ceboyd

I'm thinking I'm going to put my stock heavy cat back on and sell these for some extra spending $$ to allow me to keep going to DE days while being unemployeed (still now after a year so funds are getting tighter).


I have to check now but last time I looked they were priced something beyond rediculous for brand new like $2600 EACH side (and you need 2 of them). Mine have been used all of last season and so far in April of this year. There is nothing wrong with them. The are stainless steel so they now have a nice patina to them from the heat. (they started out very nice stainless color when I got them and I've managed to make them turn pretty colors).

They are indeed very nice units and save a lot of weight.


I have them set up to allow mounting of all 4 o2 sensors on my 96.


I took some photos of them to demonstrate how they look on the car.

If any rennlister is seriously interested, please PM me your best offer and It'll help me decide if it is worth loosing them (as they also help provide that nicer air -cool exhaust sound) ... I never realized how much the stock cat muffles the sound until I installed these... I'd go as far as to say my exhaust sounds just like the RSR setup (maybe just a hair louder) without actually having RSRs (I only have Motorsound exhaust).

..so I will miss that beautiful sound but in reality it isn't a necessity to keep going at DE events.. it's just one of those nice sounds, nice to have lux items..


BTW: Since I'd be reselling these for income purposes while unemployeed, I'm sorry to say I can't just give a 'super great deal' to a fellow rennlister and would need to get top dollar (again, I realize that means most likely less than half new) but I'd rather see if a rennlister is interested first before I try the ebay route and to get a feel for resale value before I go through removal of them. (removing them alone probably won't happen for at least 3 weeks from today as I need to wait on eric's schedule to open up to do the swap back to stock for me)

Dan V

I'm curious: how did you decide to go with sport cats rather than cat bypass, since this is mainly a DE car? Seems you could just bolt in the stock cats every 2 years just for the emissions test, then run the straight pipes otherwise.

ceboyd

yes, you can go with cat bypass if you wanted of course... but I didn't want to risk getting a ticket (for noise OR pollution/smell of no cats) since I do drive in the street to/from the track... and didn't want to deal with either having to tie off the o2 sensors OR risk the computer freaking out (OBDII system) with not getting any readings from the O2 sensors..

I know other cars run like complete crap when O2 sensors fail and I just didn't want to risk that happening on the OBDII system.

I see the cat bypass as Ideal for the 95 993 owner who only has ONE O2 sensor to deal with.

So each to their own.. and I will only go back to the stock cat and NOT a bypass..

LAT

Besides, sound and weight savings do they make any difference in power output?

ceboyd

BTW everyone, I just found out the part number is the same for C2, C4 OR C2s or C4S (only the TT has a totally different part number so these can NOT be used on a TT)


These are from my 96 so I get confused as to what that means for exhaust (I think that means gillet but maybe it means bishoff).. all I know is these wouldn't have fit on Eric's 95 993 because that was a different style mount (again I get the whole bishoff and gillet thing confused but the 95 was different)

ceboyd

Top end power is better (meaning I can accelerate to a higher top speed on the straight at Road America).... I noticed better top speed with the supercups as well (but I sold those last year already).

Once I went back to stock mufflers, my bottom 0-30 speed seemed to improve but I lost some top end power BUT the sport cats still afford me a little more top end power..

I expect to loose that top end power going back to stock and gain a little low end again..

Honestly Road America (with that big straight) is the only place I clearly saw the difference.

WITH supercups and WITH sport cats I saw a top speed of 139 at the straight, with stock mufflers and the sport cats I saw a top speed of 134 at the straight and I remember with the total stock system I saw a top speed of 129 at the straight. ...so I'm not sure how significant my non-scientific observations are.


I also have Steve's chipped ECU that probably factors in to all of the above.

Paulsha911

ceboyd, I'm confused. Are you saying the sport cat gives you better top end power but you lose some in the low end?

I have Steve'e ECU also. Did he have to make special adjustment for the sport cat? or is it the same?

Thanks in advance.

ceboyd

Steve made a special program adjustment for when I had the supercups and he warned me about loosing low end power when I had them (but since I'm up higher in the rev band on the track, I never really noticed it as a hinderance)

Steve did NOT do any special programming for the sport cats.

