Go Back   Sports Car Forum - MotorWorld.net > Automotive Brands Forum > Porsche

Porsche Porsche - the finest German Cars



Closed Thread
 
Thread Tools Display Modes
Old 07-22-2004, 02:10 PM   #1
lakatu
Regular User
 
Join Date: Oct 2003
Location: United States
Posts: 408
Default Is the Rear Engine Design Fundementally Flawed?

I have noticed that JW members have been overlooking what I think is a potential jewel at JW . A while back before the creation of “Porsche Central” (PC), members who loved Porsches would click on “Car Chat” when they first logged on to JW because within car chat was “Porsche News”. Porsche News used to be a place were people gathered to share and discuss their thoughts about anything and everything related to Porsches.

Since Jabba in his wisdom created St-angers Porsche Central it is hard to tell but I think the sharing of thoughts and opinions concerning Porsches has slowed. Maybe it is summer and everyone is out on vacation or maybe it is because those comments are now distributed over many different sections that it seems that way. Anyways, I think st-anger did a great job of trying to recreate that type of atmosphere when he added the “Q&A Porsche discussion” section but I have noticed that it doesn’t receive the attention that I think it deserves. So to draw some more attention to this section and maybe get the ball rolling so to speak, I thought that I would write a series of posts about a topic I have been interested in for a while which is…why did Porsche make the 911 a rear engine car? What are the advantages to that design and why doesn’t anyone else follow the design nowadays?

Why a series? Well if you are like me you have probably amassed a large collection of material from JW that you are back logged in either watching or reading. I figured most people would be put off by an extremely long post and it would give me more time to write it. But mainly, I was hoping to spark interest and comments by others about the topic that I could build off and to accomplish the building of interest in this section of PC.

Why a Rear Engine Design?
I have been looking forever for someone to really explain this in detail. I’m sure most of you could give the basic pat answers but I wanted to know more about it in greater detail. But strangely I haven’t been able to find anything more than a few sentences about the topic. Porsche itself doesn’t even highlight or explain this in brochures.

What sparked my interest in writing about this topic is a comment in an article posted by TT ( http://www.motorworld.net/forum/showthread.php?t=13925 ) that started off stating that the rear engine design is a fundamentally flawed design. Frequently I read in articles about how Porsche though it's great technological know-how has been able to tame this horribly conceived design and somehow make it work. You would think by the way they write this that it has required Porsche gaining access to alien technology to overcome the laws of physics . To be honest I really hate people taking shots at the rear engine design because I don’t think that it would have been in production for so long and so successful in racing if it was a bad design.

Also I recently saw a post ( http://www.motorworld.net/forum/showthread.php?t=13204 ) concerning what was the most difficult car to drive. One of the suggestions was the 1978 930 Turbo. Just as a point of reference since I am rather fond of older 911s and the newer 911’s handling are considered to be less tricky so I thought I would begin with the 1970s-80s 911s in mind. I think this is a good starting point for another reason this was the era where Porsche spent a lot of effort developing and supporting racing derivatives of the 911.

So why were earlier Porsches rear engine cars? In part to answer that question you have to look at the Porsche philosophy. Porsches have always been small, light sports cars that tried and incorporate as much practicality as a sports car can. To be practical Dr. Ferry Porsche wanted room inside the 356 and 911. The rear engine incorporated these factors because incorporating the engine and transaxle together makes for a lighter system compared to a front engine rear drive which requires a drive line. Another benefit of placing the engine either in the rear or in the middle is it allows a more compact design and a smaller frontal area because it decreases the space normally taken to house a front engine. This lower frontal area reduces aerodynamic resistance allowing for faster high speed acceleration and higher top speeds.

In order to demonstrate the compactness of the 911 I compare it to competitors in the 1970’-80’s. The 930 weighed depending on options between 2850-3000 lbs, was 168.9 inches long and had a wheelbase of 89.4 inches. Compare this to a Ferrari 365 GTB/4 Daytona which is an awesome front engine car that weighed 3600 lbs, was 174” long and had a wheel base of 94.5”. The Ferrari 308 GTB QV that weighed 3320 lbs, was 174.2” long and had a wheel base of 92.1”.

A rear engine design also means the engine doesn’t need to sit right behind the driver so there is room for small seats or storage space. Additional advantages are the ones that are more frequently cited such as greater weight over the rear wheels provides greater traction in acceleration or braking. These may sound trite or insignificant but I think that they are the keys to the 911s success.

So do I think that the 930 is one of the hardest cars to drive? Well in a word Yes. Here is something to collaborate that, in an article by Car & Driver in 1979 Danny Ongais (A Porsche driver for the 935) tested a 930. In the article they cited a West Coast Porsche dealership reporting that 40% of the 930’s they had sold had been crashed backwards.

Danny had the following to say about the car.
“The Porsche is a compromise between what you need to run on a race car and a street car, I suppose. If you don’t allow it to take a set before you attempt to drive it hard, it’s very sensitive and it unloads. It wants to go from an immediate understeer into an oversteer, which is almost uncontrollable because you only have three wheels on the ground. You need to get the weight transferred very smoothly; then it will set and bite very nicely. It’s very sensitive to the throttle on slow and intermediate comers. It does very well in the high speed situations…you turn in gently and apply the power and it works, it’s pretty neutral.”

“I wouldn’t say that changes directions very well. You have to be very much on your tiptoes, but it’s more stable in fast corners. It may be that the aerodynamic influence of the rear spoiler helps considerably.”

Danny Ongais personally owned a 930 and he related that after his first drive in the car he decided to only drive it fast in a straight line.

So wait doesn’t that prove that the rear engine design is flawed ? Well I don’t think so. Let me give some examples of rear weight biased cars that were excellent handling cars.

To read the rest of this post go to the Q&A Porsche discussion section at http://www.motorworld.net/forum/show...utation#207955 and scroll down to the highlight of the word reputation. This is where you left off. Also you can post any comments there.
__________________
Porsche, there is no substitute. Well except RS Tuning and Manthey.
lakatu is offline  
Old 07-22-2004, 02:26 PM   #2
X-ale
Regular User
 
Join Date: Nov 2003
Location: Br/Can
Posts: 989
Default

Yes and no. In resume, as long as you have grip it makes perfect sense. When you don't, it's fishtale happyoland, not to be confused with happy Holland. :fadein:
__________________
" Memories will be lost in time like tears in rain "
X-ale is offline  
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump