Audi LMP1 Discussion

[Mal]

Originally Posted by chernaudi

Some one on Fourtitude admitted to seeing an Audi Sport trailer driving south on a highway in the direction of south Florida month in a half ago. Either it was to move equipment, or Audi did something at either Sebring or some other south Florida racing circuit. They could've tested an R18, R15, R8 GT3 or a Lamborhini GT2 car for all we know--Audi has tested R8s at Sebring before. It couldn't just be transportation of equipment unless Audi have rented a barn, unused aircraft hangar or some large storage facility at or near Sebring.

And does anyone know if anyone can just rent an unused barn or aircraft hangar at Sebring for storage?

And on your point, why do NA engines that suck in the same air but are of different capacities still have the larger engine making more torque? Turbo engines can't be immune to displacement differences.

I am sure I read they would be testing at Homestead as well.

[gwyllion]

Originally Posted by chernaudi

And on your point, why do NA engines that suck in the same air but are of different capacities still have the larger engine making more torque?

That is elementary physics. For a given number of revolutions per minute, a engine with larger displacement sucks more air and hence produces more torque.

However, the ACO does not regulate the amount of torque that different engine configuration makes. They only care about the power that engines produce. This is where the air restrictor comes in place. The restrictor chokes the air and hence restricts how high an engine can rev. Remember power = torque x rotational speed (see wikipedia).

If you look at the technical regulations of LMP and GT, you see that smaller engines get a bigger air restrictor and as such they can rev higher. Look for instance at 2 LMP2 engines for this year:

• Judd HK (BMW derived): 3.6 liter -> 2 x 29.6 mm air restrictor
• Nismo VK45DE: 4.5 liter -> 2 x 28.3 mm air restrictor

Originally Posted by chernaudi

Turbo engines can't be immune to displacement differences.

And yet from a power/torque perspective, there is no difference. All turbocharged engines get the same air restrictor, so they can rev equally high, and a higher turbo boost compensates for a smaller displacement.

Clearly there are other factors that play a role, e.g., turbo lag, fuel consumption, drivability, ... For instance, one of the reasons why Audi and Peugeot went for maximum displacement with their previous diesel engines, is that engine compenents have to be stronger/heavier in case of a higher turbo boost.

[Lola T70]

I have an extreme headache now by reading all these fictional facts based on pure speculation and hearsay.

Please keep some sort of short answered reality into the posts......Please

[chernaudi]

Speaking of engine specs, it's obvious why Audi went with the 6 speed gearbox that the R18 has, and it's not because the 908 had one.

With about 550-600ft/lbs of torque, a 6 speed should be capable of handling that--the Corvette C6R made those numbers, as did the Audi R8. So there should be no worries there. But since the R15 has to make do with a 5 speed, what would Audi have to do there? Gear it like the R18, with 1st=2nd, et al, since Audi with the R8's 6 speed typically made it like a 5 speed, with first being used to get on and off pit road.

Under the rules, that could be the R15's biggest stumbling block compared to an up to speed R18--having more gears means more adjustability and flexibility with gearing, and in theory, better accelleration. That is unless Audi uses the R15's five speed as an actual 5 speed, instead of it being the usual 4+1 speed (with gears 2-5 seeing actual use most of the time, aside from to get on and off pit road).

However, I did hear a theory that Audi may've had an advantage with the 5 speed in the R10 and R15--less shifts and less power flow interuptions. But we don't know how Audi plans on gearing the R15, let alone the R18, since we haven't had any R18 onboard. However, I'll bet it'll probably be like the R8: 5+1, with first being used to get on and off pit road or from a dead stop.

[Lola T70]

Originally Posted by chernaudi

Speaking of engine specs, it's obvious why Audi went with the 6 speed gearbox that the R18 has, and it's not because the 908 had one.

With about 550-600ft/lbs of torque, a 6 speed should be capable of handling that--the Corvette C6R made those numbers, as did the Audi R8. So there should be no worries there. But since the R15 has to make do with a 5 speed, what would Audi have to do there? Gear it like the R18, with 1st=2nd, et al, since Audi with the R8's 6 speed typically made it like a 5 speed, with first being used to get on and off pit road.

