Does anyone have any experience with 100cel race cats on the GT2?

I know everyone goes with 200cel, can you please list the benefits between the two?

 

My best memory of what I was told when I got my 200 cell about 18 months ago.
100 cell will be much louder, not pass smog, and give very little performance gains in comparison to the 200 cell.

 

100 cell will flow more exhaust gases than 200 cell, that is a given so for our turbo motors that is always a benefit since it means reduced backpressure which takes heat out of the turbo and generally makes the engine more efficient (ie greater power potential)

The problem with 100 cell is that unless the ECU program is altered in the correct way a CEL will be illuminated. Amazingly some tuners fit 200 cell cats to their higher hp offerings:

EVOMS

Can't get the link to work but that is a "720hp" offering with 200 cell

http://evoms.com/marketplace/ViewProduct.asp?Now=2%2F24%2F2013+4%3A20%3A39+AM&P roductID={5DAC5A8C-98AE-4A13-817F-F8039D5FBC21}&OrgID={CA5E16BC-D877-4137-8237-7EB9084DD3D8}&ParentID={8A0D0DD4-A04D-491F-906D-D080053B9BFA}&Curr={8A0D0DD4-A04D-491F-906D-D080053B9BFA}

AWE

http://www.awe-tuning.com/awe-tuning...-power-package

9ff

9ff Fahrzeugtechnik GmbH - Best technology for the best performance - 997 Turbo MK1 720 VTG

Their reasoning will be that the 200 cell cats are "OBD compliant" etc but in fact 100 cell cats with correctly tuned ECU program are also totally emissions compliant. The basis Cargraphic/RS Tuning 600hp package comes with 100 cell cats:

Performance

I don't think "sound" has anything to do with it there is very little difference on a GT2 with standard Akrapovik factory muffler between 100 and 200 cell (I have had both fitted at some stage).
The reason has to be that some tuners find it easier to tune with the 200 cell and keep the CEL off in fact the AWE people even specifically state this on their 750hp conversion blurb
Additionally, our system utilizes German made 200 cell high flow catalytic converters so your car can enjoy a horsepower increase without any Check Engine Lights
This statement sort of sums it up as it implies 100 cell DO illuminate CEL which is totally untrue IF the program is done properly but I'm surmising that GIAC (AWE's programmer) does not/ cannot do this or maybe it is difficult to write this sort of program remotely ?

Ultimately using 200 cell means that your engine is not breathing as well as it could and back pressure and VTG temperatures will be higher than they would be on a 100 cell cat set up - this is a bad thing for many reasons not least as you will have less power.

I have a set of Cargraphics 200 cell units for sale, they are as the link below.

Exhaust Systems

I actually purchased these and stuck them on with the idea that at a later stage I would go for the aforementioned CG/RS 600hp kit but I found out later than the 600 kit uses the 100 cell so the 200s were surplus and are sitting on my shelf doh !

It is worth mentioning that a set of 200 cells on a stock GT2 set up is a nice bolt on upgrade which gives some more torque in the mid range, you can feel it on the road and it makes a lovely sound to the exhaust and obviously reduces backpressure/temps.

Interestingly the lack of CEL which 200 cells are famous for was not quite true for me, the 200 cell set up used to occasionally trigger the CEL (basically it is the flow numbers going out of factory programmed ranges) but didn't happen a lot and Durametric could easily extinguish the CEL.

 

^^^ Very informative. Really appreciate all the info even though I'm not the OP.
Rep to you

 

What about a cat-bypass pipe vs 100/200 cell cats?

 

Hey thanks for saying so appreciate that

I am quite aware that a lot of my posts come across as being negative to various tuners, it is not intentional, I just try to cut through the hype since EVERY tuner knows best

It seems Europipe use a different Emitec 100 cell cat (everyone else seems to use HJS motorsport units) which they say does not give CEL issues with standard program, all I can think of with this one is that it doesn't flow outside factory parameters ?

Europipe
Stainless Steel Sport Exhausts for Porsche 996 Turbo / GT2 / 996 GT3 / 997 Turbo / 997 GT2 / 997 GT3 / 997 S

Akrapovik who make the OEM GT2 muffler also use 100 cell units in their aftermarket upgrade and they say ECU programming is needed to prevent CEL

Porsche S-PO997GT2SO2 Slip-On Line (Titanium) - Akrapovi

It would be great if the "200 cell" tuners would post and explain what it is about the 100 cell ECU programming which causes them problems but then that would be admitting "something" which none of them will do, maybe they want to sell what will give the least hassle to them and will keep the customer happy and still do an OK (if not best) job which I guess makes sense

 

Has to be the ultimate for back pressure reduction but DEFINITELY will need ECU work to prevent CEL

 

Incidentally I have the exhaust below on my engine but mine has 100 cell cats,mine was the development exhaust for CG

Sport rear silencer with flaps
Exhaust Systems

 

Toby,

You are awesome man. Wow that was really informative.

Let me get this straight...

So as far as safety is concerned to the motor there is no difference between the two?

100cel allows for better for which means more power?

GIAC will be tuning the car, I am concerned with CEL coming on, will they be able to handle it in your opinion?


Thanks a ton man... your the best

 

Hey, appreciate the sentiments

As far as safety there will be no problem with 200 cell or even stock since the ECU program will adjust everything to keep the motor safe if eg the tuner dials too much boost in...

The answer has to be that 100 cell are the best in terms of keeping the engine cooler and potential for more power but then it's no good if the CEL is on all the time - it would be great if you asked GIAC these questions, if they say 200 cell "will be fine" ask them "wouldn't 100 cell be better" and if they say they cause CEL issues then say you have some pals who run 100 cells with no CELs.

I'd be very interested what the reason is for not using 100 cell, it would be tempting to say that US or ROW GT2 engines have different emission numbers so the CEL is triggered earlier (or something similar) but I know of a Canadian GT2 which received the CG/RS 600 kit and whilst there were a lot of differences in the program (I know this as I sort of got involved as the ECU programming took longer than expected and the owner asked me to speak to RS to find out what was going on - it was the extensive re-writing of the 600 program on the engine dyno which took some time), this car wears 100 cell and passes emissions with no CEL.

Please keep us informed...