Porsche back in Le Mans!

[rscsr]

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...

Brandon Hartley was unbelievable quick in the endurance races he did. And Mark Webber was driving in LeMans before F1, although without the chicanes. So I would really doubt that this car is much of a gamble. They just want a really quick car against the 24h sprint against Toyota and Audi.

[Sebp]

Do you mean the chicanes on the straight?

They've been there since 1990:
[youtube]http://www.youtube.com/watch?v=i1ECE3oT-Z8[/youtube]

Webber's last run around was most definately not earlier than that (1999).

[rscsr]

I thought that they were introduced later but ok

[bdr529]

The 2 chicanes on the Mulsanne straight were add in 1990 to slow the cars down after they started reaching 250mph
this video is from 1983 so not that much slower
[youtube]http://www.youtube.com/watch?v=yni-W7s3Hp4[/youtube]

[Tommy Cookers]

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

RERUN ...... in the light of the later (Feb 12) report of the V angle well over 90 deg .......
a big V angle would (with a simple 2 throw 'race' crank give less uneven firing intervals but some uneveness of inertial intervals)
a 2 split-throw road crank would be a direct substitute, giving near-even firing intervals (and inertial intervals less even again)
this engine fits the tradition, but be shorter and have less friction than a flat 4, or they might go 4 throw V4 that wouldn't
presumably the (twin clutch) manual would anyway manage gear selection to avoid potential transmission snatch ?

[Huntresa]

Tech details on the 919 http://www.autosport.com/news/report.php/id/112546

[Holm86]

Two interesting bits here.

The Porsche 919 hybrid World Endurance Championship challenger is powered by a two-litre V4 engine, the German manufacturer has finally confirmed.

So they confirm to run a V4 engine.

The exhaust-driven energy-retrieval system developed by Porsche is distinct from that used by Audi and in Formula 1.
Rather than running off the turbocharger, the motor-generator unit on the Porsche is driven by a separate turbine in the exhaust system.

This is also quite interesting. Right now I can't see the advantage in this. But they must have their reasons.

[Huntresa]

Two interesting bits here.

The Porsche 919 hybrid World Endurance Championship challenger is powered by a two-litre V4 engine, the German manufacturer has finally confirmed.

So they confirm to run a V4 engine.

The exhaust-driven energy-retrieval system developed by Porsche is distinct from that used by Audi and in Formula 1.
Rather than running off the turbocharger, the motor-generator unit on the Porsche is driven by a separate turbine in the exhaust system.

This is also quite interesting. Right now I can't see the advantage in this. But they must have their reasons.

Am i reading that last part correct if i think that adds another component to the engine/exhaust system like a 2nd turbo but only used with the MGU and also if thats the case how would that get the exhaust gases, i mean dont you want them to pass to the turbo without stuff in the way ?

[Holm86]

Two interesting bits here.

The Porsche 919 hybrid World Endurance Championship challenger is powered by a two-litre V4 engine, the German manufacturer has finally confirmed.

So they confirm to run a V4 engine.

The exhaust-driven energy-retrieval system developed by Porsche is distinct from that used by Audi and in Formula 1.
Rather than running off the turbocharger, the motor-generator unit on the Porsche is driven by a separate turbine in the exhaust system.

This is also quite interesting. Right now I can't see the advantage in this. But they must have their reasons.

Am i reading that last part correct if i think that adds another component to the engine/exhaust system like a 2nd turbo but only used with the MGU and also if thats the case how would that get the exhaust gases, i mean dont you want them to pass to the turbo without stuff in the way ?

Thats how I understand it. A turbo + a seperate "turbo" without the compressor but who is just running the generator.

This can be done in a few ways. Either the generator turbine is placed before or after the real turbo. Or they will run 2 cylinders to drive the turbo and 2 cylinders to drive the generator turbine.

But this also means that they cant use the MGU-H to spool the turbo.

[Huntresa]

Thats how I understand it. A turbo + a seperate "turbo" without the compressor but who is just running the generator.

This can be done in a few ways. Either the generator turbine is placed before or after the real turbo. Or they will run 2 cylinders to drive the turbo and 2 cylinders to drive the generator turbine.

But this also means that they cant use the MGU-H to spool the turbo.

I guess they can getaway with the turbolag in terms of speed when it comes to endurance racing, but does turbo lag affect fuel consumption anything or is just flat performance loss?

[Holm86]

Thats how I understand it. A turbo + a seperate "turbo" without the compressor but who is just running the generator.

This can be done in a few ways. Either the generator turbine is placed before or after the real turbo. Or they will run 2 cylinders to drive the turbo and 2 cylinders to drive the generator turbine.

But this also means that they cant use the MGU-H to spool the turbo.

I guess they can getaway with the turbolag in terms of speed when it comes to endurance racing, but does turbo lag affect fuel consumption anything or is just flat performance loss?

Turbo lag should influence the driving just as much in endurance racing. You are still braking and accelerating alot.

[Tommy Cookers]

it has a 'gu-h', not an mgu-h ?

[acosmichippo]

Thats how I understand it. A turbo + a seperate "turbo" without the compressor but who is just running the generator.

This can be done in a few ways. Either the generator turbine is placed before or after the real turbo. Or they will run 2 cylinders to drive the turbo and 2 cylinders to drive the generator turbine.

But this also means that they cant use the MGU-H to spool the turbo.

I guess they can getaway with the turbolag in terms of speed when it comes to endurance racing, but does turbo lag affect fuel consumption anything or is just flat performance loss?

my understanding, from road cars at least, was that you get better mpg out of boost. boost causes more oxygen in the cylinder, which the engine counters with more fuel. that leads to more power, but less distance/fuel efficiency. but maybe it's different in motorsports.

[aleks_ader]

it has a 'gu-h', not an mgu-h ?

It seams so.

But still they could with 2nd turbine spoil 1st one?

They made some sort bypass system?

Advatage? Because the Lemans circuit is very long maybe they dont need constant spoiling of turbo at all. So in areas when they don't have enough energy is ERS-H turbine in pointless and make engine performance worse =>bigger engine turbo LAG=>less inertia on turbo=quicker spoil. And 2nd thing maybe they dont want to spoil turbo at all and is they plan to use much as energy on the acceleration on front axle. So mechanical efficiency vs. engine thermal efficiency (f1 car)? Maybe is that solution for Le Mans lap ideal solution. Fuel and engine economy and potential weight penalty (addition radial or axial turbine) could be diminish..

But to final judge that options and how that set up effect Power unit need to be studied in MathLab sims (or similar tools)....

[aleks_ader]

That dual turbo system could also easily act as a variable turbine? Lemans rules forbid variable turbines?