Effects of Removing the Cats
10-18-2007, 10:27 PM
#1
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Effects of Removing the Cats
What will be the downside of removing the cats? I heard something about it reduces low end torque because the cats create backpressure which creates the torque. But how much will really be lost? Any effect to gas mileage?
When removing the cats, what will I have to add on additionally? Will my check engine light come on?
When removing the cats, what will I have to add on additionally? Will my check engine light come on?
10-19-2007, 09:25 PM
#6
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RE: Effects of Removing the Cats
So all I'm going to do when I get my car back from the body shop is hack or grind saw before and after the cats, then weld new piping in place of the cats.
I'd have to switch it back for my emissions test, unless I can get it done at the dealership I work at and have them pass it. What would be the easiest way to swap between cats and no cats? I don't plan on keeping the car for years and years so I think I will just swap it back in before the emissions, then swap out and back in when I sell it.
I'd have to switch it back for my emissions test, unless I can get it done at the dealership I work at and have them pass it. What would be the easiest way to swap between cats and no cats? I don't plan on keeping the car for years and years so I think I will just swap it back in before the emissions, then swap out and back in when I sell it.
10-19-2007, 09:33 PM
#7
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RE: Effects of Removing the Cats
Backpressure doesn't create torque. I have no idea why everybody thinks this. You want as little backpressure as possible for maximal power. The more backpressure, the harder the engine has to work just to push the exhaust out through the pipes. The harder the engine works doing stupid **** like that, the less power you get out of it.
10-19-2007, 10:35 PM
#8
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RE: Effects of Removing the Cats
ORIGINAL: Xemeth
Backpressure doesn't create torque. I have no idea why everybody thinks this. You want as little backpressure as possible for maximal power. The more backpressure, the harder the engine has to work just to push the exhaust out through the pipes. The harder the engine works doing stupid **** like that, the less power you get out of it.
Backpressure doesn't create torque. I have no idea why everybody thinks this. You want as little backpressure as possible for maximal power. The more backpressure, the harder the engine has to work just to push the exhaust out through the pipes. The harder the engine works doing stupid **** like that, the less power you get out of it.
Man your lack of auto knowledge is scary. Yes you do need some back pressure or you will not have any low end tq. Even most race cars run a muffler of some sort and it's not just for noise, it's to get better cylinder scavenging due to "back pressure". Even in my door slammer I dropped almost 3 hundreths off my et just by adding a 2' x 2.5" straight pipe to each collector. If a totally free flowing exhaust makes the most power like you say then tell me no one runs dual 3" pipes with no cats on these cars? Because they wouldn't move under their own power is why! Next time before you open your mouth and put your foot in it AGAIN do some research and get your reply right!
10-19-2007, 10:36 PM
#9
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Join Date: Apr 2006
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RE: Effects of Removing the Cats
ORIGINAL: Xemeth
Backpressure doesn't create torque. I have no idea why everybody thinks this. You want as little backpressure as possible for maximal power. The more backpressure, the harder the engine has to work just to push the exhaust out through the pipes. The harder the engine works doing stupid **** like that, the less power you get out of it.
Backpressure doesn't create torque. I have no idea why everybody thinks this. You want as little backpressure as possible for maximal power. The more backpressure, the harder the engine has to work just to push the exhaust out through the pipes. The harder the engine works doing stupid **** like that, the less power you get out of it.
10-19-2007, 10:49 PM
#10
RE: Effects of Removing the Cats
+1
While too much backpressure hampers an engines performance, too little can be just as bad and can potentially cause the engine to suffer damage (under rare circumstances). In any since, the goal is to reduce stock backpressure, but to a point, because there is a balance of backpressure and free flow, and the goal is to hit that middle ground to maximize performance. Generally high flow cats will allow for this balance, and or no cats on a 2.25" system, but 2.5" O/R may tip the scale to the too high flowing end, which can reduce overall power and low end torque. Granted, all this depends on the engine, application, and what not, but for sixers, a high flow catted 2.5" system is one of the best ways to go, and or an O/O 2.25" system, but sometimes, there is no getting around the 2.5" O/R system, which, while not bad, will cause the performance to be a little less on a stock vehicle than the other two, however, the sound will be better.
While too much backpressure hampers an engines performance, too little can be just as bad and can potentially cause the engine to suffer damage (under rare circumstances). In any since, the goal is to reduce stock backpressure, but to a point, because there is a balance of backpressure and free flow, and the goal is to hit that middle ground to maximize performance. Generally high flow cats will allow for this balance, and or no cats on a 2.25" system, but 2.5" O/R may tip the scale to the too high flowing end, which can reduce overall power and low end torque. Granted, all this depends on the engine, application, and what not, but for sixers, a high flow catted 2.5" system is one of the best ways to go, and or an O/O 2.25" system, but sometimes, there is no getting around the 2.5" O/R system, which, while not bad, will cause the performance to be a little less on a stock vehicle than the other two, however, the sound will be better.