Peugeot 908 discussion

[The Badger]

When it decideds to detonate , the flames should look a whole lot more spectacular from the top of the rear engine deck !!!

[CTD]

Originally Posted by The Badger

When it decideds to detonate , the flames should look a whole lot more spectacular from the top of the rear engine deck !!!

It will then be the new Batmobile, going even faster

[Laurent]

Originally Posted by Pandamasque

PS: a strange place to put access panels, don't you think?

I don't think these are access panels but heat protections

[Bentley03]

Originally Posted by Laurent

I don't think these are access panels but heat protections

Definitely, but very large.

[TF110]

how hard would it be to route those exhausts in a 180 degree fashion and shoot the exhaust gases through the diffuser? I guess the heat shielding could be placed underneeth where they are right now, top and bottom? Wouldn't that effectively blow the diffuser? I wonder if it would even benefit them though. Perhaps not, and maybe that's why they don't do it?

[The Badger]

Originally Posted by Bentley03

Definitely, but very large.

Pugs throw out very large flames , as seen last June Mr.B !!!

[Victor_RO]

Originally Posted by TF110

how hard would it be to route those exhausts in a 180 degree fashion and shoot the exhaust gases through the diffuser? I guess the heat shielding could be placed underneeth where they are right now, top and bottom? Wouldn't that effectively blow the diffuser? I wonder if it would even benefit them though. Perhaps not, and maybe that's why they don't do it?

MulsanneMike posted quite a few pages ago that diesels' exhaust flow isn't too suited to being used for blown diffusers.

[gwyllion]

Burning fuel in the exhaust for the sake of a bit of extra downforce is probably not worth the effort. In Formula 1 the blown diffuser was only good for a few tenths over a lap. Moreover, it is bad for reliability (cilinder head, exhaust valves and exhaust pipes suffer from excessive heat) and fuel economy; therefore Red Bull mainly used it in the Q3 session. Given these drawbacks, it is probably less suited for endurance racing.

[chernaudi]

Especially since Peugeot probably don't want have an event like Le Mans all over again in the attempt to just gain a few tenths of a second when other, more conventional means can achieve the same aim.

Only reason why it could work on the R18 is because if it's got a twin turbo engine (which would explain why the exhaust exit is very large considering that it's one pipe) the exhaust flow is combined and concentrated. Given that, however, I don't think that the diesels rev high enough to produce the volume of air to make something like that especially useful.

Granted, with the R18's exhaust blowing into the diffuser exit flow and the Pug's exhaust blowing on the tail gurney will have some effect, but you'll need a windtunnel with telemetry to see it, and though you can feel the exhaust flow behind the car, the data will probably be inconclusive about it's usefulness, and probably wouldn't make a marked difference on track.

[gwyllion]

Originally Posted by Victor_RO

MulsanneMike posted quite a few pages ago that diesels' exhaust flow isn't too suited to being used for blown diffusers.

This is his post: http://tentenths.com/forum/showthrea...45#post2829645

Another drawback of a blown diffuser is that the exhaust flow must be kept even when the driver is off the throttle (e.g. in braking zones and turn in of corners); otherwise downforce will be lost. As explained in http://scarbsf1.wordpress.com/2010/0...teams-q3-pace/ this can be down with retarded ignition, which burns fuel in the hot exhaust. Diesel fuel is not as flammable as petrol, so I am not sure if it can be burned inside the exhaust.

[chernaudi]

And if that's the case, could it also be hard on the engine? A 2 hour F1 race is one thing, 24 hours in another.

Edit: reading that article, it seems that Red Bull's system is very similar to the anti-lag that old F1 and WRC cars used, and it can do damage to the engine in a longer race. Not really worth if for a minor and hard to quantify gain.

[TF110]

Hard to quantify? I don't think you know what you're saying here. It gained teams about a half second per lap on tracks that were 4-5km in length. If it could be done in endurance racing, who's to say it won't gain as much or more? Teams are still doing it, even though the diffuser is single level instead of double this year in F1. It's good to see some type of innovation in F1, seeing as how it's hardly got any room left for things like this.

[Lola T70]

Originally Posted by TF110

Hard to quantify? I don't think you know what you're saying here. It gained teams about a half second per lap on tracks that were 4-5km in length. If it could be done in endurance racing, who's to say it won't gain as much or more? Teams are still doing it, even though the diffuser is single level instead of double this year in F1. It's good to see some type of innovation in F1, seeing as how it's hardly got any room left for things like this.

Not really innovation, blowing diffusers has been around for a long time, it was on most car in the early 90's.

It has too much negatives to be widely used in Sportscars I would think.

[chernaudi]

That half a second a lap isn't very useful in sportscar racing, because you can be half a second faster one lap, then lose a second or so, if not more, in traffic.

And it has to be remembered that the Red Bull system is based broadly on old F1 and WRC anti-lag, which could easily burn pistons, valves and even cook the cylinder heads in extreme cases. Hence why it was only typically used in qualifying. Peugeot lost LM last year because of connecting rod failures, which are rare and attibuted largely to the engine guys pushing too hard.

Fuel mileage and this anti-lag/blown diffuser exhaust concept can be easily tuned during a race, and burnt pistons and burnt/dropped valves are common causes of engine failure in all forms of motorsport.

With these cars, due to the concpet of having to last longer than a couple of hours to win these things and that the .5 second advantage can be erroded by traffic and can damage the cars' engines makes it of dubious value. In '09, RBR didn't have the blown diffuser that Brawn had until mid season, but were still as fast as Brawn.

I'm pretty sure that similar gains can be made elsewhere for less potential expense.

[Tim the Grey]

This is ENDURANCE racing. Anti lag throws fuel into the hot exhaust...
Think about it.

