2011 Sebring Audi R-15's (thread currently closed)

[Victor_RO]

Originally Posted by Lola T70

However...

Originally Posted by MulsanneMike

I don't see any connection between the wide tires I presumed Audi tested on the R15+ and the R18 diffuser. Why would Audi go to the design trouble of retrofitting the R18 diffuser onto a car they never intended it to race, just because it fits around the wide tires? Let's over look the fact it's designed for a completely different aero package.

I can fix their problem with the current R15+ diffuser with an angle grinder, a cutoff wheel, and about 10 minutes.

It makes a LOT more sense for the R18's test bed to be the R18 itself.

[Lola T70]

I was just answering Tim the Grey's question.

I agree as per my previous post you cannot just put bits from one car onto another.

[Victor_RO]

Originally Posted by Lola T70

I was just answering Tim the Grey's question.

I agree as per my previous post you cannot just put bits from one car onto another.

I was just making a point about that post not being accurate.

[chernaudi]

Pruett said that the R15 would test various bits of the R18 on it (almost all of which have to do with the wide tires) as well as the wider tires themselves. Only big variable is that the R15 makes quite a bit more power now than the R18, and is an open cockpit car. With the R15 having to be modified to run with less engine power, that variable is eliminated.

And of course, the R15 parentage can't be denied in the same way that one can't deny the R8's influence on the R10(and that apparently the R8 influenced the R18 under the skin, but that's another story).

Of course, Audi's PR on the R18 hasn't mentioned jack and you know what about any of the major details on the R18 aside from the engine and why the closed cockpit was chosen this time around. And there was only a passing mention of the R15 and no explanation of what the "plus plus" means.

However, at the same time, Pruett thus far has only said that the most major change on the R15 will be the suspension changes to accomodated the wider wheels and tires, and he hasn't hinted at much else, though obvously there'll have to be bodywork changes for much the same reasons.

We probably won't know anything about the "new" R15 for quite a while, as it seems that inspite of it being obsocent with the new regs, Audi is in no big hurry to get the R15 out there like they were with the R18.

[Tim the Grey]

Nope, I don't see anything there to confirm the R15 is testing R18 components. Merely trying wider fronts on an R15, which MMike mentioned at least a year ago as a distinct possibility, due to the bolt on wheelarch panels.

This MAY then give them baseline data from a known car to refer back to R18 as it tests prior to first race. I don't see that ANYTHING off an R18 will, in itself, be used on an R18!

[cmk]

Some of this discussion boils down to semantics. If you believe that the wider front tyres Michelin has designed for 2011 are an R18 component, then they will test R18 components on the R15. If you don't consider that to be the case, then it's likely that they won't (maybe the odd common suspension piece?). We could go around in circles about this for days...

[chernaudi]

It seems that the new tires are an R18 oriented item (that the Pug 90X probably also share), which means that if they're going to run them on the R15 at Sebring, they're at the very least going to have to modify the suspension.

As I mentioned, we probably won't see the R15 in '11 configuration anytime very soon, and spy photos of the R18 will be more likely now.

Of course, Audi can just mount the nose of the R18 on the R15, but due to bodywork differences (the channel between the crash structures being deeper on the R15, among other demensional differences) pretty much precludes that solution.

[gwyllion]

Originally Posted by chernaudi

Of course, Audi can just mount the nose of the R18 on the R15, but due to bodywork differences (the channel between the crash structures being deeper on the R15, among other demensional differences) pretty much precludes that solution.

The R18 is probably also designed for different target aero numbers (less drag, so probably also less frontal downforce).

[Tim the Grey]

Do you really believe that Audi can just 'bolt on' an R18 front end onto an R15?
At teh very least this hybrid would have to be crash tested before it's allowed to race.

For what would be, at best, limited data.

The cars at Sebring will be full R15s. They will likely run wider tyres. On wider front rims. This MAY involve fitting some R18 suspension parts onto the R15. Assuming they will fit the older chassis in the first place.

Your interpretation of Mr Pruett, IMHO, is not making sense.

[chernaudi]

Audi will obviously will have to do something to the nose of the R15 to make the wider tires work, aside from the wider wheel clearence bulges. As on the Acura, Audi will have to do something to get the aero balance back due to having an extra inch of wheel and rubber being mounted inboard where the diffuser is.

Here's the solutions that I can see Audi doing:

1--mount the R18's diffuser, which is designed for the wider front tires, on the R15's crash sturcture, if the mounting points are the same.

2--run more aggressive dive planes to get the areo grip/balance back.

3--hope that the wider fronts produce enough mechanical grip that any areo losses are canceled out.

