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I own a 718 Spyder with an aftermarket OPF and valved muffler. The weird stock valve programming is immaterial on backroads where I can keep the revs up, but puttering around lower speed roads, you can’t really bypass the muffler and unleash the exhaust unless you frequently downshift to first gear, in which case it is obvious you are just trying to be obnoxious. I have been considering the various valve control options (Soul/Cargraphics/Kline) vs ECU flash and possibly the DSC module option that is supposedly in the works, but I’m just annoyed I have to go through this process.
I know the inane valve programming supposedly stems from the upcoming European noise regulation but was wondering if the 992 911s have similar programming, specifically the new GT3s which apparently has a exhaust note not far off from the 991 gen. Does anyone know? If the new gen 911 is exempt from these valve programming changes, then this would be another example of Porsche inexplicably holding back cayman/boxster products.
I own a 718 Spyder with an aftermarket OPF and valved muffler. The weird stock valve programming is immaterial on backroads where I can keep the revs up, but puttering around lower speed roads, you can’t really bypass the muffler and unleash the exhaust unless you frequently downshift to first gear, in which case it is obvious you are just trying to be obnoxious. I have been considering the various valve control options (Soul/Cargraphics/Kline) vs ECU flash and possibly the DSC module option that is supposedly in the works, but I’m just annoyed I have to go through this process.
I know the inane valve programming supposedly stems from the upcoming European noise regulation but was wondering if the 992 911s have similar programming, specifically the new GT3s which apparently has a exhaust note not far off from the 991 gen. Does anyone know? If the new gen 911 is exempt from these valve programming changes, then this would be another example of Porsche inexplicably holding back cayman/boxster products.
Save yourself the angst, just install the valve controller and enjoy the car...
Sustained High rpm operation or overheating will not be a concern when the valves are 100% closed as long as the pipe diameter of the closed path is equal to or larger than the OAP pipe diameter. The valve closed path on most aftermarket rear muffler sections have smaller pipe diameter than the OAP pipe; however, I found an aftermarket exhaust with closed path pipe diameter as big as the OAP pipe so I don't think you will have any problem using that exhaust with valves 100% closed. The exhaust that I am speaking about is from a UK vendor called Ninemeister.... I am leaning toward getting this one unless there is another one out there that has larger closed path pipe diameter and an X-pipe design....
Originally Posted by 808c2s
I believe CG has 2.5" for both closed and open valve pathways, thus they can be ran in close position 100% of the time if desired.
For what it's worth, here's a little education on the factory PSE muffler and our Valved Exhaust System and why we designed it this way.
The valves closed flowpath on the factory PSE muffler necks down to just about 45mm or 1.77". In addition to that, the flowpath of the exhaust is not straight tubing. It gets routed into a big chamber, where it's then forced through a perforated wall and small pipe before making it way back to the tip outlet. From the perspective of flow dynamics, heat soak, and any other variable you want to measure for drawbacks on high rpm use...I have never seen an aftermarket exhaust be worse than the factory PSE muffler valves closed. Video explanation below so you can see it for yourself.
Our Valved Exhaust System in the valves closed condition uses a 2" diameter flow path. The muffler we designed specifically for this system internally also uses a 2" diameter flowpath, however it has no internal restriction. It is a perforated straight piped flowpath that blends internally in an X pipe in the middle, before making it's way out to the tip outlets. Below is diagram of our design, and a schematic of the internals of our muffler for reference. Due to the larger tubing diameter, unrestricted flowpath and smaller muffler size than the factory muffler, our Valved Exhaust System with valves closed outperforms the factory PSE muffler in flow dynamics, heat soak, etc. Valves open, the primary flowpath our exhaust bypasses the muffler in a 2.5" diameter X-Pipe. Head to post #360 for our full Valved Exhaust System release or our Website Product Page for more details.
