Universal High Flow Cat

Jun 6, 2010 | 09:19 PM

discomonkey

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From: Elkton, Maryland

Universal High Flow Cat

I currently have turbo xs cat back and a turbo xs mid pipe. I am thinking about going to a high flow cat. Could i buy a universal 3" high flow cat and just weld it into my current mid pipe?

Jun 6, 2010 | 09:23 PM

invasion08

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From: New jersey

Call up Rotary Performance http://www.rx7.com/store/rx8/rx8exhaust.html. Maybe they will sell you one of there super cats, so you can weld it into your current midpipe

Jun 7, 2010 | 12:12 AM

alnielsen

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From: Buddhist Monastery, High Himalaya Mtns. of Tibet

Below are links to some hiflow cats. I recommend the first one. After I found it, one member put it on his car and now has over 20K miles on this cat. The other two to my knowledge haven't been tried.

http://www.davesport.com/cgi-bin/davesport/DCAT100.html
http://www.performancepeddler.com/de...T_ID=SUP200605
http://www.ppeengineering-onlinestor...sc?productId=5

Jun 7, 2010 | 05:46 PM

HiFlite999

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From: MI

Quote:

Originally Posted by alnielsen

Is there any advantage/disadvantage to the 100 cpi vs. the 200 cpi? Any CEL issues with the davesport?

Jun 7, 2010 | 09:27 PM

GeorgeH

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From: Portland OR

100 cpi will probably make more power (particularly with a good tune), but smell worse.

I've been running a Davesport for a year with no CEL issues.

Jul 27, 2010 | 03:56 AM

GaMEChld

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From: Long Island (Suffolk), NY

I was thinking of adding a high flow cat. Currently I have a straight pipe, but the lack of cat combined with some rich running with my turbo, yields some noticeable flames. That can get you into trouble with cops.

Would a High Flow cat eliminate that, or would fuel still get by it. Also, if you are running rich, would the excess fuel just kill the cat in an extremely short time, making it a futile gesture?

Jul 27, 2010 | 05:21 AM

Krazed_Rx8

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From: Glendale, California

Quote:

Originally Posted by GaMEChld

* Note that
extremely
rich mixtures
will cause
even these
catalytic
converters to
overheat and
fail. If you
have a
mixture
problem it's
best to cure it
first!

Copied from 1 of those websites

Jul 27, 2010 | 03:44 PM

GaMEChld

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From: Long Island (Suffolk), NY

Thanks. Though I'm not sure if mine is all that extreme. Either way, I should get it tuned, so I might as well do that first.

Aug 14, 2010 | 10:18 AM

Renesis07

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Isn't that why RX8's (stock) run so rich anyways, to preserve the life of the cat converter? Figured running lean would toast the cat faster than running rich?

Sorry for thread bump btw lol

Aug 14, 2010 | 11:38 AM

#10

Highway8

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Rich runs cool, lean runs hot.

Aug 14, 2010 | 11:58 AM

#11

TeamRX8

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if it's excessively rich and oxygen is present the cat converter will light it off internally like a blow torch

Aug 14, 2010 | 12:10 PM

#12

Renesis07

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Quote:

Originally Posted by TeamRX8

if it's excessively rich and oxygen is present the cat converter will light it off internally like a blow torch

makes sense.

Aug 14, 2010 | 01:05 PM

#13

trustbuddy

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Quote:

Originally Posted by alnielsen

alnielsen, thanks for all the links. they were exactly what I was looking for.

Aug 15, 2010 | 07:43 AM

#14

yiksing

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From: in the basement

Quote:

Originally Posted by Renesis07

Isn't that why RX8's (stock) run so rich anyways, to preserve the life of the cat converter? Figured running lean would toast the cat faster than running rich?

Sorry for thread bump btw lol

Link below was a short discussion of cat life vs lean/rich mixture, don't know how true it is but thought i should share
http://www.imazda.com/forums/showthread.php?t=8389

Aug 15, 2010 | 11:10 AM

#15

HiFlite999

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From: MI

Quote:

Originally Posted by alnielsen

I'll be trying this one pretty soon:

http://www.summitracing.com/parts/MPE-59959/

Aug 15, 2010 | 11:17 AM

#16

HiFlite999

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Quote:

Originally Posted by Charles R. Hill

I will soon switch back to my MazdaManiac tune since I am satisfied that the cat works as it is supposed to.

.

What I have been waiting on (for 6 weeks now) is the first MM tune (for stock), then I'll put all the stuff on, and try to get another one. I was going to try other stuff with tunes too, but it now seems unlikely I'll get more than 2 tries during the 6 month period (The AccessPort also died and had to be fixed). Perhaps the tune is done, and it's sitting somewhere for me to download, but I have no idea how to do this.

Aug 15, 2010 | 10:23 PM

#17

Renesis07

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From: Lake County IL

Quote:

Originally Posted by Charles R. Hill

One thing people often forget is that (unless their car is a track-only car) they will spend the vast majority of their running time in closed-loop mode, wherein the PCM targets a 14.7:1 A/F ratio. Hardly rich and certainly not likely to roast a cat. The factory tune can get a bit rich at the upper RPMs but most of us don't really spend much time up there.

As an anecdotal, I have been using the DaveSport cat for over 1,000 miles and those first 500 my ill-maintained engine was randomly dropping into 10.8-11.0 A/Fs while on the freeway. This was during a recent trip to CA. I fixed the car when I got there and the engine and cat have performed flawlessly ever since. I am also running the factory mapping and I have no 420 CEL. I will soon switch back to my MazdaManiac tune since I am satisfied that the cat works as it is supposed to.

The DaveSport cat inlet and outlet are actually 3.1" I.D. so installation on a 3" midpipe will require the midpipe to be stetched a bit before welding can take place.

Mine has been fluctuating between 14.7-15.4 at idle. Its a little rough as if the system is trying to figure itself out. I desperatly need coils/plugs/wires, waiting to get them so I can install to see how that affects things.

Im sure my hot air intake isnt helping anything, its only at idle that things get goofy, cruising around it seems to hover around 14.7 with no issues.

Aug 16, 2010 | 12:12 AM

#18

TeamRX8

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CPI is just a general reference term. It doesn't necessarily mean much without also knowing both the total area and also the percentage open area. It's totally possible for say, a 300 CPI cat to outflow a 100 CPI cat. The devil is in the details ....