I also don't know if my 'top speed' that day at RA had anything to do with weather conditions and my state of mind (thus very UNSCIENTIFIC).

So the bottom line is there is NO reprogram CPU adjustments for the sport cats and I noticed more of a difference in the low end changing from/to supercups than anything.


The biggest differences I see on the sport cats are the huge weight savings and the very pretty sound yet NOT having the stinky exhaust of cat bypass and still being able to mount up the 4 o2 sensors instead of having to tie them off to never-never land.

ceboyd

Here is part of the 'cargraphic' badge right on one of the cat's as an FYI folks

NineMeister

I use the Cargraphic N-GT version of these cats on my 415bhp n/a 993RSR and fit a similar version to our 993+1 (cams/cats/remap = 330bhp) & +2 (9m/4T heads/cams/cats/remap = 350-360bhp) n/a conversions. I can confirm is that in testing none of the engines would make much above 315bhp when we tested them fitted with the standard cats, so in my opinon there is a bargain to be had here if the price is right.

Secondly, since none of our engines lost bottom end or mid range torque with the cats fitted, if you are experiencing a loss in this area from using the cats imho it is the ecu mapping that will be the problem, not the cats.

ceboyd

thank you for that update!

I guess that means I'll notice a LOSS when I remove them... so be it.. I'd rather loose some power and KEEP the car right now..

Eventually I might have to part with the whole car

..and I seriously doubt anyone buying the car would pay the 'premium' for these and I'm much better off selling alone seperately (slowly parting out the car I guess)

NineMeister

Oh, forgot to mention, the current UK price for these cats is in the order of £1800 for the pair.

I also thought that I should point out that Ceboyd has the rarer "Gillet" version which only fit the Gillet manufactured heat exchangers with a round hole triangular outlet flange. In the UK the "Bishoff" heat exchanger is the more popular fitment which has an oval outlet and uses the old 911SC/3.2 Carrera heat exchanger gasket.

The only difference in the kit are the two short pipes which connect the heat exchanger to the cats, and whilst you can buy these seperately from Cargraphic, they will charge you about £520 for the pair....... nice.

ceboyd

yes, it was a USD $580 premium to be paid for the style I have 'GILLET' (I guess they didn't make as many).. and thank you for telling me which I have.. I know I always get that confused! I just know they won't fit 95 993 but will fit most 96 (except early ones with same fitment as 95) up to 98 993. PLUS you wouldn't want these for a 95 993 anyway since it is OBD I and has only ONE o2 sensor.

I made a bunch of changes at once to my car to get it a little more hp and better performance when I was making updates (so basicly I did Steve's ECU upgrade, Supercups and these cats and boy did I notice a huge difference)... I noticed a loss of top end power and a gain of low end power between having and NOT having the supercups installed... so far that is the only part I have removed and sold off....


BTW: If my conversion is correct... 1800 pounds from England means $3152 USD -- but that doesn't factor in expensive ship costs, duties, etc. (AND that isn't for this 'gillet' style)

I actually never ran into anyone else with 100 cell cats on their 993.. the only other thing I ran into was 95s with cat bypass (usually the fabspeed ones)

ceboyd

here is a photo I found of how cargraphic adverises them..

BTW: I'm 99.9% sure I remember seeing a CA CARB LEGAL exemption plate on them but that plate is hidden from view when mounted (I can feel it but cannot see it).. so until I get to that point of having them removed, I will NOT see what that plate actually says..

PLEASE NOTE That this is for the cats ONLY (and the attached piping) an does NOT include the mufflers or heat exhangers or exhaust pipes (those are all still stock on my car and remain with my car)

ceboyd

well, I thought I was doing a good thing trying to record the sound of idle with the sport cats but unfortunately my camera microphone must be the cheapest crap around because it just doesn't sound the same (you can't seem to hear that beautiful burble you hear in real life)..

So FWIW: Here is a poor quality recording of idle with the sport cats:

http://media.putfile.com/air-cool