That all said, the PSE muffler is well designed. It KILLS sound and drone with valves closed, whoever Porsche outsourced the design development to did a great job at meeting their sound goals and regulations. You can add our headers and OAPs to a factory PSE and with valves closed it's still darn quiet and reasonable in cabin. The goal with our Valved Exhaust System with valves closed was to improve the sound character/tone of the car, bring up sound level to the point the car doesn't sound dead with valves closed, make the flowpath more efficient, and keep the drone level in cabin reasonable even with adding headers and/or OAPs into the mix at the same time or down the road. Did we try larger tubing diameter with valves closed? Yes. Did it drone noticeably more than the smaller tubing diameter? Also Yes. We nailed exactly what we were after with our VES. You can drive it around comfortably flying under the radar with valves closed (especially with that sound symposer deleted), it sounds awesome even with valves closed and it’s a real ripper valves open.
For what it's worth, from a liability standpoint we (along with any other manufacturer) is going to tell you to run exhaust systems valves open under sustained high RPM use, or sacrifice cabin presence to run a larger diameter with valves closed more similar to the PSE muffler valves open (about 55mm or 2.165"). It's just logically the smart thing to do to cover your butt, noone is going take a car out on purpose and run it valves closed for hours on end until it has a problem and create that datapoint. Porsche maybe, and their PSE muffler opens the valves at high rpm so that is the best basis the exhaust industry has to work off of. Now I did have a long and interesting conversation with Bob Rouleau (the OG Mr. Rennlist) about a year ago. Bob and his massive network of Porsche enthusiasts up in Canada have been running at the most sound restricted track in North America (Tremblant) where none of the PSE equipped Porsche are able to pass sound. To pass sound at Tremblant, for years they’ve all had to wire their valves shut or install a valve controller kit to override the PSE programming to run the valves closed through the entire rpm range. GT4s, GT3s, GT3RSs, 997/991 Carreras, 987/981/718 Boxsters + Caymans, etc, many with factory exhausts just as restrictive as the 718 GT4 with valves closed. They have tried measuring temperatures, drag racing each other down the straights, looking at mph and lap times. When I spoke with Bob, they have had no issues with their cars related to running valves closed, and they’ve found no appreciable difference in any of the variables they tested. This is the only time I’ve ever found any real world testing and datapoints on this particular topic, and it was more along the lines of being a non-issue.
The end conclusion here for me...run valves open when you can, it’s only logical. If you have to run valves closed through the top of the powercurve every now and then (especially with our valved exhaust system as it’s less restrictive than PSE) you can do so with some more confidence of not having any short or long term issues. That’s simply what the real world experience has shown so far from guys beating the crap out of their Porsches that way for years, and if you have a problem it was likely going to happen anyway and from a different variable.
Food for thought.
Best Regards,
John Gaydos
__________________ SOUL PERFORMANCE PRODUCTS Quality Exhaust Solutions, Fair Pricing, and Outstanding Service
John Gaydos- Owner, Performance Specialist
Cell - (484) 883-6197 johng@soulpp.com
I own a 718 Spyder with an aftermarket OPF and valved muffler. The weird stock valve programming is immaterial on backroads where I can keep the revs up, but puttering around lower speed roads, you can’t really bypass the muffler and unleash the exhaust unless you frequently downshift to first gear, in which case it is obvious you are just trying to be obnoxious. I have been considering the various valve control options (Soul/Cargraphics/Kline) vs ECU flash and possibly the DSC module option that is supposedly in the works, but I’m just annoyed I have to go through this process.
I know the inane valve programming supposedly stems from the upcoming European noise regulation but was wondering if the 992 911s have similar programming, specifically the new GT3s which apparently has a exhaust note not far off from the 991 gen. Does anyone know? If the new gen 911 is exempt from these valve programming changes, then this would be another example of Porsche inexplicably holding back cayman/boxster products.
The new 992 models are actually worse off and more difficult to play with the valve functionality.
