appear

Can someone tell me the width/Ø of the standarc catalytic donverter inserts?

I have searched exstensively for an answer to this question.

I am considering the Cargraphic 100 Cell (w. 200 Cell inserts) Catalytic-X sports cat. However in thread on the turbo forum I read that the cargraphic cat-inserts are only 105mm (Cargraphic has confirmed this) and the stock inserts are 130mm. If that is actually true it is just bad design in my opinion.

My alternative solution is fitting 200 Cell units (from Carnewal) to my stock cat which is still in perfect condition at 50k Miles. Fabspeed and DACH seems to be impossible to source (from new) in Europe, and import costs are much too high here in denmark. (25%).


Thanks

geolab

THE original factory catalytic cartridge is 105 mm thick x 130mm length,
not 130 mm thick if my memory is still good

appear

Okay, thanks geo! Can anyone here confirm?

chaoscreature

I just cut some open so i can fonfirm the length for the 1996-1998 bricks.
There are two of them (four total), the first one is 5" long and the second one is about 3.5" long. Diameter was right about 4".
I will be posting pictures of the dissection tomorrow.

chaoscreature

What was interesting is that the two exhaust banks are 100% seperated... I always thought that they could crossover in the middle.

geolab

Would like to see the pictures.
In ROW the left and right catalytic banks are not separated
regards

Bill Verburg

I'd like to see pics too, all the ones i've seen have a central mixing chamber, which is not designed for flow efficiency but rather to mix all the gases, create turbulence and increase residence time in the cats, the 2 t's increase cat efficiency reducing emissions.

chaoscreature

Okay,
here is a pic shot down one of the opened sections towards the middle of the cat. Notice the plate that was welded in between the two banks, completely seperating the two.

Bill Verburg

I'm having a tough time seeing anything there
is the this the type of cat that was used? '95US and '94-98 RoW

ToSi

I suspect the difference is due to 95/ROW (single bank /o2) vs. 96+ US (dual bank)

Here's a photo (thanks Google) of what looks to be a '96+, has 2 distinct inlets into the cat & what appears to be a circumferential weld mid-way between. This was likely done to separate allow catalyst monitoring diagnostics by comparing upstream / downstream o2 sensor readings.



Has anyone actually measured backpressure in the exhaust before & after swapping parts? Porsche made it easy by providing a service port ahead of the catalyst. Would be a good way to quantify the improvement from different mufflers, high flow cats & other shiny parts.

Bill Verburg

Thank me as I took and posted that pic over on Pelican.

It makes sense that the '96-98 US OBD2 cats w / 4 O sensors would modify the mixing chamber to keep the sides separate. They went to a lot of trouble and expense to be able to measure each banks pre and post cat O levels. I've never seen on of those opened up.

chaoscreature

The cat I cut up was exactly like the one in the above picture and it was definitely from a 96+ 993.
I would love to dissect my 95 cat and put some 100 cell "inserts" back in, but I need to keep it around to pass smog.
The one that was cut open for that little picture (I need to become a member so I can post real pictures ) will be getting a special treatment, but I will start a new thread on that once I get started.

John@Fabspeed

Hey Appear, PM Sent with more information on whats available.