Talk:Rear mid-engine, rear-wheel drive layout

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Contents

[edit] History

The second half of the history section was more about the history of motorsport than the MR layout, so I took it out.Paulgush 19:49, 5 August 2006 (UTC)

[edit] The first MR car?

Is the Zündapp Janus (1957) really the first MR car? // Liftarn

I don't understand why the following sentence about the RR format is included in this article:

"The spectacular failure of the RR Chevrolet Corvair caused all rear-engine designs to lose favor, apart from sports cars such as the Toyota MR2."

Is it trying to say that because the RR format lost favour, the MR format became more popular? It doesn't actually say this but it would seem to be the only reason to include this sentence. Also, it appears to cite the Toyota MR2 as a rear-engined car but surely the MR2 is mid-engined? SamH 21:15, 13 Jul 2004 (UTC)

I believe what the article is trying to say with "all rear-engine designs" is that that all non-front engine designs lost favor. Perhaps a rewording is in order. – PlatinumX 23:03, 13 Jul 2004 (UTC)
Oh, I understand now. I see Sfoskett has now re-worded the sentence to make it more clear. SamH 12:10, 14 Jul 2004 (UTC)

The Porsche 986 has to mentioned, it is a mid engine design. Further mid engine layout doesnt always mean that the engine is behind the drivers compartment. The engine can be infront of the drivers comportment and behind the front wheels. The important aspect to remember about mid engine design is that the engine is inboard of the wheels of the vehicle.Slavik914

We already have sufficient examples of mid-engined cars so I don't think we should add the 986 (aka. Porsche Boxster) unless there is somthing special about it. As for your second point, although I have sometimes heard people calling a car with the engine in front of the driver "front-mid-engined", I think the term "mid-engined" is commonly understood to apply to only to cars with the engine behind the driver. Is this other people's understanding or am I incorrect? Also, I courteously request that you sign and date your messages. SamH 16:48, 24 Aug 2004 (UTC)

Since there is a list of currently produced mid-engined cars I figured it was only fitting. I didnt know how to sign, I do now. Sorry about that.Slavik914 13:54, 25 Aug 2004 (UTC)

We already mention the "front-midships" layout in the FR layout article. Maybe a link here? FM is not MR... MR implies "behind the driver".--SFoskett 03:02, Aug 25, 2004 (UTC)
And "mid-engined" ALWAYS means an engine behind the driver, too. "Front-midships" isn't the same thing. I note that, despite all the hype about such cars, the idea ain't new. There were lots of cars that way in the past; it fell out of favor because of pressure for space-efficiency on the low end and the MR layout on the high end. —Morven 08:06, Aug 25, 2004 (UTC)

Was the term MR used before Toyota came out with its MR2?Slavik914 13:54, 25 Aug 2004 (UTC)

The impression I get is that these terms (FF, FR, MR, RR etc) are Japanese in origin; certainly the first time I ever became aware of them was from Japanese-sourced games. —Morven 18:33, Aug 25, 2004 (UTC)

Well it's not so much a list of mid-engined cars as just a few examples. If you think that the Porsche Boxster article better illustrates what a mid-engined car is, then you could swap it for one of the other links. You could also start a list of mid-engined cars but I don't think there would be any benefit. SamH 16:12, 25 Aug 2004 (UTC)

A category would do better, if you wanted to do it, than a list. —Morven 18:33, Aug 25, 2004 (UTC)

I don't think this is interesting, because MR is similar to the layout of cars, when angular ineria was less important than whether the car could move forward under its own power at all. David R. Ingham 07:19, 11 February 2006 (UTC)

[edit] handling

The understeer part, in particular, needs discussion. Angular inertia is important and needs to be worked in. I suppose mid engine was common in the earliest cars, before the Panhard front drive configuration became dominant. Some microcars, such as the Messerschmitt KR200 might have been sports cars if they had had bigger engines. --David R. Ingham 02:00, 25 August 2005 (UTC)

[edit] F-35

I don't see the relevance. It is stated that the control laws are different. It is mainly the roll angular inertia that limits a fighter. A fighter's engine takes up a large part of its length. I thought this article was about cars. David R. Ingham 05:28, 26 February 2006 (UTC)

Quite. An airplane layout is irrelevant to this article, and the section is inaccurate. The primary reason that the F-35 will have one engine is for the cost saving. While some versions of the F-35 will have a vertical takeoff and landing (VTOL) capability, once in the air, the performance of the F-22 will be superior, as it is an air superiority fighter, rather than a multi role aircraft. Furthermore, in both aiplanes, the engines are behind the pilot, and as with all planes with tricycle undercarriages, the center of gravity of both is just in front of the main wheels.Paulgush 22:06, 26 February 2006 (UTC)

[edit] Pontiac Fiero

When it came out, I thought "This is their replacement for the obsolete Corvette." Unfortunately, Americans are not that sophisticated. David R. Ingham 08:46, 2 March 2006 (UTC)

[edit] Toyota Minivans

Toyota made at least two series of minivans (one was the Previa) with a mid engine design. The engine was an inline 4 cylinder mounted exactly in the center, lying on its side underneath the floor. These vans were also available with four wheel (possibly full-time AWD) drive.

