94 replies to this topic

[Pong]

What if the gearbox was moved in front of the engine instead of behind the engine?

The gearbox would be placed low in the centre of the car with the driveshaft running through the Vee into the differential.
The space normally taken up by the gearbox would be filled with a very small and stiff structural part serving to connect the engine with the differential and as a mounting point for various suspension members.

Advantages:
1. Very low weight on the rear. The car could run much less rear wing while preserving downforce. This would again result in a very high top speed for overtaking.
2. More space for the diffusor. This would increase diffusor performance. The car could run even less rear wing resulting in a fantastic top speed.
3. Better weight distribution. Lower moment of inertia will increase low speed handling.
4. Better hydraulic distribution. The radiator for the gearbox would be placed much closer to the gearbox resulting in fewer hydraulic lines crossing over the engine. Saves space.
5. Enabling the gearbox to be used as a engine - chassis mounting point. This may enable a stiffer chassis.


Disadvantages:
1. Due to the longer driveshaft center of gravity is likely to increase somewhat.
2. The longer driveshaft may result in a increased engine response time.
3. Driveshaft in space now occupied by the airbox will decrease size of airbox by a small volume (some litres).
4. Gearbox will take up space in the fuel tank. So what? 3 stop strategy seems to be the way to go.


What are your opinions on this ?

regards,
Pong

[Ali_G]

I don't understand your reasoning. For a start isn't the engine heavier than the gearbox and so you would only be increasing the weight further back and hence have to run more downforce at the back.

How could yo run a driveshaft through the V ? The space between the V is taken up by the airintake and various other bits and pieces. Putting the drive shaft above the engine is not possible. You also have the problem of the fuel thank. WHere are you planning to put it ? The gearbox to accomodate such a reversal system would have to be taller, bigger and heavier and modern gearboxes might need a completely different system to run such an operation. ANd this change might do some bad things to the efficiency of the gearbox.

You would then also need to raise the real differential above the real axel and then connect it to a second differential on the axel as the drive shaft ould be coming way higher over the engine and couldn't possibley meet the differential.

IMO not possible and if so pointless.

Niall

[Ray Bell]

I think he means to put the box into the area below the driver's back rather than move the engine backwards...

Now that fuel loads are small, it might be worth looking at.

[Ali_G]

Originally posted by Ray Bell
I think he means to put the box into the area below the driver's back rather than move the engine backwards...

Now that fuel loads are small, it might be worth looking at.

Yeah. Chassis - Gearbox - Engine - Differential. To accomodate this the engine would have to move back, wouldn't it ?

Niall

[Pong]

Clarifications:
the engine does not move.
wheelbase does not change

the gearbox simply moves into the fueltank.
the driveshaft goes through the Vee, not above the engine.
(yes, this may require alterations on various bits and pieces)

the differential stays in the same place.

more questions?

[DOHC]

The Lotus 63 had the gearbox in front of the engine, in 1969.

[Pong]

it did !?

would you have any idea how I got hold of a drawing of this?
I would be most gratefull.

[Pong]

Oooops!

I forgot to ask:
why was the design discarded?

[Double Apex]

Where does the fuel tank go?

[DOHC]

It was a 4WD F1 car. By the late 60s, it was thought that 4WD would have traction and grip benefits, but that was a cul-de-sac. First, mastering aero downforce provided much more grip and and traction too (useful when the more powerful engines arrrived), and second, 4WD led to heavier machinery, in particular in the transmission (drive line). So 4WD was never a success.

The layout was such that a central drive shaft from gearbox to front and rear ran alongside the driver (to the left of the driver), and underneath the engine, between the "left" cylinder bank and the exhaust headers of the Cosworth DFV. Of course, the engine was reversed too, to have the clutch in front of the engine, so it was actually the engine's right cylinder bank that was on the car's left side.

The car's designer was Maurice Phillippe, then chief designer under Colin Chapman at Lotus.

[Pong]

Fuel tank stays in the same spot. Volume is somewhat reduced due to the gearbox being mounted in the same location.

[Double Apex]

Originally posted by Pong
Fuel tank stays in the same spot. Volume is somewhat reduced due to the gearbox being mounted in the same location.

In that case it would be reduced by quite a few litres! A gearbox aint that small. I am willing to think along with you, but somehow this just doesn´t seem to add up.

