[vetteflier]

Originally Posted by ///AVM

Thank you Vette

Do you are saying you did not put plastic housing back on?

You just secured diaphragm in place and left plastic housing off?

I'm more inclined to your screwdriver suggestion, and will give it a shot.

///AVM

Exactly. I have the modules (housings) and the bolts I took off, with the shaft in full closed position. Just stuck them away in a plastic bag. I really don't think you'll hurt anything by slowly turning the shaft. I doubt it is locked in any way--needless expense to manufacture. If a future owner for some reason wanted it returned to stock, would take 10 minutes to put back on. Shaft would be in closed position, so I'd rotate the flaps back to full closed, Would index easily.

[TrentMeister]

Originally Posted by vetteflier

Couple of things. To LB--were the valves open or closed when you got home? From what you said, they should have been closed. Having flown fighters, the dihedral effect would mitigate against exhaust flow closing the valves, as I said it would need much lower angle of attack at the back valve edge than the front (opened) valve which is in the airflow. Exhaust flow is linear, although turbulent. I see no way this could occur. And it certainly didn't when I test drove yesterday. But, in an abundance of caution, if you will--you can wire the valve to hold it open. Several ways to do it, from a paperclip on the right side to steel wire on the left. Simply hook the end of the "bar" in the housing that turns you want to remain closed to one of the bolt holes or tie off on the side of the housing. There is then no way it will close against that restraint.
AVM--plug the electrical connector into the module. Have someone rev the car until you see the shaft rotate to the full open position. Unplug immediately. You can then fit the module to the housing and the slot on the shaft will fit into the housing. As I said, you need to do it for each side--and a helper. Do it quick, as the valves close suddenly, it seems, and for reasons I don't comprehend.

Yes closed when I got home. I know that goes in the face of science but they were.

I'll try to wire them open, should be pretty easy.

Ideally I'll get someone to help me out getting the servo fully open and locked.

UPDATE: I have concluded that my right side valve is faulty and loose inside of its housing.

It's the source of the rattle and is freely spun by hand which explains why it may have shut itself.

I think I may have have had my left side valve closed for the entire first test run.

So I pulled the left side actuator and opened the valve and left the right side completely in tact.

Sounds nice. And I guess it's the compromise I'll be living with.

[///AVM]

OK, I have tinkered all day on this project and find its not happening for me. I do not want to wire it open and cannot get the housing shaft to fully open (to allow me to put is back on to an open diaphragm/valve).

Vette and LB I am very appreciative for all of your guidance and feedback but I think I am going to try and track down an aftermarket valve controller . . . or just live with it stock.

///AVM

[TrentMeister]

@///AVM

Look into replacing your resonators with a true x!

It sounds REALLY good.

Totally quiet in efficient and nice and throaty in s+

Cheap, easy to reverse, and really effective.

[///AVM]

Originally Posted by LBbluem2

@///AVM

Look into replacing your resonators with a true x!

It sounds REALLY good.

Totally quiet in efficient and nice and throaty in s+

Cheap, easy to reverse, and really effective.

Thank you LB

I have been a mod queen for a few years now and TRYING to keep it simple. . . . I would be happy if I could keep the valves open at this point.

I did hear your ride and it does sound good.

///AVM

[vetteflier]

That makes sense, LB. The valve shouldn't freewheel on the shaft, and if it is who knows what position it will end up in. Certainly would explain the rattle. AVM--they are available from AWE and CG Precision--VSC-2. But no way I was going to spend 2-300$ for one that could be duplicated mechanically for free. Very pleased with my freebie mod that vastly improved the one complaint I had with the M4C--exhaust note, and wanted to share it with the forum for those interested. Everyone can make their own decision, and leave it stock, do my mod, or get an electrical controller as they choose. At the end of the day, hopefully we're all happy with the choice.

[LuckyBrand]

Originally Posted by vetteflier

Exactly. I have the modules (housings) and the bolts I took off, with the shaft in full closed position. Just stuck them away in a plastic bag. I really don't think you'll hurt anything by slowly turning the shaft. I doubt it is locked in any way--needless expense to manufacture. If a future owner for some reason wanted it returned to stock, would take 10 minutes to put back on. Shaft would be in closed position, so I'd rotate the flaps back to full closed, Would index easily.

Originally Posted by LBbluem2

@///AVM

Look into replacing your resonators with a true x!

It sounds REALLY good.

