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exhaust cutout

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Old Jan 19, 2005 | 12:43 PM
  #11  
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Rogue has said he doesn't want a loud exhaust, however he may run faster if he pops off the downpipe or something.

If nothing else cutouts are fun when you're at a light with some lil 16 year old driving an engine half the size of yours.
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Old Jan 19, 2005 | 01:01 PM
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Originally Posted by BonneMeMN
If nothing else cutouts are fun when you're at a light with some lil 16 year old driving an engine half the size of yours.
I was going to say the same thing! Scare the crap out of them!
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Old Jan 19, 2005 | 05:29 PM
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I bought some cheap ones from JC Whitney a few years back, but ended up returning them before install. From visual inspection, it seemed that even when in "closed" position (so your exhaust operates normally) that gasses would still escape around the small plate that directs the exhaust. That would make your exhaust sound really crappy, or too loud... not great options, IMO. :?
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Old Jan 19, 2005 | 07:39 PM
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Originally Posted by swartlkk
Originally Posted by BonneMeMN
If nothing else cutouts are fun when you're at a light with some lil 16 year old driving an engine half the size of yours.
I was going to say the same thing! Scare the crap out of them!
It wouldn't scare me much. Even in my 2.3L Calais I would rev back, and most of the time, I'd be in front when the light changed. (it is a low-mid 15 second car afterall)

I am considering putting an electric exhaust cutout on my STE. It will reduce backpressure which should help my undersized turbo at high RPM'*, although I would probably only use it at the strip, which I don't plan on going to much, which is why I don't have a cutout yet. It will also be pretty loud but thats just a plus.

Personally though, if you are looking to just go faster at the track, drop the exhaust. That way you save weight and reduce backpressure at the same time. But if you want to scare some people on the street, then an electric cutout is the way to go.

Shawn
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Old Jan 19, 2005 | 07:51 PM
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I had to drive my Chevelle to the muffler shop after I put headers on to get the exhaust system replaced. It was only a 6 mile trip, but man did I have a headache when I got there. Open headers right under the floor boards are LOUD!!! I didn't really like the performance all that much either with the open headers. It seemed to have much more pep once the system was on.
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Old Jan 19, 2005 | 08:00 PM
  #16  
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Even in the GTP with it being just a V6, with the stock cam, we drove it 5 miles to the dyno and with headers and a 3" downpipe, it was loud. You couldn't talk in the car, and you definately have a headache, and I will add that after we dynoed and then went home and bolted the exhaust back on it made 11whp more IIRC.

Shawn
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Old Jan 19, 2005 | 09:54 PM
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Yeah i fired mine up with only a cat + some pipe on mine @ 2am..... car was backed into the garage as well... Damn it was good.
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Old Jan 19, 2005 | 11:27 PM
  #18  
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ok has anybody tried this with a smaller sc pulley
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Old Jan 19, 2005 | 11:33 PM
  #19  
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[quote="BonneMeMN"]Backpressure isn't good on any engine, at all. Going with too large an exhaust pipe lets the exhaust gases expand and cool so they don't go as fast. [quote]

Ask any good engine builder, and they will tell you that small displacement engines need backpressure. The reason is that at low RPM'*, if there is little backpressure, a small engine cannot keep enough air in the combustion chamber during valve overlap (time that intake and exhaust valves are open). This results in less air to expand when ignited, which results in less expansion, and therefore, less power. As RPM'* rise, overlap is not as much of a factor, and less backpressure is good to get the burnt gases out of the CC to allow fresh air in.

A larger exhaust merely allows the exhaust gases to leave the engine easier, so it doesn't work as hard to expel it, so therefore, you get more power. As pipe diameter increases for the same length, flow resistance decreases (that is what Mr Bernoulli tells us).
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Old Jan 20, 2005 | 02:31 AM
  #20  
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Originally Posted by Greg L.

A larger exhaust merely allows the exhaust gases to leave the engine easier, so it doesn't work as hard to expel it, so therefore, you get more power. As pipe diameter increases for the same length, flow resistance decreases (that is what Mr Bernoulli tells us).
Yes but a bigger pipe is only better when the gas doesn't change temperature. We're dealing with HOT gas trying to expand and cool.
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