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Old 07-07-2019, 09:04 PM
  #46  
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Originally Posted by fjpdds View Post
RSR.... she is wide!
That shows the reason for the mid-engine and side exhausts: huge diffuser with no conflict from the exhaust or rear engine...
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Old 07-07-2019, 09:23 PM
  #47  
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Originally Posted by GrantG
I think the side exhausts on the racing version of the Ferrari 365GTB/4 Daytona sounded great (but I guess a straight six sounds pretty good...)
Very true. I guess straight 3s and 5s not so much. Not that the RSR sounds horrible to me, just not the traditional Porsche race car sound.
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Old 07-07-2019, 09:39 PM
  #48  
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Originally Posted by GrantG View Post
That shows the reason for the mid-engine and side exhausts: huge diffuser with no conflict from the exhaust or rear engine...
Yes, though remember that with Balance Of Performance any improvement in absolute pace is simply taken away again to keep the racing as close as possible, so that added downforce by itself is of limited use and not worth the trouble. What both the mid engine and downforce do as a consequence, however, is reduce wear on the rear tires. That in turn improves average pace on long runs, and that’s how you win under BOP regulations. It’s a bit of a shame that it works out this way; while the mid-engine layout in undoubtedly more effective it sounds like crap. And I do feel it’s somewhat disingenuous in a “911”.
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Old 07-07-2019, 11:49 PM
  #49  
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Any issues with rear tire or brake temps with side exhaust? I assume no given how many cars have run side exhausts but came to mind looking at the closeup pics (and how close the exhaust outlet is to the leading edge of the rear tire.)
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Old 07-08-2019, 01:25 AM
  #50  
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Originally Posted by Petevb View Post
Yes, though remember that with Balance Of Performance any improvement in absolute pace is simply taken away again to keep the racing as close as possible, so that added downforce by itself is of limited use and not worth the trouble. What both the mid engine and downforce do as a consequence, however, is reduce wear on the rear tires. That in turn improves average pace on long runs, and that’s how you win under BOP regulations. It’s a bit of a shame that it works out this way; while the mid-engine layout in undoubtedly more effective it sounds like crap. And I do feel it’s somewhat disingenuous in a “911”.
With BOP its important to have dynamic range across all areas - that way you have more variables with broader range to play with e.g. maximum optionality. Also do agree that is becoming a little disingenuous to keep the 991 tag given the layout is that of a cayman - admittedly largely because of tires and aero

Also I wonder where they are going with active aero - controllable rear wings and control flaps have been around for a long time e.g. to go from high down force to lower downforce and lower drag.
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Old 07-08-2019, 08:24 AM
  #51  
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A lot of comments about exhaust note: you can be pretty sure the package will evolve and the sound change significantly as the unveil car adopts race trim.

Outboard exhausts: there are many successful contemporary examples with similar designs... the AMG and Aston GT3 products have had that for years. The exhaust flows into their tire outwash and pretty much gets dispersed immediately to the side. Think of air as a fluid: the forward-facing part of the tires has to push through this fluid at the speed of the car. That fluid must go somewhere; in this case it's "squirted" to either side of the tire contact patch. That's outwash, and carries with it the exhaust gases and their temps...

In any case if tire temps are your concern, it's normally the inboard side of the tire that you care about.

Lastly: the left-to-right merge may help with a certain kind of sound quality but FWIW our Cups on the least restrictive (i.e. Supercup) setup don't merge them either. And they sound darn epic

Last edited by CRex; 07-08-2019 at 09:18 AM.
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Old 07-08-2019, 10:37 AM
  #52  
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The last thing on a race team's mind is how the exhaust sounds to fanboys. They are in the business of building a race car and winning races, not crafting the exhaust note to appease Rennlist members. I'm talking about the RSR here.

RE: tire temps due to exhaust placement. Who cares. It's a race car. And as said above, you don't really have to worry about it due to the way the gasses flow. They want the tires to be hot anyway. And they use new tires every race and during the race. So it's not like they care if they don't last 5,000 miles. Again... this is for the RSR. The production GT cars will not have side-exit exhausts. I'm willing to bet.
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Old 07-08-2019, 10:43 AM
  #53  
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I'll bet you 48 someone in the aftermarket will do it "because race car"
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Old 07-08-2019, 10:46 AM
  #54  
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Originally Posted by groundhog View Post
I'll bet you 48 someone in the aftermarket will do it "because race car"
Of course. Because fanboys will buy it.
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Old 07-08-2019, 11:26 AM
  #55  
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[QUOTE=FourT6and2;15958740]The last thing on a race team's mind is how the exhaust sounds to fanboys. They are in the business of building a race car and winning races, not crafting the exhaust note to appease Rennlist members. I'm talking about the RSR here.

Of course if this were entirely true the rear engine 911 would have been scrapped decades ago and to hell with the "fan boys" many of which are also known as customers.
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Old 07-08-2019, 11:54 AM
  #56  
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Originally Posted by djcxxx View Post

Of course if this were entirely true the rear engine 911 would have been scrapped decades ago and to hell with the "fan boys" many of which are also known as customers.
Porsche the motor car company not the race team added mid engine to their line up years ago. Why would they scrap the 911 if it's still making profit? The 911 engine has been marching forward over time as well.

Do you think 95% of the 911 buyers actually know what rear vs mid engine means or would be able to extract any more performance out of one platform vs the other. I don't think so.
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Old 07-08-2019, 12:07 PM
  #57  
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Originally Posted by djcxxx View Post
Of course if this were entirely true the rear engine 911 would have been scrapped decades ago and to hell with the "fan boys" many of which are also known as customers.
Nothing to do with exhaust sound. You're making a false equivalency. BTW, the new RSR is mid-engine...

My point is that the sound of the car is purely a result of function. They don't care about wasting time/energy/money to force the car to sound a certain way. They build the car to perform and how it sounds is just how it sounds.
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Old 07-08-2019, 03:56 PM
  #58  
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They better make the street car sound better.
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Old 07-08-2019, 06:34 PM
  #59  
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^ Be careful what you wish for...I'd rather have slightly less appealing natural sound than internal/external speakers playing a soundtrack...
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Old 07-08-2019, 08:11 PM
  #60  
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Do you think 95% of the 911 buyers actually know what rear vs mid engine means or would be able to extract any more performance out of one platform vs the other. I don't think so.[/QUOTE]

‘Maybe not now if your response is typical of current buyers, but that was definitely not the case in past generations of 911 owners.
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