Chambered mufflers? Options

[dawnoforigin]

Is there any positive experience with these types of mufflers? I know most go with the straight through design, but I know they would be way too loud and not sound the way I would like. I also was considering this because I don't want to lose any low end power by getting a straight through design. Low end is much more important then high end to me. I was thinking about looking into a Dynomax Super Turbo or possibly a Flowmaster. Any input is appreciated.

http://www.dynomax.com/superturbo.stm

[mkernz22]

As far as back pressure goes, I know our engines don't need it, but doesn't it help with gas mileage on N/A cars?

[Galcobar]

As far as back pressure goes, I know our engines don't need it, but doesn't it help with gas mileage on N/A cars?

No. Backpressure is an inelegant reference to the amount of energy required to move exhaust out of the engine. The higher the backpressure, the harder the exhaust is to move.

Backpressure means one of two things: either burnt fuel is left in the combustion chamber because backpressure is preventing exhaust from exiting the engine quickly, which reduces the production of power, or; energy which could have gone towards turning the wheels is instead being used to help the pistons push the exhaust gas out of the engine.

Either way, you end up burning more gas to get the same performance.

Small pipes are used by the factory because most driving is done at low RPMs, with low exhaust flow. The idea is to minimize backpressure (precisely opposite of what you're asking) where the engine spends most of its time. There's no point in strapping a three-inch pipe onto an engine to achieve peak efficiency at 7000 RPM when the engine actually spends 90 per cent of its time below 3000 RPM producing only enough exhaust to efficiently use a one-inch pipe. To achieve a range of reasonable efficiency, the exhaust system ends up with a compromise size of say two inches.

This post has been edited by Galcobar: Feb 12, 2013 - 1:11 AM