Description
DEVELOPMENT GOALS
- Improve upon the factory design and achieve a throatier / smoother / higher pitched tone.
- Increase the presence and character of the exhaust note in the cabin while maintaining a reasonable level of resonance / drone while driving in both the valves closed and open modes through our signature drone fighting capabilities.
- Heighten aggressiveness with valves open while maintaining an overall sound level potential / quality that can still be reasonably driven on the street in combination with other complimentary aftermarket exhaust components – such as competition over axle pipes and header replacements.
- Offer the ability to notably reduce the sound level of the car outside to fly under the radar when necessary.
- Achieve an effective delta in sound between both modes for two usable, well engineered experiences – mild and wild.
RESEARCH & DEVELOPMENT
With valves open, our Valved Exhaust System follows a similar design to our Race Exhaust System through an X-Pipe that merges the exhaust flow for a higher pitched, smooth sound. With valves closed, the exhaust is routed through smaller piping and a bespoke SOUL muffler we designed to fit with the X-Pipe in the confined space above the rear diffuser and meet our sound goals. This muffler was crafted to match our high standard of drone fighting mufflers like the rest of our existing Boxster / Cayman line that we have become known for.
Internally this muffler is quite unique. It has little to no restriction in the flow path, using straight through piping that is perforated to allow exhaust gasses to escape and become muffled in the surrounding packing material of the muffler body. We incorporated a second internal X-pipe to allow the exhaust flow to merge smoothly. These characteristics combined were crucial towards reducing and smoothing out the drone in the 1,800-3,000rpm range while enhancing that higher pitched note we were after in both the valves closed and open conditions.
In addition to the bespoke muffler design, there are several other unique characteristics we’ve brought into play on this system which revolve around the secondary flow path entering the muffler. The key thing to note here is that the valves open flow path is not limited to the 2.5″ external X-pipe flow path only, some of the exhaust flow is still going through the secondary flow path even though the valves are open. This design is essentially utilizing the entire secondary flow path and muffler design to smooth out the tone and drone while running valves open. Please note the carefully tuned length of the piping entering the muffler, as the sound waves and exhaust pulses have a longer distance traveled through the piping for a notable effect on sound attenuation. Utilizing this secondary flow path for honing in on the optimal cruising cabin presence, we were able to go aggressive on the design of primary flow path with larger diameter 2.5″ piping without incorporating resonators or mufflers.
DRIVING IMPRESSIONS
Changing just the PSE muffler with stock over axle pipes offers a superb change in tone. It is smoother and higher pitched, more in line with the flat 6 character we’ve come to appreciate with previous generations of Boxster / Cayman. The PSE running valves closed had no real tone to it, we’d describe it as tinny, hollow, and rather boring as you can hear more of the intake than the exhaust. With our Valved Exhaust System the exhaust now has real character, and you can hear more of it everywhere with valves open and closed. Expect a smooth transition between valves closed and open modes. With the rest of the exhaust stock, the overall sound level at WOT with valves open may not sound dramatically increased. This is due to how aggressive the flow path is with valves open on the new 718’s PSE muffler. However, on our system the larger tubing diameter, distance traveled, and blending of the X-pipe gives the sound more depth and changes the tone to a smooth / higher pitch song. It sounds incredible especially from the outside, offering a true sporty note one would expect from the high end 4.0L.
