Little known Porsche model features and facts

[thegreenhell]

mollytherocker said:

It was also confirmed that many front engined Ferraris like the 612 are now technically mid engjned as are many BMWs!

This I can well believe, as many cars do have their engine mounted well behind the front axle. However, in the case of the 991 I find it harder to believe, as the engine appears to be substantially, if not completely behind the rear axle centreline.

[OlberJ]

anonymous said:

[redacted]

Yeah the driveshafts already run through the box half way down that, so behind axle line you've got engine and half a gearbox theoretically.

Now I know they shifted the engine forward so the shafts v back towards the hubs which shifts the whole weight forward from the virtual axle line.

Using that I could see the whole box being in front of the virtual axle line and if heavier than the engine then voila 51% and "mid" engined.

Unless they have gone the Audi route with the 991 and put the diff next to the flywheel (genius design). This helps packaging no end.



Apologies for the application, I had a moment of madness!

[thegreenhell]

The Porsche 924 is technically rear engined. This is if you include the transmission which is rear-mounted and gives the car a 48/52% front/rear weight distribution.

[OlberJ]

That's across both axles. With the 911 we're just talking weight distribution over the rear axle.

Taking in both like the 924 that's mid engined I believe. Overall the most weight is between the axle lines.

Still, ask me and unless the engine physically lies between the axle lines, it's not mid engined, even if it has a mid engined weight distribution.

[OlberJ]

Here we go. They are like the Audi box.



So if the shafts V back to the hubs then it may well be 51% weight in front of rear axle.

Rear engined car with mid engined weight distribution.

[tali1]

Apparently a 1978 911 turbo Martini cost more than £78,000 when new (that’s around £320,000 by today’s standards.
And a 930 Turbo SE(the flatnose) in real terms would cost more than the latest 911 Turbo S.

[thegreenhell]

OlberJ said:

That's across both axles. With the 911 we're just talking weight distribution over the rear axle.

Taking in both like the 924 that's mid engined I believe. Overall the most weight is between the axle lines.

Still, ask me and unless the engine physically lies between the axle lines, it's not mid engined, even if it has a mid engined weight distribution.

In case you hadn't guessed I was just being facetious. I do completely agree with your last statement though.

[thegreenhell]

anonymous said:

[redacted]

So the Box/Cayman must therefore be 'rear-engined', non?

Honestly, this must be the first time anyone has ever argued that gearbox weight and location somehow attributes a different engine location to where the engine actually and physically is. The engine is the engine and it is where it is. Any other moniker applied as a result of adding the mass of some other component is wrong, plain and simple.

[belfry]

mollytherocker said:

sidicks said:

996TT02 said:

Surely this can't be right.

Otherwise the gauge would only work on the way down.

If you were near empty and you filled up to less than half a tank, the gauge would not register as it would have no means of knowing that you had filled up, and by how much.

That happened to me.

It is a pretty poor design. But Porsche believed that this was a good solution! Things like this become character over time though!

Thank you so much for posting this information. I occasionally have to use London's most expensive petrol station (in Sloane Avenue, Chelsea). When I am really low on petrol in my 997 C4 S I had occasionally put in £15 worth of petrol (at £1.65 p). Last time that I was there I paid for my petrol got back into my car and there was no change in the fuel gauge. So, I went back into the kiosk and furiously told them that the pump was not delivering petrol! Now I feel a little foolish.

[uktrailmonster]

thegreenhell said:

Honestly, this must be the first time anyone has ever argued that gearbox weight and location somehow attributes a different engine location to where the engine actually and physically is. The engine is the engine and it is where it is. Any other moniker applied as a result of adding the mass of some other component is wrong, plain and simple.

Spot on.

[uktrailmonster]

anonymous said:

[redacted]

Fair enough, I guess I should have said final drive (i.e. rear wheel centreline) in front of engine. If the engine is behind the rear wheel centreline it has to be rear engined. I can't see how a 991 can be classed as mid-engined with that layout.
But not something to lose sleep over!

