dyna-niet

I already wrote my opnion about this suspect at porsche gt3 threat but ill write it again becaus lately me and klier where thinking what porsche will do withe their engines, i mean how much bigger will they get?? anyone a clue??

cheers dyna

german car engeneering: the best their is!!!

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siko

I read somewhere (I'll try to find the reference) that the displacement limit for the flat-6 is is about 4 litres... so not much more room left.

A possible step would be to go up to a flat-8, like they had in the Porsche 908!?

NarutoRamen

Siko, I highly doubt they would do that because the Boxter is their entry level car. They can't drop a flat-8 or anything close to that in that car because then they will piss off the rest of their customers. May-be they should make the next Boxter into...Boxter T (turbo)?

dyna-niet

Siko i think your right, i think also that their engine will grow a bit bigger but after that they will have a problem, flat 8 customers will be bust, or not! thanks for your opinion anyway

cheers dyna

dyna-niet

naru i think your right, the customers will be pissed but how big will they go?? i just need to know what porsche will do next

Centurion

The GT3 houses the 3.8L engine and is just about pushed to the limit. A 3.9L engine allowing with tweeks might be featured in the next gen 911. A flat 8 is also an option but much more weight at the rear of the car can be disastrous.

Top Secret

I'm unclear why a flat-6 cannot go over a displacement of over 4.0L, is it because of efficiency reasons or something else? Anyone care to clear this up for me? Martinbo, I'm looking at you....

As for the future of the flat-6, it's virtually impossible to say, really. I know that Wiedeking has said that an eight-cylinder 911 is a possibility, but I suspect that that's a fair few years away. I suspect that back in the 1950's and 60's that Porsche engineers engineered the 911 knowing that the flat-6 had a limited lifespan, but no one suspected the 911 would have survived for as long as it has. It's such a compromised platform in so many ways, it's still a wonder to see it alive now.

The only thing I can really say is that Porsche will use the flat-6 for as long as it possibly can. There's no doubt about that. The longevity and cult status of the 911 insures this.

martinbo

I recall Jeff Daniels explaining the concept of optimum cylinder displacement in EVO a few issues back. I don't have the copy on me now but I can remember some of the more salient points. He described the optimum engine displacement (for a performance road car) as being around 500 to 600 cc per cylinder as a rule of thumb in current times. Anything bigger is subjected to either high reciprocal masses (i.e. if the bore is large then the pistons are bigger and heavier) or high internal piston velocities (i.e. if the stroke is long). So both Porsche's 3.8 litre 6 cylinder and Subaru's 2.5 litre 4 cylinder are at the limit of efficient per cylinder displacement, whereas something like the M5's V10 is bang on optimum - with room to spare!

Conversely cylinders that fall below the optimum will suffer the consequences of poor thermal efficiency if I recall correctly...

Fortunately, constant improvements in engine technology mean that Porsche can still employ emerging technology like direct injection to make meaningful power gains without resorting to forced induction or increased displacement.
Thereafter, there are plenty more innovations still to come for the petrol engine, things like camless valve actuation (electro-magnetic) will drastically alter the course of petrol engine development and a new benchmark will be set for specific output.

The boxer engine's definitive attribute of a low centre of gravity is fundamental to the 911 and Boxster / Cayman's prodigous handling ability so I don't see them dropping the layout too soon.

siko

911 Turbos already use a Boxer T!

martinbo

Perhaps there's a little mis-communication here, I think Naruto was referring to the Boxster model and not the Boxer engine layout. Hence his suggestion for a turbo'd Boxster. As for the rest of us, we're all talking Boxer engine.

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