Franko T

This has probably been beaten to death, but i'll put my take on things. 991.1 GT3 fitted with RSS exhaust, which features an X-Pipe design. I must have read every forum thread, and watched every video + listening and experiencing

With Factory side mufflers + Valves connected = Fairly quiet and uneventful until 3800 or so when the valves open, then all hell breaks loose. The noise I would say starts off with a bassy howl until it picks up near the end of redline which sounds very F1 like, especially in tunnels.

My view on this setup: Its quit boring while driving around normally, and makes you want to drive like a hooligan around town probably leading to some crazy tickets eventually. You're always chasing the exhaust note, which can become frustrating and times too On/Off ish. You also loose tons of noise on downshifts.

Next idea, what about disconnecting the valves. Easy, grabbed some rubber caps and twist ties, 10 min job.

With Factory side mufflers + Valves disconnected = fairly loud startup and more loud than I want under 4000rpm

I thought what the heck, lets see how it sounds. I'm not sure I would call it a drone, but its just feels too loud for civilized driving, making you want to shift now TOO EARLY (the opposite) trying to prevent drone and annoyance. See the tone is not refined enough to enjoy (such as Ferrari's do even under low RPM). No more transition but still at 4K the exhaust gets substantially louder. Call me crazy but I think the RSS might even be too loud up top. The downshifts are much more enjoyable however.

After looking at various other manufacturers and designs, I came to the conclusion the H-Pipe designs lead to more bassy tones than the RSS which has an X-pipe design. All other designs I threw out the window. RSS at least merges the exhaust paths canceling some of the bass, nonetheless, it still has more bass at 4K RPM than I want, I guess i'm used to higher pitched Ferrari tones which are more musical.

My next step after listening to Youtube video's (I know not accurate but better than nothing) I'm going with the bastard child IPE exhaust and here are the reasons:
I like how it has a valve that can work with factory operation cutting out drone (Hopefully)
I like how it has a resonator involved which hopefully control the volume to the right levels below 4K but hopefully not boring levels
I like how it has even a higher pitched tone than the RSS (which already is higher pitched than many other exhausts)
I like how it will save me another 10lbs over the RSS and reduce heat on the tires with sides gone
I am hoping its not louder than what I have, but if it is, I certainly hope its not as loud with valves disconnected as my current setup.
I don't like how its made in taiwan
I don't like how it cost another arm and leg
I hope hope this will put an end to my 1st world problem
Side note: I didn't care about HP and we all know Catbacks don't' do Jack for HP

Regarding putting the factory muffler back on and changing the sides, somehow I feel the sound is not as high pitched as I like, just not interesting enough. Who knows, maybe with time i'll end up there, but yes I fell into the exhaust rabbit hole

DHI

Just perfectly sums up the GT3RS ownership experience on the street...

-"Its quit boring while driving around normally, and makes you want to drive like a hooligan around town probably leading to some crazy tickets eventually. You're always chasing the exhaust note, which can become frustrating and times too On/Off ish."

Franko T

Update, IPE exhaust installed. Installation ended up being a pain in the *** because removing the side mufflers out will not happen on race ramps without removing the rear bumper, bumper reinforcement and side shields. TONS of bolts.

The IPE first attempt installing was fairly straight forward, but the way it mounts is more Chinese than I like, but after all its a CHINA muffler made in CHINA, yes box came from CHINA Sadly not even Taiwan. The mounts are clamps you use to attach to the factory point, not a screw which was kind of cheap of them to do so. Quality wise muffler looks decent, welds looked fine, internal design is straight through for the larger pipe and I cannot see any way this can loose power. Time will tell if it rusts.

It installed uncentered and then I had to take it to a shop to have them fix it as I was out of muscle.

The tips that came were chrome and looked decent, but I don't like Chrome so I painted them with HIGH TEMP PAINT which turned out SO-SO but can easily be redone.

