Originally Posted by MrFunk

Since installing my Kline (Inconel) system - I've had my valve collars set at the most conservative position and have really enjoyed the exhaust note, natural progression of sound (loudness) and nuances/sophistication. I've got about 1200 miles on it now and from reading a lot of comments here I felt I needed to play with the collars a bit.
A few days ago I set them to "full open"... and went for a good drive around town, then out to the country and back home on the highway to get various driving scenarios. I live at the bottom of a hill and my first impression was climbing up the hill from my house in 2nd gear - the boominess (between 2k and 3k) RPM almost immediately gave me a headache. It wasn't just light, it's quite overwhelming. The remainder of the drive I found myself trying to avoid that RPM range which is really hard to do under most driving scenarios. It actually ruined the whole experience for me and I promptly set the collars back to the position I had them originally. Today I took the car out again for a drive and was back to loving the exhaust again. Zero boominess between 2-3k...

At WOT and aggressive driving having the valves locked open was certainly more aggressive sounding in the lower RPM range, but anything above 4k and it's no different to my current set up with the valves kept open only slightly. In the lower range with the valves held open you lost all the beautiful tone and sound I love about this exhaust - it's just drowned out by that boominess (I'd actually call it heavy drone) between 2-3k RPM. It's obvious why Porsche designed the valves to always close between that range.

Just my personal opinion of course, and I'm sure Uncle Dude and I are in the minority here in our more "tame" valve set up... perhaps the amount of patience I have for boomy exhausts is now set extremely low after driving a supercharged S2000 with headers, high flow cat and Miltek exhaust for 5 years ...

Originally Posted by MrFunk

Since installing my Kline (Inconel) system - I've had my valve collars set at the most conservative position and have really enjoyed the exhaust note, natural progression of sound (loudness) and nuances/sophistication. I've got about 1200 miles on it now and from reading a lot of comments here I felt I needed to play with the collars a bit.
A few days ago I set them to "full open"... and went for a good drive around town, then out to the country and back home on the highway to get various driving scenarios. I live at the bottom of a hill and my first impression was climbing up the hill from my house in 2nd gear - the boominess (between 2k and 3k) RPM almost immediately gave me a headache. It wasn't just light, it's quite overwhelming. The remainder of the drive I found myself trying to avoid that RPM range which is really hard to do under most driving scenarios. It actually ruined the whole experience for me and I promptly set the collars back to the position I had them originally. Today I took the car out again for a drive and was back to loving the exhaust again. Zero boominess between 2-3k...

At WOT and aggressive driving having the valves locked open was certainly more aggressive sounding in the lower RPM range, but anything above 4k and it's no different to my current set up with the valves kept open only slightly. In the lower range with the valves held open you lost all the beautiful tone and sound I love about this exhaust - it's just drowned out by that boominess (I'd actually call it heavy drone) between 2-3k RPM. It's obvious why Porsche designed the valves to always close between that range.

Just my personal opinion of course, and I'm sure Uncle Dude and I are in the minority here in our more "tame" valve set up... perhaps the amount of patience I have for boomy exhausts is now set extremely low after driving a supercharged S2000 with headers, high flow cat and Miltek exhaust for 5 years ...

Originally Posted by MrFunk

@subwoofer - do you have the SS version or Inconel? I wonder if that produces enough difference in resonance for us to have different experiences?? There's certainly a 2-3k boominess that I know others have noticed with the Inconel system with the valves open. I also agree that it's worse when the system is cold...
@tigerhonaker - great vid! Your exhaust sounds great! I didn't notice any annoying boom - but it's difficult to capture in a video... love the shoes!!!

Originally Posted by subwoofer

I've never liked the OEM low rpm sound of any of the three Porsches that I have owned. My 991.2 4s sounded like a bucket of bolts at startup and at low rpm, the whistling of the turbos and the mechanical racket from the engine made it sound very unrefined. It only sounded nice above 4k rpms. My 981 Boxster with the 3.4 liter also only sounded good when revving it out. The 4 liter in my Boxster 25 sounded even worse (muffled) when I bought the car last year. Strange because boxer engines are supposedly very well balanced but they don't sound smooth to me. I have no clue why they sound so bad (to me at least) at low revs.. An exhaust, I think, can only do so much to fix the low rpm sound. Kline, from what I have experienced so far, is pretty darn good. Can't complain.

Originally Posted by MrFunk

@subwoofer - do you have the SS version or Inconel? I wonder if that produces enough difference in resonance for us to have different experiences?? There's certainly a 2-3k boominess that I know others have noticed with the Inconel system with the valves open. I also agree that it's worse when the system is cold...
@tigerhonaker - great vid! Your exhaust sounds great! I didn't notice any annoying boom - but it's difficult to capture in a video... love the shoes!!!