Rennolazine

Even stock mufflers drone. But theres drone, and then theres DRONE, you know what i mean. Doesnt seem like its horrible and i appreciate your honest description. If you have perforated baffles in the resonator that should kill enough sound frequencies before it exits to be smooth. Are u thinking 2 borla style resonators before the x pipe or a resonated mixing chamber in the center? Honestly JAhmed got what is prolly the sweet spot. Even if i got the valved exhaust, knowing me id disconnect the valves anyway... so fuggit.

GT4MF

thanks John @Soul Performance - very useful.

To this point, is there any negative effect in terms of velocity/scavaging by removing the OPF casings/filters and replacing the piping? I’m sure you have thought this through (Including the timing aspect) I’m just curious to hear the explanation Forgive my ineptitude!

Soul Performance

Indeed I do haha, I've experienced all manner of drone over the years. At this point on this car I've driven probably about 20 different configurations of prototype setups that include replacing the rear PSE muffler. The drone range on this car is 1200rpm wide from 1800-3000rpm. The top of the peak peak of that drone is in the 1800-2400 range. By implementing resonators, anti-drone tubes, valves, smaller tubing diameters, blending the exhaust or not blending the exhaust, etc you can shift the drone range around a bit and lessen/smoothen it out and certain areas. However, if you do not use a muffler no matter what you do you are still going to have drone and a decent amount of it in that 1800-2400 range. With our race exhaust it is there, with resonators it is still there but less than without them. I found it drivable and loved ever minute of it, it's my favorite setup to date. If you want that same sound with less cabin presence, we've got that covered with the valved exhaust system coming. But for now, if you want to drive this car and you don't want just a bit more sound, you don't want it to sound how it should have from factory....you want it to rip snort and scream like a flat 6 pissed off hornets nest and giggle like a school girl going up next to the nearest highway divider or through a tunnel with the windows down....you've got to try out this race exhaust

No problemo, happy to help : ) Most of the scavenging (at least where it's most important) is taking place in the headers merging the exhaust flow off each cylinder together. The over axle pipes are after the flow has been merged and scavenging has taken place, all it is at that point in a cork of the flow in the middle of the system. Eliminating it only serves a benefit. Think of it like some really basic fluid dynamics. Three streams have merged into one larger river. Now way downriver a pesky beaver decided to build a dam after all that hard work merging those streams together, backing up the overall potential flow. Ditch that dam, everything is going to flow much smoother and faster than before. I hope that makes sense, but always feel free to ring me and chat about it at 4848836197

Best regards,
John Gaydos

dmk2

Have there been any back pressure related issues with these modifications? Does it interfere in anyway with the cylinder deactivation functions?

Soul Performance

No in both regards

Soul Performance

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Continued off the previous post above, the final production version has been test fit and we are taking pre-orders! Please refer to our previous R&D post above for more product details, or our product page at the link below. Here is some additional on pricing/weights, final production photos, as well as a video of it in action.
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718 GT4 Race Exhaust Product Page
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Pricing
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Resonated: $2695
Non-Resonated: $2495
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Weights
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Factory: 57.4lbs
SOUL Resonated: 30.85lbs (-26.55lbs)
SOUL Non-Resonated: 27.5lbs (-29.9lbs)
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Tip Options
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This system can be used with your factory exhaust tips, and our upcoming tip solutions will be a direct bolt-on once available (4" Slash Cut or Straight Cut, Double Wall or Single Wall, Signature Satin (Silver), Brushed, Polished, Black Chrome, or Satin Black)
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Lead Time/Ordering
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If you are interested in placing an order, please know there is a lead time of several weeks once the order is placed and added to the tail end of our fabrication list, which is growing. My direct number is 14848836197 (also available on Whatsapp) or you can email me at johng@soulpp.com. If you place an order through our website at the product link above, please note me as your representative and I'll be sure to follow up with you with an estimated lead time. Text/Call me any time to chat cars and discuss exhaust options to meet your goals
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Best regards,
John Gaydos

Soul Performance

Thank you for all of your inquiries and orders! We're building your components as quickly as we can while maintaining our high quality standards.



-Mike

DocMo

Great products and explanations!! Is there a chance you’d make an Xpipe catback that bolts to stock GPF or to your OAP?

Soul Performance

Thank you very much! Yes, our upcoming valved exhaust system will have our bespoke muffler (post #88) for valves closed, and valves open will have a similar X-Pipe flow path as our race exhaust

Best regards,
John Gaydos

spyderphile

Great progress, John. Few questions:

- 'Resonated' means 'Valved'?
- Does 'Resonated' muffler work with stock Cat and Header?
- If it works with stock Cat and Header, would you know if it will pass CARB emission tests? If you haven't done those tests yet, would you be able to do so, as you're further developing the products?
- Is the 'Resonated' muffler 'merged' design?

Thanks.

Mojonito

@Soul Performance

Do you have any pics of your race pipes installed from the bottom? Also, when are the gpf pipes shipping? I’ve got a drive coming up in September. Boxtoberfest for all the Texas out there. Social stuff is cancelled but the drive is still on!

Soul Performance

Sorry for the late reply Henry, I just got back from the track and just now catching up. Your over axle pipes are in production as we speak along with several others, Max is working on yours in the photo below we took earlier this morning. They will be shipping out your way this week Also below us a photo of our race exhaust from underneath before the final finishing/qc process that turns it our signature satin.

Poupon McArr

Would love to see a highway cruise video of the race exhaust to get a sense for the drone. But realistically, every time I've bought a valved exhaust I open the valves as soon as I get in the car and never close them... not sure why I even bother with the valves

Soul Performance

Nope, resonated means it has resonators. Resonators are resonators, mufflers are mufflers, and valves are valves, all three are different components in an exhaust system and do very different things. Our Race Exhaust can be optioned with resonators in the system to cut down on the overall peak sound level and resonant frequencies, it does not have mufflers or valves. Our upcoming Valved Exhaust System will have a muffler and valved, and the flow path will route 100% of the exhaust through the muffler with valves closed, and allow the exhaust to bypass the muffler with valves open. Both our Race Exhaust and Valved Exhaust System will bolt right up to the factory header/cat assemblies so hypothetically they should pass CARB after your 6 year grace period is up, as long as they don't consider those faux particulate filters a CARB required component to keep on the car. For your reference both our Resonated and Non Resonated Race Exhaust, and our Valved Exhaust System have a blended/merged X-Pipe design.

Best regards,
John Gaydos

Soul Performance

As much as I would love to accommodate that for you, a video will do absolutely nothing for you regards to judging drone. Drone/resonant frequencies is something you feel more than hear. As you can't feel a video, you lose most of the impact of giving someone a realistic expectation of drone. Watching a video won't cut it, you have to experience it for yourself and/or speak to someone that has. As luck would have it, I have driven our Race Exhaust (and every other combination we offer) quite extensively and would be happy to have an in depth chat about it to help you make an educated decision. If you're up for a call, shoot me a text or give me a ring at 4848836197

Best regards,
John Gaydos