Audi LMP1 Discussion

[MulsanneMike]

Originally Posted by MihokS5

I wonder the same thing. Can you shed some light Mike?

The wide nose on the R15 was to provide for superior crash protection well above and beyond the ACO regulation. I'm presuming this philosophy has carried through for the R18.

[MihokS5]

Originally Posted by MulsanneMike

The wide nose on the R15 was to provide for superior crash protection well above and beyond the ACO regulation. I'm presuming this philosophy has carried through for the R18.

In your opinion can the wider nose create more drag on a car? The R18's nose seems so large

[MulsanneMike]

Originally Posted by MihokS5

In your opinion can the wider nose create more drag on a car? The R18's nose seems so large

No, the nose doesn't project and effect the car's frontal area.

[Félix]

Originally Posted by MulsanneMike

The wide nose on the R15 was to provide for superior crash protection well above and beyond the ACO regulation. I'm presuming this philosophy has carried through for the R18.

On the first R15, what probably motivated the choice of two small crash structures with a gap in between was the air channel in that design. It probably made it a bit challenging to design two smaller parts that would pass the crash test. I guess being able to play around with the shape of the nosebox without re-homologating it (as long as the 2 pillars are intact) is still a big enough plus to justify keeping it. If they had drag to waste they would be able to re-use the 2009 nose slot...

[MulsanneMike]

Originally Posted by Félix

On the first R15, what probably motivated the choice of two small crash structures with a gap in between was the air channel in that design. It probably made it a bit challenging to design two smaller parts that would pass the crash test. I guess being able to play around with the shape of the nosebox without re-homologating it (as long as the 2 pillars are intact) is still a big enough plus to justify keeping it. If they had drag to waste they would be able to re-use the 2009 nose slot...

No, the air channel was secondary. The primary goal, I am told, was to improve crash protection first and foremost. And actually the two structures makes it easier to design to meet and exceed. The "standard" nose offers what ultimately is too small a cross section and therefore the front end needs to be loaded with material to achieve the require deceleration given it's short (compared to F1) length. The motivation was simply that the ACO regulations haven't been updated in a number of years. And the R15's nose was designed to not only reduce the impact to the driver, but to also limit injury to other drivers in the event of T-bone type accident. Apparently Tom Kristensen's DTM accident really got Audi thinking. I'm told, "If Timo´s car would have hit him (Kristensen) 0,5 meter closer to the center of his car he would for sure not have raced any more." Audi has sort of a history of going above and beyond the crash regulations. As an example, the Audi R8 LMP900's roll over hoop not only well exceeded the push standards of the day, it exceeds the current regulation by 2.5 times.

[gwyllion]

Over 500 pictures that George Achorn of fourtitude and Jim Fets of Audi of America toke of the Sebring test are online on http://forums.fourtitude.com/entry.p...ing-in-Sebring

There are a number of closeups of the car stationary.

[gwyllion]

According to http://www.autohebdo.fr/endurance/il...-ligne-de-mire the R18 set a lap time of 1:45.7. That is almost 1 sec faster than the pole of Sarrazin (1:46.571). Of course we don't know whether Peugeot showed the ultimate pace of the new 908. Probably not... Anyway, the R18 is rumoured to be 1.5 sec faster than the grandfathered R15.

[chernaudi]

Which seems to back up the claim that the R18 produces similar downforce numbers to what the R15 did, but with less drag (closed cockpit, optimized around the new regs rather than adapted, know-how gained from the R15, etc), and also backs up a general claim that Mike made about the R18 and the new 908 that downforce for the new cars is about the same as before, but generated more efficently.

I also wonder if the R18 is faster in a straightline than the R15 in a similar aero spec considering the R18's closed cockpit and it was built around the new regs. It should be faster in cornering because of the wider front tires and improved aero there, as well as being a bit lighter.

[MulsanneMike]

R18 to "Evolution 2" specification according to Audi PR.

"The "Evolution 2" Audi R18 is the result of the findings of previous test drives and wind tunnel testing, with a particular focus on improved aerodynamic efficiency and cooling of the interior of its V6 TDI engine. It clocked up its first test kilometers on a proving ground in Florida last week, as the 12 Hours of Sebring were held."

[gwyllion]

Audi tests next R18 evolution

BTW "cooling of the interior of its V6 TDI engine" is a synonym for "cooling of turbocharger"?

[gwyllion]

Originally Posted by gwyllion

According to http://www.autohebdo.fr/endurance/il...-ligne-de-mire the R18 set a lap time of 1:45.7. That is almost 1 sec faster than the pole of Sarrazin (1:46.571).

Duncan Dayton confirms the lap time of the R18:

The Audi R18 was testing with us after the race and was turning laps in the 1 minute, 45 second bracket, so we know they are going to be significantly faster at Le Mans.

source: http://www.highcroftracing.com/news/...dayton-qa.html

[gwyllion]

Laurent did an interview with Baretzky about the new V6 TDI engine: http://www.86400.fr/articles/147-aud...as-ete-facileq

According Baretzky there are a number of reasons why the V6 configuration was picked, but he could only disclose two reasons at this stage. I assume that the turbo in the middle might be another reason.

