cat. converter

[mad hooker]

i have a question, i dont have a cat. converter on my van, the pipes go straight from the headers to the exhuast pipes,and out. i dont a muffler either. i was reading in chevy hi performance thats it isnt good not to have one. i know its a filter, but does anybody know if i keep running without one if it will effect my engine and if will bring down performance? would it be smart to have one added?

[firebird45331]

not having a cat won't effect the motor. It's not really a filter. It heats up and burns unburned gas and other pollutants. You should have a muffler though. from my understanding just having straight pipes can have a negative effect on performance

[mad hooker]

oh thanks for clarifying that, whats the best mufflers sound wise? cuz my van is really loud and i wanna keep it like that , so what do you think would be best for it sound wise? right now its loud and has a slight "choppy" idle . thanks

[mad hooker]

how would a muffler effect performance? or not having one? airflow maybe?

[firebird45331]

don't know the physics but they help suck the exhaust out. I noticed a difference in torque when I had open headers vs a full exhaust. My torque increased after the exhaust was put on

[Ives Bradley]

Engines produce sonic and thermal waves. Scavenging is done by using the size and length of pipe that is the best compromise. Including the type of muffling device. Ssometimes giving power and efficiency, but not always.

[Swifster]

An engine is an air pump. An exhaust system provides backpressure. A small amount is good and a large amount is bad. Pipe diameter and muffler type can tune the amount of backpressure in the system.

An open exhaust system will increase overall peak horsepower, while a muffled system may decrease horsepower but can maximize torque. You'll need torque to get that heavy van moving.

I would also check your sound requirements for your state. Many have decible limits.

[mad hooker]

thanks for the tips, ya california does have decible limits, put hey i ran the van good and loud anyways, the pipes are about2 maybe 2 and 1/4 and my van screams, my dad thought i was nuts and dumb when i told him i wanted bigger pipes ha it was pretty damn funny. with my setup, headers and just pipes, how much power do u guys think it adds to the engine? they are regular sized headers. also, whats the difference on shorty and long headers? which adds more torque or power and why? thanks