Totally quiet in efficient and nice and throaty in s+

Cheap, easy to reverse, and really effective.

Originally Posted by ///AVM

Thank you LB

I have been a mod queen for a few years now and TRYING to keep it simple. . . . I would be happy if I could keep the valves open at this point.

I did hear your ride and it does sound good.

///AVM

So I read this thread this morning as I too have either unplugged or modified the flap to not close on previous cars. Here's what I've found.

I looked into the pipes prior to start and the valves are completely closed. I then put car into sport plus and started. Immediately I quick checked the valves with the car running (yes the fumes sucked lol) and the valves were only partially open so assuming the only way to get them to open fully would be to actually drive the car or wind it out parked which neither option work for me and to try an unplug an actuator while doing so.

Another thing I found that you could do and I was tempted but didn't is when you take off the servo where the the actuator connects. The actuator is on a spring in between a bracket. You could pry the spring actuator out and reinstall the servo and no one would ever know the difference but I didn't want to pry the bracket apart in case I damaged it. There is quite a bit of play but none the less I didn't.

On my other cars the set ups were different and easier and like many of you I just can't see an easy way without removing the servo completely like the OP did. This is what I ended up doing myself and I am gonna try it for a bit. I am gonna hopefully do an exhaust mod anyways so we'll see where this takes me.

Another thing I found as I was test driving after the mod is the active sound button and if there was much difference in volume now that the button doesn't control the flaps anymore. The sound inside the car changed some as expected with more fake sound being pumped in with the button active. The exhaust by itself with no active being pumped in did okay but here is the interesting thing I found with the active sound button as I'm assuming nobody would have thought this. Not only does the button control the flaps for quiet mode, fake sound generation, but it also makes the burbles louder on the outside! I know a lot of people have talked of Bimmer Coding the active sound out but I did a test standing outside the car and I'm telling you it made a huge difference in the burbles with the active sound button activated vs turning active sound off. That seemed odd that would be all tied together as if you code active sound out will it still give you the burbles now? I would love to hear someone that has done the code could chime in on this.

One more thing is that even with active sound off (I have a manual tranny) when I depress the clutch the sound gets louder almost like no matter button on or off the sound is pumped in slightly? This has been an interesting science project and there is a lot of stuff we will all be learning the next few months as more people start playing around.

[///AVM]

Originally Posted by LuckyBrand

So I read this thread this morning as I too have either unplugged or modified the flap to not close on previous cars. Here's what I've found. . .

LuckyBrand

Excellent post

My problem is that I did not want to leave the actuator off . . . just me and my preference. Yet, I could not get the actuator shaft to ever turn enough to match the fully open valve position. I tried everything, but the actuator just never seems to want to turn to fully open . . . which makes me wonder if the valves are ever fully open??

Regarding the spring action, I considered this, but a little differently than you outline . . . even if the actuator shaft is not lined up with the receptor (what I have been referencing as the 'diaphragm'), you can 'force' it over the receptor and secure it in place because receptor will depress due to its spring. Again, for whatever reason, just did not sit well with me doing that. . . or trying to remove the spring altogether.

vetteflier mentions ACG-VSC2 and AWE aftermarket options, however, neither website indicates anything for the G80/82 as of yet.

I really wish I could figure out how to get the actuator shaft fully open? That would solve everything. Again, I seriously doubt it every fully opens, which makes me wonder if we ever hear the exhaust with the valves fully open? I sat under my car (in P, obviously) in Sport+ with my wife giving full revs and the actuator shaft never turned to fully open.

vetteflier suggested trying to manually turn (force) the actuator shaft into fully open position with a flathead screwdriver. I tried and that thing will not budge.

///AVM

[vetteflier]

I assume you did the Active Sound test with the flaps fully opened, per my mod. I did note previously that for the first time I heard burbles on the over run after the mod. I leave active sound on, just as I did before the mod. Have no idea what it sounds like outside the car, though. My logic was always increasing exhaust free flow = better sound, inside or out. That it did. I wasn't aware that Active Sound had any control over flap position. Just pumped in nicer exhaust sound. Irrespective of that, happy with my results, and once it stops raining, will take it out for the second test drive.

[vetteflier]

Originally Posted by ///AVM

LuckyBrand

Excellent post

My problem is that I did not want to leave the actuator off . . . just me and my preference. Yet, I could not get the actuator shaft to ever turn enough to match the fully open valve position. I tried everything, but the actuator just never seems to want to turn to fully open . . . which makes me wonder if the valves are ever fully open??