Since Audi is using at least one old R15 as a test bed for the R18, using some of the bodywork designed around the wider front tires will obviously be done. But since Audi has only mentioned the re-revised R15's only in passing, we don't know what they'll do with them. Until someone can get a spy shot of the R15 in action testing the new tires and whatever else Audi feels that the R15 needs at Sebring, all that can be done is speculation.

I just can't see Audi throwing away Sebring, as it's an ILMC round, and they'll likely be at a big enough straight-line speed disadvantage (air restrictors) to give up anything else.

[chernaudi]

Depending on how you read it, there might not be a ton that Audi can do to the R15 unless they get permission from the ACO--at Planet Le Mans, the cars must run in 2010 configuration, and unless otherwise indicated, can only change the fuel capacity and air restrictor sizes/turbocharger boost.

It'll be interesting how that'll play out if the ACO will let Audi make any modifications to the R15 for the wider front tires, unless Audi has submitted their proposed changes to the ACO to have them homolgated by the Oct 31st deadline that was floated about. Here's the passage at PLM in question:

In 2011 the Automobile Club de l’Ouest will also accept 2010 cars. These cars must run in their 2010 specification and are only accepted if they ran in at least one Automobile Club de l’Ouest-sanctioned race in 2010. The only changes made to the 2010-spec cars are modifications to the engine for the new air restrictors and the fitting of smaller (75 l) fuel tanks.

[MulsanneMike]

Originally Posted by chernaudi

Audi will obviously will have to do something to the nose of the R15 to make the wider tires work, aside from the wider wheel clearence bulges. As on the Acura, Audi will have to do something to get the aero balance back due to having an extra inch of wheel and rubber being mounted inboard where the diffuser is.

Here's the solutions that I can see Audi doing:

1--mount the R18's diffuser, which is designed for the wider front tires, on the R15's crash sturcture, if the mounting points are the same.

2--run more aggressive dive planes to get the areo grip/balance back.

3--hope that the wider fronts produce enough mechanical grip that any areo losses are canceled out.

Since Audi is using at least one old R15 as a test bed for the R18, using some of the bodywork designed around the wider front tires will obviously be done. But since Audi has only mentioned the re-revised R15's only in passing, we don't know what they'll do with them. Until someone can get a spy shot of the R15 in action testing the new tires and whatever else Audi feels that the R15 needs at Sebring, all that can be done is speculation.

I just can't see Audi throwing away Sebring, as it's an ILMC round, and they'll likely be at a big enough straight-line speed disadvantage (air restrictors) to give up anything else.

As stated adnasuem, the R18's front diffuser is only relevant to the R18. I'm pretty sure the R15+'s front diffuser took advantage of the 2010 only addendum to 3.5.4, thus the R18's diffuser is even less relevant: completely different flow fields coming off the different diffusers given the different lengths. Hell, the inboard profile of the front fenders is different, I don't see any way to interface the R18 diffuser onto the R15. And I don't see why they'd want to do that, the R18 is designed for lower downforce and drag. Sebring is a pile-on-as-much-as-you-can downforce track after all.

[chernaudi]

Could Audi tack on R18 dive planes on an R15 nose if that's the case? If anything, given the LM "tabs" shown on the presentation car, the R18's high downforce package might be fairly aggressive in terms of downforce.

But than again, Audi can pile on more downforce for the same amount of drag compared to the R18 if it was an open car.

The only issue I'd have with R18's diffuser is that it's a ground effect item. Ground effects reduce drag by getting rid of wings, dive planes, gurneys, et al. However, at LM, ground effect cars struggled until they got the brute horsepower to deal with them.

Who knows, maybe the R15 will run it's own diffuser based off of the Acura's, or maybe the R18's, but whatever Audi does, unless they see Sebring as a throw-away deal and decide to "points race", they'll have to do something to restore the front areo balance, seeing as Sebring is a downforce track, while at the same time doing it in respect to the wider front tires.

Which takes us back to the little thing I added about ACO homologation. 2010 cars have to run to their basic format to be grandfathered without further restrictions. The only caveat there is that the ACO it seemed did allow teams to submit homologation proposals to the ACO until Oct 31st. Whether or not anyone did that is unknown, but if Audi had anything significant to offer up for the R15, they probably submitted it before then, as obviously the plans to run wider fronts on the R15 festered for quite a while before that rumor broke along with the plans for the R18 and the 90X to use similar wheels and tires.

[Tim the Grey]

Or, they have taken the pragmatic decision that they cannot adequately test the R18 BEFORE Sebring, so why not run a proven race FINISHING package, to grab what points they can, while they can?

