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Removing my Cat Converter.

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Old 03-06-2014, 09:41 PM
  #21  
qwank
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No emissions test - no cat. Get it out of there. If anyone says anything tell them you bought it that way.
Old 03-07-2014, 03:19 PM
  #22  
jso789
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I took the cat off of my 81. The original cat was rusted and had leaks so I replaced it with a test pipe. Slight increase in power but overall the biggest increase was in sound. The exhaust seems much more freely flowing than it did with the cat. It definitely will help your car breathe better if it is an original style flat cat on your car. They clog up with carbon and become very restrictive over time...
Old 03-07-2014, 06:19 PM
  #23  
gcusmano74
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Originally Posted by Roughrider
You can always install a modern performance cat...they're not that expensive and don't restrict flow like early ones did. Check with Summit Racing or Jegs and see what's available.
Old 03-07-2014, 08:35 PM
  #24  
BEVO76
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Originally Posted by scottyp99
I'm not advocating doing this, but let's say, hypothetically, you were to remove your cat, ya know, to inspect it, and while you were inspecting it, you accidentally jammed a big pipe into it. Let's further assume that you are very clumsy, and accident prone, and you kept accidentally doing this, over and over, until all the guts crumbled and fell out of the cat. Then, maybe you went back in the house, cleaned up, made a sandwich and ate it, watched some tv, and forgot all about the accidents with the cat and the pipe. Then you went back out into the garage and re-installed the cat, because you didn't remember that it was just a big, empty shell now.

If this particular series of events were to take place, then you would have a more free flowing exhaust system, which would be just a hair louder, and anyone who looked under your car would see the original cat sitting there, just as pretty as you please. No one would be the wiser. Not even you, because you forgot all about it. All hypothetical, of course. I would never advocate doing anything illegal. I'm a good boy. I drink the Kool-Aid, just like I'm supposed to.

Scott
I like this!!!

Or just tell them you have really really small cats that are installed in your straight pipes.....they are there you just can't see them. But for me if you looking under my car than your entirely too close to my car
Old 03-08-2014, 09:01 PM
  #25  
gcusmano74
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In New Jersey motor vehicle inspections, was a time when the DMV guys would shove a mirror attached to a pole under the car to see if the cat was still installed. Dunno if they still do that.
Old 04-19-2014, 04:16 AM
  #26  
mauiwilly
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It's a no brainer....easy way to get a few extra HPs....get more air in....and more out !!
Old 04-19-2014, 02:43 PM
  #27  
John Holmes
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Deleting the cat is worth 8 rear wheel horsepower, I know because I measured it on my '79.
It was also worth 1/10 in the quarter mile.
Old 04-19-2014, 10:14 PM
  #28  
terry82
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Originally Posted by maverickmk
Hmm, this sounds vaguely familiar. Maybe it was a dream?
have heard this many times from so many that have had the same dream and performance gaines
Old 04-19-2014, 10:41 PM
  #29  
7t9l82
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until recently i wouldn't have worried about it, but with S.W.A.T teams showing up for cattle eating grass i may re think that.
the official story is my 79's emissions system was vandalized 2 days after it left the factory
Old 04-19-2014, 10:49 PM
  #30  
tektrans
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Originally Posted by John Holmes
Deleting the cat is worth 8 rear wheel horsepower, I know because I measured it on my '79.
It was also worth 1/10 in the quarter mile.
That 8 rwhp # could be more or less on a given car depending on the set up and the condition of the cat that was removed and the 1/10th quarter mile gain would be a stretch to verify and depending on the quarter mile range of the car that 8rwhp could see much less than a tenth or close to a tenth but rule of thumb is would take at least 10 rwhp to give you a tenth back with all other variables being consistent.
Old 04-19-2014, 11:18 PM
  #31  
John Holmes
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That 8 rwhp # could be more or less on a given car depending on the set up and the condition of the cat that was removed and the 1/10th quarter mile gain would be a stretch to verify and depending on the quarter mile range of the car that 8rwhp could see much less than a tenth or close to a tenth but rule of thumb is would take at least 10 rwhp to give you a tenth back with all other variables being consistent.
The 1/4 mile times were easy to verify, I ran this car a couple dozen times before the cat was removed. A stock car with an automatic transmission is easy to run consistently and I keep very detailed records of my track experiences going back to 1976.
Old 04-20-2014, 08:05 AM
  #32  
7t9l82
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Originally Posted by tektrans
That 8 rwhp # could be more or less on a given car depending on the set up and the condition of the cat that was removed and the 1/10th quarter mile gain would be a stretch to verify and depending on the quarter mile range of the car that 8rwhp could see much less than a tenth or close to a tenth but rule of thumb is would take at least 10 rwhp to give you a tenth back with all other variables being consistent.
i agree it takes more than 10 horsepower to shave a tenth in a 1/4 mile. i don't doubt removing a convertor would pick up that much, you should have replaced the exhaust with a good dual exhaust and you would have picked up more.

Last edited by 7t9l82; 04-20-2014 at 08:10 AM.
Old 04-20-2014, 10:49 AM
  #33  
garygnu
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I removed my cat and put it in a safe place to prevent it from being stolen .
Old 04-20-2014, 10:58 AM
  #34  
scottyp99
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Originally Posted by 7t9l82
i agree it takes more than 10 horsepower to shave a tenth in a 1/4 mile. i don't doubt removing a convertor would pick up that much, you should have replaced the exhaust with a good dual exhaust and you would have picked up more.
Those old cats were so heavy, the weight loss of removing it may have contributed to the reduction in E.T.

Scott
Old 04-20-2014, 11:33 AM
  #35  
cv67
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Magnaflow make a real good quality cat that flows very well and they are reasonable

Useless piece of info, I am leaving my smog equipment on the car because i think it will effect the value down the road if it is removed

There are some simply awesome cars on Cl for sale out here that are COMPLETELY worthless cause theres not one piece of smog equiptment on them. We got these STAR state run stations now you get that on your renewal notice theres no paying anyone either it passes or no tags for you!

Just spent too much on 2 Ca approved cats for my 02 Chevy pu. Think they are a waste of money but a necessary evil.
Could of almost bought me 1 AFR head with that for the toy



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