Regarding the spring action, I considered this, but a little differently than you outline . . . even if the actuator shaft is not lined up with the receptor (what I have been referencing as the 'diaphragm'), you can 'force' it over the receptor and secure it in place because receptor will depress due to its spring. Again, for whatever reason, just did not sit well with me doing that. . . or trying to remove the spring altogether.

vetteflier mentions ACG-VSC2 and AWE aftermarket options, however, neither website indicates anything for the G80/82 as of yet.

I really wish I could figure out how to get the actuator shaft fully open? That would solve everything. Again, I seriously doubt it every fully opens, which makes me wonder if we ever hear the exhaust with the valves fully open? I sat under my car (in P, obviously) in Sport+ with my wife giving full revs and the actuator shaft never turned to fully open.

vetteflier suggested trying to manually turn (force) the actuator shaft into fully open position with a flathead screwdriver. I tried and that thing will not budge.

///AVM

Yeah, the two sites say nothing, and neither bothered to respond to my question about that. But the Youtube video I say that led me to this showed the module looking identical to mine in a 2 or 3 year old M2. I can't see any reason for BMW to reengineer such a cheap part with only one simple function, but who knows?
You may be on to something with the valve never fully opening, which is why you couldn't manually turn the shaft on the module. Before the mod, the best I saw was mostly opened a few seconds after the initial cold (super rich but valves closed) start kicked down, and then closed quickly. On my Vette, it was full open or full closed, with the default when you pulled the fuse full open. Easy and logical. German engineers tend to outthink themselves, imo, on simple stuff. But, as I said, point is moot to me now. And returning to full stock would take 10 minutes--not that I ever plan on doing so.

[///AVM]

vetteflier

Yes, my wife revved the hell out of the car in S+ engine mode. While the shaft did turn to open (and quickly turned back to closed), it never turned close to fully open position of the shaft receptor (valve). Hence, I have serious doubts the valves are ever fully open, and infrequently open to approach fully open. WHY???!!!!

I still have no idea how you managed to hold the valve open with a paperclip??

Perhaps you can provide a pic?

If I had the capability to 3D print I could probably make a lot of money by producing an insert that with a central shaft mold that went over the shaft receptor (matching the shape of the shaft) and secured into the opening around the shaft receptor.

///AVM

[FITM3NT]

One more thing is that even with active sound off (I have a manual tranny) when I depress the clutch the sound gets louder almost like no matter button on or off the sound is pumped in slightly? This has been an interesting science project and there is a lot of stuff we will all be learning the next few months as more people start playing around.

Don't remember where but there was video that stated the the values would open when depressing clutch pedal, perhaps trying depressing clutch then having someone pull the plug?

[vetteflier]

Once you turn the valve 'lever' to fully open, insert a bent paperclip into the lever pulling down to keep it at full open. A slight bend to the clip is all you need to insert it behind the lever. Turn it to hold the lever in position, and then pull it through one of the bolt holes as tightly as possible. Wrap it around and make sure the clip in the lever is tightened. An alternative is to use thin, doubled over steel wire. Make a "hook" and do the same as you would with the clip--pulled down firmly, tie off in bolt hole. It really is a belt and suspenders fix, as airflow will keep the flap open, but easy enough to eliminate any possibility, remote as they are.

[LuckyBrand]

Originally Posted by vetteflier

I assume you did the Active Sound test with the flaps fully opened, per my mod. I did note previously that for the first time I heard burbles on the over run after the mod. I leave active sound on, just as I did before the mod. Have no idea what it sounds like outside the car, though. My logic was always increasing exhaust free flow = better sound, inside or out. That it did. I wasn't aware that Active Sound had any control over flap position. Just pumped in nicer exhaust sound. Irrespective of that, happy with my results, and once it stops raining, will take it out for the second test drive.

Oh yes the flaps were fully open due to I removed the servos just like you did and yes I heard more burble sound then I have previously. You should have someone in the car while you stand outside and take a listen with active sound on and active sound off. It surprised me. As far as I am aware the button is there to close the flaps when needed so the outside exhaust is quieter just like the inside.

Originally Posted by FITM3NT

Don't remember where but there was video that stated the the values would open when depressing clutch pedal, perhaps trying depressing clutch then having someone pull the plug?

The plug is already pulled and servos are off along with active sound off and it still made a different sound when depressing clutch pedal.