[OlberJ]

uktrailmonster said:

thegreenhell said:

Honestly, this must be the first time anyone has ever argued that gearbox weight and location somehow attributes a different engine location to where the engine actually and physically is. The engine is the engine and it is where it is. Any other moniker applied as a result of adding the mass of some other component is wrong, plain and simple.

Spot on.

It's not arguing over the semantics, it's that the weight distribution on 991s is now that of a traditionally mid engined car rather than a rear engined one.

The layout is not the same as the weight distribution characteristics.

Ergo, the 991 isn't really a 911 any more, it's a 4 seater Cayman with bowel problems. :rasp:

[ORD]

It's still rear-engine. It has a 50-50 (or so) weight distribution, but then so do some FR cars that we still call front-engine.

I think most people would say the 991 still has a slightly rear-biased feel relative to a Cayman, but I agree that it is barely any different these days.

[paralla]

At least the one thing everyone agrees on is that the best place for an engine in a sports car is between the axles like a cayman or boxster.

[OlberJ]

The real question is, does a 991 still handle like a 911 or is that 1% shift to mid engined weight distribution deliberate to make it handle like a middy?

It's the concentration of weight that matters to the handling, not where things are located.

[Risotto]

The steering wheel badge on the 2000MY 996 (and possibly other Porsche models of that year) was black/silver rather than gold/black/red.

[uktrailmonster]

paralla said:

At least the one thing everyone agrees on is that the best place for an engine in a sports car is between the axles like a cayman or boxster.

I would agree for a track car, but for a road going sportscar there's actually a lot of merit in the rear engined layout. For a start traction and straight-line braking are both better with a rear biased weight distribution. Sure you lose a bit of overall lateral grip compared to a mid-engined layout, but for road use it isn't so critical i.e. you may often reach the limit of traction or braking in a road car, but you rarely step over the lateral grip threshold. On the track you are pushing the lateral limits much harder and hence a mid-engined layout is king.

[Ian_UK1]

uktrailmonster said:

I would agree for a track car, but for a road going sportscar there's actually a lot of merit in the rear engined layout. For a start traction and straight-line braking are both better with a rear biased weight distribution. Sure you lose a bit of overall lateral grip compared to a mid-engined layout, but for road use it isn't so critical i.e. you may often reach the limit of traction or braking in a road car, but you rarely step over the lateral grip threshold. On the track you are pushing the lateral limits much harder and hence a mid-engined layout is king.

There was an post on here some time ago by one of the regular racers (can't remember who now) who explained very well how the weight distribution of the 911 can, in suitably skilled hands, make it faster on track than a mid-engine equivalent. The gist was (IIRC) that the 911 has equal weight distribution under braking, therefore best turn-in was with brakes still applied (trail braking). Being able to brake all the way into the apex meant that braking could start later - hence gaining an advantage. Once the brakes are fully released, the natural rear weight bias (more traction) allows power to be re-applied earlier than possible with a mid-engine car, to gain further advantage on the exit from a corner.

[uktrailmonster]

Ian_UK1 said:

There was an post on here some time ago by one of the regular racers (can't remember who now) who explained very well how the weight distribution of the 911 can, in suitably skilled hands, make it faster on track than a mid-engine equivalent. The gist was (IIRC) that the 911 has equal weight distribution under braking, therefore best turn-in was with brakes still applied (trail braking). Being able to brake all the way into the apex meant that braking could start later - hence gaining an advantage. Once the brakes are fully released, the natural rear weight bias (more traction) allows power to be re-applied earlier than possible with a mid-engine car, to gain further advantage on the exit from a corner.

Well you'd have to balance that lot against loss of overall lateral cornering grip. Mid-engined cars have dominated most forms of track racing for many decades, so I'd be very sceptical of a rear engined car being faster on track.

[TB993tt]

mollytherocker said:

The 993 was meant to have a totally new dash but this was shelved very late in the design stages due to the cost. It is believed by some that it is this design that eventually saw the light of day in the first Boxster concept cars.

Can you say where you got this nugget from, the dash of the aircooled 911s is a structural part with the instrument holes as part of this structure isn't it ?