SOUL | Porsche 718 GT4 Competition Over Axle Pipes

Say hello to our new R&D project, the 718 GT4! There’s been a lot of talk over the last few months about this car and a lot of discontent with some popular KZbin videos comparing the 718 GT4 and 981 GT4. Starting at the front, we have the headers and primary cat assemblies. The exhaust then bolts to a set of over axle pipes with canisters at the end, which then connects to the factory valved muffler system.
The Over Axle Pipes
These factory over axle pipes appear to have a faux OPF matrix completely unmonitored by the computer system, unlike the Euro spec cars with monitored OPF cores. These were the first to go, and as you can see and hear this is going to be one of the best returns on investment for sound and performance improvement with a single product replacement. Uncorking these over axle pipes makes much better use of the factory valved PSE muffler. It maintains a very reasonable, almost factory-like sound inside of the car with valves closed, and valves open it is quite transformed. Eliminating the restriction of the headers and over axle pipes and keeping the factory PSE on the 718 GT4 / Spyder will without a doubt be the golden ticket setup for this platform.
PSE Programming
This is where things get interesting. European sound restrictions have been getting more and more severe over the last decade or so. Every time a new GT car comes out from Porsche, the PSE programming becomes more and more invasive in controlling the sound level of the car on full throttle. As many of you I’m sure have experienced on your previous Porsches, even with the PSE button pushed the programming will override this and close the valves until you reach a higher rpm range. The 718 GT4 is no different, and in fact it’s worse. With the button pushed, the 991 GT3 I drove the other week would shut the valves on hard throttle and then reopen around 3500rpm. With the button pushed, this GT4 keeps the valves closed until about 5000rpm. Now more than ever, the most inexpensive mod on sound you can perform on a GT car is unhooking the vacuum lines from the valves and plugging the lines so you don’t have a vacuum leak. Especially when unrestricting the exhaust upstream it makes a huge difference. Take the over axle pipes for example, below is a video where I drove this GT4 with our prototype over axle cat delete pipes. There are two takeoff clips in that video, the first take off clip is with the vacuum lines pulled and the valves in the default open position. The second take off clip has a large truck in it, during this one the PSE button was pushed/active for that takeoff and you can hear the valves close and then open at about 5k rpm. Completely different sound experience.
Now, for those who still want valve control but don’t want the PSE programming to override your fun we have one option now and are working on a couple others. We have our universal valve controller kit that simply works off constant 12V power, vacuum, and ground and has been used with great success on all of our valved exhaust systems for Porsches over the years. On this car it would serve to override the PSE button so it will no longer function, and the key fobs with our kit control the valves 100% closed or open. You can also sync the signal of these key fobs to your garage door buttons of the HomeLink system, so you can use existing buttons in the car instead of the key fobs if you so choose.
A second option may be an ECU tune. I’ve spoken with Scott at Softronic, our dedicated Porsche tuner. He intends to look into the PSE programming itself to see if he can reprogram the ECU to simply keep the valves open 100% of the time when you press the PSE button. Along with all of the other benefits of software tuning Scott offers - such as power - this would be adding icing to the cake.
A third option is our friends over at DSC, those suspension tuning wizards you’ve all come to know and love for the DSC suspension modules to maximize the potential of Porsche’s PASM system. They have been working on an addition to the DSC module that allows you to have full control over programming your valves to do whatever you want when you want.
Stay tuned for the full release and more videos: soulpp.com/product-category/p...
Have questions? We're always here to help:
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IG: @soulperformanceproducts

[@cd6hokie]

What a beautiful sound

[@sanderhawkins533]

Great job guys. The sound is perfect.

[@SoulPerformanceProducts]

Thank you! - Mike

[@NathanElcoate]

Whao that sound.

[@fareselias]

Excellent !😉👍

[@SoulPerformanceProducts]

Thank you! - Mike

[@zeezy21]

Heavenly

[@982spyder5]

Can't wait for my 718 Spyder to be delivered so that I can hang the Soul system on it. Their valved exhaust was magical on my 981 BS.

[@SoulPerformanceProducts]

Thank you so much! - Mike

[@carlitoxb110]

you are a lucky boy

[@HemiBurns]

WINNER!!!

[@gboyer78]

Best solution I have seen so far... even better than the Uk 🇬🇧 options developed in the last 6-9 months... !

