Learn Me: Mid-engine, Front wheel drive dynamics & handling.

I'm wondering about how this chassis set up works or what not. Seems an odd design, but lots of types for the few examples out there. Some with reverse layouts, and others with conventional layouts, but with a forward facing differential instead of rear facing differential.

One example......shows differential in front of engine & gearbox as well as behind shock towers at a 15 degree angle to the motor mounts.

What cars are Mid-Front?

As an amateur it sounds like a recipe for some FWD-esque corner entry understeer followed by washing out.

I can't think of a single one.

MR2 in reverse..?

I know of one.

http://www.roadandtrack.com/car-culture/classic-cars/a31663/1964-mini-cooper-v8/

"It was lethal to drive."

There are a few. All have odd drivetrains and many are different from one another. The BSA Scout, Acura Vigor, various Citroens, Renault 5, Cord 810, Saab Sonett, Saab 900 (somewhat), Tempo Matador, Toyota iQ, etc. All are Front mid engine, but they're all so very different powertrain-wise. Some reverse layout, some drive the front wheels via the sump (Vigor), and others are horizontal except with the differential facing forward. Very odd set up, but if used on a short wheelbase car like the iQ (78.7" wheelbase), I can imagine it'd be somewhat promising?

Nissan's LMP1 car in 2015 used a mid-engine FWD layout. It even had wider tires up front, like 14" vs 9" in the rear. It didn't do well but I'm not sure if that had anything to do with the drivetrain layout.

MugenReplica wrote: There are a few. All have odd drivetrains and many are different from one another. The BSA Scout, Acura Vigor, various Citroens, Renault 5, Cord 810, Saab Sonett, Saab 900 (somewhat), Tempo Matador, Toyota iQ, etc. All are Front mid engine, but they're all so very different powertrain-wise.

AFAIK none of those are mid-engined. Mid-engine has the engine between the passenger compartment and trunk. If the engine is in front of the passenger compartment, it's front-engined.

In reply to Knurled:

Incorrect. According to several items online. All have drive wheels in front of engine which puts the engine IN THE MIDDLE aka mid-engine of the 4 wheel layout and are driven by the front wheels. It's called MF and MR is mid-engine rear wheel drive.

"In automotive design, a Front Mid-engine, Front-wheel-drive layout (sometimes called FMF or just MF) is one in which the front road wheels are driven by an internal-combustion engine placed just behind them, in front of the passenger compartment. In contrast to the Front-engine, front-wheel-drive layout (FF), the center of mass of the engine is behind the front axle. This layout is typically chosen for its better weight distribution (the heaviest component is near the center of the car, lowering its moment of inertia). Since the differences between the FF and MF layouts are minor, most people consider the MF layout to be the same as the FF layout.

However, the mid-engined layout uses up central space, making the resulting vehicle rather long. This may be why no manufacturer currently offers the MF layout.

Examples of road cars using the MF layout include the Acura Vigor, Cord 810, BSA Scout, Citroën Traction Avant, Citroën DS, Renault 4 (and derivatives R5 and R6), Renault 16, Saab Sonett mk1, and the Citroën SM, also some commercial vehicles like the Tempo Matador. These vehicles have longitudinal mounted engines; transverse engined vehicles are possible in theory if the issue of passenger footwell location is addressed. The Toyota iQ comes close to this by having its front differential in front of the engine,[1] however despite this, the iQ is still considered to have an FF layout.

Traditionally, the term mid-engine has been reserved for cars that place the engine and transaxle behind the driver and in front of the rear axles[citation needed], as in the Lamborghini Countach or Ferrari Testarossa, but an engine placed in front of the driver's compartment but fully behind the front axle line also qualifies as mid-engine"

In reply to maschinenbau:

Correct. It was supposed to have corner aided rear wheel assisted steering/drive, but they never finished or fixed it to work in competition. The full only front wheel drive setup, was very inefficient to all the other setups it performed against.

In reply to MugenReplica:

I've auticrossed a friend's well-built LeCar several times and can't say it drives any differently than any traditional underpowered/lightweight FWD cars. Although IIRC the engine is more on top of the front axle centerline than behind it.

Pete Gossett wrote: In reply to MugenReplica: I've auticrossed a friend's well-built LeCar several times and can't say it drives any differently than any traditional underpowered/lightweight FWD cars. Although IIRC the engine is more on top of the front axle centerline than behind it.

This is exactly what I was curious of. Thank you for chiming in and curious if anybody else has any experience.

Too little weight over the front wheels will cause a severe lack of front traction under acceleration. This is why most FWD cars have the engine and transaxle somewhat ahead of the front axle line even if they have a fairly even front:rear weight distribution (like a DC3 Integra, everyone's ideal of a good-handling FWD car).

I'm pretty sure no FWD car was ever made with the engine close to the center of the car, some of the cars MugenReplica listed may be front-midship FWD where the engine is behind the front axle line and therefore technically a mid-engined car.

You might want to check out some FWD EVs for better examples. The Nissan Leaf has the motor and controller roughly on top of the front axle, although they're not that heavy compared to an ICE, and the real weight is in the battery pack which takes up the entire floor space between the wheels.

Of the cars listed as examples, the only ones I'm familiar with would be the Vigor and Saab 99/900, and I can assure you the engine is sitting on top of the drive axles. The balance would be roughly the same as a transverse mounted engine. Front wheel drive cars without transverse engines generally hang the engine way too far ahead, as in Audi and Subaru.

You could be right with the Cord 810, and I think some Indianapolis cars were built the same way back in the 40's.

Renault R4 have the engine behind the gearbox and thus are technically mid-engined.

They're also anything but a good foundation for a track or Auto-X car, if you can even find one in the US.

MugenReplica wrote: In reply to Knurled: Incorrect. According to several items online.

According to the SAE, whose job is to define the terminology, it's not. "Front mid engine" is a marketing term like "road hugging weight".

Unless you believe that you can create a different vehicle layout by moving an axle centerline four inches. Which is all you generally have to do in most cases to get the front axle centerline wholly in front of the engine.

Knurled wrote: Unless you believe that you can create a different vehicle layout by moving an axle centerline four inches. Which is all you generally have to do in most cases to get the front axle centerline wholly in front of the engine.

I'd say you can. If you discount "front-mid engined," you're just moving one of the lines back a bit.

Edit: Also consider that in most mid-engined supercars, the engine is sitting barely ahead of the rear axle.

This is interesting. I've always wanted to restomod a Traction Avant while retaining the FWD configuration. Not easy to do. Another vehicle that would benefit from this layout would be a FWD three-wheeler.

This thread is a waste of time!

I seem to remember GM playing with a Front Mid sedan in the 90s. they designed the transverse transaxle so that it was placed forwards of the engine. This was done for better handling, crush zones, and a lower hood line. Obviously it must have never come to fruition.

I believe that the Volvo 850 and S70 BTCC cars were just barely mid engine. They used a different transmission than the road cars which put the axles in front of the engine so you could move it a foot back in the car.

Other than the prototype all Sonnets were front engine same as the 96.

Just my addition to the trivia.

The GRM Berzerkely had this layout. The crew had a hard time taming the beast, as I remember

That was mainly a matter of track width, wasn't it?

Kreb wrote: That was mainly a matter of track width, wasn't it?

It had a lot to do with stuffing 50lbs of engine into 5lbs of car, and the resultant compromises led to a somewhat unpredictable machine.