). But what you described doesn't sound like surge. Merely DV flutter.

Just in case it's not good ol' DV flutter, under what specific driving conditions are you experiencing this flutter/surge? And was it always there? Or has it suddenly appeared? If it suddenly appeared, did you change anything on the car before it started happening?
 
#5 ·
Thanks it just suddenly started to happen when I was going up big bear mountain I haven't changed anything on my car
It usually happens when I'm at 2500rpm on gears 3-5.
I read that thread and everyone thinks is the DV I'm going to take a look at mine but like I said i haven't changed anything and the car wasn't making that noise before I went to big bear
 
#6 · (Edited)
What you're experiencing is tune related. If you were on the an aftermarket BOV it could be BOV related, but realistically, a tuner should be able to fix this for you. It requires reducing MIVEC intake advance in low load low RPM areas. (2k-3k ish). Once I swapped back to my DV (I fixed it), I had to reduce my intake advance in low load 2k-4k rpm areas since the stocker tends to crack open under part throttle for improved drivability while the synapse I had wasn't opening at all, or as much.

Bottom line is, you need to get a tuner to fix this.

By driving up a mountain you are hitting different load cells and the temperature has likely changed which in turn caused this to crop up whereby it didn't before.
 
#7 ·
Thanks for the info I'm talking to a tuner right now and see when he has time to tune my car

But weird thing is my friend was hearing the same noise when we were going up the mountain on his Evo but unlike me he doesn't have the flutter noise now
 
#9 ·
I usually shift at 3000rpm mostly when there's cops around (which is most of the time) cause I have loud exhaust
 
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