Has anybody out there fabricated a weber dcoe plenum/hat for a blow through setup?I was wondering what dimensions they used or what the dimensions are for the plenum they are currently using. I'm going to try my luck out with welding my own carb hat out of aluminum for my 48 dco.

 

Can't really help with exact dimensions, but Robert at Rotary Shack makes them and you can find cast aluminum ones made for the VW Webers. That might give you a reference point to start with. The ones I've seen appear to be about the same size as the air filter setups and you need to have room for the velocity stacks.

 

Why do you have to include the velocity stacks in the plenum? I didnt think it would make a difference becouse the carb will have equal pressure when boosting. right?

 

Stacks will still smooth out air going into the carb. You might check out how Maserati did it on the BiTurbos up until about '86 or '87. They have a nice cast aluminum box for the whole carb(and yes it was a Weber on those cars)

 

Why use the stacks, well it all comes down to the principles of fluid dynamics, and yes, gases behave like fluids and it would be a very long lesson to explain. Simply put, using the stacks causes the velocity of the intake charge to increase.

 

Thanks for all the advice. I will use the velocity stacks. Would be nice to have some pics &/or dimensions though.