Turbo Discharge Question

[Maliboost]

on my turbo the flange for the exh on the turbine is 5", but down in it where the wheel is, there a flange that the wheel sits in. its about 3.5" down inside where the 5" flange is. My question is why is there such a large volume there?

If the output of the turbine is 4" why not take it out to a 4" flange?

Here is a picture of what I am talking about.

thanks
Bob


http://www.gofastzone.com/modules/gallery/albums/album02/Mod_Turbine_Exh_picture.jpg

[Six_Shooter]

To make sure there is a transition from radial flow to axial flow. A sudden change in diameter will promote this.

Also the larger the tube is after the turbine, the quicker the turbo will spool.

[Maliboost]

So If I run a 6" exh that will help it spool, faster than a 5 or 4"?

Bob

[gilsbachracecraft]

burns stainless offers transitions we use to reduce the exhaust side of the gt 47s to 4" http://www.burnsstainless.com/Transitions/transitions.html

[Maliboost]

thanks again Bill, thats where I ended up getting it, I was just wondering why its got such an open space there in the output of it. I was kinda hoping that the PT&E folks would have some insight as to the technical reasoning behind it. I guess that six-Shooter, must have knocked it out of the park, or they would have commented.

thanks again, I appreciate all the help you pro's, give us homegrown guys.

Bob