what is a down pipe?

what exactly is a downpipe, and does it give your factory exhaust a more aggressive sound? My recent car that i had prior to my 09 335xi was a infiniti g35 coupe, the factory exhaust on my g35 coupe sounded "sexy" and had a more aggressive sound than my 335xi. Help! lol

Originally Posted by loso81

what exactly is a downpipe, and does it give your factory exhaust a more aggressive sound? My recent car that i had prior to my 09 335xi was a infiniti g35 coupe, the factory exhaust on my g35 coupe sounded "sexy" and had a more aggressive sound than my 335xi. Help! lol

Get the BMW performance exhaust for a finer acoustic quality.

downpipe

Originally Posted by loso81

what exactly is a downpipe, and does it give your factory exhaust a more aggressive sound? My recent car that i had prior to my 09 335xi was a infiniti g35 coupe, the factory exhaust on my g35 coupe sounded "sexy" and had a more aggressive sound than my 335xi. Help! lol

The pipe that goes down from the cyl head to the exhaust pipe running aft.

Sound? Wikipedia "muffler"

Add'l info for 335i - click Post #2 links.

Beware. Changing back pressure on an engineered-to-the-edge ride like yer 335i is fraught with performance issues. You're safe with BMW performance exhaust, which comes with a factory software adj and $1100+ wallet lightener.

Much tech info at N54TECH and E90POST.


.

Dare I post this? http://www.e90post.com/forums/showthread.php?t=80661

it's easily reversible if you have any negative side effects, though may store fault codes in the ECU.

are there any other exhausts out there that will give my car a more aggressive sound than than the bmw performance exhaust, they are rather pricey

Originally Posted by loso81

are there any other exhausts out there that will give my car a more aggressive sound than than the bmw performance exhaust, they are rather pricey

Plenty. Just depends on how much drone you can stand.

I believe your exhaust has resonators which can be removed and increase the sound. May be the cheapest option for you if sound is all you are looking for.

in your opinion which is a an exhaust thats good but not too costly that gives a nice "growl". also sometimes when i rev my car, i hear a "rattle" sound at times, could that be something with the exhaust?

Originally Posted by E90Dad

Dare I post this? http://www.e90post.com/forums/showthread.php?t=80661

it's easily reversible if you have any negative side effects, though may store fault codes in the ECU.

Back pressure reduction reduces torque below, what, 3k rpm. Increases sound, true. Easiest exhaust mod by far. Leaves flap that routes all exhaust to the right pipe open so it flows through both pipes.

Just crimp the line at the driver side actuator with wire tie. Easier, and much easier to reverse.

Naturally, you do this at your own risk. I didn't like the effect and sound was iffy enough that I went back to stock.

Originally Posted by loso81

in your opinion which is a an exhaust thats good but not too costly that gives a nice "growl". also sometimes when i rev my car, i hear a "rattle" sound at times, could that be something with the exhaust?

No clue. I can't stand drone so if I went with another exhaust, I would get the BMW Performance Exhaust. You can buy them on ebay all day for $1099.

The rattle is a gate that is closed while the car is warming up and you are hearing it open/close. Very normal. As indicated above you can disable it in a couple of ways, if it bothers you.