We found that the particulate filters in the over axle pipes put a big damper on the overall sound level and how it carries into the cabin. Think of it like a cork in the middle of the exhaust, letting a PSE muffler replacement tease you but not giving you the full experience. Combining our Valved Exhaust System with our Competition Over Axle Pipes is when the skies open up, the sun shines down and the Porsche Gods have blessed us with the sound we’ve all been waiting for. Inside and outside the car, windows up and down, the experience is nothing short of transformational. At wide open throttle it sounds like a weapons grade symphony. Very reminiscent of a GT3 at 9k, and arguably better than any stock GT3 you’ll ever hear on the street. Ditching the factory over axle pipes finally allows the car to have some burble on deceleration but nothing too over the top, just enough and just right. When you do a hard shift, a visceral crack erupts to really put a smile on your face. Not like a shotgun blast going off, more like a reward for actually driving the car how it’s meant to be driven. The sound is aggressive, but not overly so like you just took an RSR off the track for street shenanigans. When you’re off throttle cruising around, it’s relatively docile and comfortable (that secondary flow path at work). If you want to fly under the radar and significantly cut down on sound level outside the car, you simply close the valves and away you go in stealth mode. However, even with valves closed the tone and character of the exhaust is still there, not dead muted like the PSE muffler. It has cabin presence, some ever so mild drone/resonance in low rpms that we consider quite reasonable compared to the other configurations we’ve tested – even with valves open it’s quite reasonable. We’d almost say it’s more a character of the system and it’d be a shame if there wasn’t any to tease you into squeezing on the gas to hear more of it. We highly recommend installing a SOUL Valve Controller Kit to override the PSE programming at your convenience, and hear what it has to offer under 4-5k rpm in the first few gears – it’s worth it!
CONSTRUCTION: Each system is assembled in house in the USA out of mandrel bent, thick wall .065″” T304L stainless steel. Back purged TIG welding (with ARCAL™ Prime argon gas) ensures proper weld penetration and longevity. Water jet cut flanges are made to ISO 9001:2015 standards with tolerances of +/- 0.003 inches for extreme precision. We fabricate each exhaust using thick gauge aluminum fixtures which act as a great heat sink during the welding process and prevent warping not only of our products, but the fixtures themselves to ensure perfect fitment.
BOLT ON AND GO: Every component is rigorously quality-checked, tested in a fixture to guarantee fitment, and then foam packed to ensure they arrive in perfect condition. New high grade hardware is included for installation.
LIFETIME WARRANTY: Enjoy your SOUL exhaust components with confidence on both the street and track as they are covered by our Lifetime Warranty! Our team will quickly work with you to resolve any issues or answer any questions that you may have.
Tim Freeman –
Installed the GT4 valved exhaust. Are you kidding me. This thing rocks! Gurgles and pops. Sound is amazing.
Driv200 (Rennlist) –
Oh My Gosh! This is the perfect exhaust combo with valved muffler. (Race headers no cats, OAP’s, and valved muffler).
First day impressions:
* It’s now a proper GT Car!
* It’s higher pitch than expected and I freaking LOVE IT! Formula One V10 kind of sound!! Absolutely sounds like a true exotic.
* up shifts are amazing. 3rd to 2nd-BOOM!
* the long gearing is now a BONUS. 45mph speed limit in first gear sounds like 180mph Ferrari. It’s that good.
* it screams when you want it. It’s docile ‘police friendly’ w/ gentle throttle input still in full open mode. And that’s without flipping switch to quiet or closed. it’s completely docile in the low rpm when you want to be quiet. This part amazed me even when it’s on full open.
* throttle snaps are immediate & awesome. Parking lot blips are fantastic quick barks!
* mustang / camaro guys are jealous at your favorite gas station when you start it.
The range of the exhaust up to 8000rpm is insane. Better than I expected. Absolute dream perfection for the GT4.
I’m having a hard time finding any drone. Sure, on decel with windows up around 2590-2900 you can hear it in cabin, but it’s more audible note than drone. This is the race headers and no cats’..of course you hear it. But it’s not tinny or droney at all. Windows up, AC on, I can carry a conversation at normal talk level. It’s a very balanced system. I’m trying to look for drone to post about it here. I really don’t have an issue thus far. My wife might even get to dinner w/o complaining or noticing it.
Most vids I have seen were with race muffler or race header or OAPs. This is full system with race headers(no cats), OAP’s, and Valved exhaust. The Valved exhaust is in full open (loud) mode b/c the chip for remote close is on back order. The exhaust in open loud mode allows me to be quiet with low throttle input. I’ll never use the closed ‘quiet’ function except for morning start up. At start up, the GT4 explodes to life! Freaking amazing every time. Once it warms up, it quiets down very nicely.
