Audi LMP1 Discussion

[joeb]

Originally Posted by chernaudi

Since the Sebring test started yesterday, does anyone think that the R18 or the 908 can run 1:44-1:46 lap times? The Lola Aston Martin ran a 1:50 yesterday, and LMP2s ran 1:45s in qualifying in 2007, and one or two of the Porsche RS Spyders that year ran a 1:46 in the race.

Are we effectivly back to 2007 laptimes now with the power reductions, or do the diesels (grandfathered or new) have an advantage with the wider tires (newer cars) and huge reserves of torque?

I think it is definitely possible to see 1:45's. I would also expect the dyson and Cytosport times to fall once q'ing starts next month in "hopefully" warmer weather. I am really interested in seeing how the new LMP1's compare to the grandfathered cars on q'ing day as well.

[chernaudi]

Dagys from Speed reports that the R18 won't be at Sebring for the race in part due to a parts shortage--again, shows that Peugeot by having a 3-4 month head start means that the 908 will be ready earlier.

And that means that even if the R18 has the reliablity and speed to challenge the 908 (neither of which is a fully known quanity, as Audi has had only one major endurance test at Sebring, and times mentioned on the ALMS fan forum by who knows who and how he got those times), Audi is taking the safe way out, like with the R15 last year, which was due to many of the same issues (endurance testing and spares shortages).

Better to score points/possibly win with a proven car with a spares reserve than to race a car that even with proven reliablity and speed, but with a parts shortage and straining logistics as a result--and Audi themselves said that logisitics was a major part of the decision to run the R15 at Sebring.

[Lola T70]

Originally Posted by chernaudi

Dagys from Speed reports that the R18 won't be at Sebring for the race in part due to a parts shortage--again, shows that Peugeot by having a 3-4 month head start means that the 908 will be ready earlier.

I do not think Audi ever said they were going suggesting it was never planned as per 2010.

[chernaudi]

Audi didn't even get a 2010 R15 built up and tested in any form until a few weeks before Sebring last year. And Audi only launched the R18 in November. When Audi sent out the R8 and R10, luck played a bit of a role, in that they had a somewhat rushed but successful test program with no major snags.

With the R15, Audi had a horrid test program in '09, hence why they're doing a lot of testing in the US right now, so weather won't interupt their program.

And even if Audi knew that the first tests of the R18 would be as successful as they seem to have been and duplicate or improve those results, it would still be a long shot to make Sebring. And I bet if the new 908 had started testing a couple of months after it did, Peugeot would likely be in the same boat, again due to logisitcs, namely a lack or worry of a lack of spare parts.

What Audi is banking on is that the R18 will have a highly successful endurance and performance test run before the LM test, which by then if anything needs to be changed, they'll have a stockpile of parts for all their cars. Only reason that Peugeot can bet on that now is that the 908 has been testing since 3-4 months prior to the R18 starting to do the same, and even their test program was delayed briefly because of one of their cars being destroyed and lack of spares to revert to.

Hence, Audi knew that logistics were their biggest enemy, and instead of rushing to fight it, enter cars that are proven and may have a resonable chance for a good result and not rush the R18 into battle unproven, and with a shortage of spares even if it's speed and reliablity is proven.

[chernaudi]

An another though that goes back to a though that Mike had about the R18 and it's front brake cooling.

It was though that the cutouts inboard of the bottom of the headlight cluster could've been supplementary brake ducting. However, could the intake on the nose be for brake ducting (as unlikely as it is) or to cool something else, such as the power steering pump/motor or for the AC system?

And since we can't see the front brake ducts in head on shots, could they be narrow in width but tall like what F1 cars run or what the Acura ran, or could they be fed by excess air from under the front diffuser, or could they be fed by air as is comes over the diffuser?

