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Tried searching on the forum but did not get some clear answers. Really appreciate if someone with such knowledge can share the idea.
Background: Since I have to get my 991.1 GTS repaired I figure it a good opportunity to finally change the appearance to 991.2 GT3 which I always adore as the Top 3 engineering design by Porsche.
My idea and info: I would like to retrofit OEM 991.2 GT3 front and rear bumper, and side skirts if possible. Obviously I have to make the exhaust compatible to the OEM .2 GT3 rear bumper/diffuser. The original plan is to use OEM GT3 exhaust, however I soon was told by a 911 specialist dealer that it would not fit no matter if I'm using GT3 OEM whole pipe/ mid + rear pipe / rear pipe only. His only solution is custom made.
Question: Would .1/.2 GT3 OEM exhaust be fit onto a 991.1 GTS, or for more people's interests, any AWD 991 model with a wide body? If not, is there any other straight forward choice of exhaust (aftermarket?) to fit OEM .2GT3 rear bumper? (I understand that .1GT3 exhaust tip may not flush with .2GT3 diffuser but that would be a minor problem.) Hopefully I dont have to go custom made since it could be such a pain to keep PSE valves while having reasonable design for performance.
I'm happy to share the result regardlessly after I finish reapring my GTS
Use the GT3 muffler/muffler bracket. Use GTS headers. Buy a set of GT3 side deletes and have them change the flanges where they mate to the headers, as they are different, and modify the pipes a bit where necessary. Easy work for a quality shop. This has been done numerous times on RL.
Last edited by AdamSanta85; 12-14-2022 at 10:37 AM.
Use the GT3 muffler/muffler bracket. Use GTS headers. Buy a set of GT3 side deletes and have them change the flanges where they mate to the headers, as they are different, and modify the pipes a bit where necessary. Easy work for a quality shop. This has been done numerous times on RL.
Thank you very much for your information!
To summarise the plan you suggested: GTS header + GT3 mid pipe (modded to fit with hearder) + GT3 tail pipe/muffler.
This definitely sounds neater and more reliable than getting customised mid+ tail pipe suggested by my shop, as all I need is GT3 mid+ tail pipe plus a bit of labour for one flange modification.
I do have another question though: Are the valves on GT3 mid pipe the same as GTS/ plug and play as the OEM carrera/GTS PSE valves? (GT3 valves compatibility to carrera/GTS ECU?)
Are the valves on GT3 mid pipe the same as GTS/ plug and play as the OEM carrera/GTS PSE valves? (GT3 valves compatibility to carrera/GTS ECU?)
The valves on the GT3 are located on the side muffler deletes, so you will need to just T the line that comes out of the fitting behind your muffler and run longer vacuum lines to the valves on the side deletes. They function the same way as Carrera.
I would just start with some good condition used side deletes and have them modified.
Last edited by AdamSanta85; 12-14-2022 at 12:08 PM.
The valves on the GT3 are located on the side muffler deletes, so you will need to just T the line that comes out of the fitting behind your muffler and run longer vacuum lines to the valves on the side deletes. They function the same way as Carrera.
I would just start with some good condition used side deletes and have them modified.
Really appreaciate your detailed and clear instruction again! Will post some results for other's reference once I finish this project.
Been wanting to do the same but didn’t want to lose my side mufflers due to being able to shut it off and enjoy quiet time when it’s not appropriate.
Was going to modify just the center section only and try to move the valves - but I believe ultimately the way suggested is the only way to achieve the end result.
Use the GT3 muffler/muffler bracket. Use GTS headers. Buy a set of GT3 side deletes and have them change the flanges where they mate to the headers, as they are different, and modify the pipes a bit where necessary. Easy work for a quality shop. This has been done numerous times on RL.
Exactly. I used a pair of used Fabspeed GT3 side deletes that i bought from a member. My car was non PSE so i used the non-valved bypass pipes.
Exactly. I used a pair of used Fabspeed GT3 side deletes that i bought from a member. My car was non PSE so i used the non-valved bypass pipes.
