what is the best performance exhaust set up,I've got a 49 sedan and was thinking either dump'n behind the front wheel wells or lakes,am also going to be running full lenght exhaust with mufflers so the dumps or lakes will be capped untill needed. Any opinions on this?
It all depends on the engine combination. Typical street motors from stock to stout like the scavenging of a full exhaust system, as long as it's sized properly, say 2.5" with a good crossover. 3" duals is for the stout end. Mufflers should be as far away from the motor as possible to make the most of the scavenging. I like a 2 into 1 into 2 mufflers. Look at late model Vettes and performance sedans from Japan and Germany. It doesn't take big pipes to breathe well.
Up to about 450 HP, 2.5" pipe will work fine. Headers are a big part of it. There is a reason $1200 headers are $1200. Ceramic coated headers build power. the longer the collector, the better. An H-pipe will increase low end performance, an X-pipe will increase power throught the RPM range. the X-pipe should be close to the collectors as practicle without having any bends that are to sharp. Mandrel bending is a must for high performance, and all your bends should be as gradual as practicle. . As far as mufflers go, as long as they flow enough for you needs, all the brands are about the same. Like Scotty said, the further back, the better. See the website below for a muffler flow comparison. http://impalassforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=21;t=002698#000006
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