Obviously, it gets it's front brake cooling somewhere, but with the front bodywork so low, we can't for sure see what's going on, and I kind of wonder if the air as it goes though the front of the car can "see" the ducting effiectently. Of course, wind tunnel and real life testing should tell Audi if their solution is effective or not, as in volume, the ducting will probably admit air in the same volume as the R10 and R15's, ducting systems did, or the old/new 908.

[Tim the Grey]

If you look carfeully, you will note the wheels are handed, so they likely have an air extraction system built into them. I have no idea if it sucks, or blows, but no doubt your usual full analysis will confirm this?
It pretty much negates any need for specific ducting, as you have already spotted.

[chernaudi]

Problem is that the wheel spokes have the same issues that normal turbochargers do with turbo lag and engine power--you'll need high speed for the best effect. Just as turbos function best as high engine RPM, the wheels need to spin at a very high RPM to extract the air at their full capacity. To do that, you'll need a long straight, something that outside of LM and a few circuits can't entirely be counted on.

And I noted in a close up photo that it seems that there's an extension on the diffuser just inboard of the wheel well fairing. Is it for aero (as a cut-out device on the Acura ARX-02 was believed to be for), or is it to channel air to the brake duct, or both or neither?

Look between the diffuser arch and the wheel well. There seems to be some ramp-like device that extends back further than the diffuser TE:

http://www.ultimatecarpage.com/forum...6&d=1292009482

At least with the 908 we know that the brake cooling architecture is similar to the old car, due to the similar front end aero package. With the R18, things are blurry, because Audi has done a good job of staging their photos to keep certian bits of the car obscured, and even though the basic aero concept up front is derived from the '10 R15, there are noticeable differences, namely with the body being mounted so much lower due to a lowered tub.

I wonder if those extensions on where the diffuser/wheel well join has a purpose, and if so, what does it do?

[gwyllion]

Originally Posted by chernaudi

Look between the diffuser arch and the wheel well. There seems to be some ramp-like device that extends back further than the diffuser TE:

http://www.ultimatecarpage.com/forum...6&d=1292009482

Sorry, that link does not work for me. Apparently you need to login, but I don't have an account...

[chernaudi]

It's on Ultimatecarpage's forums in their multimedia secton. I don't know if you'll need a log in or not, but Pieter from UCP sometimes frequents here.

But if you can't get the link to work, may I pose an alternative:

http://www.flickr.com/photos/audiusa...7625445912021/

Whatever it is, it seems to go beyond the front diffuser trailing edge, and looks to either be some aero device to divert air somewhere, as I don't think that it's simply part of where the mold was made, as the R18's diffuser is a machined aluminum casting like the R15's. And even if it was, if it doesn't serve a worthwhile purpose, why have it?

And as for the R18's V6, which seems to be more likely, as we have no definite info on it, for the cylinder angle or crank arrangement:

The only two possiblilites now is a 90 degree oddfiring V6, either with or without a ballancer shaft (split journal cranks tend to be weaker than a normal 120 degree crank), or a 120 degree V6.

60 degrees is ruled out due to CG reasons and if the R18 is running turbos within the V, 60 is too narrow for that packaging.

90 degrees means that the engine can made using cut down (but heavily modified) castings for the V12 and V10 engines, but a 90 degree V6 isn't well ballanced as far as it's firing order without a split journal crank or a balancer shaft. Such an engine also has a low CG.

120 means a balanced firing order, and lower CG, and plenty of room for the rumored turbos within the V arrangment. However, compleltly new castings would be needed, though that's little less of an inconvience than with the 90, as a new casting (different bore/stroke, just to name one factor) would practically be needed, as all Audi LMP engines are stress mounted to the chassis and are desinged around chassis requirements (and the same with the chassis as it relates to the engine).

[gwyllion]

Originally Posted by chernaudi

The only two possiblilites now is a 90 degree oddfiring V6, either with or without a ballancer shaft (split journal cranks tend to be weaker than a normal 120 degree crank), or a 120 degree V6.