The 718 and previous model Porsches have had vacuum actuated mechanical valves that are default open via spring pressure, and vacuum is pulled on the valves to overwhelm that spring pressure to close them. They are either 100% closed or 100% open, depending on the signal that opens or closes the vacuum solenoid controlling vacuum to the valves, or interrupting/changing that vacuum to the valves with an aftermarket valve controller kit.
The new 992s have mechanical valves, but they are controlled by an electronic valve body. No more vacuum. The programming for those valves now allows Porsche to do whatever they want and open them to percentages, and even with the PSE button pushed its closed primarily until WOT at high rpm. Now it's a buzzkill that can't be easily resolved, as you have to change the programming itself and that's more invasive/complicated and not as warranty friendly as a valve controller kit playing with a vacuum source
Regards,
John
Last edited by Soul Performance; 09-16-2021 at 03:59 PM.
For what it's worth, here's a little education on the factory PSE muffler and our Valved Exhaust System and why we designed it this way.
The valves closed flowpath on the factory PSE muffler necks down to just about 45mm or 1.77". In addition to that, the flowpath of the exhaust is not straight tubing. It gets routed into a big chamber, where it's then forced through a perforated wall and small pipe before making it way back to the tip outlet. From the perspective of flow dynamics, heat soak, and any other variable you want to measure for drawbacks on high rpm use...I have never seen an aftermarket exhaust be worse than the factory PSE muffler valves closed. Video explanation below so you can see it for yourself.
Our Valved Exhaust System in the valves closed condition uses a 2" diameter flow path. The muffler we designed specifically for this system internally also uses a 2" diameter flowpath, however it has no internal restriction. It is a perforated straight piped flowpath that blends internally in an X pipe in the middle, before making it's way out to the tip outlets. Below is diagram of our design, and a schematic of the internals of our muffler for reference. Due to the larger tubing diameter, unrestricted flowpath and smaller muffler size than the factory muffler, our Valved Exhaust System with valves closed outperforms the factory PSE muffler in flow dynamics, heat soak, etc. Valves open, the primary flowpath our exhaust bypasses the muffler in a 2.5" diameter X-Pipe. Head to post #360 for our full Valved Exhaust System release or our Website Product Page for more details.
That all said, the PSE muffler is well designed. It KILLS sound and drone with valves closed, whoever Porsche outsourced the design development to did a great job at meeting their sound goals and regulations. You can add our headers and OAPs to a factory PSE and with valves closed it's still darn quiet and reasonable in cabin. The goal with our Valved Exhaust System with valves closed was to improve the sound character/tone of the car, bring up sound level to the point the car doesn't sound dead with valves closed, make the flowpath more efficient, and keep the drone level in cabin reasonable even with adding headers and/or OAPs into the mix at the same time or down the road. Did we try larger tubing diameter with valves closed? Yes. Did it drone noticeably more than the smaller tubing diameter? Also Yes. We nailed exactly what we were after with our VES. You can drive it around comfortably flying under the radar with valves closed (especially with that sound symposer deleted), it sounds awesome even with valves closed and it’s a real ripper valves open.
https://www.youtube.com/watch?v=axDA_8ltLDU&t=2s
For what it's worth, from a liability standpoint we (along with any other manufacturer) is going to tell you to run exhaust systems valves open under sustained high RPM use, or sacrifice cabin presence to run a larger diameter with valves closed more similar to the PSE muffler valves open (about 55mm or 2.165"). It's just logically the smart thing to do to cover your butt, noone is going take a car out on purpose and run it valves closed for hours on end until it has a problem and create that datapoint. Porsche maybe, and their PSE muffler opens the valves at high rpm so that is the best basis the exhaust industry has to work off of. Now I did have a long and interesting conversation with Bob Rouleau (the OG Mr. Rennlist) about a year ago. Bob and his massive network of Porsche enthusiasts up in Canada have been running at the most sound restricted track in North America (Tremblant) where none of the PSE equipped Porsche are able to pass sound. To pass sound at Tremblant, for years they’ve all had to wire their valves shut or install a valve controller kit to override the PSE programming to run the valves closed through the entire rpm range. GT4s, GT3s, GT3RSs, 997/991 Carreras, 987/981/718 Boxsters + Caymans, etc, many with factory exhausts just as restrictive as the 718 GT4 with valves closed. They have tried measuring temperatures, drag racing each other down the straights, looking at mph and lap times. When I spoke with Bob, they have had no issues with their cars related to running valves closed, and they’ve found no appreciable difference in any of the variables they tested. This is the only time I’ve ever found any real world testing and datapoints on this particular topic, and it was more along the lines of being a non-issue.
