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PostPosted: September 27, 2017, 4:36 pm 
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A while ago I brought up the subject of rear engine versus mid engine which stimulated a lively conversation on this list. Today my attention was drawn again to a media report featuring the Porsche 911 GT 2 RS beating any previous lap times on the Nurburgring track:

http://driving.ca/porsche/auto-news/new ... 7-lap-time

http://www.google.ca/search?q=Porsche+9 ... ne%25252Fe

https://www.autoevolution.com/cars/pors ... 36-biturbo

Yes I am biassed, I like the rear engine, and I like the traditional Porsche flat 6 design. I also believe that the rear engine design has been prematurely buried :D


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PostPosted: September 27, 2017, 5:08 pm 
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Rear engined or midships rear, there's a big difference.

How many decades did it take for Porsche to tame the rear engine handling ills? How much money did they throw at it? What are the odds a home builder would get it right before it killed them?

Transverse, mid rear (FWD drivetrain in the rear) is about as far rearward that I think one of us is likely to be able to successfully implement.

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PostPosted: September 27, 2017, 6:27 pm 
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phil wrote:
I also believe that the rear engine design has been prematurely buried :D


I think Porsche just buried the rear engine 911, by finally admitting mid-engine superiority.

http://www.roadandtrack.com/motorsports/a31304/2018-911-rsr/

http://www.carbuzz.com/news/2017/9/8/The-Mid-Engined-Porsche-911-RSR-Is-Already-Sold-Out-7740938/


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PostPosted: September 27, 2017, 7:10 pm 
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I think that the rear-engine layout is largely misunderstood, and definitely underappreciated.

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PostPosted: September 27, 2017, 7:45 pm 
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Clearly rear-engined is a superior layout. That's why all the supercars and race-specific vehicles have gone that way.


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PostPosted: September 27, 2017, 10:19 pm 
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kreb wrote:
Clearly rear-engined is a superior layout. That's why all the supercars and race-specific vehicles have gone that way.



They haven't gone REAR engined, they've gone MID engined in the rear and I'd agree that is the best way to go, although mid front engined is pretty danged good.

Porsche/VW are the only ones I know of that have a true rear engine with the engine behind the rear wheels.

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PostPosted: September 27, 2017, 10:43 pm 
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I was joking. Clearly mid-engined is the configuration that contains the most performance potential. Obviously rear and front-engined cars can be made extremely fast as well, but this one is really a no-brainer. And please don't mention "front mid-engined" which is a term which marketing people came up with recently.


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PostPosted: September 28, 2017, 11:45 am 
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carguy123 wrote:
Rear engined or midships rear, there's a big difference.

How many decades did it take for Porsche to tame the rear engine handling ills? How much money did they throw at it? What are the odds a home builder would get it right before it killed them?

Transverse, mid rear (FWD drivetrain in the rear) is about as far rearward that I think one of us is likely to be able to successfully implement.



Thanks for your points.

I am aware of the difference between mid engine and rear engine. I am also aware of the fact that most mid engines referred to on this list (rear transaxles)are technically rear engines. I am building a rear engine seven based on a 1965 Corvair power train ( In our World, the closest thing to a 911). Or I should say a poor man's Porsche. On my design the flat 6 cyl air cooled engine weighs about 200 -220 lbs and the transmission is in front of the transaxle. I believe that the weight distribution on my build will not be all that far from that of many front transaxles moved to the rear wheels .

Your point about Porsche spending decades improving their designs...Who did not?

In Europe, RWDs started off a long time ago as the norm (Fiat, Renault, Simca, BMW, etc). They were known to be over steerers. In race drivers got used to them. Then came the FWDs, under steerers. I believe that in race drivers prefered over steering tendencies......But I myself never raced, so all I am doing is repeating what I have heard. :cheers:


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PostPosted: September 28, 2017, 11:48 am 
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JonW wrote:
phil wrote:
I also believe that the rear engine design has been prematurely buried :D


I think Porsche just buried the rear engine 911, by finally admitting mid-engine superiority.

http://www.roadandtrack.com/motorsports/a31304/2018-911-rsr/

http://www.carbuzz.com/news/2017/9/8/The-Mid-Engined-Porsche-911-RSR-Is-Already-Sold-Out-7740938/



I think that you are being interpretative of what Porsche engineers are thinking. Nowhere is it suggested that Porsche admitted the superiority of a design over the other!!! :cheers:


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PostPosted: September 28, 2017, 1:04 pm 
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I didn't have to do much interpreting when Porsche says this:

'Switching to a mid-engine layout is Porsche's way of leveling the playing field, even if it loses its rear-engine traction advantage.

"It was clear for us that we give up our weight advantage, but we gained the advantage of the aerodynamics and the weight distribution," said Walliser. "Yeah, we gave something up, but we gained more on the performance side."

"Aerodynamics, weight distribution, inertia. All these things are optimized," said Walliser.'

http://www.roadandtrack.com/motorsports/a31703/porsche-911-rsr-frank-walliser/


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PostPosted: September 28, 2017, 3:20 pm 
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JonW wrote:
I didn't have to do much interpreting when Porsche says this:

'Switching to a mid-engine layout is Porsche's way of leveling the playing field, even if it loses its rear-engine traction advantage.

"It was clear for us that we give up our weight advantage, but we gained the advantage of the aerodynamics and the weight distribution," said Walliser. "Yeah, we gave something up, but we gained more on the performance side."

"Aerodynamics, weight distribution, inertia. All these things are optimized," said Walliser.'

http://www.roadandtrack.com/motorsports/a31703/porsche-911-rsr-frank-walliser/


Point taken. However Walliser talks about trade offs in a specific class context. Not absolute superiority of a car design vs another.

In addition he does not have yet the proof that the mid engine 911 will do better than the rear engine traditional one The Porsche mid engine Cayman failed (handling and other performance criteria) to demonstrate that Porsche would do better with a mid engine.. After Daytona and LeMans, 911 fans will decide .
For us on the road, the main thing is that Walliser and Porsche see this mid engine 911 as one of many race oriented engineering that come and go. Walliser admits that this is only a race thing; no plans are made to produce a road car.


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PostPosted: September 28, 2017, 6:16 pm 
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Believe what you want, but physics/dynamics don't lie.

I don't think the Cayman has failed at anything. The reason they sell the Cayman with less horsepower than the 911 is so it underperforms the 911 icon.

Why is the 918 Spyder mid engine?


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PostPosted: September 28, 2017, 6:25 pm 
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Phil, with all due respect, you are being silly. The best vehicle engineers in the world have chosen mid-engined as the performance configuration of choice. This is not fashion, this is science.

That said, I have a rear-engined car in my garage. I have no "issues" with rear-engined machinery whatsoever. It's limits are high indeed - just not as high as mid-engined. Why you persist as if there's a conspiracy against rear-engines I have no idea.


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PostPosted: September 28, 2017, 11:31 pm 
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And front mid is not marketing speak.

Mid simply means the engine is placed within the wheelbase not outside of it. Front or rear mid is only a convenient way to differentiate engine placement. Both are mid.

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PostPosted: September 29, 2017, 12:00 am 
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I understand what it means, but I never recall seeing or hearing the term prior to the last 10 years or so. When I did, it wasn't from engineers, but marketing people. I think that it's a poorly descriptive term because front-mid and rear-mid are so inherently different, but the terms evoke something similar.


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