Diesel engines don't rev so the V angle is not that important. Peugeot has shown this with their 100° V12. You can see on http://en.wikipedia.org/wiki/V6_engine#Other_angles that a lot of other V angles have/can been used; e.g. Honda RA168-E was a turbocharged 80° V6.

Anyway, Marshall Pruett thinks that it will be a 120° V6 with single turbo. See http://auto-racing.speedtv.com/artic...he-audi-r18/P2

[TerribleWone]

Originally Posted by gwyllion

Diesel engines don't rev so the V angle is not that important. Peugeot has shown this with their 100° V12. [/url]

Thats not a good example as a V12 will always be balanced regardless of the angle.

[gwyllion]

Kristensen on the R18: http://www.autohebdo.fr/endurance/le...otre-audi-r18-

His comments are similar to those of the Peugeot drivers: a big power loss with the smaller engine, but higher cornering speed (better balance and more mechanical grip) and later braking. The visibility is a lot worse compared to an open car, especially because of the wider front tyres and the straight wind shield; the driver seat is lower and further back compared to the R15.

[chernaudi]

Problem is that Peugeot is in the same boat, as the cockpit on the new 908 is clearly modeled on the old car, and depending on where the camera on the onboards were mounted, the old Pug had good forward visibility, but the rest of the issues were probably no better than the old Bentley GTPs.

Even at that, the old Bentley had a shorter tub with the driver sitting slightly further back than in the R8 of the same period to optimize weight distribution.

Hardly unique, and seems to be a problem endemic of the closed cars, period, as you have a roof and windows, while with the open cars you have nothing but the restraint bodywork built into the cockpit.

One big difference between the old and new 908s is that the newer car run wider front wheels and tires, and will probably have similar issues, and that the R18 runs a curved windshield, where as the 908 has a flat windshield, and I wonder if that make much of a difference.

And anyone notice that part of the drivers' right hand headrest seems to be glued to the R18's door window?

[gwyllion]

Originally Posted by chernaudi

One big difference between the old and new 908s is that the newer car run wider front wheels and tires, and will probably have similar issues, and that the R18 runs a curved windshield, where as the 908 has a flat windshield, and I wonder if that make much of a difference.

According to Davidson (see here) the visibility of the new 908 has improved.

It is very different from the old 908 despite its resemblance, there are so many details that make it completely new, with a new chassis, a new driving position to better see the sides even if the vision of the front is reduced, and definitely a huge evolution from that of last year.

[chernaudi]

Even with what AD said, it seems that Peugeot have had to compromise front visibility to see out the sides, which with the head restraints and the HANS is basically useless, and not a good decision as they're running wider front wheels and tires.

The Acura ARX-02 had no roof, and some drivers complained about visibility unless they looked straight ahead because of the larger wheelwells. Of course, good mirrors can help with side visibility, and what of the old camera system that Corvette used to run? I did notice that the new 908 has some type of monitor on it's dash beside the steering wheel.

But this is the price that Audi and Peugeot have chosen to pay in favor/exchange for performance at Le Mans and elsewhere, as the reduced drag should allow them to run more downforce in the sprint races, and even at Le Mans.

Both cars will have similar issues with visibility, and are probably similar to the old Bentley GTP, because of similar design principals combined with both cars having a narrower tub then the Bentley, and both cars having the driving positions further back than in an open car.

Makes one wonder if the Lola LMPs have had similar issues, and what the differences between the closed and open cars are.

[Lola T70]

Originally Posted by chernaudi

Both cars will have similar issues with visibility, and are probably similar to the old Bentley GTP, because of similar design principals combined with both cars having a narrower tub then the Bentley, and both cars having the driving positions further back than in an open car.

The Bentley and closed cars of that time were designed to a different set of regulations regarding cockpit sizes and so I would not compare them.

[gwyllion]

Originally Posted by chernaudi

The Acura ARX-02 had no roof, and some drivers complained about visibility unless they looked straight ahead because of the larger wheelwells. Of course, good mirrors can help with side visibility, and what of the old camera system that Corvette used to run? I did notice that the new 908 has some type of monitor on it's dash beside the steering wheel.

