catalytic single or dual
Thread Starter
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
I highly doubt a dual exhaust with hi-flow cat would take that much out but if it did, I would be OK with it, until the next engine.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
With metallic cats, there are fewer cells/inch. To compensate, manufactures add more catalyst (dip them more times?) during manufacturing.
Ceramic cats are closer to the 350cfm end while metallic are 450ish. That's in the Magnaflow line. I'm fairly sure RT claims higher flow numbers but I haven't looked recently.
With a dual 450cfm system, you'd have 900cfm system flow. Divided by 2.2cfm (Vizzard's ideal), you'll see it would support about 400HP.
If you have more than that, it could be beneficial to check out the RT cats. It kinda depends on how much higher than 400HP you really are.
Thread Starter
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
Metallic cats (vs ceramic) will hurt the least. Magnaflow has these as does Random Tech (the reported "Cadillac" of cats). This is also what Mick refers to as a stainless core.
With metallic cats, there are fewer cells/inch. To compensate, manufactures add more catalyst (dip them more times?) during manufacturing.
Ceramic cats are closer to the 350cfm end while metallic are 450ish. That's in the Magnaflow line. I'm fairly sure RT claims higher flow numbers but I haven't looked recently.
With a dual 450cfm system, you'd have 900cfm system flow. Divided by 2.2cfm (Vizzard's ideal), you'll see it would support about 400HP.
If you have more than that, it could be beneficial to check out the RT cats. It kinda depends on how much higher than 400HP you really are.
With metallic cats, there are fewer cells/inch. To compensate, manufactures add more catalyst (dip them more times?) during manufacturing.
Ceramic cats are closer to the 350cfm end while metallic are 450ish. That's in the Magnaflow line. I'm fairly sure RT claims higher flow numbers but I haven't looked recently.
With a dual 450cfm system, you'd have 900cfm system flow. Divided by 2.2cfm (Vizzard's ideal), you'll see it would support about 400HP.
If you have more than that, it could be beneficial to check out the RT cats. It kinda depends on how much higher than 400HP you really are.
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 110
From: Austin Texas
Mick, Larry, Joe etc........
If you talk to Jim he will mention that cats really take power away (sort to speak).
Are you concerned of this at all Larry? Maybe the FAST will hit the tune more spot on, and eliminate a bit of that smell that both of us are not too found of.....
If you talk to Jim he will mention that cats really take power away (sort to speak).
Are you concerned of this at all Larry? Maybe the FAST will hit the tune more spot on, and eliminate a bit of that smell that both of us are not too found of.....
It is getting progressively harder to get a car without CATs inspected, and I just didn't want the hassle.
Besides, it's a blast to pull into the pits on the trailer and see the competition looking the car over, then beating the snot out of them with a "true" street-legal car.
If GM can get 500+ HP out of a C6 with all the environmental equipment on them, so can we. My 427 SBC will be closer to the 700 FWHP mark, and I'll STILL run it through CATs...and a full 3" exhaust system (I might add).
I can always see it in their eyes when I go to the inspection station. A rumbling Corvette not at all stock. They get into the pit to look under it and the CATs are there and they just come out with a little smile on their faces.
That alone is worth it to me to keep it legal.
Thread Starter
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
of course it is a restriction, I am not concerned about HP loss, my days of squeezing every last single HP and TQ number are over. With that said,, if the FAST gives me the result I am looking for, then I wont put a cat on.
Pro
Joined: Feb 2007
Posts: 740
Likes: 2
From: San Antonio TX
He's got factory GM hangers on the back...you can see the springs on them in the photo. They are located at the 3rd member, just inside the camber adjustment bolts.
I'd guess he used the same factory mounts at the trans for the exhaust system. Bolts right onto the trans and holds it up at the front.
I think my hangers ran me $40...
I'd guess he used the same factory mounts at the trans for the exhaust system. Bolts right onto the trans and holds it up at the front.
I think my hangers ran me $40...
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