Under the rules, that could be the R15's biggest stumbling block compared to an up to speed R18--having more gears means more adjustability and flexibility with gearing, and in theory, better accelleration. That is unless Audi uses the R15's five speed as an actual 5 speed, instead of it being the usual 4+1 speed (with gears 2-5 seeing actual use most of the time, aside from to get on and off pit road).

However, I did hear a theory that Audi may've had an advantage with the 5 speed in the R10 and R15--less shifts and less power flow interuptions. But we don't know how Audi plans on gearing the R15, let alone the R18, since we haven't had any R18 onboard. However, I'll bet it'll probably be like the R8: 5+1, with first being used to get on and off pit road or from a dead stop.

Gear usage and ratios are changed track to track and also in traffic and in R15 case I am sure 1st will be used at the hairpin at Sebring anyway as the drivers have done in the past.

I am completely sure the R15 "biggest stumbling block" at Sebring is not having a 5 speed gearbox.

[Lola T70]

Originally Posted by chernaudi

I have little worry about the R18 being up to speed soon, but if this is a possible hint that the ACO may've messed up their own equivlancly formula, it's an embarassment on the ACO's part, as you'll need a diesel to race competitivly--let alone outrun--the theoretically obsolescent old LMP1s. And the ACO don't want the newer cars to be shown up by old ones.

.

Whaaaaaattttt, you cannot honestly suggest the ACO have made a mistake on their grandfathered car equilivency formula based on one man, with a camera, no stop watch and no information on test programmes, who by chance saw a 2010 car overtaking a 2011 car in a closed test 2 months before the first race?????

Are you seriously suggesting this?

[chernaudi]

No, since we don't have a 100% reliable comparison yet. But if a developed R18 is slower than a "crippled" R15, it's not a good sign. Especially as the ACO don't want to see any pre-LM sandbagging like in years past.

Big problem is that the ACO want the cars to all perform within a 2% window. Problem is that at LM, 2% in laptime=about 5 seconds. At Sebring, that's perhaps a 2-3 second window.

The ACO got the equivlancy "wrong" in the past: to beat the Audi R8, you needed a turbo engine, a much lighter car usually with a turbo engine, or a big 6 liter engine. The diesels, especially at Le Mans have enjoyed a huge advantage. One can say that the ACO's rules have been tilted towards forced induction engines for the better part of the last 15 years, be it gas or diesel. And who have run forced induction engines in the past? Audi and Peugeot--big factory teams.

The ACO will always bend to the will of the manufacturers, no matter what. If the factories pushed for the new regs, the ACO will make sure that the newer cars are favored. Otherwise, there'll be a massive protest against the ACO by the factory teams.

Right now, we only have limited information, but if the R15 proves to be faster than the 90x at Sebring--which on paper, performance should in theory be similar--then everyone will be glad that Audi has no plans to sell R15's to a factory supported privateer team that can get the job done. And right now, there is a slight chance that the older cars will be at least as fast as the newer machinery that the ACO seems to actually favor.

[Lola T70]

Originally Posted by chernaudi

No, since we don't have a 100% reliable comparison yet. But if a developed R18 is slower than a "crippled" R15, it's not a good sign. Especially as the ACO don't want to see any pre-LM sandbagging like in years past.

Please, how do you know that an R18 is slower than a "crippled R15"?

[chernaudi]

Originally Posted by Lola T70

Gear usage and ratios are changed track to track and also in traffic and in R15 case I am sure 1st will be used at the hairpin at Sebring anyway as the drivers have done in the past.

I am completely sure the R15 "biggest stumbling block" at Sebring is not having a 5 speed gearbox.

Since '07, Audi has used 2nd out of the hairpin at Sebring, and have done so the whole of the R15's existance.

The issue of 5 vs 6 here is one of putting the power down, as each time a gear change is made, the time it takes from the paddle being pulled to the sequence of the shift without lift taking over, the clutch disengaging, the next gear being selected and engaged, and the cutch being re-engaged full thottle operation being resumed only takes about .15-.2 of a second. But that split second means no power going to the rear wheels, and the resultant jolt of everything coming back in force.

