F1technical.net

langwadt wrote:

Tommy Cookers wrote:a race-type V4 configuration would surely give a better race engine than would any flat 4
but would be useless for a road car, because of the uneven spacing of the power impulses
rather important at 2 or 2.5 litres
or wouldn't Porsche be going for the 'we race what we sell' angle ?

how much worse would a V4 be compared to the big bang I4s all the "racing" bikes brag about now?

exactly the same as the cross-plane (ie 'big bang') I4s and the V4s in road and race bikes
ie bloody awful in a 2/2.5 litre road car with manual transmission

which is what I was trying to say

The 4-cylinder is most likely due to efficiency concerns. The I4-V4-F4 configuration decision is much more difficult because the consequences are less drastic. Each config has its merits in terms of packaging, CoG and stiffness. I happen to believe that stiffness with CAD design isn't a real isssue any more. It is more likely that packaging the power unit for best aerodynamic performance will make the difference. So in my view it will become a race between I4 and F4. I4 may be the best engineering solution but it may have marketing draw backs. Hard to tell how Porsche has decided that issue. In the end they have an in house problem of an Audi R8 and other Audi sports cars of the future going up against them with the same I4 concept at some time. For their own brand sake it would be so much better to make the F4 work.

WhiteBlue wrote:I happen to believe that stiffness with CAD design isn't a real isssue any more.

Ehh... I think you would have trouble making an I4 as stiff as a V4 in Torsion. It would either add a lot of weight or require a spaceframe around it (which also adds weight). So you can achieve the same stiffness in the end easily enough, but which one does so for less weight?

Lycoming wrote:

WhiteBlue wrote:I happen to believe that stiffness with CAD design isn't a real isssue any more.

Ehh... I think you would have trouble making an I4 as stiff as a V4 in Torsion. It would either add a lot of weight or require a spaceframe around it (which also adds weight). So you can achieve the same stiffness in the end easily enough, but which one does so for less weight?

This is not my opinion. The view was expressed by Baretzki.

A render of exhaust passing through the cylinder head.

WilliamsF1 wrote:A render of exhaust passing through the cylinder head.

https://d2t1xqejof9utc.cloudfront.net/s ... medium.JPG

nice pic, could be even more compact/less piping if the turbo was on top of the engine, swapping exhaust and intake port on the head and using normal side exit for the exhaust

langwadt wrote:

WilliamsF1 wrote:A render of exhaust passing through the cylinder head.

https://d2t1xqejof9utc.cloudfront.net/s ... medium.JPG

nice pic, could be even more compact/less piping if the turbo was on top of the engine, swapping exhaust and intake port on the head and using normal side exit for the exhaust

The intercooler is actually on top of the engine (between the intake plenum) and turbo is compounded to the driveshaft.

WilliamsF1 wrote:A render of exhaust passing through the cylinder head.

https://d2t1xqejof9utc.cloudfront.net/s ... medium.JPG

Is this yours?

So they will use 4 cyl + ERS H and probably somesort ERS K with flywheel recovery store system like AUDI i belive...

Below electro motor + front diff and gearbox housing...

aleks_ader wrote:

WilliamsF1 wrote:A render of exhaust passing through the cylinder head.

https://d2t1xqejof9utc.cloudfront.net/s ... medium.JPG

Is this yours?

NO

[youtube]http://www.youtube.com/watch?v=gHjrxiE85Mg[/youtube]

In those Porsche recent 3 videos became most obvious fact that they use asymmetrical exhaust exit (realy big hole! no like Audis =>2 small ones on each sides). So the in-line 4 cylinder engine makes sounds most plausible choice.

I wrote a mail to the author of this article ( http://www.sportauto.de/motorsport/lmp1 ... 14374.html ) in which you can read that:

"Beim Motor setzt Porsche im LMP1 919er auf einen Zwei-Liter-Vierzylinder, aber nicht in Reihe angeordnet, sondern als kompaktes und steifes V4-Triebwerk. In der weit geöffneten Zylinderbank sitzt der Mono-Turbolader."

"Porsche uses a 2l-4-cylinder engine for the 919 LMP1 car. The engine isn't build as an inline configuration, it is a small and stiff V4 engine. Inside the V, which is wide open (=more than 90°) the single turbo is placed."

I asked the author where he's got this information from and he said that these statements are based on personal contacts with Porsche engineers during the Portimao test. So for me this is the confirmation of the V4 configuration.

V4 seems likely at this point, but it won't be long now til we get see. Endurance racing season has already kicked off in the states. 1st round of WEC will be April 20, just over 2 months to go. Has it been confirmed whether or not Porsche will contest all rounds of the WEC this year?

More interestingly, Webber will be sharing his car with Timo Bernhard and Brendon Hartley. On the one hand, Bernhard is a Le Mans winner, but I find Hartley to be an interesting choice. He's pretty young and has little Endurance racing experience, though he has loads of experience in lower formulae open seaters. While he is no doubt a very good driver, I would think him to be somewhat of a gamble compared to Bernhard and Webber, considering that Le Mans is more about staying out of trouble than anything else. You don't really want the kind of driver that's trying to prove something and takes unnecessary risks...

Perhaps they're hoping some of the old guys' experience will rub off on him, but I think it will be interesting, given that 2 of their 3 drivers for that car have little experience at le mans and its various intricacies, such as night racing. Their other car, on the other hand, is filled with familiar faces to those who watch Le Mans. Looks to me like Porsche have a bit of a split strategy going on here with their drivers...

Blanchimont wrote:I wrote a mail to the author of this article ( http://www.sportauto.de/motorsport/lmp1 ... 14374.html ) in which you can read that:

"Beim Motor setzt Porsche im LMP1 919er auf einen Zwei-Liter-Vierzylinder, aber nicht in Reihe angeordnet, sondern als kompaktes und steifes V4-Triebwerk. In der weit geöffneten Zylinderbank sitzt der Mono-Turbolader."

"Porsche uses a 2l-4-cylinder engine for the 919 LMP1 car. The engine isn't build as an inline configuration, it is a small and stiff V4 engine. Inside the V, which is wide open (=more than 90°) the single turbo is placed."

I asked the author where he's got this information from and he said that these statements are based on personal contacts with Porsche engineers during the Portimao test. So for me this is the confirmation of the V4 configuration.

Then is even more interesting why they use asymetrical exit. I know it is hard build shark fin to avoid that. Anyway on another hand still V4 makes more sense in chasis wise. Let see...