Muffler shops?
Thread Starter
Advanced
Joined: Jun 2010
Posts: 74
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Muffler shops?
So I am thinking about getting a new exhaust system for my '80 L48. Now the problem is that I want a dual with no cats. I read somewhere that the shop will not remove the cat. Is this true? I would also want to put the cats back on easily when I need to pass smog or go "off track". Is that possible? Maybe a pipe I can just remove to bolt the cats back on. Btw i live in California if that helps! Thank you! 
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
A lot depends on state laws...it may well be illegal for a shop to install a non-cat system when cats are required if they originally came on the car.
If you buy a true dual system from a vendor like Corvette Central, Eckler's, et al, they MIGHT install it for you. Again...depends on state laws and their desire to avoid legal liability.
In my state (The People's Republic of Maryland), once a car is over 25 years old it can be registered as historic, and no longer has to pass emissions testing. Technically, it's a fine line, especially if federal law might enter into it, but I was OK with installing a true dual system on a '78 L82 I used to own. I didn't use a muffler shop...I went to a service station where I knew the owner and tech well and they were happy to do it for me.
If you buy a true dual system from a vendor like Corvette Central, Eckler's, et al, they MIGHT install it for you. Again...depends on state laws and their desire to avoid legal liability.
In my state (The People's Republic of Maryland), once a car is over 25 years old it can be registered as historic, and no longer has to pass emissions testing. Technically, it's a fine line, especially if federal law might enter into it, but I was OK with installing a true dual system on a '78 L82 I used to own. I didn't use a muffler shop...I went to a service station where I knew the owner and tech well and they were happy to do it for me.
Melting Slicks
Joined: Oct 2008
Posts: 2,154
Likes: 69
From: Regina Sk Canada
Well i have a 1980 as well. And i bought a true dual cross member from a 79 vette. Now i also bought a dual exhaust system from Bairs, for a C3 with manifolds. but will have to have the muffler shop make header pipes back. Will post pics when i get it back.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
I don't know of any muffler shop in Calif. that will break the law for you, your stuck with single exhaust but, you can install a high flow Cat in your Vette. Good luck in your search, and bring cash to pay them off.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Have the muffler shop install the CATs; but make the CATs removable. Put flanges on the CATs and mating flanges on the exhaust pipes. That way the muffler shop can say they installed the CATs when they did the work...but you can pull them out and insert "test pipes" when you need to 'test out the system'. (nudge, nudge; wink, wink)
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
http://www.epa.gov/compliance/resour...hsysrepair.pdf
See this document to see what you are up against.
See this document to see what you are up against.
Racer
Joined: Dec 2007
Posts: 341
Likes: 29
From: vancouver washington
So I am thinking about getting a new exhaust system for my '80 L48. Now the problem is that I want a dual with no cats. I read somewhere that the shop will not remove the cat. Is this true? I would also want to put the cats back on easily when I need to pass smog or go "off track". Is that possible? Maybe a pipe I can just remove to bolt the cats back on. Btw i live in California if that helps! Thank you!
Thread Starter
Advanced
Joined: Jun 2010
Posts: 74
Likes: 0
http://www.epa.gov/compliance/resour...hsysrepair.pdf
See this document to see what you are up against.
See this document to see what you are up against.
What the hell do you guys do to get around this? Thanks for all the help.
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Drifting
Joined: Oct 2008
Posts: 1,496
Likes: 6
From: springfield ohio
You could always buy after market cats and install them at the collector at the end
of the headers. You will have to replace or modify the cross member for the duals.
Here is what I used on a recent install on my truck, This is not were I bought it from through
its just a link to give you an Ideal.
http://www.hottexhaust.com/Catalytic_Converters.htm
Don't forget to throw in an H or X pipe behind the cats also while your in there.
Hope this helps,
Riggs.
of the headers. You will have to replace or modify the cross member for the duals.
Here is what I used on a recent install on my truck, This is not were I bought it from through
its just a link to give you an Ideal.
http://www.hottexhaust.com/Catalytic_Converters.htm
Don't forget to throw in an H or X pipe behind the cats also while your in there.
Hope this helps,
Riggs.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Most shops will not add true duals with 2 cats on their own. Most inspection stations do not enforce this rule. If you take the car in to the muffler shop with 2 cats, they will likely take it from there without a problem-at least here in the South. California may not be so easy, either at the shop or getting inspected. Good luck.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
FedorC3....
