And it gets better in time. Mine makes way more sounds vs when it was newly installed

 

Impatiently waiting for this - any first opinions from you/ the soul team about this pairing with the race exhaust?

 

Development

The factory headers on these cars are a restriction point on both performance and sound. Factory cats average 400-700 cells per square inch in density, and on top of that you can see in the photo below there are a few other areas that hinder performance as well. The runners are very short and have a relatively lackluster merge collector. You can see that the exhaust flow of the three primary tubes terminates into a small offset opening into the cat core. From there, the exhaust flow goes through the cat and then enters a very short end cap with another hard offset exit into the over axle pipes. It’s probably one of the more restrictive designs we’ve seen from Porsche save for perhaps the 987.1 headers or all the log style manifolds on turbocharged 996/997/991 models.

Our goals for improvement were to minimize flow restriction and maximize exhaust velocity, while working within the factory envelope to maintain modular fitment to factory or aftermarket over axle pipes. This was no small challenge as the headers are tightly packaged giving us less room to work with than the previous generation GT4. Regardless, we were able to maximize the length of the primary tubes with a much smoother, larger and straighter entry into the cat core through an improved merge collector with velocity spike. We also lengthened and straightened the end cap significantly after the cat to bring that exhaust flow smoothly back down into a single flow path. We use large radius HJS HD 200 cell cats for maximum flow while keeping the catless smell and CELs in check. The triple metal winding matrix and brazing stripe lock the core in place and will withstand heavy abuse which is paramount in a GT car.
Results

While we know this new 718 GT4/Spyder/GTS platform is the more restrictive of the Boxster/Caymans we’ve experienced on the exhaust side, it is still an absolute joy to experience the improvements first hand. We installed our prototype Street Headers on a gorgeous Gentian Blue GT4 equipped with our Race Exhaust System. The results of our headers in combination with the Race Exhaust was nothing short of awesome. Driving that car (video below) with this combination had the traction control kicking in hard on take offs, and once the traction control was turned off you can also hear it spin through the top of 1st gear. The car felt GREAT with more power everywhere. From a performance perspective it is a superb compliment to the Race Exhaust.

As for sound it is another noticeable increase over just the Race Exhaust, but nowhere near the sound level or rawness/unrefined all out race car sound of the Competition Headers/Race Exhaust - definitely not for the faint of heart. On top of the noticeable volume increase, our headers also bring in new character to the table. Adding the Street Headers to the Race Exhaust adds more depth to the exhaust note in the low end and mid range, and becomes higher pitched in the upper rpms. Think about every change you’ve experienced or heard with the Race Exhaust but amplified just that much more. The most notable change in tone that’s not just more of the same is a subtle addition of “rawness” - a bit more crisp, sharper engine note if you will but at the same time a smidge less refined with “I can be a race car” character. When you’re light on the throttle it’s angrier, more lively - like a middleweight boxing champ dancing on his feet ready to rip your head off. You can hear and feel the car begging you to punch the throttle more so than before and boy does it respond, and with more of a bad boy attitude then before.

If you are running our Race Exhaust or our Sport Package (OAP/VES) and are looking for the next logical step in performance and sound enhancement - it’s our Street Headers. If you are running our Competition Over Axle Pipes with the PSE exhaust, and you want more power and sound level with some added aggressiveness...this is the logical next step for that as well.

If you have more questions, we have more answers. Please ask away, and thank you all for the continued interest in our development on this platform!


Lead Times on Street Headers

We have the precision cast header flanges being implemented on the production versions, and their estimated availability is mid May so that would be the earliest estimated fulfillment. That said, we have fabrication scheduled through the first week of May already, so please keep the lead time in mind and be as proactive as you can in planning your purchase. I am always happy to provide you with a current update on lead times for various products, so please ask. We just had a very big expansion, are adding three more fabricators in the next two weeks, and are interviewing for another five. We aim to add some SOUL to your life as quickly as possible haha.

Placing an Order

If you’d like to order a set, please shoot me an email at johng@soulpp.com or text/call at 484-883-6197. The product page is live for preorders and the price point is $3,795. If you do place an order on the website please reference that you came from Rennlist and select John Gaydos during check out, I’ll be sure to oversee your order and be available for updates as you move through the production queue.

Thank you!

