I have a 93 and i undertand that the o2 sensors are b4 the cat, my cat is going bad so i was wondering if it would do any harm to hollow it out? Will it get very loud if i do? Also will i do harm to the truck in terms of back pressure issues etc.? I don't wanna screw it up so any thoughts opinions, suggestions very much appreciated.
TO Hollow out Cat?
- Thread starter evsweat1
- Start date
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do you have emissions checks? if so you will not pass, if you dont what is the harm in just leaving it be? is it plugged?
Two things.
1. It will sound raspier than it does now
2. Exhaust flow will actually be poorer than with internals in place
My suggestion is to buy a suitable aftermarket replacement. Companies like Carsound make fairly cheap replacements.
1. It will sound raspier than it does now
2. Exhaust flow will actually be poorer than with internals in place
My suggestion is to buy a suitable aftermarket replacement. Companies like Carsound make fairly cheap replacements.
Buy a Catco or similar universal replacement. It's only $60-70. I just did mine last weekend. It's worth it for being legal and for being environmentally friendly. Tread Lightly.
I believe it is a federal crime to alter your cat. If you are never caught by the emissions police, you will still have to worry about taking it in for work and if you sell the vehicle with illegal emissions tampering.
Exhaust flow is more complicated than just getting the air out as smoothly as possible, especially for low end power. You want the exhaust velocity to be just right so the pulses travel at just the right speed to help the engine perform how you want it, when you want the performance. I don't know how altering your exhaust is going to make it perform, and more importantly neither do you. An exhaust engineer like the ones working for Mr. T. are pretty good at it.
I believe it is a federal crime to alter your cat. If you are never caught by the emissions police, you will still have to worry about taking it in for work and if you sell the vehicle with illegal emissions tampering.
Exhaust flow is more complicated than just getting the air out as smoothly as possible, especially for low end power. You want the exhaust velocity to be just right so the pulses travel at just the right speed to help the engine perform how you want it, when you want the performance. I don't know how altering your exhaust is going to make it perform, and more importantly neither do you. An exhaust engineer like the ones working for Mr. T. are pretty good at it.
[quote author=evsweat1 link=board=2;threadid=17325;start=msg167676#msg167676 date=1086152450]
why would the flow be worse i don't get it the air can run out smoothly now? please explain
[/quote]
How do you plan to hollow it out? Probobly like everyone else- by taking a pipe and ramming it through until stuff falls out right?
Now you have lots of broken pieces and rough edges, dead space, etc.. in your cat. How is this going to help flow at all? Then when you put the converter back on, all the stuff in the top of it will hang down into the new 'hole' you just made.
So you have a small hole through the middle of it, it won't matter. Converters are constructed to flow as well as possiable for their size/application while eliminating greenhouse gasses.
why would the flow be worse i don't get it the air can run out smoothly now? please explain
[/quote]
How do you plan to hollow it out? Probobly like everyone else- by taking a pipe and ramming it through until stuff falls out right?
Now you have lots of broken pieces and rough edges, dead space, etc.. in your cat. How is this going to help flow at all? Then when you put the converter back on, all the stuff in the top of it will hang down into the new 'hole' you just made.
So you have a small hole through the middle of it, it won't matter. Converters are constructed to flow as well as possiable for their size/application while eliminating greenhouse gasses.
- Thread starter
- #9
No i know a guy that owns a mineke shop and he said he would take it off and i dumped it out and replace it thats it. So it is possible for worse performance that sucks. I have no emision testing here at all and when i move to florida they dont have it down there anyway. The reason i want to do it is my friend had an mitsu eclipse years ago and he hollowed it out and he said it made a huge difference. Also people with the classic cars take them off as well they poluting no lesss than i would be doing so i figure if it will sound better, cheap mod, better flow i would be all for it
I've run a couple of LCs catless. We have a not so legit exhaust shop in town that would do new exhaust systems without a cat. It is a real PITA when you want to go to sell a rig and it doesn't have a cat. You never know where the future buyer is going to live. In my 60 I put a TBI 350 and it burned cleaner without a cat than my old 2F did with a cat. I've seen no performance gains from removing the cats from a stock motor and stock exhaust. If you had a plugged cat you might see some gains. I just had a new exhaust put on my 91. The guy told me that he could not work on a exhaust 10" from where a factory cat convertor was located if removed or was evident that it had been tampered with. The only legitimate reasons I can see for removing a cat is if it is nonfunctioning or you live in an area like I do where there is a huge risk of wildland fires from the heat on dry brush on the trails. This new exhaust guy is pretty good, he said a lot of folks buy into exhausts that claim more power. He sells a lot of big diesel exhausts and he said that if you dyno'd them before and after you would not see the huge increase in hp and torque people are claiming. But if you shelled out $600-1100 for a new exhaust your brain would feel more power to justify your expense. The one advantage he does note about some of the exhaust systems for diesels is they bring exhaust temps down. But this big exhaust thing has been catching on with other motor groups, look at the imports and even gas pickups. 3 and 4 inch exhaust is common now.
