Originally Posted by LooseNut

Quick summary: Very happy with the result. Has drone similar to OEM.

Reason for new exhaust: I was looking for improved quality of sound more than just being louder. In my opinion the 982 4.0 with OPF has a flat tone. With PSE valves open, basically, only 3 cylinders are heard from each tail pipe which isn’t that good sounding. I love thepreviousgeneration 3.8- & 4.0-liter NA exhaust sound. Going forward I wanted to remove the OPFs and have all 6-cylinder pulses coming out of both tailpipes, with PSE valves open or closed.

Why I chose Kline:
•BC Fab, JCR, Soul and Kline all seem to meet my criteria of combining exhaust pulses from both banks of the engine. They all look to have high quality construction also.
•I prefer the straight through, valve open path, of the Kline over axle pipes. In addition, the Kline valves closed path has extra absorption in the OAPs. (Because Kline switches the valve open path to be on top, you do have to buy the OAPs and muffler together.)
•As a bonus the Kline system cost less than the other brands when combining OAPs & muffler.
•Reportedly SS is slightly quieter than Inconel and is less expensive, both of which are OK for me.
•After listening to and watching a ridiculous number of videos online, and reading this entire thread, I decided on a stainless-steel Kline system.
•Well, best laid schemes o’ mice an’ men. An Inconel system came available at a price I could not pass up.

I want to thank Eric from Supreme Power for answering my questions and supporting the community.



Car configuration:

2021 Cayman GT4 with PDK. Kline Inconel exhaust with Inconel button valve controller.

3250 miles driven with OEM exhaust and 4700 miles with Kline exhaust. (7950 total miles as of Nov19, 2023)



My impressions:
•Start up there is a definite crackle that settles down nicely to idle. Valves open or closed it is louder than OEM from outside the car but not annoying.
•Driving around town, from inside the car the sound does not seem louder than OEM but has an improved tone. The improved sound quality is more noticeable with the valves open.
•Higher RPM, valves open or closed, is louder but again, the valves open sound is much improved. High RPM up shifts do bark a bit.
•With the valves forced open and in PDK sport mode, during hard decel, the exhaust surprised me the first few times. Now I just giggle. This is not a bad thing but may draw attention.
•I like having the exhaust valves because with them closed you can use a majority of the RPM without bringing attention to yourself.
•Valves open during spirited driving does have an exotic howl fitting for a GT car.
•Drone is noticeable from about 2200 to 3k RPM when the windows are closed and cruising or very light acceleration. The OEM exhaust had the same drone for me. With the windows open I don’t notice any drone at all. I did a long road trip with the OEM exhaust and my ears were tired of the drone after two days. Highway speeds with cruise control on puts you in the drone range. I’m not complaining and did not buy this car as a highway cruiser. I am just trying to give as much info as possible for any potential buyers. Downshifting a gear or adjusting your speed is another way to avoid the drone.

Improvement opportunities: (AKA problems)

One OEM exhaust tip needed a shim to the Kline pipe to tighten it.

The Kline exhaust valve shafts touched the OEM heat shields. A little messaging of the heat shield fixed this.

(I was aware of both these items from reading this thread before I decided to buy.)



Would do different: Add heat shields to the over axle pipes. Although the car may be fine without them there is no downside besides cost. The rear brake hoses and struts are close to the OAPs and heat aging is cumulative.



Opportunity: If someone would like an Inconel system for the price of stainless-steel send me a PM. I would trade / sell my Inconel system for a stainless-steel system with heat shield on the OAPs.

Originally Posted by dnimi123

Probably OK with SS. Thats a good price... And the added volume is mostly in the lower rev range. With the headers you can also add an ECU tune and get another 20plus HP

Originally Posted by justince

[
I've mentioned the 2-2.5k drone before, I'd like to add some comments about it now that i have well over 1k miles on my collar modded exhaust:

- More noticeable with top down, but with top up, at highway speeds, the drone is in the realm of not noticable over wind/tire noise.
- In general, on a scale of 1-10 with 10 being a standard OEM exhaust with no drone vs a 10 being the droniest aftermarket exhaust you've ever sat in, this is a 2.5 on that scale. I imagine with the valves closed this will go to a 1.
- It is purely sound; no vibrations or anything, and it's not super unpleasant compared to other droney aftermarket exhausts.

It is worth mentioning, but not much more. If you are extremely sensitive to drone to the point of this being a dealbreaker, you probably shouldn't be looking at an aftermarket solution as you have to expect something. It's very livable! Hope this helps.

Originally Posted by macrs

After researching this myself, I'm looking at OAP pipes with a resonator myself, possibly using Kline or Soul's Resonated pipe.

