Porsche 981 GT4 / Boxster Spyder / Clubsport SOUL Long Tube Street Headers

I've had the Soul headers w 200 cell cats and the stock PSE for a couple years now and it sounds fantastic. I get a lot of compliments on the high RPM howl and find myself driving at higher than necessary RPM's on the street just to hear it myself! It is nice and quiet at start and low RPM's, not at all too loud, at least to my ears. At higher RPM's it really comes into it's own. Headers and a tune transformed the car.

When I purchased my headers for the GT4 I was prepared to also purchase Soul's rear muffler box etc but John was forthright enough to tell me that the stock Porsche PSE was flow through enough that there wouldn't be a significant enough gain. Which is why a year or so later when I bought a 718 GTS 4.0 GTS I immediately went back to Soul and did buy the cat back exhaust for that car and it sounds great as well. I'd say that the 4.0 Boxster with the valves locked into the open position is louder than the GT4 at start up and lower RPM's.

Big fan of Soul's customer service and their facility is impressive.

Originally published on SOUL Performance Products.

I have a 981 Spyder that's all stock, and a second one that I have modified.

The second one started with a Soul valved exhaust which I was unsure about until I took delivery. I love the OEM PSE and didn't think I would care for anything louder. After taking delivery and driving the car the Soul valved exhaust seemed to be be basically a PSE turned up to 11. It had a little bit more bark when the valves opened up but nothing outrageous. I felt like all the low end burbles were more significant and happened with more regularity, specifically at low rpm off throttle points. It was a little bit much, but not the end of the world. I quickly fell in love with it. After driving it a few months I decided to take the plunge and purchase the Soul street headers with the HFCs and add a Softronic tune to go along with it.

After installing the headers I was a bit surprised at how quiet the car still was. Warmed it up with several trips around the block, nothing of any speed or RPMs, revved it a little bit. Got it back on the lift to listen and check for any exhaust leaks. It wasn't until I got out on the freeway and drove the car to the point that the valves opened up that I heard the full extent of what I had done. It sounds glorious, but it's not what I would call quiet. I'm a fan of low key tame exhausts, and this is not that. There is no drone, and it's perfectly livable when you are driving the car like a normal human being, but when you get after it everyone knows. I keep going back and forth on if it's too loud or not, I don't really need or want attention (I say that with a bright red Spyder), but holy **** the car sounds good. I've heard it standing behind it while my neighbor revved it up to hear it, it really is a fantastic sound and tone. It's just a touch loud.

Drive both cars back to back, the biggest thing that stands out to me with the with the Soul exhaust & headers versus completely stock is the valves closed section. On both set ups when the vales are open it makes a lot of noise, the full Soul set up is several levels above the OEM car. It's the valves closed around town driving that really stands out in the Soul car. While it's relatively quiet and refined with no drone, there is absolutely more noise there than the stock car. It's not obnoxious or detrimental to the experience, but it's noticeable. When I drive the blue one it feels very under the radar and stealthy by comparison. All that being said I'm so happy with the Soul combo I hardly find myself reaching for the keys to the blue one these days when I want to take a car out. It's about as loud as I would want a street car to be and it sounds exceptional. Seriously. The car now sounds like it looks.

Originally published on SOUL Performance Products.

Finally gotten around to order a set of Soul Street (catted) headers for my 981 GT4. I personally am not a fan of race headers on the street as psychologically I feel de-catted headers end up being a major health hazard (especially if I have my kids around the car) even though it might not be the case

The quality is top notch as many have mentioned on Rennlist. I was cheap/lazy and figured ceramic coating/additional heat shields aren't entirely necessary for what I do with my car.

The only "mod" I have on the car is a Softronic tune from a few weeks ago, and then I added these headers along with some K&N filters as the engine air filter was starting to look bad. These headers definitely enhanced throttle response (perhaps the K&Ns might have added to that marginally as well). The Softronic tune made things nicer for sure, and I would say these headers kinda added something very similar to that on top of the tune. The sound coming out from the back of the car is a tad louder than stock from what I noticed when going 80% on the throttle. Didn't get a chance to go full WOT as streets are still kinda wet (it's been non-stop raining for >1 month already), and my car's still riding on 6-year old Cup 2s (which surprisingly are still feeling "ok" once warmed up). I didn't notice any more or less burbles coming out of the exhaust after headers are in, while the Softronic tune actually reduced burbles my car got. One thing I noticed is that in the first 15km or so of driving is that the engine wasn't running very smooth when I was crawling at very low speeds in 1st and 2nd gear (say 1200rpm-ish). The engine revs were a little unstable, and the car would end up bucking a bit. I suppose the ECU is adapting to the newer readings. However, that kinda went away after 15km or so of driving. As much as it's a bit of cliche, I would say Softronic tune + Soul headers definitely suits anyone looking for an OEM+ setup. I'm only looking to get a bit of smoother and better response on the car, as well as a notch up in volume. I would say these really did the job for me. So for anyone on the fence but got the budget to spare, I would highly recommend this combo.

Originally published on SOUL Performance Products.

I opted for Soul Long Tube with cats and Softronic tune. My goals: Keep the same sound (tone and timbre) but amp it up a little bit when the binoculars button is pushed. Be able to go into stealth mode in the hood or when I just generally want to keep a lower aural profile. ZERO drone (had it with two different 911 Turbo aftermarket exhausts, it was deafening), eliminate the flat spot in the power delivery, and as a bonus get a few more ponies if it happened, but even if it didn’t I’d be okay with that as it wasn’t my primary objective.

