[WEC] Porsche Prototype Discussion

[prototype]

Originally Posted by Spyderman

Very interesting: http://www.endurance-info.com/en/int...he-919-hybrid/

Very interesting that Porsche can wait to determine what Megajoule class to be in. It almost sounds like they could switch classes from race to race.

I am sure there are homologation rules against this, but interesting that this hasn't already been determined.

[J Jay]

I suppose that speaks to the superior energy density the battery system offers compared to (for instance) Toyota's supercapaticors which has the best power density* but needs to be used to the max to make the most of the ERS allocation.


*Of the electrical hybrids

[TF110]

Batteries are good for that. Being overweight last year probably added to the decision to do 6mj. Youll have to increase the battery's output or it wont be as light for more power. I guess they did this?

[J Jay]

I assume so. It makes sense that Porsche would want revise as much as possible with the goal of making more weight headroom for a bigger battery. We've seen the advantage in versatility that using all/most of the hybrid energy in one go can give.

[Articus]

What it sounds like is they reduced weight everywhere else in the car so now they can be within weight target even with an 8MJ system. Battery energy density development does not grow exponentially. They are not just throwing in an 8MJ system with equal or lesser weight of the 6MJ system from last year.


And it still doesn't really answer the question of what we saw all of last year that you kill the battery pack discharging and charging at such high rates and with cooling issues Porsche had. This means the Porsche pack capacity is less by an appreciable amount at the end of a 24 hour race than it is at the beginning. And suddenly a 6MJ system looks like a 4MJ system plus the extra weight.

Does anyone have any semi-official figures on what that pack performance loss figure might be?

You can deter this by oversizing the battery pack. But then you add more weight which is critical in racing. Porsche still get the benefit of being able to store more energy and release at a single moment than Toyota and Audi can claim to do with their non battery systems.

[Lagunaseca_4life]

Originally Posted by Spyderman

A nice piece on testing:https://grrc.goodwood.com/race/moder...he-919-testing

Awesome!!

Thanks for that link.

I don't know which car im going to like the most this year,can't wait to see toyotas and audis updates.im feeling more excited for this year than last! Haven't felt this way about lmp1 since the audi vs. Peugeot days of 2010 and '11 when it got really exciting.

[YorkshireLad]

Originally Posted by Articus

What it sounds like is they reduced weight everywhere else in the car so now they can be within weight target even with an 8MJ system. Battery energy density development does not grow exponentially. They are not just throwing in an 8MJ system with equal or lesser weight of the 6MJ system from last year.


And it still doesn't really answer the question of what we saw all of last year that you kill the battery pack discharging and charging at such high rates and with cooling issues Porsche had. This means the Porsche pack capacity is less by an appreciable amount at the end of a 24 hour race than it is at the beginning. And suddenly a 6MJ system looks like a 4MJ system plus the extra weight.

Does anyone have any semi-official figures on what that pack performance loss figure might be?

You can deter this by oversizing the battery pack. But then you add more weight which is critical in racing. Porsche still get the benefit of being able to store more energy and release at a single moment than Toyota and Audi can claim to do with their non battery systems.

Won't using a battery system always have a reduced power amount after so many charges and releases?

Even with a bigger storage area, if using it all the time it will still reduce the power figure.

Or could they have two separate areas contained in the storage device so after 12 hours and a noticeable dip in power and recharge figures, mean they could then switch to the secondary area which would then maintain the same storage and release figures as when the race first started.

You'd obviously have to take into account the weight:usage ratio, to see if it actually would make a benefit in the race. They could even end up having a, sort of, reserve tank. Meaning if they dipped in the last few hours they could switch.

Hope I've described it well. Haha.

[GasperG]

I think battery can be durable if it has sufficient cooling, cooling ads weight so obviously there must be minimum cooling that is necessary to last it 24 hours. Porsche will obviously try to find the best compromise.

There is also ERS-H energy, that can be routed directly to the wheels if battery is not "feeling well". Or maybe they always route it to the wheels to avoid battery charge/discharge loses?

[GingerPixel]

Last year the Porsche had some level of battery degeneration, although I'm not sure if it meant a significant reduction in performance.

[porman]

Marc's interview is up on the site. Unfortunately, my wonderful IPad isn't cooperating in posting the link. He does mention that they have improved the braking as it was an area they knew that they needed to improve upon.

[Gingers4Justice]

Originally Posted by porman

Marc's interview is up on the site. Unfortunately, my wonderful IPad isn't cooperating in posting the link. He does mention that they have improved the braking as it was an area they knew that they needed to improve upon.

Thanks for the heads up, Porman! The link is here for anyone wanting to read it https://grrc.goodwood.com/race/moder...leib-interview

I remember standing at Abbey on Saturday morning last April, and I noticed the 919 was braking where I was standing - only a few metres after the LMP2 cars and much, much before the Toyotas, Audis and even the Rebellion Lolas.

It was also pretty clear watching them at Luffield in particular that the 2014 car suffered from some pretty horrid mid-corner understeer. They're going to have a very good car if they get those two things sorted out.

[Richard C]

Originally Posted by porman

Marc's interview is up on the site. Unfortunately, my wonderful IPad isn't cooperating in posting the link. He does mention that they have improved the braking as it was an area they knew that they needed to improve upon.

Link...

https://grrc.goodwood.com/race/moder...leib-interview



Richard

Edit (Opps, Gingers4Justice beat me)

[Richard C]

Just finished reading. Very nice article/interview with Lieb. I liked the comments about taking risk as well as the mention at the end about the 25 page manual on how to operate the steering wheel! I would love to see something like that manual. Maybe at some point in the future when the 919 is no longer in service we might see a copy of something like that.

Richard

[The Badger]

GI wish they wpuld remove that hideous wing !

[Spyderman]

If only...

[YorkshireLad]

Originally Posted by Spyderman

If only...

That looks sweet as..

[MyNameIsNigel]

Originally Posted by Spyderman

If only...

Funny how easily one gets used to the shark's fin. It doesn't look quite right in this photoshopped picture

[porman]

Originally Posted by MyNameIsNigel

Funny how easily one gets used to the shark's fin. It doesn't look quite right in this photoshopped picture

I hear you as the rear-end does seem to be a bit out of proportion to the rest of the car. That being said, I like it sans the billboard. Oh well!

[Pandemonium]

Exactly. It just looks better with the fin.

[Pontlieue]

The rear looks really long without the fin. A modern prototype without a fin looks a bit weird at first, I could get used to it. But only if they find a better way to keep cars oin the ground.

Another thing I wonder: If the fin wasn't mandatory, would the teams still keep them? In Formula 1 most of the teams used fins in 2009 and 2010, before they were banned in order to get rid of the F-Ducts.

[lms]

Originally Posted by MyNameIsNigel

Funny how easily one gets used to the shark's fin. It doesn't look quite right in this photoshopped picture

I agree. it looks too front-heavy.

[CTD]

Perhaps because of the new cockpit rules?
Also the BHF might change the way the cockpit is designed to fall towards the rear end.

[cokata]

The BHF looks good on the current P1s. But the older wider and lower ones looked better overall. I was watching recently the 2010 Le mans and the Peugeot looked stunning. And the BHF is enhancing performance not hindering it unlike the BHHs.

[Articus]

This is the 2010 Peugeot 908


Right now in 2015, I see it in the same light as the Porsche without a BHF (odd looking) but this looked completely normal to me in the era before the BHFs.

[TF110]

I hope the new rules drop the fins. They're not irreplaceable. There has to be other solutions that aren't so unappealing.