Firstly, they wanted a short engine in order to have enough room for the future addition of KERS.

Secondly, there is a trend in production cars to go for smaller engines, which (automatically) produce more performance per cilinder. With a 3.7 V6 engine they had the opportunity to develop solutions for dealing with high combustion pressures and run them in very tough (race) conditions. He was proud that they were able to accomplish this ambitious challenge.

He would not tell how much power the R18 engine produces, but he did say that it produces more the V10 of the R15++.

[chernaudi]

Mike is now reporting something that I brought up about the ducting in the front fenders behind the headlight bins--it's to direct hot air out of the light bins, as LED lights produce a lot of heat when used for prolonged periods.

Also, the small ducts that are covered up on the front fenders near the Michelin Man are appearntly supplmental intakes for the LEDs.

Also be prepared for more photos, as Audi Sport Press have a few of their own appearently.

[chernaudi]

Originally Posted by chernaudi

Mike is now reporting something that I brought up about the ducting in the front fenders behind the headlight bins--it's to direct hot air out of the light bins, as LED lights produce a lot of heat when used for prolonged periods.

Also, the small ducts that are covered up on the front fenders near the Michelin Man are appearntly supplmental intakes for the LEDs.

Also be prepared for more photos, as Audi Sport Press have a few of their own appearently.

Update: Quattroholic has at least some of the Audi Sport Press shots, including one (albeit not great) of the interior of the car with Dumas behind the wheel--it seems as if the R18 and the 908 share steering wheels:

http://www.quattroholic.com/2011/03/...olution-2.html

PS: appology to the mods--I thought I hit the edit button.

[chernaudi]

I just found some HQ testing photos from Audi Sport Press here:

http://www.flickr.com/photos/phunksh...7626353112200/

And are those two paddles on the steering wheel (ie, like the McLaren F1 car's wheel of a few years ago)? (view in HQ):

http://www.flickr.com/photos/phunksh...7626353112200/

It seems that the new 908, as mentioned previously, has a similar wheel setup as the R18.

[JAG]

Originally Posted by gwyllion

Duncan Dayton confirms the lap time of the R18:
source: http://www.highcroftracing.com/news/...dayton-qa.html

Amazing to think how much development manufacturers are putting into these cars to be able to match the pace of last years cars with 100+bhp less.

I guess the difference will be bigger at Le Mans but it's still impressive.

[gwyllion]

Originally Posted by chernaudi

And are those two paddles on the steering wheel (ie, like the McLaren F1 car's wheel of a few years ago)?

The extra paddle(s) might operate the clutch or the snap-on/quick release connector.

[gwyllion]

Apparently during the Sebring test the drivers were also able to sample the new car on a wet track: McNish like the R18 in the rain (autohebdo.fr)

[gwyllion]

Originally Posted by gwyllion

Apparently during the Sebring test the drivers were also able to sample the new car on a wet track: McNish like the R18 in the rain (autohebdo.fr)

Comments from McNish about the R18 in English: http://www.quattroworld.com/audi-mot...-allan-mcnish/

[chernaudi]

Originally Posted by gwyllion

The extra paddle(s) might operate the clutch or the snap-on/quick release connector.

The big rumor about the McLaren MP4-23's wheel and it's extra paddles is that they were used to increase/decrease the amount of torque/power available at the rear wheels. The MP4-23 was McLaren's '08 F1 car that Hamilton won the WDC with, and '08 was the first year of the quasi-spec McLaren/Microsoft ECU, which did away with traction control.

And ASR doesn't work efficently on diesels because diesels don't have spark plugs to cut out, so a driver adjustable system to cut or boost power and torque to the driving wheels maybe just as if not more effective, whether or not teamed with ASR.

It could also be for the rumored KERS system, but wouldn't Audi go for the Peugeot automatic system or one with a simple push button (or both types of actuation) instead of paddles to operate it?

And they're probably not to release the steering wheel--there's the anodized gold disconnect chuck behind the wheel still. And of course, the R18 and the 908 have similar wheels and look to be about the same as what most current F1 teams use.

And it will be interesting how the R18 will stack up against the 908, as Audi ran consistant mid to high 1:45s, 1:46s and low 1:47s during that test, which appearantly included an endurance phase. It's also of note that Audi didn't run the R18 in what I'd call a sprint race downforce trim (compared to the R15 and the 908), and that Allan overall seems to think that the R18 is at least slightly but noticeably better in almost all important areas, and we know how in the race the R15s at times hassled the new 908s, which may've been holding back slightly, but like in F1, I don't think that you can make up nearly a second without some moderatly major upgrades because of how close things are now.

[vyselegend]

Originally Posted by chernaudi

It could also be for the rumored KERS system, but wouldn't Audi go for the Peugeot automatic system or one with a simple push button (or both types of actuation) instead of paddles to operate it?