[LuckyBrand]

Just a quick update. I went out for a spirited run with a passenger and we could both tell a difference now with the flaps fully open and active sound on. Burbles are definitely there although nothing earth shattering and exhaust is better overall for the grand total of zero dollars.

[acre22f90]

Any chance we could get some images to support this method? My head is spinning a bit after reading all these parts.

Much appreciated!

[///AVM]

Originally Posted by ACremona22

Any chance we could get some images to support this method? My head is spinning a bit after reading all these parts.

Much appreciated!

1. Confirmed exhaust valves closed (pic 1)
2. Disconnected actuator plug (pic 2)
3. Removed actuator by removing three 10 mm bolts (pic 2)
4. Manually turned valve lever into fully opened position (pic 3)
5. Confirmed exhaust valves fully open (pic 4)
6. Secured valve lever in place with led-based soldering wire* (pic 5)
7. Placed electric tape over male end of actuator plug and secured to chassis with zip tie (pic 6)

*I used led-based soldering wire because it is very pliable and easy to manipulate.

///AVM

[acre22f90]

Thank you!

Sorry If I am being dense but two questions.

Do you reattach the actuator after completing the turn and getting it stuck into place?

Is it obvious how you are to wedge the wire to keep it from moving back? I am sure I will learn more once I get under my car. It arrives Monday, so nothing to toy with.

[vetteflier]

Great pictorial instructions, AVM! Solder wire an excellent idea, as well. Cleaner looking than my bent paperclip. But as nobody is apt to be looking under the car...lol! AC--read AVM's post about how the actuator--what I call the module, can't be turned all the way open to reattach. Besides: why bother? Just hang on to them if you ever want to return to stock. As to "wedging" the wire--it will be obvious to you once you see it. There will be no force from the exhaust that would push the valve anyway but full open, so doesn't have to be super tight. Only an "abundance of caution" add on.

[acre22f90]

Originally Posted by vetteflier

Great pictorial instructions, AVM! Solder wire an excellent idea, as well. Cleaner looking than my bent paperclip. But as nobody is apt to be looking under the car...lol! AC--read AVM's post about how the actuator--what I call the module, can't be turned all the way open to reattach. Besides: why bother? Just hang on to them if you ever want to return to stock. As to "wedging" the wire--it will be obvious to you once you see it. There will be no force from the exhaust that would push the valve anyway but full open, so doesn't have to be super tight. Only an "abundance of caution" add on.

Makes sense! I was just double checking that you didn't in fact have to reattach the module.

As for the wedging, I am sure it will be straight forward once I take a closer look in person.

Thanks for guinea pigging this everyone!

[LuckyBrand]

Originally Posted by ///AVM

1. Confirmed exhaust valves closed (pic 1)
2. Disconnected actuator plug (pic 2)
3. Removed actuator by removing three 10 mm bolts (pic 2)
4. Manually turned valve lever into fully opened position (pic 3)
5. Confirmed exhaust valves fully open (pic 4)
6. Secured valve lever in place with led-based soldering wire* (pic 5)
7. Placed electric tape over male end of actuator plug and secured to chassis with zip tie (pic 6)

*I used led-based soldering wire because it is very pliable and easy to manipulate.

///AVM

Originally Posted by vetteflier

Great pictorial instructions, AVM! Solder wire an excellent idea, as well. Cleaner looking than my bent paperclip. But as nobody is apt to be looking under the car...lol! AC--read AVM's post about how the actuator--what I call the module, can't be turned all the way open to reattach. Besides: why bother? Just hang on to them if you ever want to return to stock. As to "wedging" the wire--it will be obvious to you once you see it. There will be no force from the exhaust that would push the valve anyway but full open, so doesn't have to be super tight. Only an "abundance of caution" add on.

Hey guys I like the way the car sounds with the flaps open. Should sound like this all the time but it is what it is.

Anyways, I have my 1200 mile service next week and thinking I should put the everything back to stock as they will be back by the diff and all and don't want to attract any unwanted attention. What do you guys think?

[vetteflier]

Any adjustment to exhaust behind the cats are legal in virtually every state, including MI, and have no bearing on the car's warranty. Moss Magnuson Act. My 1200 is next week, too. As I said, only reason is noise reduction, which is stupid as at its best, the exhaust is too quiet. That's why Corvette made it so easy to leave the flaps fully open on the NPP--just pull a fuse. 'Too' easy for German Engineering, obviously...don't worry about it.