That seems to be a 'no-brainer' from here.

I come from an age when new F1 cars would come in at the start of the European season, and last years 'known' cars would go to flyaways. Seems to me, Audi are doing exactly that. LOADS of spares, lying around anyway, so it's a cheap win-win...

[TF110]

Perhaps Audi will get away with the R15++ being a new car altogether, at least new enough. Maybe. Not saying for sure, but maybe they can convince the ACO not to make it so they have to run the exact same car.

[Lola T70]

Originally Posted by chernaudi

Audi will obviously will have to do something to the nose of the R15 to make the wider tires work, aside from the wider wheel clearence bulges.

I just can't see Audi throwing away Sebring, as it's an ILMC round, and they'll likely be at a big enough straight-line speed disadvantage (air restrictors) to give up anything else.

Audi were quite happy to throw Spa away last year running Le Mans downforce so what makes you think Sebring with an old car that is restricted will be any different?

Personally I think the only changes will be dictated by ACO.

[chernaudi]

Originally Posted by TF110

Perhaps Audi will get away with the R15++ being a new car altogether, at least new enough. Maybe. Not saying for sure, but maybe they can convince the ACO not to make it so they have to run the exact same car.

Depends on if Audi sent the ACO the homogation papers, and if the ACO signed off on it, even though we all know that the ACO has tended to back up factory teams more than privateers in recent years.

Depending on what Audi wanted to do, I have no worries if Audi filed the paperwork properly and it got in the ACO's in hands in time.

Still, that leaves us no closer to any offical answers. Pruett said that the R15 running wider front tires at Sebring is a definite given, but aside from obvious suspension changes, he hasn't really hinted at much else. And of course, no one from Audi Sport has been talking, given what little we know about their new "baby", the R18.

[Lola T70]

Originally Posted by chernaudi

Still, that leaves us no closer to any offical answers. Pruett said that the R15 running wider front tires at Sebring is a definite given, but aside from obvious suspension changes, he hasn't really hinted at much else. And of course, no one from Audi Sport has been talking, given what little we know about their new "baby", the R18.

Any reason that I am missing suggesting Pruett actually "knows" something on R15++ and not pure speculation?

[pdxracefan]

Well, I am not going to weigh in on something that I don't know a hell of alot about, I am just damn glad that Audi is actually coming to Sebring. I don't really care what they are bringing, but I'll bet it will be competitive, if not a winner. I mean Sebring is not an aero track, but just one where you bring the fastest car that can last 12 hours on that track. That's it, nothing more. Plus, I really missed them last year.

[gwyllion]

We can stop speculating because according to http://www.mulsannescorner.com/newsnov10.html

Upon further inquiry, we understand that in fact no changes will be allowed to be made at all to the Audi R15 other than changes in order to equalize it's performance to the new 2011 cars; therefore, only changes to the inlet restrictor (smaller), boost (reduced), and fuel cell (reduced). Don't expect wide tires, R18 front suspension, or any R18 aero bits.

[porsche91722]

This may be a good move on Audi's part. Although running a knackered R15+, this should give them a pretty good indication as to how far off the pace they are from their main opposition, and where they have to go with the R18 before it's debut. After all, showing their cards early, as they did with the R15 at Sebring, really didn't help them over the long run.

[chernaudi]

Depending on how much faster or slower the 90X is compared to the "equalized" R15, Audi may throw away a win at Sebring in order not to sacrifice the R18, or may be hoping that the 90X has the same early reliability problems that the 905 and 908 had.

Unless the cars are truly "equalized", Audi has little chance of winning Sebring unless the new Pugs have trouble, which reliable LMP2's (and LMP1's) have had gitches that have cost them races in the past.

The only advantages that Audi will have is more torque (larger engine) and if Sebring is held to IMSA sporting regs, faster stops with the open car. As well as the fact that the R15 should be at least reliable.

[Acid09]

It seems to me that Audi has not learned their lesson from 2009 and is showing up at Le Mans with a poorly raced new car again.

Peugeot is doing exactly the right thing, who cares if the 90X has a hard time at Sebring, the weaknesses found there will make the car stronger at Le Mans - where it counts.

[Plex]

I must say i was very surprised to see the R15 + coming to race at Sebring 2011 instead of the R18.

Audi should have race one R18 as a test and see how it performs.

Sebring is the best test and to find out if the car has any problems. That track is brutal..But the truth comes out.

[joeb]

I wonder if audi would be running the r18 at Sebring if they found an american partner to run the r15 in the alms.