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Discussion Starter #1
After a conversation with 2 local (competing) performance shops they tell me High Flowing Catalytic Converters are just marketing ploys, and that everything is regulated by EPA, which includes flow rates.

Is this true??? Because after my cat went bad (it is currently at the dealership for repairs) I went to thinking... Why wouldn't it happen again after another 35k miles???

I've heard that with the placement of the cat so close to the header/engine area increases the heat in and around the cat thus causing premature failure. If that's the case then I would just rather pay someone to make a custom pipe from the header to my cat back exhaust, and move the cat further back in the chain. I've heard moving the cat closer to the flex pipe is advantageous in a few respects... Of course I would make sure they would use at least 2.25" tubing throughout so that the bottleneck is truly the cat and not the old/smaller flex pipe. I would probably need to buy a cheater O2 plug so that the CEL does not go off.

What do you guys think???
 

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i replaced mine w/ a random tech. look it up at mcnewsautomive.com and its definately high-flow. and it passes emissions
 

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Discussion Starter #3
Originally posted by Wedge1212:
i replaced mine w/ a random tech. look it up at mcnewsautomive.com and its definately high-flow. and it passes emissions
<font size="2" face="Verdana, Arial">Did you even notice a difference between this and the stock cat??? I told the guys about the Random Tech Cat and they were like, well if the flow is any better it is likely due to larger diameter pipe and a cleaner 90 degree pipe turn...and NOT due to the cat being able to flow anymore than stock. They felt that a stock cat could flow as well or better than a high flow exhaust, so why bother paying more for the marketing hype.

Not sure if any of this is true, just curious as I was about to plop down some cash on a high flow cat and flex pipe.
 

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trust me, it flows more, when i had mine way back in the day, it was a very noticable difference compared to stock...the stock one is extremely restrictive
 

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its the whole design of the cat. The random tech has very gradual bends. and the catalyst chamber isnt huge either. Its large enough to hold the catalyst material and that's it. However the stock cat is a huge and really decreases exhaust flow speed because of the incrase in overall diameter (High school physics). Now once the stock cat has reduced the exhaust gas speed it then slams into the bottom of the cat and has to make a 90* bend shaped exactly like an L before going into a 1.75" piping. Now onto the make of the catalyst. When I looked in to my stock cat the catalyst was basically a large lump of gray **** shaped like a cone. The random techs catalyst is honey combed and as far as i know cylindrical in shape. So you can take it how you want. From two people who have or are using the cat. Or someone who's never touched one
BTW i really recomend it. Definately the big bottle neck in the exhaust system
 

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I had a high-flow cat welded in behind my turbo, post-flex; I put it in a few days after I installed my race header. It's noticeably perkier than stock, but it could just be that a) the header does a better job of scavenging exhaust pulses from the head and b) the cat has 3" in/outlets (I have a 3" exhaust from the turbo to the tailpipe).

That's my experience, anyway. I can't speak to the results of putting a different cat in the same place as stock.
 

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" If that's the case then I would just rather pay someone to make a custom pipe from the header to my cat back exhaust, and move the cat further back in the chain. I've heard moving the cat closer to the flex pipe is advantageous in a few respects..."

In the Focus, the cat is IMMEDIATELY before the flex-pipe.
It can't get any closer to the Flex-Pipe. It's RIGHT in front of it.
Yes the Hi-Flows Flow w/ less restriction. Typical HP gains are 3-5 HP.
That's about the same for installing a quality catback.
Every link in the chain helps a little, and NO, the cats are NOT marketing, IF it's a reputable brand. (Don't trust the generic Fleabay stuff...)
 

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I Just killed my clogged cat problem a half hour ago by installing a ORP, Car is runnin like it never ran before.... Big gain....
big noise
 

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What's the longevity of the high flow cats? I seem to be going through stock cats like a 5 year with a cold goes through kleenex. If I plunk down the cash for a high flow cat, will it last a lot longer than the OEM Ford units?
 

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Discussion Starter #10
Originally posted by ZX3 Canuck:
What's the longevity of the high flow cats? I seem to be going through stock cats like a 5 year with a cold goes through kleenex. If I plunk down the cash for a high flow cat, will it last a lot longer than the OEM Ford units?
<font size="2" face="Verdana, Arial">I guess that is my concern also. If I buy a $350 high flow cat will its guts just clog my exhaust again a year or 2 down the line??? I would hope it would last for the duration of me owning my car.

I've heard that moving the cat AFTER the flex pipe, rather than IMMEDIATELY after the the header would be preferrential.

Please see this thread:
http://www.focaljet.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=2;t=010602#000004

[ 12-13-2002, 11:27 AM: Message edited by: jdp72 ]
 
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