Called up John Gaydos at Soul and had a nice succinct convo with him. That’s who steered me towards Softronic. He was familiar with my shop (the owner runs Soul headers on his 991 GT3) and said it was a good idea to have them order it, which I wanted to do. I placed the order, backlog was about 3 weeks. It all came in and I had it installed and tuned (and plugs replaced while they had the header off) on Thursday.

Soul has delivered exactly what I was looking for. Zero drone, authoritative bark of the flat-six under half or more throttle, docile sounding at low throttle or with the binoculars button not pushed, flat spot absolutely gone, no CELs. The only thing I haven’t confirmed is not tripping sound meters at the local tracks (Road Atlanta, AMP, Barber) but having heard cars that passed there and now this Soul header, I really don’t think it’s going to be a problem.

Fantastic product! I’m just sad I can’t see the things, they’re so beautiful. Where’s that plexiglas engine cover??? (I guess you still couldn’t see them. ) Well done, John and crew!

Originally published on SOUL Performance Products.

After the install I was of course eager to get the car and experience it. My installer friend is about 45 minutes away from me, so that meant a bit of freeway and some side streets home. Right when starting the car I definitely noticed a bit more noise when turning the key. Not a lot, but enough that I could tell it was more aggressive. That said parking lot speeds and low rpms are basically OEM. There's not a real noticeable change at slow speeds which is a good thing.

However pulling out and getting on gas down the street with Sport Mode and Exhaust on.... AMAZING. This is what the car should sound like stock. Exactly what I was hoping for. In my opinion this must be what the engineers at Porsche wanted the car to actually sound like. I feel like they must have designed the engine and exhaust, slapped each other on the back in approval, and then been told by managers they had to put on 800 cel cats, thrown up their hands in disgust and gone to eat some bratwurst. The sport cats amplify the already amazing PSE sound back to a fantastic level.

For me personally the volume is basically perfect, maybe slightly on the cusp of entering the loud side. It gives me the "more" that I wanted when at mid to high rpms with the exhaust open. I would say maybe 75-80% of race header volume...which is what I was looking for. If race headers on an open road actually sounds like being inside of a parking garage..this is approaching a similar level but not quite to that full amount. Windows up amazing tone of the PSE and engine. Windows down sounds even louder and I can only imagine how epic it sounds behind the car. I can't wait to go through a tunnel... If I had to use a word to describe it I would say the exhaust is more "trumpet" like now with loud revs. It's still the oem sounds but just blasted out more.

In addition I really wanted a smooth pure tone... the Soul headers are definitely doing that. It's not gritty or coarse like I was worried it might be, and which race headers tend to do as you get fully open flow from the engine. If anything it is smoother and purer than even my OEM setup sounded, or maybe I'm just hearing more of it. But it's fantastic. You get the Porsche 3.8L sound in spades. All I can say is YES YES YES. This is what you want to be hearing when driving your Porsche.

When cruising on the freeway or bumper to bumper traffic at lower rpms it's fairly close to stock. With the exhaust open I was getting 76-78 dbA with the windows up/closed. On the gas and higher RPMs with exhaust on and windows up/close it was 87-90 dbA. I did in fact turn OFF the exhaust for a bit, something I never had to do before. That quiets it more on the engine rev side since OEM PSE exhaust is closed anyhow at low rpms. That said you can still have a conversation with someone inside. But I felt like it was marginally louder perhaps. Something to consider if you have to use the car for long journeys.

Even without headers, the stock system has some drone around 2500-2800 rpm...minimal but there. I wouldn't say that it is worse with the Soul headers, but there is more volume overall... so if you are sensitive or doing a long drive the volume might be a concern. For me I found the overall volume to be right where I wanted it. Loud enough to now hear it and have to maybe turn the radio up a bit more than before...but not so much that it's overbearing. I took the car to work the other day and honestly I felt like I could easily drive silently just keeping revs down. At 2800 and below it is basically stock. That is sort of my barrier, if I can go to work now and then and not feel self conscious driving. At the same time I definitely had some fun with hard accelerations, down-shifts etc... you WILL get more attention with headers. But I feel like it is the right level for this car.

Being that OEM Cats are 800 cel, Sport Cats are 200cel HJS cats and Race are basically 0 no cats... it makes sense. The sport cats let about 75% more flow or volume through. So it isn't quite race header insanity but up there.

Oh one other benefit... a bit more "pops" when letting off throttle. The GT4 doesn't do this much as my 981CS did (which is done by computer). The GT4 doesn't fake it so you get way less pops with stock setup. But with the new headers I got a handful of nice loud backfires. It is still fairly infrequently ... but sounds good when it happens but there are definitely more burbles now overall.

My drive home was mostly traffic even on the freeway. But the car definitely pulled nicely. Not that it was horrible before. After arriving at home I transferred on the Cobb OTS Stage 2 map with my accessport and did a quick drive around town. It was hard for me to register much with the "butt" dyno and just street driving. I will say when I had stage 1 on my Cayman S it was similar... I couldn't tell a difference from…

Review shortened to fit Judge.me's 5,000-character import limit. Originally published on SOUL Performance Products.