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Anyone have a solid suggestion for a test pipe for a 78 to remove the converter (off road use of course!!!!)?
Has 4 bolt flanges on both ends, I can MAKE one but checking to see if someone has already have them in production.
TIA!
Dave
Anyone have a solid suggestion for a test pipe for a 78 to remove the converter (off road use of course!!!!)?
Has 4 bolt flanges on both ends, I can MAKE one but checking to see if someone has already have them in production.
TIA!
Dave
Dearp
Haven't seen any in quite a while.
If you can cut and weld then you can always gut the existing cat and bolt it back in. OR, for that matter if your cat has flanges then cut out the cat and weld in your desired pipe. Probably what I would do just for the fun of it.....well, if Smog Checks for 78s weren't a thing.
Originally Posted by Dearp
Anyone have a solid suggestion for a test pipe for a 78 to remove the converter (off road use of course!!!!)?
Has 4 bolt flanges on both ends, I can MAKE one but checking to see if someone has already have them in production.
TIA!
Dave
There’s definitely significant gains to be made from removing that heavy restrictive cat, but there’s even more to be had going from the restrictive 2-1-2 to a full dual exhaust. Corvette Central sells a kit that has been used by a number of people on the here. It fits great and sounds much better than the stock pipes.
Last edited by Piersonpie; Nov 6, 2024 at 01:38 PM.
i went down that road too several years ago.. nothing was available anymore..
suggest biting bullet and putting duals on..
also there was no way i was not getting cat off without damaging 4 bolt flanges, and only had 28000 miles..
I did this on mine when I first got it. I just went to an old school muffler shop. I think they made a bolt in test pipe, exact fit for the cat for like 30 bucks + the cost of the metal.
I did something better than that, I had the catalyticremoved from the car and then I busted the ceramic plated part into a million pieces. I shook the parts out and had the catalytic replaced on the Car. Then I drove over 400 miles home that day without a hitch. The engine was able to pass the emission test here in VA without a functional catalytic.
Technically, removing or disabling the emission equipment violates FEDERAL LAWS and most smart Professional mechanics will not touch removing them. I replaced the Catalytic on my C4 with a High Flowing Catalytic Converter and with a free flowing exhaust I was able to break into the 30 mpg range and the engine is running with no drone and clean emissions.
On the C4's if you remove the catalytic converter you will get a drone that won't go away. Sometimes a good exhaust can control it but not always.
Actually, in South Eastern Wisconsin. They do have emissions. Just Milwaukee and surrounding area back when I was there 16 years ago anyway.
But I'm thinking a car that old shouldn't be a issue.
I have collector plates on the car so no testing. In my County we still have testing but there's workarounds...
True duals are great, but everything under the car is new, including the exhaust system. I can build my own test pipe, and fortunately I've already have had the converter off.
If you have a 2 into 1 into 2 system, just eliminating the (new) cat may not gain you much. If you can convert to a true dual system, you will be well ahead (then the exhaust manifolds will be the restriction).
Try Facebook Marketplace. Used systems pop up there. But Corvette Central has new systems for $600-. Just be sure to specify a 74 or earlier car. How much is your time worth?
Guys, I removed several posts here as some of you are trying to buy, some are selling, some are talking about “dibs” which are not a thing in sales threads and some of you are literally hijacking the OPs thread.
This is not a sales thread, nor is this a sales area. So if you want to buy or sell something, use the PM function. Please don’t gauge interest in sales here either, thanks.
Test pipe...
