The collector on these particular headers is 2½" and so 2½" pipe was used throughout the system along with Dynaflow Super Turbo mufflers with 2½" inlets and outlets. Mandrel bent pipe in 180° sections was purchased from Don's Hot Rod Shop here in Tucson  to avoid trips to the mufflers shop for bending. The bends come in 4" radii only but a tighter radius is needed where the pipe curves back into the inlet side of the muffler. A hack saw and a little welding produced the tighter "radius". Even though it isn't perfect, it flows fine for the street use it will see.

Now, how do we fit all this stuff into the little tiny place that it has to go? There are three spots that really caused problems. The first (and these are in no particular order) is clearance for the shock absorber. The second was clearance for the rear edge of the body. And the third was clearance for the tire. This wouldn't be such a problem if I weren't running 215-60R14s. It was like working one of those Chinese puzzles to get thing to fit with sufficient clearance...

Right: Looking into the rear of the car with the grill panel removed, you can see there is only about 1/2" clearance between the pipe and the body work.

The exhaust piping and muffler pretty much fill all the space available. This is especially true on the driver's side because of the engine off-set. It would be very difficult to adjust the valves on the left back without removing the exhaust system. The passenger's side has plenty of room for adjusting the valves but there are still just as many clearance problems.

One of the things I was told by several people while researching the project was that the exhaust should run straight out the back of the car and the tail pipes should extend beyond the bodywork. This give the noise very little opportunity to find its way back into the passenger's compartment.

What about the noise? Well, I borrowed digital sound meter and took some measurements and compared them on three "regular" cars along with my Corsa with four different exhaust set-ups. Keep in mind that twice as loud is equal to 3 dBA and OSHA required hearing protection when levels average 90 dBA and over. We were able to reduce the noise level quite a bit over a standard header set up, but still twice as loud as a stock set up. Overall, I'm pleased with the results both in noise level and performance. The moral of the story is that if you want a quiet ride you'd better go for something newer like a Cadillac or even a Chevy Blazer. The stock Corsa exhaust system is also another good route, but the extra horses just aren't there.

The Otto headers finally gave up the ghost and were replaced with a set of Clark's Ultimate exhaust system. I added the baffles to reduce the noise a little. The noise levels are much louder than the system with the extra piping as you can see by the table below.