John Gaydos / Mike Spock

 

That took a little longer than expected to get up on here while juggling the current 992 Carrera/Turbo R&D project, sorry guys!

Not anymore, and thanks for asking! After experiencing some early systems opted with Jet Hot taking upwards of 12 weeks to come full circle through fabrication and then coating, we ended up doing some batch runs of the over axle pipes on the race exhaust systems. Now when an order comes in for a race system to get built, we can ship out the the over axle pipes to get ceramic coated ahead of time and have handy for when the rest of the exhaust comes through fabrication

Thanks for chiming in with your feedback guys, it is much appreciated : )

Best regards,
John Gaydos

 

I knew you would come through sooner or later! As I told you I am considering a 718 Spyder and I am test driving one Thursday, and I would be interested in these headers/cats; however, for those of us here that do not want the race exhaust, what is the option available? I assume it is your setup that basically deletes the particular filter? And the sound of those, along with the factory PSE, is probably much better albeit not as loud as the race setup in the video? I am sure others are contemplating this option thus the reason I am posting here.

 

The best configuration we have for those driving on the street that has the benefits of the sound/tone of the Race Exhaust without quite the overall aggressiveness or level of drone in the 2000-2800 range it our Sport Package combining our Competition Over Axle Pipes and Valved Exhaust System. Here is a link to the product page, but also scroll on back to the release on post #360. It would pair very well with the Street Headers if you end up wanting more

Sport Package Product Page

Regards,
John

 

I just listened to this video on your site (https://soulpp.com/product/https-sou...eet-headers/): does the car have just your new header/cats? And could the header/cats be combined with just the over the axle pipes (https://soulpp.com/product/porsche-7...-axle-pipes/)?

 

Why yes it does, and yes it can. That said, the PSE muffler itself has very little character or sound at all with valves closed, and is not quite as higher pitched/smooth our Valved Exhaust System in closed or open condition (ours uses an X-Pipe in the flow path with valves closed and open).

 

Thanks, that helps me, and probably others as well that are looking for an optional setup for the GT4 & Spyder!

 

John,

Thanks for the info on the headers. I am super excited now that they are being released.

Can you confirm the video is of the your resonated Race exhaust or non-resonated Race exhaust? I like loud and the car is for track and weekends only, so I am trying to decide between the resonated Race and non-resonated Race. In the video, it doesn't appear to be too too loud. I like the sound of the Chalk car in the video of Competition headers + Race exhaust, but I want to go with your Street headers. I am leaning towards Street headers + non-resonated Race.

Also, I asked a few weeks ago before you released your street headers, but maybe you have a better idea now; sound level between Race headers + resonated Race exhaust vs Street headers + non-resonated Race exhaust?

 

The video is indeed with the resonated race exhaust. There is not much overall sound level difference between resonated and non resonated race exhaust. The resonated to me is a bit smoother and refined sound characteristic. I would go with the resonated race exhaust with any combination of header change, it just sounds better haha. The difference in sound level between Competition Headers and Street Headers is significant. It doesn't matter what race exhaust system from us is on the car, if it has our competition headers it is going to be much louder than the street headers.

Regards,
John Gaydos

 

Any HP/TQ gain numbers from your testing John?

 

I have just received all components from my Valved Exhaust and I'm having some issues with the mounting topic. My car is an European car, with the European mounting above. The exhaust has been shipped with the US Mounting parts #15 / #16 / #17 / #18. Is this just a removal of mounting parts #15 / #16 from the European mounting pic, and just replace them with #15 - #18 in the US mounting pic? There are also other parts like the vacuum lines that are "mounted" on part #15 in the European mounting, so it doesn't look like it is a plug and play.

Has anyone with an European mounted car navigated this issue? Would appreciate any inputs. Thanks!

P.S The exhaust looks glorious. This speedbump is causing me a lot of grief!

 

PM heading your way now

Regards,
John Gaydos

 

We have a full range our products for this platform (including the first production sport headers shown getting built) heading to a customer in Canada. Mantis Racing has an in house dyno and will be independently testing various configurations of our products on his 718 GT4 for realistic and repeatable dyno data from a third party. We are always interested in more data, if anyone purchasing out products would like to do before/after dyno runs we are happy to cover the costs

Regards,
John Gaydos