Hey guys,
Some of my friends have been messing around with there exhaust on the BMW's at the muffler shop and they happened to make there exhaust burble or bog when they let of the throttle. I have Magnaflow mufflers welded in so the sound is already pretty nice but I'm just wondering if theres anything I can do to achieve this bog sound when I let off.

Thanks

 

do u have a example, maybe a youtube video?

 

here is an example I found, I don't expect something as dramatic but I do want some of that exhaust pop.

http://www.youtube.com/watch?v=pqP9t6_P7UY

 

Basically if you want that exhaust popping noise, you need bigger exhaust piping. Youll be making more noise, and youll lose some low end power.. But itll make the noise you want.

 

hmm I dont know if I want to sacrifice power for noise, but its something I'll keep in mind. What size piping would I need?

 

I don't really think you want to do this, as ufo said you need some backpressure for torque development. If this was a turbo car then it would be pretty easy to get the rasp, but it's not.

So let's say you want to do this anyway but not spend much, you could try go in through the tailpipe with a long spade bit, maybe 1", and perhaps try to bore out some of the flow chamber. A schematic of the inner structure of your existing muffler would be helpful, then you could see if you could reach perhaps the main deflector with a long bit and a drill.

Or hack your good stuff off, slap a couple of Thrush cherry bombs on there, hate the noise 99% of the time but get lots of pops and cracks.

 

Well this doesn't sound very appealing anymore. My friend was complaining that he could feel some low end power gone, so I think Ill just live without the popping.

 

In days of old, we would use a gadget called a "Laker Cut-Out" for the effect (and more) you are seeking.

They still make 'em: http://www.jcwhitney.com/cast-iron-e.../p2006307.jcwx

Might be a fun mod to install, make a Jag sound like a friggin' tractor!

 

Thankfully for the good ole' days, emissions inspections were not required. As JaggyX appears to be Cali, I don't think they would fly unless he can figure out a way to get his X titled as a classic or a kit car or some other loophole.

Interesting that many high end manufacturers are using a simlilar technology to the Lakers these days, I believe the new Ferrari Italia has a two stage exhaust where it can be programmed/commanded to open another exhaust outlet for additional flow, and yes, noise! Not quite a Laker, but similar.

 

LOL. Get an old ignition coil, wire it thru a toggle switch, drill a hole in the exhaust pipe under the car and thread in a spark plug. Run a lead from the coil to the plug......when you hit the switch, any unburned gases ignite making one hellof a pow! Prob more burble than you want.......and really tough on mufflers.