[Pong]

found a picture of the Lotus 63 here:

[URL=http://www.f1-legend.com/histoire/voitures/69lotus63.htm]

[desmo]

Remember the Lambo Countach layout?

Seriously, the gearbox cases are much larger than they need to be to enclose the gears and mechanicals inside to provide proper attachment points for the suspension members and to provide adequate bending and torsional stiffness for the fully stressed case. If one was to move the transmission ahead of the engine, one would probably need a similar sized structure in its place for the above reasons. Hence minimal reduction in cross sectional areas there likely I'd think. Leaving aside the issues of power transmission through the V and compromising fuel capacity, plus increased overall mass and complication from the extra prop shaft and associated bearings etc, you'd still need the diff in its current location anyway wouldn't you?

[Henri Greuter]

There were more 4WD cars with the gearbox in front of the centrally located engine. I believe about every 4WD F1 built had it. And for sure, some of the GP B's of the mid eightties. The Delta S4 had it, the Metro 6R4 too. The most extreme must be the Ford RS200. That one had the gearbox far up front in the car, shortly behind the front axle, within the cabin! Handicap was the added weight of two propshafts; (engine-box and box-rear axle). But the weight distribution of the Ford was easily one of the very best of all GP B's which improved handling. The Delta S4 had way too much weight in the tail, (intercoolers behind the rear axles for example) making the car very tricky on the limits. An Evo version of the car was planned with far more weight transplanted to the front.

As for an F1 with gearbox in front of the engine, I have my doubts. Added weight of the propshaft is one handicap. Then, how much further will the engine be and a factor to be considered is the exhausts that need room too. Anyway, the weight balance of the car would be interesting, not mentioning the aerodynamics. Ferrari has a very narrow rear end by now in between the wheels. But with the engine more to the back, how narrow can the sidepods and upper bodywork become then? Don't forget, it's not only the block you're dealing with, there is also the exhausts, witht the curren tars, located next to the engine.
This could possibly only work with a very wide angle engine with the exhausts above and the inlets on the outside of the engine (like on the older 3 liter Ferrari's of the late 60's and the first turbo Ferrari's)
But even then, I'm not sure it would work. Running a propshaft back through the engine or next to it takes a lot of room.

Henri Greuter

[Pong]

the required structural part between the engine and differential would be hollow and could allow for use as a aerodynamic device.
Alternatively, the space migth be filled with the rear-end springs and dampers. This would negate the positive effects such a design would have on the diffusor, but it would aerodynamically be cleaner.
The design intends to leave the exhaust exactly where they are ( if possible).

[Powersteer]

Lamborghini Countach has the gearbox in front of the engine with a shaft running to the rear differential. Think the Diablo also has that arrangement but think thier new V12's has a different lay out with the murcielago. Having a shaft going back adds total weight and friction though. More total weight is no good in F1 because they prefer to make the car as light as possible while using the ballast to put center of gravity as low as possible. This also allows the engineers to move weight forward or backwards to balance the car.

[Ray Bell]

Going a little further than this... but first a little more on 4WD cars...

The Ferguson, of course, had the gearbox behind the engine. But so was the driver... the Lotus 63 was the most obvious of these cars and ended up claiming the life of D-D at Goodwood a couple of years ago. It had some severe stability problems, but I don't think that was a gearbox location problem...

Now, the gearbox off the front of the engine would be closer in to the engine than it is at the rear, not requiring oil tanks etc to be in the way. As all engines are (at least more or less...) bespoke these days, I would think that you'd have the block designed to take the drive from the gearbox back beside the crankshaft. Sure, you'd need a differential at the rear... but it could be pretty small, I'd think, in particularly narrow. And nothing behind the differential.

The gearbox would protrude into the fuel tank and take up some tankage, but I doubt that it would be as much as 6 or 8 litres, all things considered. This could be recovered elsewhere, if necessary.

Back to the engine... cam drive might then be taken at the rear of the engine, and many of the ancillaries that usually drive from the front would also be moved there... some of them might have even been taking up room in the fuel tank area already?

One aspect not mentioned is the heat that might be transferred from the gearbox to the fuel tank... this would be a problem, I'd say, and plenty of insulating material would be required.

The changing of ratios might be more difficult, but splitting the car in the middle might actually be easier than taking everything off the rear end, might it not?

