The Curly 1

I never bought into or believe the bull that a motor needs backpressure. Not once have I ever seen anything car, motorcycle or anything else run better by increasing backpressure. My car runs better with the larger exhaust.

Modern cars need backpressure.
Another untrue urban legend.

Goodfellaz

"That said, it is possible that this myth about backpressure develops, in part, because, sometimes, when you decrease exhaust restriction, the engine runs more lean with the net result, less power rather than more, until the fuel delivery is retuned"

I have been racing for sometime now. I have had many different vehicles with many different engine combinations and fuel setups. If the engine runs lean, the engine runs fast, not as previously quoted that your power decreases. I am not saying that removing the exhaust will increase performance, because it will not. It needs to be tuned properly in order to achieve maximum performance. If you're looking for maximum HP then a more open exhaust is what you need, if you are looking for more torque, then a more closed exhaust is your best bet ((Think of an RV with a 454ci BB Chevy, they all run manifolds with a single exhaust same goes for a 3500 Chevy Dually) they are both towing vehicles that require a lot of torque)). If you were to install headers on a tow vehicle , you would loose low end torque, which would make your tow vehicle less efficient. When you start talking about top fuel dragsters, you are in a different ballpark. A top fuel dragster makes tons of torque and horsepower and need a rebuild after every 1/4 mile run. Another way of looking at it, if you spray nitrous into an engine without retarding your timing or adding fuel it will make more power but it will destroy the engine. By adding more fuel and removing engine timing, you fatten up the fuel mixture and lessen the power but make it safer to run ( less destructive).

Jeff90125

My last car before the HHR was a 1996 Olds Achieva. It had over 150k New England miles (snow, salt etc.). About a year before I traded it in I was driving along and heard a Pow! and the exhaust had blown apart right off the exhaust manifold.

Either the power went down or I was just scared to give it too much throttle because of the noise. I got some nasty backfires from time to time too.

IgottaWoody

I think this read will better explain the backpress thing..goes a long way to explain why different systems are.. well, different.

http://www.superchevy.com/technical/...exh/index.html

As far as single exhaust and more tq.... do not try to tell any Dirt Modified driver that,, they run nothing but big blocks