RB93

Hi,

I have recently acquired a 981 GT4 and am absolutely loving the car so far. The only thing I'm looking to change at the moment is the exhaust system. My aim is to increase the exhaust noises at lower RPM (1500-4000) such that it drowns out the higher pitched noise (not a technical expert so I'm not sure if it is drive belt or intake noise) without necessarily making it obnoxiously louder at the higher RPMs. Hopefully someone has managed to achieve such results and can point me in the right direction in terms of which exhaust system to look into. If the system can generate louder cracks, pops and burbles, that would be a win-win in my books.

Thanks in advance for your help!

KingSize.Hamster

Subscribing to thread. Interested as well

I did Soul 200-cells headers and felt it added a little more volume. I found the cat-less/race headers a bit too raspy for my preference and am not particularly comfortable having zero cats for (potential) health reasons even though it may make no sense.

Meraki Autoworks

We have Soul exhausts in stock to help you change the exhaust volume and tone!

-Josh

Last_935

@RB93 A quick (and free) way to increase the low-end exhaust note as you're waiting on your new Soul exhaust (highly recommend BTW) is to disconnect the vacuum line to the PSE. This will force the valves to remain open and in Loud mode 100% of the time. You will just want to plug the ends of the hose after disconnecting it.

KingSize.Hamster

forgot to mention. I believe RB93 and I have the Euro-spec cars in Asia, where the PSEs are fully open once PSE button is turned “on”. So we kinda don’t benefit from the vacuum hose trick

GT4_981

I also recently purchased a 981 GT4 and I went with SOUL catted headers keeping the back section stock Porsche Sports Exhaust.

After hours and hours of research, it's pretty clear that this was the best solution for me. It opens up the sound in all areas, if I could be more specific to your question...lower RPM probably increases by 30% although the rear diff whine you're talking about doesn't completely get drowned out. Honestly, that's a sound that is unique to Porsche and it's a characteristic that, if you knew, might grow on you over time. Above 5k RPM in WOT, I would say sound has increased by 70%.

Catted Header vs Open Header: These cars don't need more power so using a header with a cat on there has many more pros than cons...power being the only issue. The car doesn't ever smell and with the PSE valves closed, it sounds the way the completely stock setup did with valves open.

Perfect scenario but you still have to bend over and pay the Porsche tax. Headers for American cars are like $2500 and GT4 headers are $4000.

RB93

Thanks a lot for this. Out of curiosity, was there any reason you chose to do the headers instead of the exhaust/both?

@Alpha.GT4 this sounds like your current system. Maybe you have already nailed the set up.

KingSize.Hamster

Maybe I am deaf. I feel like I still want more volume down low lol. WOT I am actually quite ok with what it is now. So I wouldn’t really wanna make higher revs louder

GT4_981

There were quite a few reasons I didn't go with cat-back exhaust and I will list them in the order of importance:

1. STORAGE: When you own a GT car, it's imperative that you keep as much of the stock components as possible as a stock vehicle will be worth significantly more money. With that in mind, including keeping the stock wheels, I do not have the storage space to fit an exhaust system.
2. VOLUME: After riding in a friend's header only setup, WOT is plenty loud. Quite frankly, the stock GT4 with open valves isn't legal where I live...not saying the legal limit is reasonable but if you consider the PSE is already aftermarket weight and quality...just because it's factory doesn't mean it needs replacement. The flexibility of being headers only is huge, let me try to explain with three ranges of volume.
Stock Volume levels 1-4 where 4 is WOT with valves open.
Header only Volume levels 2-7 where 7 is WOT with valves open.
Header with cat back 5-9 where 9 is WOT with valves open.
Personally, I prefer having a wider range of sound possibilities so that I can remain flexible to have it quiet AND decently loud. I want to also point out that at 75mph on the freeway in 6th at 3k rpm, it's already kinda difficult to talk on bluetooth with the header only setup...can only imagine what it is with an additional 30% volume.
3. POWER: This is a modern day momentum car and what I mean by that is today's turbo cars are 500+ whp. With that said, I didn't buy this car for power, I bought it for its surgical driving precision. It doesn't need more power so the measly 5-8% you might get from catback doesn't make sense to me.
4. LEGALITY: While a 200cel cat isn't technically legal in CA, it would pass visual and if I get pulled over because a cop hears a 7 WOT, I have plausible deniability by showing him that my tips/muffler is stock. Additionally, I think the car would pass on a state REF situation where an aftermarket exhaust would instantly fail visual.
5. COST: As mentioned before, the 5-8% power you might get becomes even less worth it considering Porsche tax. Headers are already $4k and to spend another $4k on a catback is just ridiculous. I would personally rather apply that on top of my previous wheel budget as I have done to stretch and get a $10k set of FI-Rs.

Hope this helps clarify. Plus...you can always get headers first as there's no incentive to buy it all at once. If it's really not enough, get the cat back later.

NoGaBiker

I have the same setup as GT4/981, assuming he has the Softronics software, and I agree with everything he says.

Unmentioned is the removal of the 4500-5000 rpm flat spot; that was annoying and the software gets rid of that beautifully. And I don't like the catless smell one bit in a street car. It's glorious at the racetrack, but I don't want it in my garage.

Highly recommend Soul long-tube street catted header with Softronics. Ridiculously overpriced, as mentioned, but all this **** is, so what are you gonna do?

Dyno showing flat spot *

*Note that both header dynos also include Softronic, even though they're not labeled as such. So 1) stock, 2) stock + ECU, 3) street header + ECU, 4) race header + ECU.

KingSize.Hamster

the flat spot fix is quite nice. I guess for me I was hoping to get something more volume down low. If anything the WOT volume I am quite happy with catted headers only. But with headers, maybe having the cat back on top would really be too loud

anyway, @RB93 maybe you could sit in my car and see if that does the job for you. And to check if i am just used to eve loudness (or that my ears are just bad … lol)

JoeB3

I wasn’t aware this was an option. First I’ve seen on it. Does this throw any codes? Any others with experience with it? Is Sport+ any louder?

Last_935

No codes thrown, It just effectively disables the PSE button by leaving the valves open all the time. The way the PSE system works is by applying engine vacuum to the valves to keep them closed (quiet mode). The valve stays closed when the button is not pushed, and opens and closes at various RPM's base on the engine's ecu programing when the button is pushed. Without vacuum to the valves (hose removed and plugged), the valves stay open (loud mode) all the time. With the hose removed, there is only one setting regardless of the mode that is selected. Hope that helps.

KingSize.Hamster

correct. However, my understand is both RB93 and I have the euro-spec cars, so the valves are always open when the PSE button is pressed. We in Hong Kong, and from what I could tell, we share the same headlight beam pattern, clear side flashers, lack of bumper tumor etc over the years just like Euro cars. So we might not benefit from this trick. That said … I should just bite the bullet and try it

RB93

I am keen to take you up on this. I did just order a set of Soul exhausts as I prefer to start with those and work my way back to the headers if needed in the future.