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991 GT3 GT3RS and 911R
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Sheepey Exhaust for 991.2 GT3RS

 
Old 04-17-2019, 01:58 AM
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FourT6and2
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Default Sheepey Exhaust for 991.2 GT3RS

Owner of car claims 600hp.
Shop claims 30whp gain over stock.

Design looks... different. Not sure what's going on with those smaller tubes up top. Are they blocked off or do they dump to atmosphere up under the rear bumper? Seems strange. Also looks like the two halves of the exhaust slip-fit together at that merger pipe?
Click the arrows in the IG post to see more photos.



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Old 04-17-2019, 04:00 AM
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dgoldenz
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Looks incredible. Seems they work on a lot of exotics. I can imagine how expensive that’s going to be.
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Old 04-17-2019, 04:19 AM
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pete95zhn
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Those tubes are Helmholz resonators, designed to kill drone in a narrow frequency band.
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Old 04-17-2019, 04:30 AM
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hashash
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Sounds nasty !
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Old 04-17-2019, 09:22 AM
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Unless there’s more to this no way do you get 30 hp with just cat back bypass.

Shop and owner can claim whatever they want.

I claim my 3RS has 625 hp. There.
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Old 04-17-2019, 10:48 AM
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Originally Posted by Waxer View Post
Unless there’s more to this no way do you get 30 hp with just cat back bypass.

Shop and owner can claim whatever they want.

I claim my 3RS has 625 hp. There.
That's what I'm thinking too. But then again... a few companies here on the forums claim relatively big hp gains with just center bypass and posted the dynos. I don't believe a center bypass increases power/torque in any meaningful way. So I also find it hard to believe this one gets a 30hp boost. But the shop says they also remapped the ECU...
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Old 04-17-2019, 10:48 AM
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Originally Posted by pete95zhn View Post
Those tubes are Helmholz resonators, designed to kill drone in a narrow frequency band.
Are they closed off at the end? Or are they open like another exhaust opening?
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Old 04-17-2019, 10:54 AM
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Sounds disgusting... they made the car fart.

Would have been great to hear what it sounds like without the tune (unless it was necessary to run this new exhaust).
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Old 04-17-2019, 11:56 AM
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I sent them a DM on IG, they said the exhaust retails for $6k but they will talk price with you if you send them a message. I didn't ask about the HP gain claims. Seriously one of the nicest looking exhausts I've ever seen though, on par with the $12k Ericcson exhausts....they also said no drone, no valves, exhaust is "always on"
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Old 04-17-2019, 12:15 PM
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Originally Posted by RLNTL3S View Post
Sounds disgusting... they made the car fart.

Would have been great to hear what it sounds like without the tune (unless it was necessary to run this new exhaust).
Here you go:

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Old 04-17-2019, 12:16 PM
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Originally Posted by FourT6and2 View Post
That's what I'm thinking too. But then again... a few companies here on the forums claim relatively big hp gains with just center bypass and posted the dynos. I don't believe a center bypass increases power/torque in any meaningful way. So I also find it hard to believe this one gets a 30hp boost. But the shop says they also remapped the ECU...
CMS is a better design especially for power imho. Scavenging design and their dyno says only 16 hp gain as I recall.
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Old 04-17-2019, 12:17 PM
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Originally Posted by dgoldenz View Post
I sent them a DM on IG, they said the exhaust retails for $6k but they will talk price with you if you send them a message. I didn't ask about the HP gain claims. Seriously one of the nicest looking exhausts I've ever seen though, on par with the $12k Ericcson exhausts....they also said no drone, no valves, exhaust is "always on"
I'm willing to bet there are minimal gains without the tune. And honestly, I don't trust any shop to retune such a high-strung engine as these. They are already pushing the reliability limits with 520hp out of a 4L 6 cyl. The actual race engine Porsche uses gets rebuilt often. So yeah, there's definitely room for more power from a tune, but at what cost...
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Old 04-17-2019, 12:29 PM
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Originally Posted by FourT6and2 View Post
I'm willing to bet there are minimal gains without the tune. And honestly, I don't trust any shop to retune such a high-strung engine as these. They are already pushing the reliability limits with 520hp out of a 4L 6 cyl. The actual race engine Porsche uses gets rebuilt often. So yeah, there's definitely room for more power from a tune, but at what cost...
Yeah I'm definitely not tuning my car, the engine was just replaced 1000 miles ago under warranty. Still a great looking/sounding exhaust from what I see. Very pricey, but you don't find workmanship like that in too many places...I was looking at the JCR race pipe but now I am tempted by this too, not sure if worth the extra money though.
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Old 04-17-2019, 12:30 PM
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Originally Posted by FourT6and2 View Post
I'm willing to bet there are minimal gains without the tune. And honestly, I don't trust any shop to retune such a high-strung engine as these. They are already pushing the reliability limits with 520hp out of a 4L 6 cyl. The actual race engine Porsche uses gets rebuilt often. So yeah, there's definitely room for more power from a tune, but at what cost...
+1.

Agreed.

Let's be honest; the car is already ridiculously fast for what it is.
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Old 04-17-2019, 12:38 PM
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Originally Posted by FourT6and2 View Post
Car sounds great here... what made them turn it into a fart cannon?
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