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Discussion Starter · #1 ·
Just wanted to show a pair of

Just wanted to show a pair of converters I just made for the 348 / Mondial T. They are 200 cell units and quoted for 250 HP each.
I tried to prevent losses as far as possible.
Your comments for improvements are welcome.
 
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Discussion Starter · #3 ·
Nice cat chris, Do you have on

Nice cat chris, Do you have one or could you make one for the 308QV or 328?
 
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Discussion Starter · #4 ·
Sorry, I cant do one for you a

Sorry, I cant do one for you as I’m located in Germany, so transport would cost a fortune. I cant build one without a sample and I only have a Mondial T what limits my production to this models and 348 cat’s.
I have spent some thoughts and asked a guy who does cat development for the German car industry. In the end I believe I have designed a really good system, as the stock part is simply wrong in any aspect.
The stock cat I fitted while doing the replacements was in perfect shape. After only 3 month on the car it has disintegrated, again, now the 3rd one.

I do not make this post to promote my parts, but to test others opinions, maybe to improve them for the next pair and encourage others to diys.
For those that are interested in costs, the raw cat is 250 Euros each over here, which equals 315 US $ including 16% sales tax. Welds are made with a simple MIG welder, using .6mm stainless wire. Fittings are taken from a stock 348 exhaust system.
Diameter is 105mm and it does not need a off set like the stock system.

Chris
 
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Discussion Starter · #5 ·
Nice work. Looks like it bolts

Nice work. Looks like it bolts right up.

I'd love to see bench flow-tests for the stock 348 cat, hyper-flow cat, and your cat.

That being said, if you are burning up cats every 6 months, then you are sending too much raw fuel through your exhaust, I hate to say.

Do you think that your new cat should have a heat shield to protect other engine components?
 
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Discussion Starter · #6 ·
Yes, they are plug n play.
I


Yes, they are plug n play.
I made my personal (not scientifically proven, but logical) flow test with a stream off compressed air, comparing a perfect stock unit to mine. Leaving the stock cat, the air is a diffused breeze, while it leaves my metal unit nearly as powerful as blown trough a test pipe. Interesting is a empty case of an stock unit. Its resistance to airflow is not as high as one with a intact monolith, but still very restrictive. Fits to my personal feeling it does not improve performance to empty the stock cases.
I must admit, there are two converter versions, the Ansa cat being better than the one made by Zeuna Augsburg, compared by flow and durability.
The hyper flow version places the lambda directly in the exhaust stream, this is not necessary and causes turbulence. Remember, it is heated. And I don’t think it will be covered by deposits, as the old converters have none at that position if examined.
My last cat was definitely not melted, but the wire mesh holding the monolith changed it’s position and the ceramic touched the casing and broke. All defective cats I had were not melted, but broken. I must admit, they all sure saw a few minutes, maybe 10 or more, flat out on a after midnight Autobahn before failing, with “Slow Down” flashing. But the problem seems more high vibrations with uneven pressure on the ceramics tilting them.

The metal converter is a up to date design, it is a heat shield itself. The outer part of the
reactor is not involved in the catalytic process, and acts like a stainless multi layer shield. That’s what I was told by the company that sold it to me. They don’t get red hot like you sometimes see it on pictures of engines on test stands, because they are for more than 250 HP and see a maximum of 160.
In fact the lowered back pressure should even reduce temperatures in the exhaust manifold.

To tell the truth, building them is not that much work. 4-6 hours and you are done with a pair, using no sophisticated tools. Welder, angle grinder, a stepped drill, that’s all. Sourcing the parts was the hard part.

Chris
 
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Discussion Starter · #7 ·
This is just excellent!

Wi


This is just excellent!

With Ferrari now wanting several thousand dollars for replacement Cats, and high flow Cats for other cars running at a handful of hundreds of dollars; an enterprising individual can make their own Cat replacements for a lot less money that Ferrari would charge.

Good work.
 
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Discussion Starter · #8 ·
Interesting Chris! I just rep

Interesting Chris! I just replaced a cat on my 355 with another used Ansa factory oem unit. The previous one had the ceramic core come loose and rattle around, just like had happened to the previous owner of my car (he replaced both one before). The factory Ansa units are not very durable, that is for sure. Seems the 348 and 355 suffer from the same poor quality cats.
 
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