In the rain, a five speed will have an edge over a six, as there is less gear changes to be required, which means fewer power interuptions and power kicking back in a split second later.

However, the six is more adjustable, and it depends on power and torque of the engine and the circuit. That being said, the R18 have one more gear in some situlations can hurt it as much as help it, the same going for the R15 as well.

It's all a compormise, though Audi's tendancy to use first gear as little as possible means fewer shifts and fewer of the split second power and drive interruptions and less wheel spin, especially out of slower corners.

And if Audi has a problem with the R18's gearbox, it's not like it's something that can't be quickly fixed, as it seems that it has the next best thing to the R8's quick change rear end. That said, when it comes to ratio changes, I think that the R15 and R10 cassette gear cluster method will be tidier. But for a rebuild, I'll bet that Audi will have a quicker time with the R18.

But then again, we do need someone to speak for the modular nature of the R18 to see if it's as true as rumored.

[Lola T70]

Originally Posted by chernaudi

Since '07, Audi has used 2nd out of the hairpin at Sebring, and have done so the whole of the R15's existance.

The issue of 5 vs 6 here is one of putting the power down, as each time a gear change is made, the time it takes from the paddle being pulled to the sequence of the shift without lift taking over, the clutch disengaging, the next gear being selected and engaged, and the cutch being re-engaged full thottle operation being resumed only takes about .15-.2 of a second. But that split second means no power going to the rear wheels, and the resultant jolt of everything coming back in force.

.

www.youtube.com/watch?v=uL-P0cr_Aek - 1st gear is being used.

Gear changes now take about 40 milleseconds, not .015 of a second as it would be in a stick shift.

Can you answer my previous questions of how do you know that an R18 is slower than a "crippled R15" and are you suggesting the ACO formula is wrong based on a person who saw a car pass another in a closed test 2 months before the first race?

[broadrun96]

And does one test really make the R18 a developed product? I would assume the R15 could put in consistent and probably faster times the first day worth of testing, even with the new restrictors in place. The whole point of the on track time at Sebring is to decrease the lap times by testing the limits of the car without beating it into too many pieces, not something easily done during the race. At least without other teams whining on about a rolling road block when it breaks.

[Old Boone]

MihokS5 - I couldn't really tell.

Audi Racer - There's a hint of exhaust noise coming out of the corners when you're directly behind the car. From the front of the car, I could hear the engine accelerating and possibly a hint of turbo whine but it wasn't as loud as the R15. This will be a very difficult car to hear during a full race.

I know everyone likes to make speculations on the new car but you guys have to keep in mind that I was only able to see the car between turns 7 & 10 (the only spots that are viewable from public areas) and I could see the top half of the car going into the straight between 6 & 7. I have NO IDEA what the cars were doing outside of those corners. I never once saw the prototypes running very close to one another. There's a chance they were driving the R18s cautiously when they were close to the R15s and letting it pass on the opposite side of the track since it's a more developed car.

[chernaudi]

One endurance test won't develop a car much in terms of speed (as that seems to not be the aim), but one would expect since the R15 and the R18 have the same torque and power specs on paper that performance, at least not withstanding other variables (5 speed vs 6 speed, open car vs closed, LM aero vs ALMS aero), that the performance would be broadly similar.

All we have are third party observations from an area of the track where torque and accelleration are important. Either Audi were conservative with the R18 and they were letting the R15 by when it was on hot laps, or the R15 is, at least currently, faster, at least in that area of the track.

The issue is if similar observations are made following the 12 Hours, by which time the R18 should have a lot more testing done, let alone if the Pug 90X gets it's rear handed to it by the R15s in the race.

If that happens from a speed standpoint, then I think the point can be made that the ACO didn't slow the older care enough. However, there is still a possiblitity that it can happen, as how many times have we seen on paper that something should happen, but doesn't happen in practice?

