M5/M6 exhaust flap mod
Discussion
My question is about the free exhaust flap mod that can be done on the M5/M6, by forcing the 2 exhaust flaps open (1 either side) in the exhaust back box. There are plenty of video's and posts about how to do this, but my questions is about why they are there in the first place.
Also, what effect if any it has on the car by having then permanently open.
Please excuse the bad picture as it is quite a hard area to get a good photo of without having the car jacked up.
My understanding is this valve is opened by a vacuum at around 3500rpm for increased exhaust flow/noise, so by fixing these open you just get a bit more noise at low revs.
It does work, but not sure of the effect on the car and why BMW would have them fitted....
Also, what effect if any it has on the car by having then permanently open.
Please excuse the bad picture as it is quite a hard area to get a good photo of without having the car jacked up.
My understanding is this valve is opened by a vacuum at around 3500rpm for increased exhaust flow/noise, so by fixing these open you just get a bit more noise at low revs.
It does work, but not sure of the effect on the car and why BMW would have them fitted....
I liked the idea of having the ability to open and close them at will and on the go, so I went for an Exhaust Meister gadget.
Very easy to install.
I have a remote fob in the car and open and close them at will with a touch of a button.
Essentially when cruising in a high gear on a motorway it does drone when open, so I can simply close them, and it makes a difference. Its quite a subtle difference and people who have them permanently wired open probably don't realise but it does make a difference.
BMW designed them to open and close for a reason and I think its very much NVH based.
Very easy to install.
I have a remote fob in the car and open and close them at will with a touch of a button.
Essentially when cruising in a high gear on a motorway it does drone when open, so I can simply close them, and it makes a difference. Its quite a subtle difference and people who have them permanently wired open probably don't realise but it does make a difference.
BMW designed them to open and close for a reason and I think its very much NVH based.
M5 London said:
I liked the idea of having the ability to open and close them at will and on the go, so I went for an Exhaust Meister gadget.
Very easy to install.
I have a remote fob in the car and open and close them at will with a touch of a button.
Essentially when cruising in a high gear on a motorway it does drone when open, so I can simply close them, and it makes a difference. Its quite a subtle difference and people who have them permanently wired open probably don't realise but it does make a difference.
BMW designed them to open and close for a reason and I think its very much NVH based.
Thanks, is there any visible wiring and where does all the kit sit? is it in the boot by the valve control?Very easy to install.
I have a remote fob in the car and open and close them at will with a touch of a button.
Essentially when cruising in a high gear on a motorway it does drone when open, so I can simply close them, and it makes a difference. Its quite a subtle difference and people who have them permanently wired open probably don't realise but it does make a difference.
BMW designed them to open and close for a reason and I think its very much NVH based.
R33FAL said:
Thanks, is there any visible wiring and where does all the kit sit? is it in the boot by the valve control?
No visible wiring at all.The unit / wiring loom sits behind trim in the left hand side of your boot, where the original control unit for the valve is. This unit simply plugs into the existing loom. No cutting etc etc
I have an M6 Gran Coupe, but location is the same on an F10 M5.
Then I have discretely velcro'd the remote fob in the interior.
http://exhaustmeister.com/
The flaps keep the noise down at low revs.
I have done the mod on my M5 and on a cold start it is louder than before. I always thought that a cold start meant the flaps were open anyway so should have made no difference but from the change in sound I was wrong.
Cruising around at lower revs is where you notice the change in noise, and it does now sound good. I wouldn't call it anti-social levels of noise and still not as loud as an RS6 for instance, but just enough to feel like it's actually got something meaningful under the bonnet.
I have done the mod on my M5 and on a cold start it is louder than before. I always thought that a cold start meant the flaps were open anyway so should have made no difference but from the change in sound I was wrong.
Cruising around at lower revs is where you notice the change in noise, and it does now sound good. I wouldn't call it anti-social levels of noise and still not as loud as an RS6 for instance, but just enough to feel like it's actually got something meaningful under the bonnet.
beanoir said:
The flaps keep the noise down at low revs.
I have done the mod on my M5 and on a cold start it is louder than before. I always thought that a cold start meant the flaps were open anyway so should have made no difference but from the change in sound I was wrong.
Cruising around at lower revs is where you notice the change in noise, and it does now sound good. I wouldn't call it anti-social levels of noise and still not as loud as an RS6 for instance, but just enough to feel like it's actually got something meaningful under the bonnet.
What did you use to keep the valves open? I have tried using metal cable ties but damn thing keeps coming off on one side every other day....I have done the mod on my M5 and on a cold start it is louder than before. I always thought that a cold start meant the flaps were open anyway so should have made no difference but from the change in sound I was wrong.
Cruising around at lower revs is where you notice the change in noise, and it does now sound good. I wouldn't call it anti-social levels of noise and still not as loud as an RS6 for instance, but just enough to feel like it's actually got something meaningful under the bonnet.
cogsy80 said:
I did notice the drone at motorway speeds the other day, but there definitely is a better sound at idle/low revs..
That exhaustMeister might be the ay ahead, to open and close as required
It works well !That exhaustMeister might be the ay ahead, to open and close as required
Also when in the off position it simply reverts to the BMW stock setup (so valves open and close as per factory specs).
When switched on via remote, the valves are permanently open, until you switch off via remote or switch the car off and when you start the car up again its back to factory spec...
I think I am over explaining this....
M5 London said:
It works well !
Also when in the off position it simply reverts to the BMW stock setup (so valves open and close as per factory specs).
When switched on via remote, the valves are permanently open, until you switch off via remote or switch the car off and when you start the car up again its back to factory spec...
I think I am over explaining this....
Where did you buy it, all the eBay links are coming from America?Also when in the off position it simply reverts to the BMW stock setup (so valves open and close as per factory specs).
When switched on via remote, the valves are permanently open, until you switch off via remote or switch the car off and when you start the car up again its back to factory spec...
I think I am over explaining this....
cogsy80 said:
Where did you buy it, all the eBay links are coming from America?
I think I bought it directly from Exhaust Meister's ebay shop. Link found on their site (NON USA purchase)http://www.ebay.com/itm/232280861772?ssPageName=ST...
R33FAL said:
What did you use to keep the valves open? I have tried using metal cable ties but damn thing keeps coming off on one side every other day....
I used aluminium wire, its been on for about 8 months now without any issue. The wire allows you to pass it through the hole in the mounting bracket of the valve, that might be where you're having problems if you're not securing it in that way? M5 London said:
I liked the idea of having the ability to open and close them at will and on the go, so I went for an Exhaust Meister gadget.
Very easy to install.
I have a remote fob in the car and open and close them at will with a touch of a button.
Essentially when cruising in a high gear on a motorway it does drone when open, so I can simply close them, and it makes a difference. Its quite a subtle difference and people who have them permanently wired open probably don't realise but it does make a difference.
BMW designed them to open and close for a reason and I think its very much NVH based.
Did you install the Exhaust Meister yourself? Mine has arrived today, just wondering if you can give me some pointers on location, before I take the whole boot apart?Very easy to install.
I have a remote fob in the car and open and close them at will with a touch of a button.
Essentially when cruising in a high gear on a motorway it does drone when open, so I can simply close them, and it makes a difference. Its quite a subtle difference and people who have them permanently wired open probably don't realise but it does make a difference.
BMW designed them to open and close for a reason and I think its very much NVH based.
Thanks
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