I'm building a car for Honda Challenge and will be running at some tracks that do not have decible restrictions so I'm not planning on running a muffler. In order to save weight I'm thinking about running my exhaust at a more or less 45 off the header out to the passenger side?
Are their any real negatives to this approach?
Only thing I can think of is that the rear drum on that side might run a bit hotter...

 

any thoughts?

 

That's going to be unbearably loud. After driving a loud car for 2 seasons, I changed my exhaust to include another, much larger, muffler. I was much happier at the last event, and my car was far from being the loudest at the track. Weight penalty was probably 6 lbs, and I was much better able to hear what the car was doing. I'd really suggest running quieter rather than louder.

 

There are few better places to have weight than in the exhaust. If you know you'll be heavy, then the exhaust is an easy target for a place to save weight. If not, you can't get ballast much lower or further back than with a big stainless muffler.