I'm sorry, but I'm pretty sure the original Toyota Van is a front-midship. You lift the driver and co-driver seats up to reveal the engine below them; so while the engine's behind the front axle, it's surely not in the rear of the van as plain "Midship" implies. Scott Paeth 00:33, 30 June 2007 (UTC)

[edit] Negative Points

I added a couple of bits about the negative points of MR. Previously, the article indicated that all aspects of MR weight distribution are essentually ideal. But that's not true. MR cars tend to be tail heavy. This is _not_ ideal for handling, where a perfect 50/50 distribution would be the most favorable. As it turns out, FR tends to have the most inherently favorable front/rear weight distribution. While MR has the more inherently favorable polar inertia. It's not necessarily obvious which is better overall, although common opinion has long sided with MR. And formats like formula cars couldn't reasonably have an FR configuration anyway (unless the driver was okay with having a drive shaft shoved through his groin). 209.128.67.234 09:18, 30 April 2006 (UTC)


Well you're simply wrong. A front weight bias only helps straight line stability (especially at high speeds). Handling generally refers to the car's agility and its grip, and in both these respects a rear weight bias has a definite advantage. In a straight line a rear bias also helps give traction to the rear wheels and better grip under heavy braking (the rearward centre of mass transfers forwards to roughly half way between the front and rear axles allowing all 4 tyres to play an equal part in stopping the car). It also gives a lower moment of inertia than a car with 50/50 distribution simply because cars do not rotate around their center of mass, but around the centre of the rear axle.

[edit] response:

I think mid engined cars come closest to having a perfect 50/50 balance. In racing today, it is an extreme configuration, to be sure. It can be hard to make a racing MR layout practical or easy to maintain for the street. In racing the MR driver is far forward. But to be realistic- todays F1 cars are really fantastically fast and have absolutely whip-like handling. No other cars honestly come close to that, and I could never see a front engined car doing that. Not even close. There have in recent years been some interesting GTO cars like the Panoz's and racing Vipers that were front engined hybrids and really fast. They did very well in some 24 hour races (as GTO cars always have). One of my all time favorite cars, was the 4WD IMSA GTO Audi's fielded by Group 44 (an old Can Am team) in 1989. By the rules they used the factory engine placement, but like the later Panoz's, they had to do some wacky things to achieve balance. The transmission was in the BACK. A drive shaft connects the engine to transmission for the back wheels. Another output shaft from the back drove the front differential and wheels. All accessories like battery, alternator, water pump, were also in the back, driven off the drive shaft, to move every possible ounce to the back. I believe Panoz's and Vipers were similar to this. I know they incorporated special carbon fiber transmission shafts because of the nasty consequnce of failure, since, as you say, the driver is right next to the shaft. Certain older high-end Corvettes had the rear transmission layout.

When it's all said and done, for racing, the driver of a front engined hybrid is _far_ back compared to the mid engined competition, space is perhaps even _more_ limited and forward visibility is a serious issue. There is also the really huge problem of creating lots of downforce over the heavy engine. Downforce is the absolute number one priority in modern race cars. It's simple to downforce the engine weight when it's in the back. How on earth can you do it in the front, and still see to drive, and maintain reasonable overall drag, and without creating lift somewhere else? (not to mention possibly looking pretty funny!). To race a competitive front engined car, you will be dealing with all of those challenges.

The inertia in the back of a mid engine racer tends to destabilize things a little under braking, but you have the big advantage that the front brakes are relieved of a lot of work, too (the back brakes can work much more). The turning is better because you have controlled oversteer instead of understeer, and acceleration is far better because the weight is over the driven wheels. So in almost every situation, you have an advantage. There are real reasons MR is now the racing layout of choice in formula and sports prototypes, and it was only accepted very obstinately even by mid engined legend Ferrari. Porsche really gets a lot of credit, and not really for race cars. Porsche's thing was eclectic, tiny little road going _sports_ cars, as opposed to formula cars.

If you want to see how it all really stacked up, take a close look at what happened when mid engined cars first appeared in any class of racing. Look at Shelby Cobras vs the big Ferraris, GT-40's and CanAm cars. Look at the front engined Indy cars of the early 60's against Dan Gurney's cars. Look at the front engined Lancia 037 and Audi Coupe Quattro group B rally cars against the mid engined Peugeot 205's and Lancia Delta S4's. They were all very fast, but the mid engine cars consistently had the edge. Frustratingly so for many excellent teams and manufacturers. Look even at top fuel dragsters. The mid engined cars were all faster for similar reasons. There are definitely long standing, hard earned reasons for the popularity of MR. It was not always accepted as it is today.

[edit] Porsche Boxster

Did the Boxster exist in 1980-1990. I am not sure, but I do not think it did. —Preceding unsigned comment added by 70.247.99.236 (talk • contribs)

the name of the section is "1980s - 1990s" not "1980 - 1990".--BSI 17:20, 21 October 2006 (UTC)

[edit] DeLorean DMC-12 was RR, not MR

It seems like a blatant mistake to list the DeLorean DMC-12 on this page, as its engine was behind the rear axle. See the last sentence of Delorean_DMC-12#Engine for testament of this fact. --Jonheese 03:56, 7 April 2007 (UTC)