K-5-Titan

ok i have a 1983 k5 chevy blazer with a 350 carbuerated engine, not sure if its stock or what. i have dual exhaust ran mid way and then pointed down for street thumpin, well i wanna make it louder and maybe increasing some hp. so my idea was to cut the mufflers off and everything past the mufflers, well i heard this decreases back pressure and is hard on carbureated engines and can burn up the valves, i dont know if its true or not and my question is will it burn up the valves? i have friends with no mufflers and theirs are fine but theres are fuel injected does this make a difference?

Thanks K-5-titan

davec66

I do not think it will burn up the valves, but I personally would not run the straight pipes without mufflers unless this is going to be a race vehicle. It's all about scavenging the exhuast out of the cylinders, then it moves to the same for the rest of the exhuast. On a street car mufflers can increase the scavenging effects of the exhaust system. I see people run flowmaster mufflers with only the little stubby end after the muffler, and this is not good. You need to run a length of pipe after the muffler to help increase the flow out of it. A long time ago flowmaster recommended to a friend of mine to run a piece of pipe between 18 and 24 inches long after the muffler. It made a difference on his camaro. I also did the same thing on my 88 carbed mustang and I could tell a difference in the bottom end pull of the car. It felt a bit stronger and all I did was add exactly 21 inches of pipe after the muffler instead of just very short turndowns. The car actually sounded better also. I hope maybe this will help you. I would go with a good set of full length headers and 3inch all the way out. 3 inch will sound better and it will help the carb, or at least it did on my mustang.

CS057

Strait piping may decrease your torque a little but will exchange it for more horse power. But problems can occur with valve burning if you don't tune your carb after you cut your pipes off though. My think is why cut your pipes off? you'll only gain 3-4 hp but also gain annoying amounts of noise.

CS057

I just did a strait through dual set up on mine that exited before the rear tires. I also backed it with full length headers. I believe I gained around 15 more horse power over the stock manifolds, single three inch pipe, magnaflow cat and muffler that i had. and I'm running a just a 305. While I'm very impressed with the power the insane amounts of noise are becoming irritating. but I would recommend it if noise isn't a problem for you. It makes a rather sweet full on race sound and makes every thump of the cam audible.