Sound: Louder than RSS + Factory sides and higher pitched, No drone under 4K because using factory valves and basically in this car you must use the valves. Less loud under 4K than RSS + factory sides with valves disabled.
When valves open up, its higher pitched than RSS and maybe slightly louder - remember the factory sides are ALMOST straight through with valves open, ALMOST

Why this muffler and not another USA or European made, I guess nobody has made one that sounds as good and has valve with Muffler design for under 4K.

R35driver

nothing wrong with driving between 4-9k from time to time if you want some sound. even if you are giving it 1/2 throttle.

its a GT3, the engine will laugh it off.

i've been thinking about doing the valve disconnect on my sharkwerks cmb though. can it be done just sliding underneath the car without needing to lift it ?

Franko T

Yes super easy to do, no lift, no ramps, just bend over and pull them out with small flat head screw drivers carefully and then seal the ends with rubber or bolts so dust and crap doesn't' get in.

Valves discount I think is too boomy, too bassy. See, the factory sides have a large cavity, so when you disable the valves the sides act like a bass box, gets annoying and too loud for me.

Jickel180

I would have just gone with the JCR Superlight Ti bypass center delete in your case. High pitched sound, not too loud, and you still have factory valve operation.

Franko T

Yea I thought of that, but you don't loose the sides. Its said the sides + center factory steel are 65lbs

The box that came said 18KG which is 40lbs

25lbs saving in total? Not terrible.

Stealth 993

I think what you are looking for are Dundon side delete and Dundon lifetime loud center muffler. Made here in the US perfect fit and finish.
Plus it has the sound you are looking for without any drone. It still sounds good under 4k RPM, and will scare people over 6k RPM's.

DSC48

Sharkwerks plus valve disconnect is a happy medium for me. Loud enough, no valve transition, and cheap. You should definitely give it a try.

ParadiseGT3

My setup as well. Only downside is cold start, I keep the garage door closed until it's finished initial sequence...

Franko T

Drove around some more, livable and the DB ratings will be under 85DB under 4K driving, with idle around low 70DB's (WINDOWS CLOSED measured inside). This makes it very safe for your ears as over 85DB over hours can damage your hearing. Above 4K it gets nasty, but with less bass which I prefer. With this setupI do feel like the exhaust is more bolted to your spine, but its a GT3 after all.

Again with RSS exhaust and valves disconnected it was not livable, too annoy for my taste, and I would imagine other rear sections would be the same.
With factory sides and aftermarket rear section + valves connected = Too quiet under 4K making it boring. See the factory exhaust routes the gases through too many chambers to quiet it, basically kills it

tvasbn

Your current setup is catback-IPE + side mufflers OEM?

usrodeo4

Interesting...I would say the GT2 in PPE is kind of the opposite; they have their best tones at idle up to 1K and up to about 4 mph putting through parking lots scaring Moms, making Guys drool and making kids wave. At around 3K some bellowing kicks in (along with snap crackle and pop if you let off the go pedal) and under minor overload (one gear too high) at around 3.5K you get a very loud rumble like a Florida thundershower is upon you. Other than that, once the Go Pedal is pushed the GT2 outruns most of the sound waves and punches a hole in the horizon. Once mine goes off warranty (perhaps before) I think I will go Dundon decatted inconhell for exhaust, along with CSF/PWR intercoolers and a tune, which apparently nets ~ 850 BHP

Franko T

Negative, IPE is a full exhaust after catback. You can't nor would you want to run factory sides with the IPE
Stock Cats, which I would advise never to touch, too loud and more air pollution. I once was for more power by decatting, but I'm totally against it after having a Gallardo which I did that on. Makes driving from indoor park ramps unhealthy including stop lights. Further you are pumping toxic gases to your neighbors. Sure you may gain 30HP but is that even noticeable???

R35driver

just did it a few days ago. sounds perfect now.
no transition, still pretty quite around town but the porsche howl starts coming in around 3-3500 now. and its probably just in my head but but it sounds louder up top too