The end conclusion here for me...run valves open when you can, it’s only logical. If you have to run valves closed through the top of the powercurve every now and then (especially with our valved exhaust system as it’s less restrictive than PSE) you can do so with some more confidence of not having any short or long term issues. That’s simply what the real world experience has shown so far from guys beating the crap out of their Porsches that way for years, and if you have a problem it was likely going to happen anyway and from a different variable.
Food for thought.
Best Regards,
John Gaydos
Just to be clear, valves open with your valved system is essentially a straight pipe? So it would produce essentially the same sound as your Race system without resonators?
Just to be clear, valves open with your valved system is essentially a straight pipe? So it would produce essentially the same sound as your Race system without resonators?
Not quite, but close to the same sound level and tone. Remember that with the valves open you still have the secondary valves closed flowpath active through the muffler. This takes the edge off the overall sound level, and more importantly is crucial in design towards reducing the drone and cabin presence with valves open in the 1800-3000rpm range compared to our Race Exhaust. Remember also, that the direct comparison we are talking about here would technically be our OAPs+VES (aka Sport Package) vs our Race Exhaust due to it being a full header-back system.
For anyone interested in a Sound Symposer Delete Kit, we came up with a pretty simplistic solution. These caps pressure fit right over the OE pieces once you take them apart. You simply remove the connection tube to the firewall, cap the OE ends and reinstall them to seal the system. If you follow the links below buy a SOUL T-Shirt or a SOUL Hat, simply mention in the notes during checkout that you'd like the Sound Symposer Delete kit and we'll throw them in for free
Not quite, but close to the same sound level and tone. Remember that with the valves open you still have the secondary valves closed flowpath active through the muffler. This takes the edge off the overall sound level, and more importantly is crucial in design towards reducing the drone and cabin presence with valves open in the 1800-3000rpm range compared to our Race Exhaust. Remember also, that the direct comparison we are talking about here would technically be our OAPs+VES (aka Sport Package) vs our Race Exhaust due to it being a full header-back system.
If someone wants a deal on Soul Race Exhaust (resonated version) send me a PM. I would up with 2 of them (long story) and 1 is for me!
Thanks again Bob for passing along the opportunity to try this out.
It’s probably not going to be the exhaust that stays in the car for good but figured it’d be a fun fling…
The only obvious bottle neck I see in the system is where the dia of piping is reduced to allow the OE tips to slip on, might get a little creative with that should I decide to keep the system!
Thanks again Bob for passing along the opportunity to try this out.
It’s probably not going to be the exhaust that stays in the car for good but figured it’d be a fun fling…
The only obvious bottle neck I see in the system is where the dia of piping is reduced to allow the OE tips to slip on, might get a little creative with that should I decide to keep the system!
Glad to help! It will be interesting to hear your opinion of how it sounds.
Arrived at 1515, installed by 1700 went on smoothly and fitment is good.
Havent be able to get the OE tips on quite yet as the ID of the OE tips and the OD of the soul exhaust doesn’t quite allow for a slip-on installation.
Car is warming up as we speak to get the wifey out for drinks.
Nice. Let us know what you think about it when you return, unless you have one too many. I would think that the OEM tips would fit since that is one of the options when ordering (reuse OEM tips) - hopefully Soul chimes in with an answer or solution.
09-16-2021 | 12:05 PM
