Quieter Dump Tubes

If you are opting for a turbo with an external wastegate and dumping the wastegate to the atmosphere consider a custom setup where the wastegate is mounted close to the end of the dump tube for quieter performance!

The wastegate "valve" is not often wide open when controlling boost. The amount it opens is dependent upon the rpms, load, turbo size, and a number of other things. In mid-load max boost conditions the wastegate may be open only a little. If a pipe is placed after the wastegate the pipe will act to amplify the sound coming from the small wastegate opening. If you place the wastegate close to the end of the dump tube, the "amplification" is reduced a very noticeable amount. Even when the wastegate is wide open it seems to be quieter.

I discovered this after installing such a rig on a '97 Spyder. The open wastegate is not offensive in the least! That particular car has a FP Green and makes 321 hp at the wheels at 17 psi on pump gas! It had a small Tial WG on the end of a 1 foot dump tube from an AHP O2 housing.

Rick
763 263 2713

[SlowWhite]

got Picts?

[Kracka]

Would placing the wastegate and the end of the dump-tube cause any side effects such as slowing boost? I wonder this beause it gives that much more area for the exhaust gases to fill before it will fully spool the turbo.

[Super Bleeder!!]

not that much more fill area. if its a 1.5" pipe and a foot long thats only *number crunch* 21.195 cm^3, which i would say is a negligable amount of volume to fill

[Goat Blower]

I would think spool would be affected, but only slightly. I'll keep my quiet setup, works well.