991.2 Cobb Accessport, post your results
#77
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Cobb has posted in this Forum (and to me personally via PM) that a .2 GTS can run the Stage 2 Map with just high flow cats and PSE, or even with the PSE. This is from Marshall when I asked about the Stage 2 93 Map on my '19 GTS with Soul cats:
"We actually have a good chunk of GTS owners using Stage 2 maps with that configuration. Since the car comes with a higher flowing exhaust standard, the high flow cats are all that is required."
"We actually have a good chunk of GTS owners using Stage 2 maps with that configuration. Since the car comes with a higher flowing exhaust standard, the high flow cats are all that is required."
- Exhaust Requirements: High flow exhaust and high flow catalyst.
#78
Rennlist Member
Join Date: Jul 2001
Location: Marineland FL
Posts: 12,533
Likes: 0
Received 3,458 Likes
on
2,361 Posts
#79
Rennlist Member
Join Date: Jul 2001
Location: Marineland FL
Posts: 12,533
Likes: 0
Received 3,458 Likes
on
2,361 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Just to be clear, it sounds like high flow cats are still required for Stage 2 even with the PSE on a GTS. That is consistent with the data on Cobb's web page which states the following. Stage2
- Exhaust Requirements: High flow exhaust and high flow catalyst.
#81
Rennlist Member
Join Date: Jul 2001
Location: Marineland FL
Posts: 12,533
Likes: 0
Received 3,458 Likes
on
2,361 Posts
#82
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
that said, I’m waiting for my Soul cats to get delivered and then will have Sam @ ByDesign protune my c4s.
He has been working his magic with my Turbo S and it is really impressive!
The following users liked this post:
JAM2 (01-25-2020)
#84
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I have a direct message from Cobb confirming that you CAN use stage 2 with stock cats and PSE.
that said, I’m waiting for my Soul cats to get delivered and then will have Sam @ ByDesign protune my c4s.
He has been working his magic with my Turbo S and it is really impressive!
that said, I’m waiting for my Soul cats to get delivered and then will have Sam @ ByDesign protune my c4s.
He has been working his magic with my Turbo S and it is really impressive!
Likely would just run rich. and not make optimal power.
#86
Burning Brakes
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Yes, I asked this same question to COBB since the Accessport option on their website comes up with 991.2 S, T, and GTS. The Accessport comes pre-loaded with tunes and when you hook up the Accessport to your car for the first time, it will recognize the model.
With regards to high flow cat requirements, I'd double check with COBB. I'm not 100% sure if the stock cats on the PSE are high flow (200 or less cell).
With regards to high flow cat requirements, I'd double check with COBB. I'm not 100% sure if the stock cats on the PSE are high flow (200 or less cell).
#88
Burning Brakes
#89
Three Wheelin'
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Naa, most of the RL members are cool dudes, no one would have chastised you. Maybe a few jabs, but nothing too bad. We all have to learn from research. Now you know.
If the PSE cats were high flow/low cell count, then no one would bother changing them. They are very restrictive, but also very effective at minimizing emissions. Most cats are in order to pass EPA in USA.
If the PSE cats were high flow/low cell count, then no one would bother changing them. They are very restrictive, but also very effective at minimizing emissions. Most cats are in order to pass EPA in USA.
The following users liked this post:
luv2sleep (01-18-2020)
#90
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
If you are running a tune that is designed for a HFC (flows better, improving the volumetric efficiency), it will potentially add more, power, expect boost to come on earlier, and perhaps expect more boost for a specific rpm.
Would suspect that it would run rich, and thus not make as much power if it was tuned 'properly.
No different than adding restriction to your stock exhaust system. An OTS tune for the PSE would not make as much power if you were not running the PSE.
Once you start removing all the restriction in the exhaust system you may run into issues with not being able to control boost on the top end, i.e. over boosting. This was an issue with RX-7s when people started removing the catalytic converters and the internal wastegate was unable to flow enough to bleed off exhaust gases and over boosting / boost creep became a real issue and people were blowing apex seals. An external wastegate or porting the internal wastegate were the solutions
Would suspect that it would run rich, and thus not make as much power if it was tuned 'properly.
No different than adding restriction to your stock exhaust system. An OTS tune for the PSE would not make as much power if you were not running the PSE.
Once you start removing all the restriction in the exhaust system you may run into issues with not being able to control boost on the top end, i.e. over boosting. This was an issue with RX-7s when people started removing the catalytic converters and the internal wastegate was unable to flow enough to bleed off exhaust gases and over boosting / boost creep became a real issue and people were blowing apex seals. An external wastegate or porting the internal wastegate were the solutions
The following users liked this post:
Porschex3 (01-18-2020)