I read a magnaflow advertisement about their straight through mufflers, and how they relieve back pressure. But after reading some posts and threads on here, I've come to the conclusion that losing back pressure is bad.
So whats the truth? What is back pressure anyway? How does back pressure effect your exhaust and performance?
One last question that has nothing to do with back pressure...How can i shrink my pictures down enough to 100x100, to fit my avatar?