Audi LMP1 Discussion

[MyNameIsNigel]

Originally Posted by TF110

Diesel is way more efficient than petrol. So that's taken into account. Also it tends to come with a heavier engine. But going 8mj may mean Audi is overweight with such a large battery pack and engine. So 6mj seems the best option for now. In the future I think they'll have to downsize their diesel or forgo it altogether.

Why is it that the KTF (which factor is supposed to compensate for the diesel engine overweight) is set to 1 in the 8MJ class then ?

[chernaudi]

What about air restrictors and torque limiters in lower gears? Like in the GTE classes? Turbo and NA engines of different capacities can race well together if the Daytona 24 and the 12 Hours of Sebring is anything to go by.

Also cheaper than the fuel flow sensors being used for BOP, with the issues with the Gill sensors and the fact that Porsche are playing with the Gill sensors to fudge the system while Audi and Toyota are hoping that the alternative sensors yield more accuracy. But even then, the teams will still use something like them for telemetry reasons--even LMP2 cars use a simplified version to map fuel consumption.

[Deleted]

Originally Posted by GT6

but good to hear audi commit to wec

Reportedly, allegedly, seemingly...

[TF110]

Originally Posted by MyNameIsNigel

Why is it that the KTF (which factor is supposed to compensate for the diesel engine overweight) is set to 1 in the 8MJ class then ?

Ask the fia.

[GasperG]

Originally Posted by MyNameIsNigel

Why is it that the KTF (which factor is supposed to compensate for the diesel engine overweight) is set to 1 in the 8MJ class then ?

Again, It's obvious why there is no KTF in the top class, because it's the TOP CLASS. Weight is obviously not an issue anymore.

[MyNameIsNigel]

Originally Posted by GasperG

Again, It's obvious why there is no KTF in the top class, because it's the TOP CLASS. Weight is obviously not an issue anymore.

Well, I have to disagree. Weight is always an issue and there is no objective reason why the diesel engine overweight is not compensated anymore in the 8MJ class (which is the purpose of the KTF).

The only apparent "explanation" is that the ACO-FIA are actually balancing - technology-wise - the 8MJ petrol class with the 6MJ diesel class, which makes you wonder why there is an 8MJ diesel class in the first place...

Once again, this balancing is not very rigorous as the current rules provide no foundation for this, but merely a balancing within each and the same ERS class. This is just a demonstration that the ACO-FIA are not sticking to their own rules and original intentions, and taking some liberty to artificially play with the Appendix B figures. This is fine as long as they do not distort competition as a result.

I again believe - as I have expressed before - that the ACO-FIA would be well advised to get rid of the KTF altogether and find another way to compensate for the diesel engine overweight, like imposing some additional ballast to the petrol cars. In this way, we could at least see all competitors opt for the highest ERS option and fight with the same weapons, both technologically and from a marketing point of view.

[Ephaeton]

Originally Posted by MyNameIsNigel

I again believe - as I have expressed before - that the ACO-FIA would be well advised to get rid of the KTF altogether and find another way to compensate for the diesel engine overweight, (...)

How about not. I'd rather see a MJ amount to spend in fossil fuels, and limitless ERS.
Whether a manufacturer brings a diesel, petrol, or wood pellet steam engine or a nuclear reactor should be up to them.

[GasperG]

Originally Posted by MyNameIsNigel

The only apparent "explanation" is that the ACO-FIA are actually balancing - technology-wise - the 8MJ petrol class with the 6MJ diesel class, which makes you wonder why there is an 8MJ diesel class in the first place...

That is precisely what I meant to say, ACO-FIA found this out too late so they just adjusted KTF accordingly. There is no class to compete against 8 MJ diesel on paper if KTF would not be 1.

The fact that 8 MJ petrol cars could be a few kg lighter or could step up to 10 MJ doesn't help because it's not in the rules.

[Artur]

Originally Posted by MyNameIsNigel

So the whole balancing between the 8MJ petrol class and the 6MJ diesel class is just crap, on paper at least. The ACO/FIA are actually playing with the Appendix B figures so as to artficially balance the whole thing.

I however hope that the ACO/FIA will come up with a more "rigorous" set of rules for 2018.

That's my view too

Originally Posted by GasperG

There is no class to compete against 8 MJ diesel on paper if KTF would not be 1.

Why not? Fuel flow and energy per lap are regulated to make Diesel and Petrol engines equalised. Why would an equalised Diesel engine be unbeatable, by a Petrol, if both ran the same ERS's capacity?

[TF110]

Originally Posted by MyNameIsNigel

Well, I have to disagree. Weight is always an issue and there is no objective reason why the diesel engine overweight is not compensated anymore in the 8MJ class (which is the purpose of the KTF).

The only apparent "explanation" is that the ACO-FIA are actually balancing - technology-wise - the 8MJ petrol class with the 6MJ diesel class, which makes you wonder why there is an 8MJ diesel class in the first place...

Once again, this balancing is not very rigorous as the current rules provide no foundation for this, but merely a balancing within each and the same ERS class. This is just a demonstration that the ACO-FIA are not sticking to their own rules and original intentions, and taking some liberty to artificially play with the Appendix B figures. This is fine as long as they do not distort competition as a result.

I again believe - as I have expressed before - that the ACO-FIA would be well advised to get rid of the KTF altogether and find another way to compensate for the diesel engine overweight, like imposing some additional ballast to the petrol cars. In this way, we could at least see all competitors opt for the highest ERS option and fight with the same weapons, both technologically and from a marketing point of view.