And to prove that since '07 or '08 that Audi has used 2nd in the hairpin/turn 7, here's an onboard of the R15 that won Sebring in '09: http://www.youtube.com/watch?v=xu6k72hzmgU

[Senna-F1God]

Is it just me or the front end is running a "bit" high...?

I bet Audi has gone totally wrong with its fourcorner reartyre´s design, and I have a strong sensation that they are having issues with the suspension setup, and even more worrying: balance problems.

If the R15 is fast enought to lap the R18, then the new Audi must have a critic problem.

Since the only successful (balanced) example of that design was the Acura LMP1 ARX-02a, one has to wonder how on earth will Audi bring its V6 TDI weight down to the LM-AR7´s 130 kg to make that concept "work"... aka adding enough ballast on the nose cone &/or diffuser.

I mean, the weight bias in the R18 is completely wrong...

[MulsanneMike]

Originally Posted by Senna-F1God

Is it just me or the front end is running a "bit" high...?

Car's accelerating hard out of the hairpin; squatting on the rear.

[The Badger]

Originally Posted by Audi Racer

Any thoughts on the exhuast note of the audi R18.

I heard it is supposed to be quiter than the R15 !!!!

[Senna-F1God]

Originally Posted by MulsanneMike

Car's accelerating hard out of the hairpin; squatting on the rear.

To make a fair comparison:





Same level of development there...

All this reminds me again of the waste of money and resources the ARX-02a project was... a chassis that is suited to the new regs as no other, with the lighter Honda LMP2 engine on its back, it would blow the Diesels away... at least at Sebring.

Instead Nick went the LMP2=>LMP1 route... with the LC75 crap. Definetively he wasted the last drop of his brightness in the ARX-02a, his F1 was even worst than the GP2-F1 Dallara...

[fiend540]

How is a car that is going on 3 years old at the same level of development as one that has NEVER ran a race? The amount of speculation in this thread is pretty ridiculous,and is getting pretty tiresome.

[Lola T70]

Originally Posted by Senna-F1God

To make a fair comparison:





Same level of development there...

All this reminds me again of the waste of money and resources the ARX-02a project was... a chassis that is suited to the new regs as no other, with the lighter Honda LMP2 engine on its back, it would blow the Diesels away... at least at Sebring.

Instead Nick went the LMP2=>LMP1 route... with the LC75 crap. Definetively he wasted the last drop of his brightness in the ARX-02a, his F1 was even worst than the GP2-F1 Dallara...

All that from a single picture?

[chernaudi]

The tires themselves have little bearing on a car's WD, in fact, with teams running more compact engines, some suspect that the newer cars may infact be nose heavy, at least very close to 50/50 WD front and rear, which makes the wider front tires make some sense at least.

The problem that Acura had is that HPD didn't do as Audi and Peugeot have done and pay for the purpose built front tires. Audi and Peugeot are using front tires designed to do the job from the box. All LMPs, and all cars for that matter, have weight shift due to velocity changes. It's a law of physics, and the R18 and R15 in those photos are traveling at too low a speed for the areo to push the nose down with the air enteracting with the bodywork and the diffuser.

Also, the R18's at Sebring seem to be in an LM aero spec, and are basically new cars. The R15 is in HD sprint trim. Also, the R18 has had fairly little testing, while the R15 is a couple of years old.

Wait a few more weeks and we'll probably have a fairer comparision.

[chernaudi]

On an R18 note in the recent photos, does it seem that the drivers are sitting really low in the R18 compared to the R15, or is it the roof making it seem that way?

It just seems that a lot of stuff on the R18 is lower than the R15--the rear wing for sure is in the R18's current spec, and the sidepods seem to be lower as well.

And then there's the snorkel for the airbox. I don't think that we can judge the number of turbo chargers from the size--it looks small for two, but big for one, but it could be two because of the ram air effect at high speeds. Could Audi be running two small VTGs for engine response and tuneablitliy? Ala the Ferrari 126C series: http://www.gurneyflap.com/Resources/JAN244418.jpg

Of course, such an arragmement may make for interesting exhaust routing, especially with two turbos.