Rear view mirrors don't help the driver to see how far the car is from the kerbs in a corner.

I don't think that the screen on http://www.endurance-info.com/versio...le908_Prez.jpg is a rear view camera, probably some diagnostics screen.

[Victor_RO]

Originally Posted by gwyllion

I don't think that the screen on http://www.endurance-info.com/versio...le908_Prez.jpg is a rear view camera, probably some diagnostics screen.

Looks like the screen that was on the old 908's steering wheel. So it's safe to assume it'll have the same functions.


As for rear view cameras in LMPs, it's not unheard of. Mike Newton has talked a few times in interviews on Radio Le Mans about various image-processing software that was being used on the closed RML Lola's rear-view camera.

[CTD]

Originally Posted by Victor_RO

Looks like the screen that was on the old 908's steering wheel. So it's safe to assume it'll have the same functions.


As for rear view cameras in LMPs, it's not unheard of. Mike Newton has talked a few times in interviews on Radio Le Mans about various image-processing software that was being used on the closed RML Lola's rear-view camera.

Corvette used it in the Gt1 cars, and probably also in the GT2's

[Victor_RO]

Originally Posted by CTD

Corvette used it in the Gt1 cars, and probably also in the GT2's

I thought we were talking about rear-view cameras in LMP cars.

[CTD]

Originally Posted by Victor_RO

I thought we were talking about rear-view cameras in LMP cars.

We were, but just mentioned it to make it more plausible that LMP teams have and will use it

[gwyllion]

Originally Posted by Victor_RO

As for rear view cameras in LMPs, it's not unheard of. Mike Newton has talked a few times in interviews on Radio Le Mans about various image-processing software that was being used on the closed RML Lola's rear-view camera.

The system is briefly explained on http://www.rml-adgroup.com/technolog...orkvideo01.htm

A second camera, fitted below the rear wing and linked directly to a monitor on the dashboard offers the drivers an unobstructed live rearward view, and is a valuable aid as they negotiate traffic on track. Images from this camera are also recorded and can be appraised later by the drivers.

[chernaudi]

This is why I'm hoping that some interior photos of the R18 will show up soon. However, Audi has had better success at not being papped like Peugeot was at Monza a few months back, an nothing has emerged from the testing photos that have been gleaned from the Audi that's out of the norm from the press photos.

[gwyllion]

One picture of the 90X taken at Monza showed up on autosport.com and Peugeot released a few pictures. James Boone posted some pictures on Flickr of Audi's Sebring test and Audi followed by release its own pictures. I fail to see the difference.

[vyselegend]

Originally Posted by chernaudi

Dagys from Speed reports that the R18 won't be at Sebring for the race in part due to a parts shortage--again, shows that Peugeot by having a 3-4 month head start means that the 908 will be ready earlier.

And that means that even if the R18 has the reliablity and speed to challenge the 908 (neither of which is a fully known quanity, as Audi has had only one major endurance test at Sebring, and times mentioned on the ALMS fan forum by who knows who and how he got those times), Audi is taking the safe way out, like with the R15 last year, which was due to many of the same issues (endurance testing and spares shortages).

Better to score points/possibly win with a proven car with a spares reserve than to race a car that even with proven reliablity and speed, but with a parts shortage and straining logistics as a result--and Audi themselves said that logisitics was a major part of the decision to run the R15 at Sebring.

Then what about Aston Martin, coming at Sebring with their new car, which (AFAIK) hasn't yet put a wheel on a track?

I think Audi are audacious in their approach of the new regs, with a totally new concept, whilst Peugeot look terribly conservative with their design. But the way Audi approach the race lacks bravery, it's disapointing. Although last year was worse.

Once again, if Aston can have their new car race ready for Sebring, Audi has no excuse IMO. But I'm still enjoying their presence and look forward to what they can achieve with the R15.