Which is THE BEST cat on the market
Sadly there's no cat good enough to handle the flow from all 8 cylinders. You HAVE to run two cats, one after each header. This way they only have to handle the flow rate of 4 cylinders.
According to David Vizard, we require 2.2cfm per 1hp to not affect exhaust flow, and thusly bhp output.
So on a stock Fbody with ~345bhp thats (345 x 2.2) 759cfm for all 8 eight cylinders.
Which is well beyond any cat. Evidently running two cats means they only half to deal with (759 / 2) 380cfm which is much more managable.
Random Technology's 7000 Series Metal Matrix cats are very good (I think LG Racing uses them in their Corvette systems). The 3" variants can flow 598cfm, so well in excess of a stock Fbody, but not good enough to run in the I pipe. These are best cats I know of.
598cfm is good for ((598 / 2.2) x 2) about 545bhp at the engine without any restriction, if you run two of them. But they are pricey.
Random Technology also offer their 9000 Series cats, these in 3" inlet/outlet for flow 502cfm so pretty darn good, but they are physically a lot bigger than the 7000 Series ones.
I think but I'm not sure, the Magnaflow Carsounds cats flow somewhere in the mid 400cfm range, so pretty good and a lot cheaper also. A slight restriction won't be much of a problem unless you are running boost and high bhp levels.
But don't run a single cat in the I pipe.

EDIT: I see from your sig you have the TSP catted Y pipe, I believe they use the above mentioned Carsound cats. They are not posing an issue with your current mod status, even if you add a cam I doubt the cats would be sucking up any more than 10rwhp, if that. And if you are having ground clearance issues, then adjust your Y pipe. If that doesn't work you have quite simply slammed your car too much. In stock trim they already have quite low ground clearance and shouldn't really need lower much if at all.
Last edited by 300bhp/ton; Feb 10, 2006 at 11:52 AM.
Sadly there's no cat good enough to handle the flow from all 8 cylinders. You HAVE to run two cats, one after each header. This way they only have to handle the flow rate of 4 cylinders.
According to David Vizard, we require 2.2cfm per 1hp to not affect exhaust flow, and thusly bhp output.
So on a stock Fbody with ~345bhp thats (345 x 2.2) 759cfm for all 8 eight cylinders.
Which is well beyond any cat. Evidently running two cats means they only half to deal with (759 / 2) 380cfm which is much more managable.
Random Technology's 7000 Series Metal Matrix cats are very good (I think LG Racing uses them in their Corvette systems). The 3" variants can flow 598cfm, so well in excess of a stock Fbody, but not good enough to run in the I pipe. These are best cats I know of.
598cfm is good for ((598 / 2.2) x 2) about 545bhp at the engine without any restriction, if you run two of them. But they are pricey.
Random Technology also offer their 9000 Series cats, these in 3" inlet/outlet for flow 502cfm so pretty darn good, but they are physically a lot bigger than the 7000 Series ones.
I think but I'm not sure, the Magnaflow Carsounds cats flow somewhere in the mid 400cfm range, so pretty good and a lot cheaper also. A slight restriction won't be much of a problem unless you are running boost and high bhp levels.
But don't run a single cat in the I pipe.

EDIT: I see from your sig you have the TSP catted Y pipe, I believe they use the above mentioned Carsound cats. They are not posing an issue with your current mod status, even if you add a cam I doubt the cats would be sucking up any more than 10rwhp, if that. And if you are having ground clearance issues, then adjust your Y pipe. If that doesn't work you have quite simply slammed your car too much. In stock trim they already have quite low ground clearance and shouldn't really need lower much if at all.
anyways, do any of the vendors on this site sell the 7000 series cat? and i saw where u said it is 4", if i have a 3" Y pipe, do they also make them in 3" or would it be impossible to get them onto the 3" pipe, thanks!!! Trending Topics
https://ls1tech.com/forums/generation-iii-external-engine/448747-high-flow-cats-ones.html
We have some prototypes for all out race classes requiring cats with 200 cell density metallics to support 640+ CFM / 4" substrate and another completely unique design part which will flow a tad bit more specifically designed to last high boost without the subtrate style core... stay tuned.
The Best V8 Stories One Small Block at Time
And all the better for those like me who HAVE to run cats.



