Sab

I found these high flow cat's on ebay and am wondering if they will work fine on the x-pipe I will receive soon.
it states they are rated at 5.9l, so I guess that would double with two and there fore be plenty. They seem almost too cheap to be true... $49.00 each.

No affiliation with the seller.

What do you guys think?

http://cgi.ebay.com/ebaymotors/ws/eB...2587944&rd=1,1

kary4th

If I recall correctly, on the '85 928, Porsche said there was no HP lost with their cat installed. Was this not the case for later models?

byrdman454

They will work, but they are a ceramic catalyst, which means massive HP losses. The cheapest route I have seen is the cats that 928 Motorsports SLC have for sale. I think they only had a 2-3 hp loss and they are way cheaper than Random cats that Louie Ott and others have used. They are still more expensive than $50 a piece. You get what you pay for...

Sab

"massive HP los..."

OK, they are not for me. Thanks for the heads up.

tv

I think what mike was referring to was the part of the pic showing the catalyst itself with a square grid pattern. A true hi flow cat shaped like that one should have a spiral catalyst.

cfc928gt

Do you have an X-pipe you plan on using them with? What you're looking for is a metalic cat. They flow much better than ceramic. About the best a high flow ceramic is capable of is 400 cells per sq inch. Motorsports sells two different types, the one that only loses 2-3 hp has 100 cells and the one that loses 6-8 hp has 300 cells. I imagine the 100 cell is louder than the 300 cell if noise is an issue. The best high flow ceramic they tested lost about 15 hp. All these numbers are from them using their X-pipe.

danglerb

Want to bet somebody in China etc. has a cat factory going, and its not a BBQ?

Those "look" just like those sold by Pypes, and listed in the CARB database as, Manufacturer Name: Automotive Edge, The (dba Hermoff), with the size stated as universal replacement up to 5.9L and tested on a Dodge pickup (D567 is the EO#)

I see "generic" weld in cats selling from a low of this guys $50, more typical is $90 for something like a Magnaflow (who make a LOT of other peoples branded cats along with Catco) to about $200 before the price takes off for "direct replacements". I spent a couple hours trying to figure out exactly how that works here in Calif, and its clear as mud.

CARB considers the cat with a pipe and fittings attached as different from a weld in cat, except when its the original company that got the cat exemption. Makes very little sense to me, but apparently Magnaflow can sell me a cat or a direct fit replacement part, Joe's muffler shop can cut out my old cat and put in the universal part, but isn't allowed to weld a new pipe with flanges on it to make a direct replacement part without getting a CARB EO#, but if my pipe is "damaged" Joe can replace the pipe as well.

Part of the CARB exemption is that the company is not allowed to tout any performance or flow improvements in any advertising or other material, so REAL information isn't easy to find. This has created a mess where places like one I visited the other day became "excited" and claimed there was no way to make HP with CATS and the only sane thing is to install a "test pipe". Fortunately I also hear from guys who do know how to make HP, and they say the loss should be no more than about 3% with a modern cat, and you can recover some of that due to reduced muffler requirements when using a cat.

So whats everybody's favorite Cat to use?