Transverse mid engined cars

[AW111]

There have been various posts over the years disparaging transverse mid engined cars as somehow "not quite the real thing".

As an owner of a mk1 MR2, I feel obliged to question that.

Criticisms seem to focus on the engine being "too high up" in the car : as the sump is the lowest part of the rear in the MR2, only a dry sump would enable it to be lower.

So : how many transverse middy have there been, and are they proper sports cars?

Off the top of my head :

Fiat X1-9
Toyota MR2 (3 models)
Lamborghini Miura
Ferrari 328 (? Not sure of model)
Lancia Stratos
(Mini) Marcos I think it was
Gem
Clan crusader?
Ginetta (several? )
All recent Lotuses

I am sure there are many more, but my memory fails me and I can't be bothered to go web searching ATM.

[AW111]

grumpy said:

AW111 said:

Off the top of my head :

(Mini) Marcos I think it was
Gem

Front engined, both of them.

My mistake. I was thinking of the Mini based fibreglass things.

[AW111]

vx220 said:

My guess is that most are "boring" four-pots, saloon car derived powertrains, so maybe other sports car owners with six-plus cylinders and more bespoke running gear (or those who think they have more bespoke running gear) look down on them?

It does seem to be Lotus that gets the most criticism, seemingly from those with flat sixes, even if they are hanging out the arse end of the car

[AW111]

ravon said:

Wonder why no racing cars, where performance is the sole criteria, opt for the transverse, side gearbox, rear axle mounted engine route ?

Maybe because packaging requirements are different?
They are single seaters for a start, so the rear of the car is very narrow compared to a road going 2 or more seater.
The engine weight is a significantly higher percentage of the total, so getting the weight further forward has more benefit.
Also the transverse mount makes most sense with a short engine (I4 is best). While a v engine can be fairly short, exhaust routing gets compromised as you need to get pipes around from the front bank.
Most race cars have a larger power plant, but I could see a 4 cyl transverse racer being competetive.

It is an interesting question, since a transverse engine / gearbox has slightly lower friction, as the drive does not have to turn through 90 degrees. I assume the packaging advantage outweighs the slight efficiency loss.

[AW111]

ravon said:

Wonder why no racing cars, where performance is the sole criteria, opt for the transverse, side gearbox, rear axle mounted engine route ?

Nearly all Formula SAE cars have transverse engines also .

Packaging is critical for race cars. It is a compromise between suspension, aerodynamics, cooling, weight distribution, engine performance, cost and serviceability.

It is the same with sports cars, but the constraints and solutions are different.
No race cars have been rear engined, or flat engined, for about 50 years, but the 911 family are still sports cars, and good ones.

[AW111]

doogz said:

When you say "race cars", do you mean bespoke prototype sort of things, as opposed to saloon/sports car based racers, such as any Porsche, anything built by Subaru, etc?

I was responding to ravon's claim that no race cars had transverse engines, so assumed he meant prototype class single seaters.

There have been numerous transverse middy production based racers, some of which have been posted on this thread.

[AW111]

ravon said:

Max Torque, interesting stuff, not so new in concept ( and very topical, Len Terry RIP ) see Len's 1950's solution to being forced to use and an Austin 7 rear axle in the 750 formula.

As described in "Racing car design and developement"?
Still one of my favourites : I even found a second hand copy to replace the one I lost years ago.

I have yet to replace Costin & Phipps, lost at the same time

The issue addressed by the design shown above is the achilles heel of transverse middies : room for a decent rear suspension.

[AW111]

No compromise indeed.

I have been involved in designing a few race cars in the past : when the race is 3200 km across Australia, and the power source is sunlight, the engineering challenges are a bit different to single seater formula cars.

The current Maclaren F1 car would have run out of power about half an hour into the race, if they had passed scrutineering.

[AW111]

Engine ahead of axle = mid engined.

Even Porsche fanboys should know this.

[AW111]

ravon said:

AW111, I'm a life long Lotus fan, Colin Chapman was my boyhood hero, which led me to study engineering, and go on to designing, developing and marketing my own products globally, I have owned an Elan for twenty years, did a road drive in it yesterday ! I have most of the books published on Lotus, many more than I have on Porsche ( and a lot more than on Lancia, still feeling deeply embarrassed by that howler ).

So, I'd say a "Car fan old man " if thats OK with you ?

...and if the engine is closer ( on top of ) to the rear axle than it is to the traditional Chapman meaning of a mid engined car, I'd call it rear axle engined !

Edited by ravon on Friday 29th August 12:19

Fair enough. The fanboy comment was a bit tongue in cheek, but it does seem to be Porsche owners who make the most fuss about transverse not being proper mid engined.
I don't know enough about the Evora to argue, but say that about my (mk1) MR2 and it's a fight to the death!

The real issue for COG height is sump clearance anyway : without dry sumping the engine, everything I look at, whether front, mid or rear has the sump as the lowest point on the car.
Had Lotus not wanted to make the Evora a 2+2, they could have rotated the engine forward by 30-50 degrees, which a lot of front engined cars have done to lower the bonnet line. In fact the original Esprit has the engine laid well over.

Would that be an improvement? I think so, but then they lose the 2+2 tag.



ps Just to be inconsistent, I hate the term "front mid engined" for front engined cars that push the engine back into the transmission tunnel and sit the driver on the rear axle.

[AW111]

Scuffers said:

dissagree.

911 has a back seat and dynamically is a better car by far, it may have the engine in the back, but they work like that, and it's very hard to argue against timesheets.

XK and DB9 are not even in the same ballpark as either.

You can't have it both ways. In the post above, you say the 911 is great despite having the engine hanging out the back, yet earlier you said (regarding the Lotus)

Scuffers said:

wrong termyou cannot correct for it, only mask it's effects.having a high COG is really hard to deal with as it knocks onto all kinds of things, yes, Lotus have done a superb job of making the evora handle like it does, but consider just how much better it could have been without the handicap of where the engine is?

That quote is equally applicable to the 911, just replace "high COG" with "rear mounted engine".

I am not bashing Porsche, just pointing out the inconsistency.

[AW111]

Scuffers said:

Captain Muppet said:

Do you really think transverse engines sit on top of the gearbox somehow? The gearbox bolts on the end of the block, just like a longitudinal gearbox does.

some do, like the Mini, some don't.

the real metric is where the crank-line is relative to the drive-line

In the MR2, the driveshafts are behind the block, around about the crank centreline.
I would guess 4cyl Lotus is similar.

[AW111]

Looking at some photo's of my MR2, the lowest points are
Exhaust (under drive shaft)
Sump
Bellhousing.

So if you dry-sumped it, you could rotate the engine forward for a lower cog.

I wonder if transverse v6's are rotated further back in their fwd homes to keep the front bank further back?

[AW111]

doogz said:

Pardon?

Behind the block. Around about the crank centreline?

I'm going off visual memory. My mind's eye says about an inch above crank.

Car is in shed and it's cold and dark.

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TheRealFingers99 said:

<snip>

But Honda won the 1965 Mexican Grand Prix with their RA272.

Great find.

[AW111]

There was a Honda race bike (ELF?) where they had the fuel tank at the bottom of the chassis, and the exhaust (expansion chambers) running over the engine where the fuel tank usually is.


Their theory was that the exhaust system was light but bulky, so taking it over the top lowered the COG.

Not a very successful bike, by the way, by Honda standards.

[AW111]

Mr2Mike said:

You probably mean the first iteration of the Honda NSR500 (mid-80's):



It didn't do that badly, they won the world championship with it in 1985.

That's the one.

I had it confused with the elf honda endurance racer of the same period, which also had exhausts over engine.