Now I have the oil cooler, even without the engine here I can make a diffuser to bring air to the face. Well at least the end of the duct where it will go from 3″ Diameter SCEET hose to the radiator face.

The Oil Cooler is from Airflow Systems 2008X Its a large 17 row cooler for 280HP+ It will be fitted just behind the sump but before the belt alternator at the lower center rear of the cowl. This position is a part of my cooling plan that frees up space at the sides for water radiators. I will split off air from the right armpit via a 3″ SKEET duct. The air must then be slowed and expanded to evenly meet the radiator face.

So what you want is a Kuchemann & Weber (KW) trumpet shaped diffuser. The name comes from a couple of scientists, Kuchemann & Weber, who performed a lot of R & D on this subject during World War II and published their findings in Aerodynamics of Propulsion sometime in 1953. These diffusers are highly utilized in aviation as well as in automotive racing.

All I had to do was stick some foam blocks together and get out a file and make the shape.

This took a while…

After I thought I had it I kept refining. I even filled in a few gaps that then made it harder to carve. Next time I’ll leave that until right at the end.

Once I was happy I covered the carved foam in duct tape. No pun intended..

It was an odd shape to cover in carbon fiber. I used four pieces with two each side making it all the way around. I laid it up for the ‘second ply’ at 180 degrees so I probably have a good three ply everywhere.

I overlapped the edges too with the idea it will make a good seal.

I used acetone to melt away the foam plug. After all, I only need one of these this particular size. Even with the duct tape on the form it gave a pretty smooth inside. I will run some sandpaper over it before use.

This diffuser is surprisingly light and very stiff and pretty much the right shape. 3″ hose fits perfectly in the top. It just might see some service,