[Henri Greuter]

The more I think this technical excersize over and over if applied on a single seater the more unlikely I think it is. A lighthter that 100 kg eninge will be tough to built with such a concept I pressume, courtesy the extra propshaft needed.
The entire concept vaguele reminds me about the March-Porsche 90P CART machine that for aerodynamic reasons had its turbo mounted in between and above the fuel tank and the engine. Interesting solution to deal with a major component within the car but a solution which created headaches for sure. And regrettably wasn't sorted out properly anymore when Porsche left CART.
Yep I know, a turbo is something different then a gearbox. But as I said, it vaguely reminds me, vaguely.

Henri Greuter

[Powersteer]

I think in a mid engined 4WD i prefer the gearbox behind the engine because the drive to the rear(or front in a vice vrsa scenario) can do away with the extra mounts and UJ that would be needed with a 4WD which would have to split its power from the middle in a front box layout. Even though if the shaft going to the back through the whole gearbox and engine, doing away with UJ's this also means its a lot heavier because of the needed expansion with the engine and gearbox to space this.


I believe the primary idea for such a layout, with the gearbox in front of the engine on a mid-rear engine car, is to cut down oversteer happiness on a limited wheelbase non-single seater chassis where the engineers can hide the gearbox in a compact package of the whole car which is between the two seats. One thing though, in a production car such as the Lamborghinis, the journalist who test drive them never seem to stop complaining about obvious gearbox noise intrusion inside the cockpit.

[Pong]

Excuse my ignorance, but how would moving the gearbox in front reduce "oversteer happiness"?

[scarbs]

This is an idea I put forward a couple of years ago, when light carbon gearboxes were thought of. Seeing as the gear ratio cassetteclutch is so small, it could be placed in a recess in the fuel tank (as with oil tanks) drive could be returned to the diff via shaft placed just above the V of the engine, the remaining structure to house the diff and rear suspension could be made of carbon as little heat or oil will be retained within it. This would place the weight of thesteel gear mechanism at the centre of gravity reducing the moment of intertia (and hence oversteer). Fuel tanks are geting smaller (even more so next year after the new parc ferme rules) so packaging wont be a problem, plus wheelbase will be retained.
The lighter carbon rear strucuture woud be hollow and hence could house, a oil tank andlower damper arrnagement or even an aerodynamically beneficial route for the exhausts. as this compnoent will be made in house the casing can be altered relatively easily, to alter suspension geomtery, wheelbase etc.
Downsides woud be added weight in the drivetrain due to the prop shaft which could affect the overall weight and slow the shift speed. access may be an issue as clutchhydraulic porblems are common with gearboxes and these might need access from below, rather than an engine out job which is currently slower than a gearbox change.

[Ray Bell]

Like I said, break the car in half, very quick operation...

Some seem to think that the drive back to the diff might be heavy... but you already have one half this long, I think, in a conventional setup to take the drive to the gearbox.

It would mean going back to a longitudinal gearbox, by the way, and the subsequent hypoid final drive behind the engine.

And no, you wouldn't take the drive over the top of the vee... not likely at all. To one side, for sure, and throught he block casting.

[RDV]

scarbs....gravity reducing the moment of intertia(sic) (and hence oversteer).

moment of inertia not germane to o/steer, u/steer, just the rate at which it will happen... try a small thought experiment =a car with an extremely high moment of inertia will be very difficult to turn , and likewise , will take a long time to stop turning once steering inputs cease... a car with a minute polar moment will change direction almost instantly, at a very small steering input... maybe even with rotational torque due to a locking brake...and likewise to straighten out....

[LMP900]

Maybe this is exactly what Ferrari have done!! Anyway it's a very good idea IMO, and I think scarbs is right - the propshaft would pass through the vee. The crank height of an F1 engine is in the region of 68mm, so a shaft passing through the vee would be about the correct height for a CWP. Avoid hypoids because of the reduced efficiency, and if the prop was to the side of the engine, it would make a nonsense of the packaging at the back - it would be very bulky.

[scarbs]

RDV I understand there is more to oversteer than just intertia, but for the forums purposes the statement is accurate enough, Many teams have done alot of work to centralise weight distribution, part of the gain in this is in reducing what we could call intertial oversteer (as opposed to power oversteer for example)

Ray the prop shaft woud be heavy but a wound carbon shaft would be at a resonable weight, the drive would be taken through the V, that is to say just above the apex of the V (just above the crankshaft) either externally or within the crankcase, this area is very low and the engine is too wide for the drive to go around the side. BTW F1 cars run longitudenal boxes any way.

