How to make it louder

[E92friendly]

Hey all not new to bummers but new to the x5 it appears someone rigged the exhaust valve to stay open however it's still quiet as heck. On initial startup it's loud and sounds amazing I'd like to keep it that way. Is there a trick to this that can be shared? I tried google can't find any good info. Maybe it's my research method, unsure.

2013 x5 35i stock exhaust.

[jersey john]

If you search for "golf tee mod", you should be able to find it.

Here's a link to one sight: DYI Golf Tee Mod

[ryansbmw]

He essentially has the golf tee mod already.

On the older cars, the exhaust flap was naturally open but vacuum held it closed. You could disconnect the line, stick a golf tee in the end and the valve would be open all the time.

On our cars, its reversed. Plugging the line will only keep the exhaust flap closes so you need to zip tie it open.

OP- if you want loud, cut the muffler off and replace it with a sportier one (M Performance or Vibrant) or some resonators.

[E92friendly]

Originally Posted by ryansbmw

He essentially has the golf tee mod already.

On the older cars, the exhaust flap was naturally open but vacuum held it closed. You could disconnect the line, stick a golf tee in the end and the valve would be open all the time.

On our cars, its reversed. Plugging the line will only keep the exhaust flap closes so you need to zip tie it open.

OP- if you want loud, cut the muffler off and replace it with a sportier one (M Performance or Vibrant) or some resonators.

Yeah someone used a steel zip tie already to hold it open. It's super loud on cold start then suddenly quiets down a lot. Is that because of some exhaust port opening to heat up the catalytic converter? I know on my M3 there were two ports tha would open up to heat the converters then close after about a minute and make a huge difference on idle exhaust note. Ha. Wish I could have found a way to keep the ports open!

[ryansbmw]

Originally Posted by E92friendly

Yeah someone used a steel zip tie already to hold it open. It's super loud on cold start then suddenly quiets down a lot. Is that because of some exhaust port opening to heat up the catalytic converter? I know on my M3 there were two ports tha would open up to heat the converters then close after about a minute and make a huge difference on idle exhaust note. Ha. Wish I could have found a way to keep the ports open!

On the cold starts, the engine is running higher to warm up the cats quicker. After ~30 sec or so, it falls back to its normal running cycle.