Brilliant work and thank you for the pictures! Since it would be my daily I wanna keep the noise down and I guess I just need the deletes with valves.
May I ask how much louder do you feel about your exhaust now comparing to OEM before? I'm not sure if I should keep the side mufflers and how much more complexity to do so.
Brilliant work and thank you for the pictures! Since it would be my daily I wanna keep the noise down and I guess I just need the deletes with valves.
May I ask how much louder do you feel about your exhaust now comparing to OEM before? I'm not sure if I should keep the side mufflers and how much more complexity to do so.
It's definitely louder but not obnoxiously loud. It's a nice tone IMO. Remember that it's still a stock muffler with restrictions made for a much powerful motor.
But if you insist on keeping side mufflers, It would probably be less labor intensive to modify GT3 Side mufflers to fit your OEM header, rather than re-routing your OEM sides to fit the center muffler. If that makes sense.
It's definitely louder but not obnoxiously loud. It's a nice tone IMO. Remember that it's still a stock muffler with restrictions made for a much powerful motor.
But if you insist on keeping side mufflers, It would probably be less labor intensive to modify GT3 Side mufflers to fit your OEM header, rather than re-routing your OEM sides to fit the center muffler. If that makes sense.
Yes that makes sense and is exactly what I thought about when AdamSanta offered his great idea. The outlet route design of the sides on GTS (carrera) is quite different from GT3, and keeping the whole side + tail muffler of GT3 leaves only the header connection bit to be worried about. The downside is that I heard about warranty being voided if modding more than rear pipe, but I think it is irrelevant to my 2015 GTS now.
Yes that makes sense and is exactly what I thought about when AdamSanta offered his great idea. The outlet route design of the sides on GTS (carrera) is quite different from GT3, and keeping the whole side + tail muffler of GT3 leaves only the header connection bit to be worried about. The downside is that I heard about warranty being voided if modding more than rear pipe, but I think it is irrelevant to my 2015 GTS now.
I don't recommend doing this if your car is still under warranty. Porsche will look for any excuse to void it.
Tried searching on the forum but did not get some clear answers. Really appreciate if someone with such knowledge can share the idea.
Background: Since I have to get my 991.1 GTS repaired I figure it a good opportunity to finally change the appearance to 991.2 GT3 which I always adore as the Top 3 engineering design by Porsche.
My idea and info: I would like to retrofit OEM 991.2 GT3 front and rear bumper, and side skirts if possible. Obviously I have to make the exhaust compatible to the OEM .2 GT3 rear bumper/diffuser. The original plan is to use OEM GT3 exhaust, however I soon was told by a 911 specialist dealer that it would not fit no matter if I'm using GT3 OEM whole pipe/ mid + rear pipe / rear pipe only. His only solution is custom made.
Question: Would .1/.2 GT3 OEM exhaust be fit onto a 991.1 GTS, or for more people's interests, any AWD 991 model with a wide body? If not, is there any other straight forward choice of exhaust (aftermarket?) to fit OEM .2GT3 rear bumper? (I understand that .1GT3 exhaust tip may not flush with .2GT3 diffuser but that would be a minor problem.) Hopefully I dont have to go custom made since it could be such a pain to keep PSE valves while having reasonable design for performance.
I'm happy to share the result regardlessly after I finish reapring my GTS
Just checking to see if you finished this or not? If you did, do you have pics and sound clips you can share of the exhaust solution you went with and the rear bumper?
I am considering doing this with my 991.1 C2S, and would like to see how others have turned out. Currently, I have found this as a direct GT3 style exhaust replacement: Cargraphic and this for the narrow bodied GT3 styled rear bumper: DarwinPro. The exhaust solutions above seem much more cost effective than the one I linked.
12-13-2022, 04:06 PM
991.1 GTS: .1/.2 GT3 OEM exhaust fit? /Exhaust solution for GT3 rear bumper retrofit
