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Maybe like 20hp, 10tq. Don't quote me on that but it's not enopugh to notice a difference. Back-pressure is also reduced giving you better gas mileage because it is less strain on the engine allowing exhaust gases to leav the engine at increased speeds.
 

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It's a hell of a kick in the pants when you take it off though! My 1st TD 10 years ago I took the cat off and talk about spool up! The car was actually kinda fast then, lol It all depends on your goals for the car but less restriction in the exhaust will result in better flow which = greater performance
 

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Actually at a Chrysler training center they proved that Cats do not provide a restriction other than their size, most exhaust restrictions come from exhaust size, bends and muffler design.

Also keep in mind if this car is driven on the street it is a Federal Law that the Cat cannot be removed with fines up to $10,000.00.
If your car is noisy/loud and you are pulled over....
 

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Also keep in mind if this car is driven on the street it is a Federal Law that the Cat cannot be removed with fines up to $10,000.00.
If your car is noisy/loud and you are pulled over....
ive NEVER had a cat on a turbo dodge that ive owned. ive NEVER been pulled over in a turbo dodge. i have a dumped exhaust right under the car. ive been pulled over in my sentra (homo car) lots of times for dum shit. but i live in a state where they dont do inspections. :dancing:
 

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Actually at a Chrysler training center they proved that Cats do not provide a restriction other than their size, most exhaust restrictions come from exhaust size, bends and muffler design.

Also keep in mind if this car is driven on the street it is a Federal Law that the Cat cannot be removed with fines up to $10,000.00.
If your car is noisy/loud and you are pulled over....
I wouldn't believe that study for a second lol. Do you think Chrysler, or any other car company that is subject to any kind of government action, would come and encourage people to take their cats off? Absolutely not.
 

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ive NEVER had a cat on a turbo dodge that ive owned. ive NEVER been pulled over in a turbo dodge. i have a dumped exhaust right under the car. ive been pulled over in my sentra (homo car) lots of times for dum shit. but i live in a state where they dont do inspections. :dancing:
My Son was pulled over and ticketed for noise twice(which he was told in court is at the officers discretion) it only takes one time to be pulled over and have an officer look under your car.
N.J. has had State Inspection for as long as i can remember and 2 years ago they changed it to Emissions only but...The law states you are responsible for the care and maintainence of your car and if pulled over for a violation you will be ticketed and depending on the offense your car will be impounded.
That law holds true for any state.
If you want to ride around without a Cat that is on you, just be prepared to pay the consequences should you be caught.

I wouldn't believe that study for a second lol. Do you think Chrysler, or any other car company that is subject to any kind of government action, would come and encourage people to take their cats off? Absolutely not.
It was not a study, it was brought up during a Chrysler Training Class for Engine Basics Refresher course and exhaust backpressure was one of the lessons with 3 seperate Grand Cherokee's on the dyno and exhaust backpressure tested, one with a cat, one with a restricted cat and one with no cat.
There was no difference between the vehicle with the Cat and the vehicle without.
 

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My Son was pulled over and ticketed for noise twice(which he was told in court is at the officers discretion) it only takes one time to be pulled over and have an officer look under your car.
N.J. has had State Inspection for as long as i can remember and 2 years ago they changed it to Emissions only but...The law states you are responsible for the care and maintainence of your car and if pulled over for a violation you will be ticketed and depending on the offense your car will be impounded.
That law holds true for any state.
If you want to ride around without a Cat that is on you, just be prepared to pay the consequences should you be caught.



It was not a study, it was brought up during a Chrysler Training Class for Engine Basics Refresher course and exhaust backpressure was one of the lessons with 3 seperate Grand Cherokee's on the dyno and exhaust backpressure tested, one with a cat, one with a restricted cat and one with no cat.
There was no difference between the vehicle with the Cat and the vehicle without.
Ok I assumed this was something you heard about but it kinda sounds like you were there?
 

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Ok I assumed this was something you heard about but it kinda sounds like you were there?
I actually brought it up and was proven wrong, again it all depends on size and how quickly exhaust can flow thru it compared to the size of the rest of the exhaust.
That is also why people use Mandrel Bent Exhaust, no sharp restrictive bends and why they go to Flow Through Mufflers instead of factory Chambered Mufflers.

The proof would be my VNT.
The VNT was designed with the exhaust (muffler) as part of boost control using enough backpressure so the turbine side would not overspool.
When I replaced my Cat with a Maremont Direct Fit the car ran the same at the track, when the OE muffler got damaged and I replaced it with a Walker Dynomax Direct fit the system had less backpressure and now I have boost creep @ 4800 RPM's in 3rd gear.
Obviously there was no difference in backpressure with the Cat but a major difference with the Muffler.
 

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I actually brought it up and was proven wrong, again it all depends on size and how quickly exhaust can flow thru it compared to the size of the rest of the exhaust.
That is also why people use Mandrel Bent Exhaust, no sharp restrictive bends and why they go to Flow Through Mufflers instead of factory Chambered Mufflers.

The proof would be my VNT.
The VNT was designed with the exhaust (muffler) as part of boost control using enough backpressure so the turbine side would not overspool.
When I replaced my Cat with a Maremont Direct Fit the car ran the same at the track, when the OE muffler got damaged and I replaced it with a Walker Dynomax Direct fit the system had less backpressure and now I have boost creep @ 4800 RPM's in 3rd gear.
Obviously there was no difference in backpressure with the Cat but a major difference with the Muffler.
Thats true, those VNTs rely on backpressure. That must be correct. But the thing you must consider is that most of these old cars have cats that are going bad, clogged or partially clogged. When cutting off the cat, or simply replacing it, an increase in performance will definitely be noticed. So in that case, people should just replace their cats if they notice increased performance without it.
 

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Thats true, those VNTs rely on backpressure. That must be correct. But the thing you must consider is that most of these old cars have cats that are going bad, clogged or partially clogged. When cutting off the cat, or simply replacing it, an increase in performance will definitely be noticed. So in that case, people should just replace their cats if they notice increased performance without it.
My point was/is if you are planning on removing the OE cat and leaving the stock exhaust you are not going to notice a change in performance.
Increasing the size of the exhaust and installing a high flow muffler would require you to upgrade to a Cat that will flow the same as the improved flow exhaust.

IMO on a DD it is not worth the chance to be caught without a Cat, it only takes one time being caught.
Also in N.J. they set up roadside inspection checkpoints for credentials and sometimes do spot emissions checks with mobile DMV equipment.
 

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My point was/is if you are planning on removing the OE cat and leaving the stock exhaust you are not going to notice a change in performance.
Increasing the size of the exhaust and installing a high flow muffler would require you to upgrade to a Cat that will flow the same as the improved flow exhaust.

IMO on a DD it is not worth the chance to be caught without a Cat, it only takes one time being caught.
Also in N.J. they set up roadside inspection checkpoints for credentials and sometimes do spot emissions checks with mobile DMV equipment.
Yeah but I was adding that people should consider upgrading their cats because their stock cat is possibly going bad and being restrictive. I removed that cat from an old Magnum and it was quite a noticeable increase in flow, but that was only because the old cat had gone bad.

As for me I will probably take it off because emissions testing ends for me in one more year.
 

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Hey now say you can still have the cat physically on the car, but it's been, uh, 'flowbenched' lol
 

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Bingo! Something like that MAY have once happened to a TD or two I owned lol
 
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