what is a "cutoff" when talking about exhausts?

Question

I'm about to buy a Trans Am from a guy, and he sais it has stock exhaust with something called a "Cutoff" or something like that. What exactly IS it, and is it good or bad? Also, will it affect my gas milage?

Answer 1

Both above are right. However I think they are only illegal if used open on the street.

Answer 2

I'll bet it has a cut-out. That is when they install an extra pipe in the exhaust that is usually capped off. When you want to run with the exhaust open, you remove the cap from the cut-out and then the exhaust just goes straight out to the air and not through the exhaust system.
Some have a cable to control the opening installed. You can just pull a knob from the driver's seat and it will open the exhaust up to the air.

These are illegal in most if not all states. But they have been around for a long time.

Back in the 50's and 60's they had Lakes pipes. They ran down the side of the car and exited before the rear wheels. You could remove the 2 bolts on the cover and open up the exhaust if you wanted to race someone.

It will give you a little better mpg, since you are not pushing the exhaust through all the mufflers. good luck.

Answer 3

I believe he is referring to the cut-out, it is welded or clamped into place, so as to be able to use the muffler or with a mechanically actuated lever, via a cable that you move with your fingers similiar to a manual choke on a carbureator, or they make electrically actuated doors that move, at the flip of a switch, so as to prevent the exhaust from going through the muffler and through the cut-out, which vents straight out through nothing thus providing no restriction, and all flow, much louder as there is nothing to muffle the combustion chambers. and illegal if you live in a state that is compliant with smog certification, and noise pollution, like california. But if you live in the backwoods, of dukes of hazard, you might like it.

Answer 4

It's a cutout. It's a valve that lets you bypass the muffler and/or catalytic converter to reduce backpressure. It also increases noise, so you have to be careful where you use it. It should help with mileage, assuming you can use it often enough.