Could you not read post #5??? That's how you get around it...you have the muffler shop put the CATs on your car, with flanges, so that you can remove them later for "testing" purposes. What do you want??? Someone to hold your hand and drive you to the muffler shop?
Sorry, I've had a very busy day... and "spoon feeding" is not my forte.
Could you not read post #5??? That's how you get around it...you have the muffler shop put the CATs on your car, with flanges, so that you can remove them later for "testing" purposes. What do you want??? Someone to hold your hand and drive you to the muffler shop?
Sorry, I've had a very busy day... and "spoon feeding" is not my forte.
Instructor
Joined: Jun 2010
Posts: 199
Likes: 0
my way of getting around the cats and having cats on.... not exactly legal but its gets the visible inspection great did this on few dodge diesels for straight threw exhaust.
1- go buy 2 cheapy cats.
2- have them installed with muffler clamps or install the exhaust yourself.
3- buy a section of 2.5-3 pipe depending on the size exhaust you placed and your cats the length of your cats you had put on
4- go home remove the cats. using a angle grind cut the welds of the cat do not split the cat inhalf just remove the flanged ends like opening a soup can.
5- beat out all cermic honey comb leave none behind or it will rattle
6- slide bought length of pipe threw the cat.
7- nicely weld back together making sure to try and make it look factory
8- replace and drive happily
and there ya go cat shells but no cats. it passes visible inspection
and trick to passing emissions if needed is do a minor tune up change plugs before you go frsh plugs will burn better cuasing passable emmisions.
hope ya enjoy and i dont get in touble lol
1- go buy 2 cheapy cats.
2- have them installed with muffler clamps or install the exhaust yourself.
3- buy a section of 2.5-3 pipe depending on the size exhaust you placed and your cats the length of your cats you had put on
4- go home remove the cats. using a angle grind cut the welds of the cat do not split the cat inhalf just remove the flanged ends like opening a soup can.
5- beat out all cermic honey comb leave none behind or it will rattle
6- slide bought length of pipe threw the cat.
7- nicely weld back together making sure to try and make it look factory
8- replace and drive happily
and there ya go cat shells but no cats. it passes visible inspection
and trick to passing emissions if needed is do a minor tune up change plugs before you go frsh plugs will burn better cuasing passable emmisions.
hope ya enjoy and i dont get in touble lol
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Upgrading your Vette from the pellet type cat to a newer one should be worth some HP. You could also probably fit a 3" single exhaust through the Xmemeber by the transmission, then split it into two 2.5" pipes after wards to some open mufflers like Dynomax or Magnaflows for good performance. This would still be able to be done under California law.
Corvette Central has very well priced systems that you can bolt on yourself if your so inclined to do it.
Corvette Central has very well priced systems that you can bolt on yourself if your so inclined to do it.
Thread Starter
Advanced
Joined: Jun 2010
Posts: 74
Likes: 0
Upgrading your Vette from the pellet type cat to a newer one should be worth some HP. You could also probably fit a 3" single exhaust through the Xmemeber by the transmission, then split it into two 2.5" pipes after wards to some open mufflers like Dynomax or Magnaflows for good performance. This would still be able to be done under California law.
Corvette Central has very well priced systems that you can bolt on yourself if your so inclined to do it.
Corvette Central has very well priced systems that you can bolt on yourself if your so inclined to do it.
Race Director
Joined: Jan 2005
Posts: 10,988
Likes: 166
From: Milford Michigan
It's a federal law to not tamper with cat converters. You need a "buddy" in the exhaust business to do a custom dual system for you. If a shop gets caught yanking cats or modifying the OE setup, they could be hit with some very heavy fines.
Drifting
Joined: Jul 2007
Posts: 1,889
Likes: 23
From: Kansas
Yes Sir; I used the 2.5 exhaust system from Corvette Central, also used the stainless bands to put them together with. Fit like a glove, installed after market Cats with same S.S. bands. These are all going down one side, because of power seat. The Army vehicles, including the Tanks don't have Cats," Atlas Shrugged ", Where is John Galt ???
Gene
Gene
Thread Starter
Advanced
Joined: Jun 2010
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So I talked to a guy at a muffler shop and he told me that I wont pass smog even if I have cats on my dual. So I guess ill just order the one from Corvette Central or have one built at a shop. Then when test time comes throw the stock system on. You guys think thats a good idea or am I crazy?
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
See post #10. Yes, you can swap systems each year, but that is a pain. You might try to use a stock system that has been optomized with a better hi-flow cat and good flowing muffler or no muffler. I have had several cars with cat(s) and no muffler.