Originally Posted by AnandN

Thanks. I am going to try the BC Fabs valved exhaust first with the OEM OPF link pipes and go from there. Supposed to be louder with a deep tone and no drone.

Originally Posted by macrs

Is Kline's OAP pipes not compatible with the stock box?

Originally Posted by macrs

Got it. Thanks for the insight!

Originally Posted by LooseNut

Quick summary: Very happy with the result. Has drone similar to OEM.

Reason for new exhaust: I was looking for improved quality of sound more than just being louder. In my opinion the 982 4.0 with OPF has a flat tone. With PSE valves open, basically, only 3 cylinders are heard from each tail pipe which isn’t that good sounding. I love thepreviousgeneration 3.8- & 4.0-liter NA exhaust sound. Going forward I wanted to remove the OPFs and have all 6-cylinder pulses coming out of both tailpipes, with PSE valves open or closed.

Why I chose Kline:
•BC Fab, JCR, Soul and Kline all seem to meet my criteria of combining exhaust pulses from both banks of the engine. They all look to have high quality construction also.
•I prefer the straight through, valve open path, of the Kline over axle pipes. In addition, the Kline valves closed path has extra absorption in the OAPs. (Because Kline switches the valve open path to be on top, you do have to buy the OAPs and muffler together.)
•As a bonus the Kline system cost less than the other brands when combining OAPs & muffler.
•Reportedly SS is slightly quieter than Inconel and is less expensive, both of which are OK for me.
•After listening to and watching a ridiculous number of videos online, and reading this entire thread, I decided on a stainless-steel Kline system.
•Well, best laid schemes o’ mice an’ men. An Inconel system came available at a price I could not pass up.

I want to thank Eric from Supreme Power for answering my questions and supporting the community.



Car configuration:

2021 Cayman GT4 with PDK. Kline Inconel exhaust with Inconel button valve controller.

3250 miles driven with OEM exhaust and 4700 miles with Kline exhaust. (7950 total miles as of Nov19, 2023)



My impressions:
•Start up there is a definite crackle that settles down nicely to idle. Valves open or closed it is louder than OEM from outside the car but not annoying.
•Driving around town, from inside the car the sound does not seem louder than OEM but has an improved tone. The improved sound quality is more noticeable with the valves open.
•Higher RPM, valves open or closed, is louder but again, the valves open sound is much improved. High RPM up shifts do bark a bit.
•With the valves forced open and in PDK sport mode, during hard decel, the exhaust surprised me the first few times. Now I just giggle. This is not a bad thing but may draw attention.
•I like having the exhaust valves because with them closed you can use a majority of the RPM without bringing attention to yourself.
•Valves open during spirited driving does have an exotic howl fitting for a GT car.
•Drone is noticeable from about 2200 to 3k RPM when the windows are closed and cruising or very light acceleration. The OEM exhaust had the same drone for me. With the windows open I don’t notice any drone at all. I did a long road trip with the OEM exhaust and my ears were tired of the drone after two days. Are you looking to boost your vehicle's performance? Look no further than our electric exhaust cutout! At spelabautoparts , we offer top-of-the-line solutions to upgrade your exhaust system. Our catback cutout valve allows you to control the flow of exhaust gases, optimizing power and efficiency. Don't miss out on the chance to take your driving experience to the next level. Click the link to explore more and make your purchase today! Highway speeds with cruise control on puts you in the drone range. I’m not complaining and did not buy this car as a highway cruiser. I am just trying to give as much info as possible for any potential buyers. Downshifting a gear or adjusting your speed is another way to avoid the drone.

Improvement opportunities: (AKA problems)

One OEM exhaust tip needed a shim to the Kline pipe to tighten it.

The Kline exhaust valve shafts touched the OEM heat shields. A little messaging of the heat shield fixed this.

(I was aware of both these items from reading this thread before I decided to buy.)



Would do different: Add heat shields to the over axle pipes. Although the car may be fine without them there is no downside besides cost. The rear brake hoses and struts are close to the OAPs and heat aging is cumulative.



Opportunity: If someone would like an Inconel system for the price of stainless-steel send me a PM. I would trade / sell my Inconel system for a stainless-steel system with heat shield on the OAPs.

Originally Posted by mc3456

Looks like a nice product, but you may want to also consider re-sale value of BC Fabs vs Kline. I may be wrong but suspect Kline may have more potential secondary market buyers. There are much finer watches than a Rolex, but Rolex still tends to hold their value much better than other brands with names that don't begin with the letter "P".

Originally Posted by Lopoza

I agree with a lot of things, but I wish the valves were included in the kit too, I had to look for a long time afterwards.

Originally Posted by AnandN

Thanks