# Flutter with MadMax DV



## Currancchs (Feb 24, 2011)

Hi guys, I installed a MadMax DV (Evo IX MR DV with crush mod and some other internal modifications). I now get some part throttle flutter. I never got this with my Forge 007 or stock 710N. I just did a boost leak test last weekend and found no issues, although I could have missed something. Looking for some advice, worried about the effects of compressor surge. Will likely get the car smoke tested if I get a chance this week, but any advice is appreciated.

Thanks,
Matt


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## Tempes_TT (Oct 24, 2010)

Are you getting the fluttering noise while reving at idle? I know it was discussed on one of the MadMax threads that the DV is a little "tighter," if you will, then stock or other DV. So unless youre under load, it wont create enough pressure to open the valve, thus surging. 

Im not owner of it yet, and I for sure want to get one, but I always wanted to get it clarified if the Evo DVs just had that signature Fluttering, or if it indeed meant something in the system (boost/vac leak) is causing you to surge. :thumbup:


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## Currancchs (Feb 24, 2011)

Tempes_TT said:


> Are you getting the fluttering noise while reving at idle? I know it was discussed on one of the MadMax threads that the DV is a little "tighter," if you will, then stock or other DV. So unless youre under load, it wont create enough pressure to open the valve, thus surging.
> 
> Im not owner of it yet, and I for sure want to get one, but I always wanted to get it clarified if the Evo DVs just had that signature Fluttering, or if it indeed meant something in the system (boost/vac leak) is causing you to surge. :thumbup:


I actually didn't rev it at idle during testing... I just drove normally and was experiencing flutter under those conditions. Boost at flutter was anywhere from 5-15 psi. I ran it WOT a couple of times and @ 19-20 psi it did not seem to flutter.

On a side note, I was just doing some reading, and Max recommends his valve to be installed in the "Push" position (Opposite stock). This is the way I originally mounted the valve, but really saw no difference in the push or pull orientations, and both fluttered. I was also surprised that this valve was actually fairly quiet (Not any louder than stock or forge, with a Neuspeed P-flo (Oval filter w/heat shield only). I know that the guy I bought it from thought it was too loud and traded for my forge for this reason...

I'd also be interested to see if this is just a characteristic of the valve or indicative of another issue. Somebody must know!


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## Tempes_TT (Oct 24, 2010)

I know Im not providing a concrete answer and may also be pointing out the obvious, but I thought Id ask away anyways... Is your system leak free? Cause I also know that to run this valve (well, any valve for that matter) you need it to be leak free to run properly and 100%. Its just more noticeable with MadMax's... or so Ive heard/read.


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## Currancchs (Feb 24, 2011)

I am pretty confident it is leak free, but maybe not. Just leak tested last week, but will bring to a shop this week and get it smoke tested just in case I missed something. Need to get reflashed to stage 2 anyways.


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## warranty225cpe (Dec 3, 2008)

Currancchs said:


> I am pretty confident it is leak free, but maybe not. Just leak tested last week, but will bring to a shop this week and get it smoke tested just in case I missed something. Need to get reflashed to stage 2 anyways.


The fluttering is normal. The surging isn't. When mine was doing this, I found that the hose going from charge pipe to turbo (turbo side) kept coming loose. It would bog and shutter when I let off the gas. Doing a smoke test won't pinpoint anything unless you pressurize to higher boost pressures. Fill the system with smoke under low pressure, then hook up a pressure tester and regulate it to 20ish psi.

If you find that the hose connection on the turbo is loose (try to turn the clamp to see if it's tight), let me know. I've got a fix for it that has held mine for over a month so far. The most frustrating part about that evo DV is the hunting for leaks after its installed.


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## Currancchs (Feb 24, 2011)

warranty225cpe said:


> The fluttering is normal. The surging isn't. When mine was doing this, I found that the hose going from charge pipe to turbo (turbo side) kept coming loose. It would bog and shutter when I let off the gas. Doing a smoke test won't pinpoint anything unless you pressurize to higher boost pressures. Fill the system with smoke under low pressure, then hook up a pressure tester and regulate it to 20ish psi.
> 
> If you find that the hose connection on the turbo is loose (try to turn the clamp to see if it's tight), let me know. I've got a fix for it that has held mine for over a month so far. The most frustrating part about that evo DV is the hunting for leaks after its installed.


Sorry, my language was not the most clear. When I say I was worried about the effects of surging, I did not mean that I am getting compressor surge during acceleration or anything, I was really just referring to the flutter. I was under the assumption that fluttering was caused by surging pressure being bled through the DV as the diaphragm opens and closes because the vacuum is not constant, but surging. I am strapped for time currently, and am taking the car to Northern European Automotive tomorrow morning for leak testing, and possibly reflashing (Don't want to reflash until problem is solved). I will post an update after they take a look at it.

