[demas]

I've known about the golf tee mod for years but never did it on any of my BMWs.

Figured since the E82 is a weekend/project ride, why not try it out. In the past, with Bimmerlink, I've opened and closed the exhaust flaps on demand in my driveway and yes there is a small difference.

Here is the sequence of events on my cold starts with no mod:

1. Before starting the car, the exhaust flap located in the left-most pipe is 'open' as in the picture below. This means that this is the default position when the car is off. (I had always thought it was left closed, but I guess not).
2. Immediately after firing it up, the flap closes which you can hear as a 'clink'
3. Car runs for about 1 min 20 seconds, then RPMs settle down to about 780.
4. Immediately after settling down, exhaust flap opens up - again confirmed by the clink sound and visual inspection.
5. After this, the flap stays open. Whether it closes again at some point while driving I don't know.


Post golf tee mod, start up sequence stayed as above minus step 2 and 4 since the valve hose was disconnected and flap remained open.


I was pretty much underwhelmed as the sound was actually better to me in the closed position.

I really like the sound of the stock cold start and have likely gotten used to it. With the flap open, I'd describe the sound like shifting the main signature from 1Khz left to 400Hz ie, changing a little of that throaty mid range, to a lower mid-bass sound. To me, it lost a little character and wasn't significant enough so ended up reverting back to stock.


At any rate, glad to have tried this anyway.


Ok, on to the next thing...