[jpimienta123]

Question for anyone who has created a diy flap controller, my control works fine when I turn the car on no problems with opening and closing the flap but while driving I can hear the vacuum activating.

Had the flap closed before driving and then I parked and went outside to see if I could hear the flap open when I pressed the open button, but the flap was already open and my control was not working. After turning my car off and on it was working again. I have my relay set to be closed on startup.

[iqraceworks]

What car do you have??

[jpimienta123]

Originally Posted by iqraceworks

What car do you have??

2012 e93 335i

[iqraceworks]

Originally Posted by jpimienta123

2012 e93 335i

It's got a button to open and close the exhaust flap?

[jpimienta123]

Originally Posted by iqraceworks

It's got a button to open and close the exhaust flap?

No, im talking about the diy controller that I made

[clegg]

Sounds like you have a vacuum leak. Pretty hard to diagnose on something homemade.

[jpimienta123]

Originally Posted by clegg

Sounds like you have a vacuum leak. Pretty hard to diagnose on something homemade.

Pretty sure the exhaust flap is set by default to open at a certain rpm and the control works fine at at start up until I start driving, if there was a vaccum leak wouldn't the exhaust flap not work at all?

[kens]

on my 09 the flap is closed on cold start, when it warms up the flap is open at idle. It only engages (closes) around 1.5-2k rpm when you start driving. It then opens again around 4k+ rpm.

It's not permanently closed or open when controlled by your car.

That's why when you stopped and tried to open it, it was already open. Normal operation for it

[iqraceworks]

Why not just plug the hose and leave the flap open all the time....problem solved.

[jpimienta123]

Originally Posted by iqraceworks

Why not just plug the hose and leave the flap open all the time....problem solved.

Golf tee mod doesn't solve my problem, also refer to my op that says this is a question for people who have done the same thing I have. I appreciate tbe input but its clear you don't know what im talking about.

[jpimienta123]

Originally Posted by kens

on my 09 the flap is closed on cold start, when it warms up the flap is open at idle. It only engages (closes) around 1.5-2k rpm when you start driving. It then opens again around 4k+ rpm.

It's not permanently closed or open when controlled by your car.

That's why when you stopped and tried to open it, it was already open. Normal operation for it

What I have now is a valvetronic type controller but I made it myself. Its supposed to stay open when I open it and closed when I close it. I plan to get a drivers side muffler delete to basically duplicate a valvetronic exhaust but at a fraction of the price. I have full control over my flap with a wireless remote but its not working properly while I drive thats why im looking for someone who possibly knows why its not working properly.

[stewbets]

I did exactly what you're describing on my E60. I gutted one of the mufflers and wired a switch to the flap. It works perfectly. If I were to guess why yours isn't working properly, I would say you tapped the wrong wire for the solenoid, or you didn't run the switch to a constant +12V source. I can't remember exactly what I had to do, but 1 of the 2 wires going to that solenoid gets switched on and off by the car's normal operation. So you've got to cut that wire and run it to a constant +12V source, with your switch in between to control it. I used a 12V accessory socket in my trunk. Does this make sense? Forgive me if this is exactly what you've already done. I just can't imagine anything else causing your issue.

[stewbets]

Here's a little clip of mine in action:

I need to make this happen on my 335xi now.

[jpimienta123]

Originally Posted by stewbets

I did exactly what you're describing on my E60. I gutted one of the mufflers and wired a switch to the flap. It works perfectly. If I were to guess why yours isn't working properly, I would say you tapped the wrong wire for the solenoid, or you didn't run the switch to a constant +12V source. I can't remember exactly what I had to do, but 1 of the 2 wires going to that solenoid gets switched on and off by the car's normal operation. So you've got to cut that wire and run it to a constant +12V source, with your switch in between to control it. I used a 12V accessory socket in my trunk. Does this make sense? Forgive me if this is exactly what you've already done. I just can't imagine anything else causing your issue.

For your controller, did you tap the wiring harness directly or create the removable attachment that you just plug into the original connectors?

[stewbets]

Directly. I had no plans of going back.

[type-dRew]

The stock valve defaults open when you shut the car off, only vacuum will close it.

So when you start the car, it will be open and if you have a controller for it, youll have to close it if you want it shut.

Very annoying. Ill be swapping to a default closed valve eventually on mine so itll be shut for cold starts and I can open it when I want only.

[jpimienta123]

Originally Posted by stewbets

Directly. I had no plans of going back.

Isn't yours and the detachable harness version basically the same wiring? Just without extra connectors? Would you mind sending over pictures when you have the chance?

[stewbets]

I'll try to get you some pics tomorrow.

[stewbets]

Sorry I took an extra day. I just wired up mine and it's backwards from what I thought. The red wire to the solenoid gets +12V constant and the white one is switched on and off with -12V. So, to get complete control you've got to cut the white wire and run it to your own switch that's connected to ground. I think the key here is to make sure that white wire is severed from its factory connection.

I did just noticed you mentioned using a relay in your original post. Depending on how it's set up, that could also be your issue. I didn't use a relay since the solenoid isn't really pulling much current anyway.

[stewbets]

Here are some pics of my gutted driver's side muffler. Check out those awesome welds!

[nsjames]

bird shit still holds.


what did you weld it with?

i'm 50/50 on buying a stock muffler on ebay and cutting it up.
is it mild steel that the shell is made of?

[stewbets]

I used my Harbor Freight flux core welder. The shell isn't magnetic, so I'm assuming it's stainless? I used the same cheap flux core wire I use for all other steel work (that makes it sound like I actually weld regularly, which it's quite apparent that I don't). In the absence of a decent bi-metal saw blade, I used a cut off wheel for all the gutting. Wouldn't recommend it as it was so much more work.