I will add videos soon. Cold starts and revs, bridge tests, etc are coming. Cell phone audio does not do it justice. Doesn’t pick up the deep tones or high notes.
mp2day (Rennlist) –
When I was recently in Philadelphia I stopped by Soul Performance. I will tell you, John Gaydos and his staff were very welcoming and are true petrol heads. I was probably there for close to two hours. I asked a lot of questions and got answers to all my questions. John then gave me a tour, and explained the R&D process that went into the 892 4.0 exhaust development as well as showed me some current R&D and talked about the results thus far. I was thoroughly impressed with the overall operation and particularly with the willingness of the owner and his staff to have frank conversations about exhaust development and performance with respect to this platform.
One of the questions I asked was why is the OAP from the factory heat shielded and the Soul OAP not. John explained that the GPF in the factory unit acts like a second catalyst. And even in US spec cars where it isn’t “activated”, it still gets very hot and the heat travels back down the OAP towards the headers. John said their OAP has no GPF and consequently doesn’t build up the heat, eliminating the need for heat shielding.
Before I left, I asked John if he was aware of any customers who had his OAP and valved exhaust on a 982 4.0 who might be willing to take me for a ride in their car before I flew back west at the end of the week. Since drone is very subjective and you really cannot judge an exhaust from a recording, I really wanted to hear the Soul setup I would be considering (OAP & valved muffler). John told me he would call one of his customers who he believed would be willing to let me hear the exhaust first-hand. John later called me back to tell me his customer had just traded the car in, and he connected me with the dealership. I was pretty excited because I’m currently waiting on an allocation, and the Spyder traded in had some of the key things I wanted. I arranged to go to the dealership and got to test drive the car. The car also had Soul’s valve controller so I was able to hear it with valves at stock setting and wide open. For me, I’m looking for the holy grail of exhaust – one that is both neighborhood friendly and will sing a glorious flat six song when asked. I need an exhaust setup that my wife will tolerate and she is *not* a fan of performance cars. So I need an exhaust that has a nice mild sound without obnoxious drone when driving around gently at lower RPMs and at the same time sounds like this car is supposed to sound at WOT > 5,000 RPMs. Even though it was a pretty short test ride, I thought the Soul OAP with Soul valved muffler was perfect. To me it did the impossible and accomplished both goals. I thought long and hard about buying the car (even going so far as to confirm financing) before I passed it up. Ultimately it was the color that I walked away from. I *loved* the exhaust setup.
I would suggest reaching out to your PCA club to ask about 982 4.0 owners with exhaust systems and see who has what and would be willing to take you out for an exhaust experience in their cars. One of my friends in the local club has the JCR silenced inbound for his GT4 and I will get to hear that too once it arrives. If you’re considering Soul (I obviously think it’s a GREAT solution), try reaching out to John and see if he can connect you with a customer running his setup. Once my car is allocated, built, arrives, and gets new exhaust I’d be glad to take someone for a ride to experience the exhaust.
A big thanks to John Gaydos and Soul Performance for taking the time to talk to me, show me around, and help me get a chance to hear the car with your setup! For those of you who find yourselves near Philadelphia, look up Soul. I am very glad I stopped in.
Scott
Arvada, CO
Igode321 (Rennlist) –
So, I am writing this to share my opinion on Soul Valved Exhaust and hope this helps the members contemplating whether they should go with soul valved exhaust.
To me, sound is one of the most important aspects of a fun car. I sold f80 m3 and m2 comp within one year of ownership of those cars because I was frustrated with the sound of S55 motor. Although they looked beautiful, they did not sound good. I was very frustrated with their farting (?) noises. It was not about those cars’ drivability, it was purely the sound.
So when I purchased gt4, I expected a better sounding experience. I, however, was not happy with its stock sound as it was rather muted and all those chirping and ticking noises were not that nice. So I had to do something, either sell the car or do a exhaust mod for the first time. And I decided to modify the exhaust and now I am happy I did.