[Bentley03]

Originally Posted by fiend540

The amount of speculation in this thread is pretty ridiculous........

I'd say the nature of the speculation, rather than the quantity. Much of it verges on the hilarious.

[chernaudi]

And that's one of the problems. Audi being mum on the R18 (understandable, as it is a new car and they want to minimize the time/ability of Peugeot/AMR to build in some of the R18's better parts into their cars), but I think them being quiet on the R15--an obsolsecent car that'll likely on do one more race, is a bit daft.

It doesn't help that there are plenty or rumors, seemingly gleaned from Audi Sport personel, about the R18's mechanical layout. The turbos mounted within the engine's V isn't new--Ferrari did it on the 126 F1 cars, and BMW have a 4.4 V8 with a similar layout now. And then there's the rumors of and R8-like QC gearbox. All will be out in due time obviously, but April and May is seemingly an eternity away. Just be glad that I'm not a Twilight Saga fangirl--they have to wait until November to see Breaking Dawn on screen.

All we have is stuff gleaned from rumors, "facts" from Audi personel speaking off the record, and photos of LM spec R18s at Sebring.

However, in those photos, namely the ones that show the cockpit, it does seem to me that the drivers have to scrunched into the car's cockpit with shoehorns and plungers, and that the seem to be sitting lower in the cars than the older open LMPs, like the R10 and R15.

I'm wondering if it's a fact (which is why I wish that Pruett's article about the drivers' impressions of the R18 was published already), or an illusion due to the R18 being RHD, due solely to the roof.

And I'm wondering about the turbo arragement, judging by the size of the roof snorkel. As I said, it looks a little small possibly to be for two, compared to the size of one of the R15's or 908's turbo intakes. However, combined, it looks to be about the size of both of the R8/R10's and the '03 Bentley's twin intakes combined. So it could be one or two, but we have no definitive proof on that number aside from what's gone in the past. I'll bet that the Pug might have a similar layout for it's turbos, owning it's roof intake. Then again, the EXP Speed 8 had a roof intake, as did the Toyota GT-One, and those had a conventional turbo layout.

And if it has turbos within the V of the engine, I wonder what the exhaust pipe layout would look like, as the demo/press shots have a single, large triangular exit below the rear wing mount pylon. Of course, routing the exhaust over the gearbox casing, and all of those electronics, can be a nightmare unless they have some good heat sheilding, and we gotta consider the packaging of the particle filters/cat. converters, which we certinaly don't know.

One thing I think we can all agree on is that the R18 wasn't riding any higher than normal. On breaking, the front end droops--hence the skids on the front diffusers. And there is a transfer of weight under accelleration. I believe that having tested and raced at Sebring for years, Audi know what they're doing and what they're trying to aim for right now.

And, as Kristen Stewart alluded to when she talked about her refusal to talk about her lovelife, when one question gets answered, it seems that about 10 more take its place. It may sound like name dropping, but it's true. Like the rumors about the R18's engine--why the possible turbo layout? And then there was a reference on James' photos of the R18 that suggested it looked rather small.

Well, if Mike's CAD measurements are accurate--and they usually are very accurate--The R18 is only slightly smaller than the R15--the almost 7 inches chopped out of the wheelbase compared to the R15 is made up for somewhat by the R18's front and rear overhangs being longer.

[JAG]

Originally Posted by Senna-F1God

Same level of development there...

All this reminds me again of the waste of money and resources the ARX-02a project was... a chassis that is suited to the new regs as no other, with the lighter Honda LMP2 engine on its back, it would blow the Diesels away... at least at Sebring.

Instead Nick went the LMP2=>LMP1 route... with the LC75 crap. Definetively he wasted the last drop of his brightness in the ARX-02a, his F1 was even worst than the GP2-F1 Dallara...

The ARX-01 is being used as a development base for the 2012 coupe and could incorporate thinking from ARX-02a, nobody knows for sure.

From what I've read at least some of the reasoning for not using the ARX-02a is due to parts availability.

[JAG]

On the ALMS forum someone said the R18 did a 1.44.