tpenta

Hi folks,

Based on the recent pictures taken in Las Vegas of the 991 (published in Total 911), one thing seems obvious (to me, that is):

The 991 is moving the engine forward. Take a look at my very crude approach at comparing the 991 to the 997. The reason the wheelbase is growing is probably to accommodate moving the whole interior forward.

Also, the rear window slope and the roofline look like they are both lower, though the front window slope is the same.

Thoughts?

-T

am722

Looks more to me like the back is moving backwards.

tpenta

Use the middle red line and see where the rear window corner ends.

Also, granted it's not a perfect portrait view of the car, but it seems the front distance from the wheel to the bumper has gotten smaller.

leneuromancer

i think without pictures that are exactly to [identical] scale, this may be an exercise in futility

winkingchef

I think this is the first time I noticed how much closer to the bumper the 991's lights are than the 997.

theporscheguy

Hard to draw any conclusions until you get to see the real car, not one that is half covered.

tpenta

Of course you can't tell exactly but it is very obvious when you align the rear axle to the corner edge of the rear window that they are obviously aligned differently. You can say the wheel has moved back, or the window has moved forward. But either way, there is an obvious shift. it doesn't require any exact scale to see that...

Just my 2 cents.

-T

tpenta

Here's what I mean. Look at yellow lines:

ADias

Let us try to understand the issues. The WB (wheelbase) is the distance between the front and rear axles measured between wheel hub centers.

The 991 WB will be 4" longer than the 997 WB:

WB(991) = WB(997) + 4 (in inches).

This WB increase is fact, not conjecture.

Thus, relatively to the front wheels, the 991 rear wheels will be 4" behind. Its engine will therefore be 4" behind relatively to the current engine position (relatively to the front wheels).

The engine and transmission will be the same dimensionally and the engine will be further back - 4" back. The space gain occurs entirely in the cockpit behind the front seats.

Any photographic comparison will have to use the 4" WB differential as its basis of comparison (not the overall length). The car length seems to be slightly larger. Perhaps not quite 4" longer due to some overhang savings (more savings up front).

Now... with a longer wheelbase, PAG has now space to flip the positions of the transmission and the engine and make it mid-engine. The 991 wheelbase (96.4") is longer than the Cayman (mid-engine) (95.1"). This may happen on some homologated series for motorsports certification. If it happens, it will be PAG's way to bring a Cayman architecture (albeit with better suspension) in 911 clothes.

P.S. - re the photos above it is quite clear that the rear cabin increased, by noticing the forward repositioning of the apex of the side rear window now slightly forward of the rear wheel hub.

alexb76

What you're showing is actually engine MOVING FURTHER BACK, instead of foward... which proves what Porsche was saying is true, there will be MORE ROOM for the rear seats!

alexb76

AHA! You might have nailed it in the head right there! It is obvious that the engine is NOT moving foward, BUT 991 might shift more weight forward by moving the transmission, and keep the engine where it is, to make old 911 drivers happy!

Very interesting... I believe Maserati does the same with their Front Engine setup to create a less front heavy car!

Something like this but backward?

Nugget

The bottom car isn't level. Draw a line from wheel center to wheel center and you'll see that the bottom car is sloped "uphill." This skews your vertical guidelines and exaggerates the differences you're pointing out. It's a very interesting comparison, though, thanks for starting the thread.

ADias

Look at the geometry... The engine/tranny mass is still in the save relative position to the rear axle. PAG is not going to separate apart the engine and tranny to move weight forward. The gain is all in front of the tranny and mktg will spin the back-seating space gain, which for some of us is a negative, but the masses think otherwise, I'm sure.

The whole WB increase is to take advantage of the ill-conceived EPA footprint reg. A side effect of that is to allow space to develop a '911' mid-engine for racing. This is what I think is going on.

gpjli2

Personally I think the "SWB" (short wheelbase) 911's will come to be known as the last "true" Porsches!

LlBr

Top car's turned slightly. Rear wheel diameter is bigger than front wheel.

Bottom car is a precise square-to-camera-lens shot.

I attempted to line up the hub center points.