DIY: 991 Exhaust Sound Mod
#35
08-15-2016, 03:40 AM
I might try this mod out and see. Any lost of MPG with this mod?
#36
08-15-2016, 09:26 PM
just meant that I wish I had done PSE sooner instead of messing around with the mod. It's definitely a noise maker but I can "feel" more horsepower haha.
I didn't notice any substantial decrease in MPG. I do now actually have a decrease because I'm revving it much much higher to hear the exhaust note.
I didn't notice any substantial decrease in MPG. I do now actually have a decrease because I'm revving it much much higher to hear the exhaust note.
#37
08-17-2016, 02:17 AM
just meant that I wish I had done PSE sooner instead of messing around with the mod. It's definitely a noise maker but I can "feel" more horsepower haha.
I didn't notice any substantial decrease in MPG. I do now actually have a decrease because I'm revving it much much higher to hear the exhaust note.
I didn't notice any substantial decrease in MPG. I do now actually have a decrease because I'm revving it much much higher to hear the exhaust note.
lol.. i hear ya about the rev. I put them in Sport/plus sometimes just for fun driving at 25 mph traffic.
#38
11-23-2016, 09:03 PM
tried this mod and loved it. I have a cab so with the top down you really get to enjoy the sound. I want to make it switchable so in the spring I'm going to install a normally open vacuum solinoid in line and run a wire to the cabin with a switch so I can switch it back and forth
#39
05-29-2017, 06:24 PM
Wow, I tried this on my 2013 S Cab without PSE, and hated the new sound. It sounds horrible just a loud muffled sound with no character. Maybe some cars sound different. I drove a few miles and went straight back to the garage to reverse it. BTW I was able to reach the T connector from the top passenger side after removing the fans. I put a rubber stopper over the vacuum Port and wrapped some vinyl tape over the connector that I removed. But like I said, it wasn't that way for long.
QUOTEe-t;4583279]
QUOTEe-t;4583279]
tried this mod and loved it. I have a cab so with the top down you really get to enjoy the sound. I want to make it switchable so in the spring I'm going to install a normally open vacuum solinoid in line and run a wire to the cabin with a switch so I can switch it back and forth
[/QUOTE]
#41
06-23-2017, 09:09 PM
Registered User
Join Date: Oct 2011
Location: West Palm Beach, FL
Posts: 156
Rep Power: 21 
Mine are capped love the sound!! However, I do have that damn check system light that comes on. The valves are capped and clamped at the ends. Any ideas of how to clear that?
#43
01-08-2018, 09:41 PM
Registered User
Join Date: Oct 2011
Location: West Palm Beach, FL
Posts: 156
Rep Power: 21 Well I’ve added catless headers as well now. It sounds wicked. There’s a little drone nothing too bad. With just the valves always open before the headers I didn’t have drone. I also ended up with a pro Cobb tune which eliminated any warnings.
#45
12-03-2018, 09:18 PM
I am seriously thinking about doing this mod as I love the way my C4S sounds with the valves open (non-PSE exhaust). My shop says they have done a few of these. Said they have done the same thing to Ferrari 458's. Wondering if anyone has a video of what this mod sounds like... thanks