The car runs completely normally, and hits about 20 psi on APR stage I. There is no shudder or bog. I know there is plenty of overhead with this turbo, and I could hit that with a fairly substantial leak though, but thought it might be relevant anyways. (N75 Duty cycle is around 80%, fuel trims are within 5%)

When you say the charge pipe, are you referring to the TIP or the outlet side of the compressor? (I think outlet side of the compressor, but just wanted to make sure)

Since you brought up smoke testing as well, I have heard of it, but always been unsure of the exact procedure. I am sure that there are VAG testers that are meant to do this, but would injecting smoke from a typical smoke machine, like the ones used at parties, into the TIP then pressurizing with a standard leak tester be OK? I just don't want to damage anything if this type of smoke is not the correct type.

Lastly, I noticed on the drive today, with the DV back in the "Push" orientation (As recommended by Max), that I am getting flutter on let off from WOT. In your video with a similar setup (although you relocated the DV) I noticed some flutter at partial throttle, but WOT seemed to not flutter...

More info to come!

Thanks for the suggestions and help guys!


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## warranty225cpe (Dec 3, 2008)

Fwiw here's my video. I had a bunch of leaks at the time.


http://www.youtube.com/watch?v=eegS0EObSIE&feature=youtube_gdata_player


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## Currancchs (Feb 24, 2011)

Ok, so I just dropped off the car to get it tested and the guy is telling me that they can't even boost leak test the car because the dv is barely opening? I have no idea why this would have anything to do with running the test, but they are going to throw on a samco dv for testing... they also gave me a hard time about using zip ties to hold on silicone hoses, and said they will replace with hose clamps... when I ran hose clamps I blew a few lines apart, I'm assuming because the clamps cut into the silicone... any comments welcome... (Note that the hose clamps were not used to connect the DV, just other smaller silicone lines I already had)

I was also told that stage 2 apr just gets rid of the CEL associated with aftermarket cats, and does not take into account a new DP or change any operating parameters... I thought it did, but could be wrong...

Sent from my PG06100 using Tapatalk


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## warranty225cpe (Dec 3, 2008)

Currancchs said:


> Ok, so I just dropped off the car to get it tested and the guy is telling me that they can't even boost leak test the car because the dv is barely opening?
> Sent from my PG06100 using Tapatalk


The last MadMax Dv I had I thought had a leak in it. I sent it back, and Max sent me a new one. He also sent me this email that I have copied and pasted for you. 

"What I had to do is put it in my car and do a leak test. Just like you, both my valve and the one you sent back leaked air on the car but not on the tester. What's happening is when we are testing, the throttle body is closed, so no pressure in the manifold. Without pressure in the manifold, there is no pressure going to the top chamber via the vacuum nipple. Without that pressure to equalize the diaphragm plate (pressure at the bottom vs pressure at the top+spring rate) there is air escaping while doing a leak test. In real life or on the bench tester, both top and bottom are pressurized ( because of pressure in the manifold) and the valve hold 45 psi steady.

I have come up with a simple solution for us (since it does the same thing with my valve too) is to reverse the valve orientation when testing. That way we can test for leaks and go back to push orientation after you finish testing and ready to drive again."

So reverse the orientation of the valve and try to test again. It worked for me




Currancchs said:


> ... they also gave me a hard time about using zip ties to hold on silicone hoses, and said they will replace with hose clamps... when I ran hose clamps I blew a few lines apart, I'm assuming because the clamps cut into the silicone... any comments welcome... (Note that the hose clamps were not used to connect the DV, just other smaller silicone lines I already had)
> I was also told that stage 2 apr just gets rid of the CEL associated with aftermarket cats, and does not take into account a new DP or change any operating parameters... I thought it did, but could be wrong...


It's ok to use zip ties, as long as they don't leak when tight and under pressure. Most hose clamps suck. And yeah, stage "II" APR isn't anything more than writing out the o2 sensor code.



.


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## Currancchs (Feb 24, 2011)

OK, well Max is the man. He just contacted me and is walking me through my issues. We are going to go through a few things and get it working correctly. I am going to reserve further forum posts until we work through these issues.


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## Arnolds64 (Nov 13, 2009)

*Flutter?*

So does it flutter when you let off the throttle at partial Throttle. Mine does this. I pressure checked my system and it was fine. I think he told me that is normal with his DV. Also I oriented my Madmax DV the stock way under his suggestion. Changed it now? Too bad he is banned here.


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## Currancchs (Feb 24, 2011)

I mounted mine in both the stock orientation and reversed (Pull only v. Push), and was getting flutter under WOT let-off's as well as under partial throttle in both orientations (I also was also toldthat partial throttle flutter was normal, but not WOT let-off). I pressure tested the vehicle myself before installation of the valve and then had a local shop pressure test again just in case I missed something, but did not find any leaks. The consensus was that my valve (which I purchased used) was overcrushed, as the diaphragm would barely open. Max was very helpful however and called me in response to an email I sent to MCPI (they sell his stuff now). He offered to replace the valve at no charge, even though I was not the original purchaser. I am swapping back to my forge valve however, just because I know that works and don't have time to tinker right now.


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