Since I want a very low restriction exhaust system, and a car that is easy to work on, I have removed the fuel tank from in front of the rear differential, and replaced it with a fuel cell in the trunk. The fuel lines are now routed along the sides, and triple wrapped near where the exhaust will exit. I will have heat shields near where the exhaust will exit on the sides in front of the rear wheels. This will allow easy access to the complete drive train for changing out rear end center section for 1/8 or 1/4 mile strips, or taking a trip. It also paves the way for it to be back halved next Winter.
The exhaust pipes will turn and go through the 3 1/2 inch pipes that go through the sub frame braces and the side of the car. This is the area previously occupied by the gas tank.
The hole cutter will have to go through 4 layers of metal. Make sure you use a LONG drill bit in the center of the cutter
to make sure it keeps the cutter going through all 4 layer on the same angle. I wore out the 1st hole cutter on the
1st side, and had to get a new one for the other side.
Here is the drivers side with the 3 1/2 inch sleeve inserted for fitting. I made them about 4 inches extra long to use the
extra as a heat shield on both sides for brake and fuel lines. The area around the 3 1/2 inch sleeves will have construction
foam sprayed in to fill it for added strength. With the snug fitting sleeve being welded in place, and the foam being added,
it will be as strong as when new. I will be adding full length sub-frame connectors and a 6 point roll bar also, so no worries
about high power launches causing any problems.
You can see the old turn downs on the Bullets through the sleeve, that still needs to be welded in place.
I will most likely use a piece of aluminum or stainless as a heat shield on the sides around the tips.
The exhaust pipes going through the body are wrapped with header wrap and heavy foil to keep head off that area. The area inside the body had some fiberglass insulation placed around the new body tubes, then filled with construction foam. The subframe brace and body in this area was reinforced with steel plates welded in place.
View of the exhaust from the bottom
Since the clearance is so close where the 3 5/8 hole cutter goes through, I suggest making a test cut at a junk yard, on a car that
does not matter if you flub or not. Once you see the angle it needs to be, you will be OK doing it on your car.