So, why aren't the people who "ran straight pipes for 20 years" bothered by the noise? They're DEAF. They just don't realize it. No, I'm not kidding.
If valve damage is caused when running straight pipes, then wouldn't you think that all the old modifieds that just ran stub pipes would have had tons of bent valves? This model a dirt modified runs a buick nailhead with 8" long stub tubes....never had a valve problem!!!!
Yes, I believe you can reduce power by increasing backpressure. I never tried it, but I think if you put enough pressure in the exhaust ports of a multi cylinder engine, it might be possible to make it run backwards, although I don't think the fuel tank will fill back up.
LOL Think about the two extremes of operation. The first is with no headers or manifold - the exhaust ports open to the atmosphere. The motor will run like crap. Now the opposite extreme - run the exhaust through a teeny tiny pipe. Of course, it will not run that way, either. Just like a guitar string can be too tight or too loose, it is a thing of beauty when it is tuned just right. For any given engine, assuming that a bigger/shorter header/exhaust pipe will always increase power is just as wrong as saying that every guitar will sound better by loosening the strings.
To me it is simple. common sense prevails. Im my way of thinking, more important than 'straight pipes' or not, is a "reasonably sized and 'tuned' exhaust. With the tuned part being more the size of the tubing than most any other variable. A well sized exhaust will add to the scavenging effect as a properly sized MOVING column of gas tends to keep moving. I don't see where the absence of mufflers can possibly damage an engine or hurt performance beyond any very narrowly defined circumstance. Can many other folks just see this in their mind or is it a curse I bear almost alone?
The Jalopy Journal