I believe the ACO has enforced that KERS must be continuously coupled to the throttle (no push to pass allowed), so it's not only Peugeot, but everyone running a KERS who must run it in "automatic" release mode. However I wonder to which degree they might be allowed to manage it. I suppose they can at least desactivate it if it's malfunctioning, or possibly make it release more or less power according to engine mapping (as part of the engine map program?)

I'm also impressed at the lap times of the R18 in the test. Did any speed trap figures get published? Maybe the single RW pillar setup is worth a few km/h in drag reduction.

At the Peugeot launch Famin said they hadn't had this solution on their car only because when they started its design 2011 rules were stating that two RW supports were mandatory. However he minimised the impact of it on overall performance (litteraly he said: "It won't prevent me from sleeping"). But he looked a bit tired, didn't he?

[gwyllion]

Originally Posted by chernaudi

And ASR doesn't work efficently on diesels because diesels don't have spark plugs to cut out, so a driver adjustable system to cut or boost power and torque to the driving wheels maybe just as if not more effective, whether or not teamed with ASR.

Please provide a source for this claim. Intuitively I would think that traction control is just a matter of cutting the piezoelectric injectors from injecting diesel in the engine. I don't see why this would be difficult.

Diesel powered road cars have all the electronic driving assist mechanisms (ASR, ESP, ...).

Originally Posted by chernaudi

It could also be for the rumored KERS system, but wouldn't Audi go for the Peugeot automatic system or one with a simple push button (or both types of actuation) instead of paddles to operate it?

As vyselegend pointed, the ACO rules explicitely state

The combustion engine and the electric motor must be controlled by the driver using the accelerator pedal (push to pass buttons forbidden).

I would say hand clutch (like in F1). Last year TK had issues with the foot clutch after his injury.

[gwyllion]

Originally Posted by gwyllion

Please provide a source for this claim. Intuitively I would think that traction control is just a matter of cutting the piezoelectric injectors from injecting diesel in the engine. I don't see why this would be difficult.

Diesel powered road cars have all the electronic driving assist mechanisms (ASR, ESP, ...).

BTW on http://www.totalmotorsport.com/Featu...play.asp?ID=29 you can see that even the old R10 had a dial with 9 positions for ASR/traction control.

Originally Posted by chernaudi

we know how in the race the R15s at times hassled the new 908s, which may've been holding back slightly, but like in F1, I don't think that you can make up nearly a second without some moderatly major upgrades because of how close things are now.

I would classify the new aero package that Peugeot tested in Monza, as a rather substantial change. Moreover, in the Monza test video the engine sounded different than in Sebring. So on the engine front Peugeot is also making changes.

[chernaudi]

I just hope that Peugeot isn't pushing the evelope too far like last year when a last minute change cost them. However, for Audi to be about a second faster at Sebring (a sprint race track) with a low downforce setup compared to Peugeot (who were ultimately running about 90-95% max downforce) doesn't bode well for non-LM ILMC events unless Peugeot have something in reserve, as I doubt that the new bodywork will have much use outside of LM.

Of course, we don't know if Audi are done testing the R18 (obviously they're not, but we don't know if they're done fine tuning it, which they most likely have more they'd like to do). Of course, the test at Sebring was done mostly to prove mechanical reliablity and dial in the mechanical set up. I don't think that they learned much from an aero standpoint (at least for prolonged straightline blasts like at Le Mans). So I'd expect them to test at Monza and EuroSpeedway's oval like last year. I'd also think that most of their testing at Homestead was on the 1.5 mile NASCAR oval.

Peugeot have almost a new car for LM from Sebring (almost every body panel has changed, with only the tub, suspension and basic powertrain remaining the same), and I wonder if Audi may massage more changes into the R18's LM bodywork. Although, as vyselegend said, we don't really have any data about the R18's trap speeds, though obvously for it to be about 1.5 seconds faster than the equivalent R15 (which has about 550 bhp and the Pugs weren't really any faster down the straights), it has to have more power (which Baretzky claims) and less drag (closed cockpit and not running a high downforce package as far as I know yet), and the wider tires and better optimized suspension (reduced zero keel=lower front CG?) means more grip and better braking.

Pretty much confirms what Allan says, that it's a little better in almost every area, and I'm surprised that Allan says that visibility from the car isn't that bad.

[gwyllion]

Originally Posted by chernaudi

I just hope that Peugeot isn't pushing the evelope too far like last year when a last minute change cost them.

Are you suggesting that low drag aero package is a last minute change? Yes, some of the changes are inspired by the R18, but there are a lot of preparation time before Le Mans.

Originally Posted by chernaudi

I doubt that the new bodywork will have much use outside of LM.

A lot of the new aero elements can also be used in a high downforce configuration: lower wing position, bigger end plates, NACA ducts for rear brakes, lower rear body work, new front dive plane solution, bigger head lights, ...