do open headers make car run slow???
11-18-2007, 01:53 PM
#21
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During the exhaust stroke, a good way for an engine to lose power is through back pressure. The exhaust valve opens at the beginning of the exhaust stroke, and then the piston pushes the exhaust gases out of the cylinder. If there is any amount of resistance that the piston has to push against to force the exhaust gases out, power is wasted. Using two exhaust valves rather than one improves the flow by making the hole that the exhaust gases travel through larger.
In a normal engine, once the exhaust gases exit the cylinder they end up in the exhaust manifold. In a four-cylinder or eight-cylinder engine, there are four cylinders using the same manifold. From the manifold, the exhaust gases flow into one pipe toward the **catalytic converter and the *muffler. It turns out that the manifold can be an important source of back pressure because exhaust gases from one cylinder build up pressure in the manifold that affects the next cylinder that uses the manifold.
The idea behind an exhaust header is to eliminate the manifold's back pressure. Instead of a common manifold that all of the cylinders share, each cylinder gets its own exhaust pipe. These pipes come together in a larger pipe called the collector. The individual pipes are cut and bent so that each one is the same length as the others. By making them the same length, it guarantees that each cylinder's exhaust gases arrive in the collector spaced out equally so there is no back pressure generated by the cylinders sharing the collector.
In a normal engine, once the exhaust gases exit the cylinder they end up in the exhaust manifold. In a four-cylinder or eight-cylinder engine, there are four cylinders using the same manifold. From the manifold, the exhaust gases flow into one pipe toward the **catalytic converter and the *muffler. It turns out that the manifold can be an important source of back pressure because exhaust gases from one cylinder build up pressure in the manifold that affects the next cylinder that uses the manifold.
The idea behind an exhaust header is to eliminate the manifold's back pressure. Instead of a common manifold that all of the cylinders share, each cylinder gets its own exhaust pipe. These pipes come together in a larger pipe called the collector. The individual pipes are cut and bent so that each one is the same length as the others. By making them the same length, it guarantees that each cylinder's exhaust gases arrive in the collector spaced out equally so there is no back pressure generated by the cylinders sharing the collector.
mostly due to firing order.
you did say LT1
11-20-2007, 12:08 PM
#27
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open headers is the sweetest sound I ever heard. Everybody at work thought my car was nasty when I let them hear it. Thats the impression I want from people, but cops didnt think it was pleasing to listen to my car
11-20-2007, 03:23 PM
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11-20-2007, 09:22 PM
#30
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Since where on the topic of headers... Would it be bad to run a stock ls1 motor without any O2sensors for a race event this weekend? On my old motor if a o2 went bad at a race I could continue, but My low end (Under 3k) would suck. Is this the same with LS1's? Ill be mostly in the range of 4k to 6k RPM...
11-20-2007, 09:56 PM
#33
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If it is a rear O2 he is talking about he should be fine witout it, he'll just have an SES light
11-20-2007, 10:20 PM
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Ok. So Im finishing my exhaust tomorrow and thursday and Im shooting them to the side of my fenders. Im sure I get the materials to put the o2's on the fronts. now would it be ok if I didnt get the car tuned?
11-20-2007, 10:32 PM
#37
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Are you going from stock exhaust to the setup you are talking about? You'll be fine without a tune, but you'll have a service engine soon light due to the lack of rear O2s and cats if that's the route you are going. It will likely run a little rich, but not dangerously bad
11-20-2007, 10:40 PM
#39
True, but SD isn't as temperamental as people make it out to be, he would be just fine at various altitudes as long as they are not drastic. He should be more worried about a summer and a winter tune if going SD. Although Vegas doesn't see much of a winter, lol.