[@SoulPerformanceProducts]

Thank you very much! - Mike

[@gboyer78]

Welcome!! I also made a mention to your system in a Porsche group in facebook ... I might be contacting you later... my gt4 arrives in 10-15 days... ! 💥

[@sultanqasim]

Sounds great! It would be nice to have GPF delete pipes that have heat shielding similar to the stock pipes in order to minimize fire risk when parking over dry grass. Could you offer a version that includes heat shielding?

[@SoulPerformanceProducts]

Like the previous generation 987.1/987.2/981 exhaust systems (not from just us but most every exhaust manufacturer) we've found heat shielding to not be necessary to include, and we expect the 718 is the same and will provide it without. If our over axles pipes maintained a giant heat soak at the end in the form a particulate filter right by the rear tire, then yes a heat shield may be necessary. However, those are gone and no longer a concern For those that simply want to go above and beyond with cost not being a factor (no such thing as too much heat prevention) we will provide an optional service of having our over axle pipes sent to Jet Hot Ceramic Coating to have the inside and outside of the pipes coated in their entirety, which would provide better thermal retention characteristics vs a heat shield covering a portion of the exhaust.

[@sultanqasim]

Soul Performance Products Thanks for your detailed answer! Doing some more research, I agree these pipes should run cooler than stock with the restriction of the filter removed. I’ve also seen that most ordinary cars don’t put any heat shielding below the pipes beyond the catalytic converters, and the temperature of these pipes (which are post-cat) should be well below the ignition point of most combustible materials when you park. With that said, Porsche did include heat shielding on the over-axle pipes even on the 981 that didn’t have particulate filters, so maybe I’ll take you up on the option of ceramic coating the pipes when I get my 718 Spyder.

[@malinois71]

What does that cost? @@SoulPerformanceProducts

[@whitecar8]

Very interested in your product. Interested to hear your experience with an EU spec car. Worry about the sensors and warning lights

[@SoulPerformanceProducts]

Thank you but these would not be directly compatible with EU cars as they have an additional sensor and are monitored by the ECU resulting in a check engine light. -Mike

[@borinvlogs]

this is a proper sound no 4 cylinders bullshit.

[@R8andGT3Fan]

😍😍😍🎵🎵🎵

[@FredSHerr]

This sounds great. Any idea on its decibel level? I go to Laguna Seca and most track days are limited to 92db.

[@SoulPerformanceProducts]

Thank you! We don't have the decibel levels available as there are so many variables in the recording process that it wouldn't be an accurate standard. It's very mild and you could run a valve controller to control the valves if necessary to keep it under control. -Mike

[@pininfarina575]

Is this video with stock exhaust (header / muffler), just the mid pipe (overaxle pipe) replaced effectively removing the OPF filter?

[@jdvg5846]

Sounds much better already with only the over axle pipe replacement. Will this exhaust system also be offered by european dealerships (f.e. in Germany) as soon as it becomes available including headers and rear exhaust?

[@SoulPerformanceProducts]

Thank you! At this time we have not done any testing on non-US vehicles which are more stringently monitored. While these over axle pipes may not be compatible, our headers and rear exhaust options likely will. - Mike

[@jdvg5846]

@@SoulPerformanceProducts Thanks and do you have any idea when the headers and rear exhaust options will become available?

[@CS21dude]

Nice, so the only change here are the over axle pipes - correct? Also your little value graphic is 👍🏻

[@SoulPerformanceProducts]

This also has our Valve Controller to give us control over the valves. We'll be launching more vids later today. -Mike

[@pininfarina575]

@@SoulPerformanceProducts but in lieu of the valve controller, if I had the simple collar mod to keep valves open (definitely less elegant of a solution) with the stock header / muffler + this overaxle pipe, this video is what the car will sound like?

[@danielahlquist2660]

So, recommended investment not applicable for EU cars?

[@SoulPerformanceProducts]

We have not had the ability to test on EU vehicles yet. -Mike

[@lepooj12]

This is ONLY axle pipes???

[@SoulPerformanceProducts]

This is our Competition Over Axle Pipes and Valve Controller to give full manual control over the valves. - Mike

[@vikd4292]

not as free breathing as the old one, still nice though

[@SoulPerformanceProducts]

That's just over axle pipes - wait until you hear it with more mods! - Mike

[@MrSalem5227]

manuall ... ephhhh