high flow cats
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Joined: Sep 2003
Posts: 92
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From: Pearl ms
high flow cats
Okay, I want to know if anyone has seen a test or knows in fact high flow cats make a difference in performance. I want to add headers to my 98 but I really want to know if high flows will make a difference. I have Corsa Indies now and want to move further. I am seeing differences on some websites of 25cfm from factory cats to after market cats and I am wondering if that much will make any difference. We all have to suffer from the cat converters if we want to stay legal but is the change to high flows even worth it?
Pro
Joined: May 2004
Posts: 551
Likes: 19
From: Morgantown WV
Originally Posted by nlreb54
Okay, I want to know if anyone has seen a test or knows in fact high flow cats make a difference in performance. I want to add headers to my 98 but I really want to know if high flows will make a difference. I have Corsa Indies now and want to move further. I am seeing differences on some websites of 25cfm from factory cats to after market cats and I am wondering if that much will make any difference. We all have to suffer from the cat converters if we want to stay legal but is the change to high flows even worth it?
If interior noise is a concern and you have a few bucks to spend on mods, consider an under drive pully. You will see the same RWHP gain for fewer bucks and no additional noise / drone.
Good luck!
Safety Car
Joined: Oct 2002
Posts: 4,434
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From: Austin TX
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St. Jude Donor '03-'04-'05
Originally Posted by jedicowboy
Are there any 'bargain" hi-flows out there? Most I have seen are up their in price. 
I paid some $ and had some Random Tech hi-flow cats installed when I upgraded my headers & mid section & X pipe.
Burning Brakes
Joined: Jun 2002
Posts: 1,037
Likes: 31
From: Richmond Texas
From what I've read and seen, your looking at 5-10 hp difference. Not worth the extra money to me. I'm doing long tubes with a 2.5" x-pipe and factory cats in a few weeks with a before and after dyno with no tuning. I'll let you know what I find out.
Drifting
Joined: May 2004
Posts: 1,904
Likes: 2
From: London(UK)/Troyes(France)
Originally Posted by BigBlue
From what I've read and seen, your looking at 5-10 hp difference. Not worth the extra money to me. I'm doing long tubes with a 2.5" x-pipe and factory cats in a few weeks with a before and after dyno with no tuning. I'll let you know what I find out.
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Instructor
Joined: Feb 2004
Posts: 124
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From: Nashville TN
Random Tech hi-flows rock. AFR did a before/after dyno with no cats vs RT cats and only gained 3 horsepower without cats! RT cats move serious air and scrub like maniacs! I have them and even without MARTA in my county I am thankful every time I roll down the window and smell that sweet air instead of burnt premium unleaded. Good Luck!