Firstly, I started with Akra OAP. Although I liked the soul OAP after viewing Matt’s (at Obsessed Garage) opinion and review about it, I did not want to wait for it (leading time was about 2 months at the time). Shortly after the installation of Akra OAP, I installed Cargraphic valve controller and removed sound symposer.
Although there may be a debate as to whether the sound symposer delete has any positive effect in reducing any unwanted noises like chirping, ticking, and drone, etc., I can confidently tell you that it reduced this unwanted boomy sound created by Akra OAP. And I agree, after its deletion, I cannot hear that nice intake noise I was able to hear when my car had stock system.
I cannot confidently say it but I was not able to hear the intake noise any more anyway after Akra OAP installation as that created boomy sound.
I was not perfectly happy with the sound of this Akra OAP at first, but sound symposer delete did help in reducing that boomy sound and I was somewhat happy with it from time to time but I knew it was not what I was expecting from P car. I wanted smooth and higher pitched sound as I rev it to redline. And Akra OAP did not give me that higher pitched, smooth sound. It did not change the tone whether you go from 5k to 8k. It’s just the same, loud, throaty, and BOOMY sound through out the rev range. I do not think it was really drone, but Akra OAP does make this uncomfortably loud boomy sound from 2k to 2,500 rpm with valve forced open. So you would not want to go 70-79 mph in 7th gear on a highway.
After 4,500 miles of driving with Akra OAP, I knew I had to change the rear section to change the tone and quality of the sound, and I finally decided to pull the trigger on Soul valved exhaust as it was always on my list. My other option was the Kline but I did not really like the sound of the system after viewing multiple videos posted by the forum members with Kline. Also this little kid in me made it impossible for me to resist getting Soul valved exhaust after reading the below on Soul website:
“Combining our Valved Exhaust Systemwith our Competition Over Axle Pipes is when the skies open up, the sun shines down and the Porsche Gods have blessed us with the sound we’ve all been waiting for.”
I know Akra OAP is not Soul comp. OAP. I, however, believed their functionality and performance in terms of the sound to be very similar with each other.
So, I installed soul valved exhaust yesterday and drove the car with valve open mostly for about 30 miles and if I can go back in time, I would not have wasted my time watching videos regarding soul valved exhaust whether that be from Soul website, Josh, Uncledude, or some random youtube because you have to listen to it with your own ears inside the cabin, not through the speaker. Crackles and pops are just enough, unlike F80. And that loud boomy sound from 2k to 2,500 rpm is gone with valve forced open. Although you get this LOUD but somehow smooth sound from 2,500 to 2,900 rpm with valve forced open (I would not call it drone or boomy sound.). Most importantly, the tone of the sound really changes as you rev up the engine. Now my car makes this loud, exotic, and high pitched but somehow smooth sound as I rev it up to redline. Plus, the car feels faster and smoother (my wife confirms it and she actually loves how smooth and fast it feels now), especially from 3k rpm.
I remember at least two members’ opinions about Soul OAP and valved exhaust that after the installation of the valved exhaust, the car somehow became quite inside the cabin. In my opinion, the sound actually gets louder but one may believe it became quite as it removed that unwanted loud BOOMY sound from OAP alone setup.
Although I have more to share about Soul valved exhaust, I will reserve that for later as I want to see how my opinion changes as I put more miles on the system.
I know this idea of a proper sound is and can be subjective, but I really love love love this system and I cannot wait to drive it want to drive it more and more.
AtoB (Rennlist) –
I started with the OAPs when I picked the car up.. they made a very noticeable difference….tive been on the fence about the SOUL exhaust, its a pretty big investment.
I took the car out for a long ride today after the install, here are my thoughts on adding the exhaust…
• its louder/smoother at idle… has a great opening rumble
• you pick up more of that ‘mechanical’ noise/ticking below 1000RPM that you hear folks talk about.
• as you rev through the RPMs it had a smoother and more dynamic tone… higher pitch… very sweet sounding for sure from 4-8K.. love that
• in general it is ‘boomier’ below 4K and you do get a bit more drone now