1982 Catalytic Converter
Thread Starter
Intermediate
Joined: Jul 2004
Posts: 25
Likes: 0
1982 Catalytic Converter
I am considering replacing the stock catalytic converter on my 82 corvette with a newer free flowing model.
Can I expect much difference in proformance and or sound ? What converter would you recommend ?
Can I expect much difference in proformance and or sound ? What converter would you recommend ?
Pro
Joined: Sep 2003
Posts: 511
Likes: 4
From: Phoenix AZ
I have a Hi Flow cat and recommend it if you have to have a cat. I'm not sure what brand mine is. And unfortunately the suppliers don't post any flow numbers.
The 82 exhaust is restrictive with the cat being a big part of that. The stock pancake style cats are not known for flowing very well. Going to a hi flow cat would remove some of that restriction and help with performance a little . Of course no cat would flow even better. The Hi Flow cat on mine gives a better tone to the exhaust and its a shade more aggressive. Nothing significant mind you.
Make sure that the heat shielding on top is still in good shape once it's mounted. Those suckers get hot. If ;you get the one that has the stock flanges on it, it's a bolt in operation. But you may want to buy new bolts and cut the old ones off with a angle grinder and cut off wheel.
The 82 exhaust is restrictive with the cat being a big part of that. The stock pancake style cats are not known for flowing very well. Going to a hi flow cat would remove some of that restriction and help with performance a little . Of course no cat would flow even better. The Hi Flow cat on mine gives a better tone to the exhaust and its a shade more aggressive. Nothing significant mind you.
Make sure that the heat shielding on top is still in good shape once it's mounted. Those suckers get hot. If ;you get the one that has the stock flanges on it, it's a bolt in operation. But you may want to buy new bolts and cut the old ones off with a angle grinder and cut off wheel.
Pro
Joined: Mar 2005
Posts: 683
Likes: 4
I bought a new hi flow from ecklers. More HP Aslo the new one will not come with a fitting that connects to the air tube. They sell a kit that connects the two with a hose. I wanted to keep my car original in appearance. I cut the fitting of the end of the tube of the old converter and had it welded to the new one. Looks just like the original
Good Luck
Steve
Good Luck
Steve
Race Director
Joined: Jun 2001
Posts: 16,483
Likes: 1
From: The Only Corvette in Gila Bend, Az.
St. Jude Donor '09
Anything you do to the original cat is going to be an improvement, yours is probably pretty plugged up by now, and they were restrictive to start with.
I hollowed mine out for awhile, and felt an improvement in acceleration. I have taken it out with true duals now...
I hollowed mine out for awhile, and felt an improvement in acceleration. I have taken it out with true duals now...
Burning Brakes
Joined: Jun 2004
Posts: 1,012
Likes: 5
From: Granbury, TX
Originally Posted by terry82
gut the cat .clean it out good put it back on, cost nothing and will help performance .
If you live in a pollution county, wait until 2006 and get it inspected 1 more time. Then gut the cat. In 2007 these babies will be 25 yrs old and no more sniffer test
. This is true for Texas and most other states, your laws may vary.
Race Director
Joined: Dec 1999
Posts: 16,945
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a gutted cat sounds like a tin can, if you have any fabbing skills & a welder put together a pipe that bolts in the cat's location, might even want to add a hookup for the AIR tube (oxydizing section feed) so the clean air from the air pump dillutes the exhaust gas...always helps a tad on the sniffer. The only problem w/ removing the cat however is heat, the catalytic converter creates a lot of heat and is a major contributor to the heat needed for the O2 sensor to operate, that's why it's there so if you remove the cat it may cause an unstable closed loop operation (lapsing back into open loop) and if that happens you will need a heated O2 sensor (easiest hooked up w/ 12V feed off battery or alternator, relay switched from the fuel pump..this is by far the best way so that the heater doesn't stay on w/ the ignition in the on position, the pump only runs for a couple of secs and so will the heater if hooked to that)
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Burning Brakes
Joined: Jun 2004
Posts: 1,012
Likes: 5
From: Granbury, TX
Originally Posted by Twin_Turbo
a gutted cat sounds like a tin can, if you have any fabbing skills & a welder put together a pipe that bolts in the cat's location, might even want to add a hookup for the AIR tube (oxydizing section feed) so the clean air from the air pump dillutes the exhaust gas...always helps a tad on the sniffer. The only problem w/ removing the cat however is heat, the catalytic converter creates a lot of heat and is a major contributor to the heat needed for the O2 sensor to operate, that's why it's there so if you remove the cat it may cause an unstable closed loop operation (lapsing back into open loop) and if that happens you will need a heated O2 sensor (easiest hooked up w/ 12V feed off battery or alternator, relay switched from the fuel pump..this is by far the best way so that the heater doesn't stay on w/ the ignition in the on position, the pump only runs for a couple of secs and so will the heater if hooked to that)
TT, Where do you splice in to the fuel pump wire?
Thanks.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Originally Posted by Clint's C3
TT, Where do you splice in to the fuel pump wire?
Thanks.
Thanks.
Burning Brakes
Joined: Jun 2004
Posts: 1,012
Likes: 5
From: Granbury, TX
Originally Posted by Twin_Turbo
Easiest will be tapping into the tanwhite one at the oil pressure sensor, that way the thing will only heat when there's oil pressure, it's even better than straight into the 12V pump feed (since the relay activates that one briefly when you turn the ignition on)
Thanks, TT.
I called Bosch and they suggested Heated O2 sensor PN 15726, 3 wires, hot, ground and sensor, only $19.99 at Auto Zone. I'm hoping this will help my slightly rough idle.
Race Director
Joined: Dec 1999
Posts: 16,945
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whatever you do, don't smear the sealant goop that's on the threads on the element and do not remove from the threads either. Do you have a O2 sensor socket (basically a long reach socket w/ a slit in the side)? Makes life a lot easier, especially if you have one for an impact wrench..makes removing those rusted tight ones a breeze
Burning Brakes
Joined: Jun 2004
Posts: 1,012
Likes: 5
From: Granbury, TX
AZ has these sockets availble in their "loan a tool" program. I don't think I'll need one on this sensor as I just had it out a few months ago.
Good tip on the thread seize compound
. That must be some tough stuff to resist the exhaust temps.
Good tip on the thread seize compound
. That must be some tough stuff to resist the exhaust temps.
Le Mans Master
Joined: Jul 2000
Posts: 6,663
Likes: 162
From: columbia city in
Originally Posted by Clint's C3
Thanks, TT.
I called Bosch and they suggested Heated O2 sensor PN 15726, 3 wires, hot, ground and sensor, only $19.99 at Auto Zone. I'm hoping this will help my slightly rough idle.
I called Bosch and they suggested Heated O2 sensor PN 15726, 3 wires, hot, ground and sensor, only $19.99 at Auto Zone. I'm hoping this will help my slightly rough idle.
Intermediate
Joined: Mar 2005
Posts: 33
Likes: 0
will i have problems taking my cat off? i put dynomax superturbos on it about 5 years ago and a off brand performance cat but i dont know how "performance" it was. i have already replaced the o2 sensor a few times b4 the car was running right. now that theres no "sniffer" test in nc for cars older than 96 im takin em off and gona build it
