Exhaust H pipe connection needed? Locations?

[Chuckcruzin1986]

Hello,

My 87 325is has tubular headers and no catalytic converter. I get a humming/howling sound at around 3000 rpm and don't like it.

Will adding a "H" pipe between the 2 main pipes coming off my headers make the [COLOR=blue !important][COLOR=blue !important]car[/color][/color] quieter? If so, what size and does the location make a difference? I heard that there is some kind of harmonics that has to be considered when deciding where to put the pipe.

I am also considering wrapping the headers if this will help cut down the noise.

Any help would be appriciated.

Chuck

[nando]

Use an X or Y pipe rather than an H. it's for exhaust scavenging, not sound. It should go near the same location of the stock x-pipe which is just a few inches behind the control arm bracket. Add a resonator after the X or Y to maximize the scavenging efficiency and help your sound issue.

header wrap is also meant for scavenging and heat reduction, not noise. It does work for both of those purposes but it's not a great thing to use on a street car. Moisture trapped under the wrap can cause the headers to crack or rust. it also tends to deteriorate when exposed to weather.

[Chuckcruzin1986]

Thanks for your ideas. Chuck

Good thoughts.