[gwyllion]

@chernaudi: Please stop making references to autosport disciplines you don't follow and technologies you don't understand.

Brawn GP was superior in the beginning of 2009 because of its double diffuser (a loophole in the rules) and Red Bull (re)introduce the blown diffuser in 2010.

Yes, retarded ignition/bang bang puts a lot of stress on the exhaust system (cilinder head, valves, manifold and pipes). However, I don't see how it would burn the engine pistons as you suggest.

[chernaudi]

I don't believe that on an endurance sportscar, the Red Bull system is very useful because of the increased temperatures it produces. I'm not sure that melting a valve or anything near the combustion point is worth it. And of course, fuel mileage can go down the drain if it's used often even if the engine doesn't go bang.

And of course, I don't follow WRC or F1, because WRC gets no NA coverage (thanks to Prodrive, as David Richards last time I checked owns the TV rights deal), and I don't follow F1 as I watch it out of boredom.

And as you said, diesel isn't as flamable as gasoline. Only variable is that the Shell GTL stuff that Audi and Peugeot have to use under the current regs doesn't seem to be conventional diesel, with the reports that once spilled, it evaporates like alcohol. But it's still diesel, and even if the evaporation story is true, it probably has a higher igniton/combustion temp.

Personally, I don't think that it's worth it because of the endurance aspect. From my reading of the article, the only time that RBR used that system was if they needed a fast lap for qualifying or maybe in a race on an emergency basis. Of course, with the blown diffuser being essentially banned in F1 by the teams assc. and it probably being illegal in LMP classes (only holes in the rear diffuser can be maintaince hatches or the air jacks), it's a moot point.

As to what we know about the 908 or the R18, there may be some resididual effects from having the exhaust blown over the diffuser airflow. However, due to the combination of a low RPM (specifically diesels), mufflers (gasoline)/particle filters (diesel) and a basically spec rear diffuser, the gains are minimal at best.

Not to mention that, this being endurance racing, that it's one more thing that can go wrong...

And speaking of the exhaust, what are the panels behind the exhaust exits made out of? Something heat resistant or just carbon?

[d.rocky]

north one television own the rights to wrc... i think.

[gwyllion]

Originally Posted by chernaudi

And speaking of the exhaust, what are the panels behind the exhaust exits made out of? Something heat resistant or just carbon?

Judging from the matt silver colour, it is most likely carbon fibre with a ceramic coating. In F1 most teams use a coating by Zircotec: http://www.zircotec.com/page/--motor...e-coatings/133

[chernaudi]

I've heard that on F1 cars that it was some type of carbon. Of course, the Audi R15 had similar outlets (let into the raised rear deck), and it seemed that they were small pieces of aluminum or carbon coated with a heat resistant material.

And I'm wondering what the motivation has been for not just Audi or Peugeot, but most Lola variants, to route the exhaust out of the rear deck? There has to be a purpose that maybe aero motivated, even if the effects may be minimal (like to direct the air flow above the cambered tail and under the wing).

Any news about the 908 from Geneva yet?

[Laurent]

Peugeot goes electric The 908 Hybrid4 may hit the track during the Le Mans Test Day...

Originally Posted by Peugeot Press release

Following the world premiere of the 908 HYbrid4 in white livery at the Geneva Motor Show, Peugeot Sport will turn its attention to meeting a target it has set for the newcomer. This is to run the car at the official pre-Le Mans 24 Hours test day at the French circuit on April 24.
Achieving this ambitious objective will depend on how well the team's preparations for Le Mans go with the new 908, and also on how the 908 HYbrid4 performs during its maiden track test at the end of March.

[gwyllion]

Originally Posted by chernaudi

I've heard that on F1 cars that it was some type of carbon.

Didn't you click on the link I posted above? In 2010 more than 70% of the F1 grid used the Zircotec solution, which is a ceramic coating sprayed onto carbon fibre.

Originally Posted by chernaudi

And I'm wondering what the motivation has been for not just Audi or Peugeot, but most Lola variants, to route the exhaust out of the rear deck? There has to be a purpose that maybe aero motivated, even if the effects may be minimal (like to direct the air flow above the cambered tail and under the wing).

Do a google search for "periscope exhaust" and you find plenty of hits. For instance http://www.grandprix.com/ft/ft00360.html describes why Ferrari introduced this exhaust configuration in 1998.

Audi motivated the choice as follows:

Short Exhaust Tail Pipes
The exhaust system mated to the Audi engine is completely new. The titanium tail pipes now emerge on the upper side of the bodywork directly behind the power unit. Shortening the tail pipes also saved weight. Furthermore, the gases are now channeled more perfectly onto the rear wing and, as a result, also have an aerodynamic function. The lighter, next generation diesel particle filters (DPF) are even more compact than those of the R10 TDI® and generate even less back pressure.

[gwyllion]

Originally Posted by Laurent

Peugeot goes electric

Most of us prefer English: http://www.peugeot-sport.com/en/endu...-hybrid4-.html

The designation HYbrid4 is very misleading because it suggest a 4WD system, i.e. electric motors powering front wheels, but this is not the case.

Hybrid system
Power: 60kW (80hp)*
* during energy delivery phases only
Delivery of recovered energy:
- To the rear wheels;
- 500kJ between two braking phases;
- Energy stored in lithium-ion batteries;
- Automatic delivery of energy under acceleration (no "push to pass" function).
It will be possible to use the electric mode only along the pit lane

BTW I love the white livery of the car. Finally a Peugeot 908 that looks nice.

[d.rocky]

it looks the dogs in that white livery.

[d.rocky]

from there fb page - http://www.facebook.com/?ref=logo#!/...18252478205270