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Discussion Starter #1
Just had a used akrapovic exhaust fitted, but on one side of the back box the valve rod is vibrating on cold starts.

Can I somehow keep the valve open all the time, if so how and does this cause a problem?


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Just had a used akrapovic exhaust fitted, but on one side of the back box the valve rod is vibrating on cold starts.

Can I somehow keep the valve open all the time, if so how and does this cause a problem?


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I used fencing wire with no adverse effects. Google round a bit, you'll find the posts on how to do it.
 

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So is it no longer staying open all the time anyway, as you say in your other post?
I'm confused too? As also mentioned in the other post, zip ties work a treat. They can be made tighter than wire, don't wear or rust through, and are easily fitted in 5 minutes.
 

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Discussion Starter #5
I'm confused too? As also mentioned in the other post, zip ties work a treat. They can be made tighter than wire, don't wear or rust through, and are easily fitted in 5 minutes.


We're all confused !

No its started to behave now, so when it starts up the valves are closed, and now one side rattles.

So I either buy a new left side muffler for £1500 of try and force the valve open and make it tight so it can't rattle.


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That's not the best way to do it, as the vacuum is positive most of the time. IN other words you'd have to seal them well enough to maintain a vacuum in the valve, and hope it never leaked at all. Any air ingression to the valve would allow it to slowly close again.

Trust me. Zip ties ;)
 

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its very simple and if people would use their noodle the solenoid for the valves is located in the left rear panel of the trunk unplug the vacuum hoses from the solenoid and connect them together evey time the car starts valves will open very simple and take all of 3 min to do
 

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I have the Exhaust Meister piece of kit.

Excellent really, especially with full remote fob operation.

Perfect for when you want the valves closed for any reason, for example when cruising on the motorway at sub 2000 rpm, where with the valves permanently open it creates quite a bit of drone and not really very pleasant, so a simple press on the remote and the setup reverts to the stock BMW operation (closed valves on light throttle openings / low rpms).
 

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I have the Exhaust Meister piece of kit.

Excellent really, especially with full remote fob operation.

Perfect for when you want the valves closed for any reason, for example when cruising on the motorway at sub 2000 rpm, where with the valves permanently open it creates quite a bit of drone and not really very pleasant, so a simple press on the remote and the setup reverts to the stock BMW operation (closed valves on light throttle openings / low rpms).
Hey Kumaran! Welcome back to the right side of the globe ;) A friend in Sweden has this same gadget on his M5 (with stock pipes), and has noticed that some wifi comms can interfere with it, or vice versa. His GoPro seemed to make it open and close randomly, and also the radio on the track was intermittently failing, when no one else's was. He swapped radios with all other cars in the end and it the only constant was his car, and this gadget. Both use the 2.4GHz band, so I presume this does too? I've had a long discussion with the guys at GoPro engineering, and the M5/M6 seems to have quite a lot of approx 2.4GHz radio comms, or at least, interference, generated inside the car, so adding another could be interesting. Have you had any funnies? It's a neat gadget though!

As for the droning noise, only the stock system seems to suffer this in my experience. The Akrapovic just sounds nice all the time, but as I've mentioned a few times - I wish it was louder!

Are you coming tomorrow? :)
 

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Yo Barney ! Yep back in town finally !

So I have had no problems with my Exhaust Meister at all. But of course the M6 and M6 GC run military grade electronics / radio technology unlike the M5s :)

I think I used the wrong wording in terms of "droning" and should rather be humming, but noticeably when looking out for it.

Its only really perceptible when you open and close the valves when pootling around on the motorway at less than 2000 rpm. With valves open you can hear something and when valves closed you can't, its silent. I find the silence is slightly nicer when you are driving in this mode for any length of time. If I had them permanently tied open like you, I probably would not even mention or complain about it at all, but when I have the ability to open and close them at will, I can notice it for sure and see why BMW have adopted valving tech in these cars.

BMW incorporated the Valving for NVH reasons I am sure. Also when they offered the MPE / Akrapovic they did not delete the valving hardware tech on these exhausts if it were deemed ideal for a straight through (valves open all of the time) setup.
 
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