[Pong]

Why exactly would the driveshft have to be run besides the Vee and not through the Vee?

[Henri Greuter]

Pong,

It depends on how low or exactly where you want that propshaft within the V!
There's for example the crankshaft of the engine and lubrication of the crank can't be disturbed without penalty.
Running that prop above the crank is not benefitial because of the weigth up high, disturbing and upsetting the GC, not mentioning the fact you need gears to bring the shaft in line with the differential. That shaft has to cope with lots of power thus will be think and strong and thus heavy.
And if weight has to be placed within the car, you want it as low as possible.
Period.
Even Jaguar had diificulties in the GP C era when they changed the 2-valve single cam cylinderheads for experimental fourvalve DOHC heads. The increased weight upset the entire handling of the car.

I am near certain that if the gearbox of the Lambo's wasn't such a big lump, greating so much overhang etc. they would have followed the example of a racecar: behind the engine.

For F1 this idea is, in my eyes hardly usable at all, too much offsets for too less benefits. It might have worked in the days of Gp C and other cars with volumous bodyworks, like rallycars.
But not in the current F1 as long as the coca cola bottle platform is the standard shape to work with.

Henri Greuter

[Ray Bell]

Originally posted by LMP900
Maybe this is exactly what Ferrari have done!! Anyway it's a very good idea IMO, and I think scarbs is right - the propshaft would pass through the vee. The crank height of an F1 engine is in the region of 68mm, so a shaft passing through the vee would be about the correct height for a CWP. Avoid hypoids because of the reduced efficiency, and if the prop was to the side of the engine, it would make a nonsense of the packaging at the back - it would be very bulky.

68mm crank height... okay, let's work with that...

The gear shaft spacing would be about 100mm, you wouldn't want any extra gears, would you? So that dictates everything.

Would there be a clear path for the shaft 100mm above the crank centreline? Remember to give clearance for rods and so on... and would you be weakening the block by running it through there?

I can see the sense of keeping it in the middle, but I would have thought keeping the gearbox horizontal would be a benefit too... and keeping the shaft lower, of course.

[Pong]

Soo.....

to sum it all up:

It is perfectly possible to build and race a F1 car with the gearbox in front of the engine.

but it remains to be seen if it would be any faster.


I guess the proof is still in the pudding.

[Ray Bell]

Originally posted by Pong
.....I guess the proof is still in the pudding.

No-o-oo...

The proof of the pudding is in the eating.

[Ben]

Originally posted by scarbs
RDV I understand there is more to oversteer than just intertia, but for the forums purposes the statement is accurate enough, Many teams have done alot of work to centralise weight distribution, part of the gain in this is in reducing what we could call intertial oversteer (as opposed to power oversteer for example)

I'm with RDV on this (incidently - nice to see you back on the forum :-) ).

From efunda.com :

The Mass Moment of Inertia of a solid measures the solid's ability to resist changes in rotational speed about a specific axis. The larger the Mass Moment of Inertia the smaller the angular acceleration about that axis for a given torque.

Under- and oversteer is concerned with the moments about the centre of mass, therefore the inertia doesn't matter, but as RDV points out the inertia does affect the rate at which this occurs.

The idea that there are two different sorts of oversteer - inertial and power - is misleading to the point of confusing the issue. It's from the same school as the argument that suggests that Porsche 911s oversteer because of the inertia of the rear mounted engine.

Ben

[Powersteer]

Why not have the diff as a gearbox. Make it a little wider and slot the primary gears next to the secondary transversely and have a very small but tough diff inside the secondary gear shaft. Between the engine to this new gearbox is all carbon fiber with a titanium prop shaft running through and have all the suspension components inside making wheelbase tuning chicken feet. This might make it easier to fabricate and make work John Banards idea of a reliable carbon fiber gearbox or has some funny metal overtaken carbon fiber?

[Wuzak]

Forgive me if I am wrong, but the crankshaft height is well below the height of the rear axle line anyway.

The primary shaft of the gearbox is below the secondary, which is about the line of the rear axle.

So putting the drive shaft through the vee of the engine should present few physical problems, except for interfering with the engine internals.

