Ram air system

My original plan was to put a bellmouth in the headlight opening and ram air straight into the engine. However, the tires are too close to the opening and the top of the fender so there was no room for the pipe. Instead, I used the gap above the radiator and built a box to direct air to the engine.

This aluminum piece holds the hood pins but it's primary purpose is to block air from going over the radiator

Underneath the piece you can see a gap between the rad and the rad/fender support. I built a box that captures air going through this gap and direct it into the engine.

And here it is all finished. I do not have an air cleaner because I do not compete in a dusty environment, I don't follow other cars on a road course which can kick up dust and all air going into the engine has to pass through the mesh grille.

Updated diffuser and belly pan

The new floor is 3 inches lower than before so I had to lower the diffuser and the belly pan 3 inches as well. The belly pan fills the gap between the floor and the diffuser at the back and it goes beneath the differential.

On the old belly pan, I had to cut a hole in it for the differential to poke through but now I can use just a single piece of 20 gauge aluminum to do the job.

All that material above the yard stick has to be cut off the diffuser

The diffuser attaches to the belly pan then rises up towards the back.

The diffuser is held on at the back by adjustable struts. In this picture the diffuser is set at it's highest position

Rocker panels

When I lowered the floor 3 inches, I also lowered the side pipes so the bottom edge of the pipes was level with the bottom of the floor. This resulted in a 3 inch gap between the body and the side pipes where the rocker panels used to be. I made new ones out of 18 gauge aluminum and riveted them on.

Video of car on track

I did a few laps on the kart track and have video from three different angles. The car smokes a lot but I think most of it is because the engine is running so rich. The handling is pretty good but understeers a little. I won't know the true handling until I get it outside on some real pavement. I think the engine sounds good.

Video from outside the car

Video from top of car

Video from side of car

Extra Transmission support

It turns out that my aluminum floor is not legal for the class because the rear tranny crossmember bolts to it and becomes load bearing, and aluminum is not allowed for load bearing structure. I simply added 1"x2" steel tube between the transmission crossmember and the frame rails and the problem is solved. The rest of the floor is held in with threaded aluminum rivets but for the crossmember, I welded 8mm nuts to the frame so it would be more secure.