How big is a gear set?

Powersteer, the idea as mooted here is to move as much weight as possible towrds the centre of the car, whilst keeping the rear end of the chassis narrow for aero purposes.

Transverse gearboxes were widely used several years ago, but have since been dumped in favour of the current longitudinal arrangement.

[Ray Bell]

Whoops... just realised we've all forgotten something...

The gear centre spacing would need to be large enough for the output shaft to clear the flywheel/clutch package... how big are they these days?

[LMP900]

The radius of the clutch is less than the crank height, so clearing that wouldn't be a problem. The shaft centre distance can be what you want it, except that with 19,000 rpm, big gears will have tremedous tip speed. But I still wonder if Ferrari, or Maclaren on the 18, may be doing it.

[Pong]

IMHO - if any team raced a car with the gearbox in front of the engine everybody would know about it. The pits are open to spying this year and engineeringwise such a car would have a impossible tight "Kylie Minogue" rear end.

[Ray Bell]

Originally posted by LMP900
The radius of the clutch is less than the crank height, so clearing that wouldn't be a problem. The shaft centre distance can be what you want it, except that with 19,000 rpm, big gears will have tremedous tip speed. But I still wonder if Ferrari, or Maclaren on the 18, may be doing it.

There has to be some size to the gears, however... carrying the kind of torque these engines produce requires gears that will stand the strain.

[JwS]

In the final analysis, it sounds to me like you are proposing that adding some extra components (drive shaft, gears, whatever) and separating mechanical assemblies that are currently a unit (gearbox and diff), will somehow deliver a more compact unit than the current setup. If they can get away with less fuel then the engine can be moved a little closer to the driver, it is the heaviest part of the car (I am guessing, based on titanium xmission case and minimized gear size). It is interesting to speculate, but I don't see the advantage in this case.
JwS

[RDV]

But I still wonder if Ferrari, or Maclaren on the 18, may be doing it.

...in a word= no

[LMP900]

RDV - tell us more about the MP4-18 - most of us haven't seen it yet...

[Powersteer]

Was it John Barbard who introduced transverse gearboxes with the V12 Ferrari. Think it was the introduction of semi-auto. I was thinking somewhere in the line of really small swatch like mechanism gearbox, like on a old Rangler bicycle maybe??

[DOHC]

Rather Forghieri, on the Ferrari 312T in 1975. (T for "transversal")

[RDV]

tell us more about the MP4-18 - most of us haven't seen it yet...

.....it`s a F1 built in Woking, silver color and uses Michelin tyres.... ..

[diego]

Seems rather inelegant.... why don't you do some rough layouts and see what kind of gain you would get.

[RDV]

re transverse boxes

DOHC --Rather Forghieri, on the Ferrari 312T in 1975. (T for "transversal")

1963 Honda RA270F 1.5 lt had a transverse box...
also have a feeling the 1956 T251 Bugatti might have one , must check...

[RDV]

.....also on subject of transverse gBox, must not forget Ferrari246, D50(1955) and 1957 801, all of which had transverse gearboxes (really sort of transaxles) even though front engined... but drifting off thread here as this is Gearbox in front of engine , maybe should be shifted to the Nostalgia forum!

[mp4]

I'm not sure about this so please don't bite my head off...
Didn't March try this with the 721(?)X?
If you wanted to put the gearbox in the middle, why not just mount the engine backwards?
That's what Porsche did with the 911 and V.W. with the Beetle.
It would remove the need for an extra drive shaft.

Cheers

[desmo]

Originally posted by mp4
I'm not sure about this so please don't bite my head off...
Didn't March try this with the 721(?)X?
If you wanted to put the gearbox in the middle, why not just mount the engine backwards?
That's what Porsche did with the 911 and V.W. with the Beetle.
It would remove the need for an extra drive shaft.

Cheers

Well that's fine if the engine is behind the rear wheels, obviously. If it is mid engine, you are going to need that extra driveshaft. A rear engine F1 car may not be entirely crazy as it sounds... then again it might.

[Bill Sherwood]

Perhaps a little tongue-in-cheek, but I have given thought to having half the gearbox on each side of the engine.
For example, gears R-1-2-3 on one side and 4-5-6-7 on the other.
Should save a fair bit of room down the back (apart from the obvious duplications of driveshafts) and move a little weight towards the centre of the car.