Maybe Audi should just build a lighter engine in the future. Mazda had a lighter-weight diesel. Sure it wasn't nearly as good, but the facts are it was smaller and lighter. Audi currently run a 4L V6 turbo. Why not a smaller capacity and therefor a lighter engine? So the calls for ballasting is imo, wrong. No one forces Audi to use a heavy diesel. Just like no one forces Porsche and Toyota to use a less efficient petrol.

[CTD]

Volkswagen is using a 2L I4 Bi-turbo Diesel in the Passat producing 240BHP and 500NM.
I wouldn't be surprised to see Audi taking a 4 cylinder approach with Bi-Turbo.

[GasperG]

Originally Posted by Artur

That's my view too


Why not? Fuel flow and energy per lap are regulated to make Diesel and Petrol engines equalised. Why would an equalised Diesel engine be unbeatable, by a Petrol, if both ran the same ERS's capacity?

I don't know what's not clear here. Diesel engine gets penalised with FTF (6,6%) because of higher engine thermal efficiency. But gets back a little of that with KTF.

That is why 6 MJ diesel has advantage over 6 MJ petrol. Agree?
That is why 8 MJ diesel would have advantage over 8 MJ petrol if KTF <1.

ACO made it simple and equalised both 8 MJ classes. The only other way out of this situation would be if they introduced 10 MJ class or lowered min weight.

[MyNameIsNigel]

Originally Posted by GasperG

I don't know what's not clear here. Diesel engine gets penalised with FTF (6,6%) because of higher engine thermal efficiency. But gets back a little of that with KTF.

That is why 6 MJ diesel has advantage over 6 MJ petrol. Agree?
That is why 8 MJ diesel would have advantage over 8 MJ petrol if KTF <1.

ACO made it simple and equalised both 8 MJ classes. The only other way out of this situation would be if they introduced 10 MJ class or lowered min weight.

Nothing would actually prevent the ACO-FIA from balancing the 8MJ petrol class vs. the 8MJ diesel class. For obscure reasons, the ACO-FIA have apparently opted to balance the 8MJ petrol class with the 6MJ diesel class, even though the FTF and KTF are only applied within one and a same ERS class.

The FTF is meant to balance the different fuel efficiencies, and that's fine. The KTF is supposed to compensate for the diesel engine overweight, and that's where it's getting all messed up, because this overweight is compensated by allocating a slighting greater fuel allocation (assuming a KTF of less than 1), rather than balancing the respective "nominal" engine weights directly. That's why I believe that the ACO-FIA should opt for a different approach to compensate for the diesel engine overweight.

[chernaudi]

And it should be remembered that the 2014 919 and 2014 TS040 were somewhat overweight because of the heavy hybrid components (batteries for the 919 and supercaps for the TS040). By the start of 2015, both Porsche and Toyota shaved off enough weight that they did have to add ballast to meet the 870kg minimum weight, though Porsche did have a pretty much new car while Toyota had a development of their 2014 car.

Even now, with the TS050, TMG are claiming that their car's a bit overweight due to the switch to a forced induction engine and a battery pack.

Through out all of this, Audi have been the only ones at least claiming that their car was below minimum weight without ballast, from 2014 to present.

To me, this is like arguing why Audi stuck with electrically-operated systems until 2016 (outside of FRIC/LSS) when the Porsche and Toyota hydraulic systems were lighter (at least Audi alleges that their hydraulic systems does make for a useful weight savings over electrics)

[GasperG]

Originally Posted by MyNameIsNigel

The FTF is meant to balance the different fuel efficiencies, and that's fine. The KTF is supposed to compensate for the diesel engine overweight, and that's where it's getting all messed up, because this overweight is compensated by allocating a slighting greater fuel allocation (assuming a KTF of less than 1), rather than balancing the respective "nominal" engine weights directly. That's why I believe that the ACO-FIA should opt for a different approach to compensate for the diesel engine overweight.

How else would you compensate engine overweight? Regulations look complicated, but at the end it all comes down to min weight and fuel (flow+allocation). Obviously you can't compensate engine overweight with min weight

The big picture here is that Audi is using "only" 2.6% less fuel energy. Is that all the hybrid diesel race car can give us?

[MyNameIsNigel]

Originally Posted by GasperG

How else would you compensate engine overweight? Regulations look complicated, but at the end it all comes down to min weight and fuel (flow+allocation). Obviously you can't compensate engine overweight with min weight

The big picture here is that Audi is using "only" 2.6% less fuel energy. Is that all the hybrid diesel race car can give us?

It would be very simple actually and I have mentioned this several times before (so why not say it again ? ).

Since the KTF is estimated on the basis of the difference in weight between the best-in-class petrol engine and the best-in-class diesel engine, the regulations could simply provide that the petrol cars carry a mandatory ballast equaling that very same weight difference. In this way, the petrol cars would be faced with basically the same challenge as the diesel cars in terms of hybrid system packaging.

No need for the KTF anymore. No need to change the minimum car weight. Simple. Fair. Transparent. Balanced.

In other words, there is a very simple solution to this problem and I honestly wonder why the ACO-FIA have followed this complex and rather obscure approach which consists in compensating engine overweight through a more favorable fuel allocation to diesel cars.

[GasperG]

This would be step backwards in overall petrol car efficiency. You will never see that happen only because of that fact and I agree with it.

[MyNameIsNigel]

Originally Posted by GasperG

This would be step backwards in overall petrol car efficiency. You will never see that happen only because of that fact and I agree with it.

I have to respectfully disagree again

This would evidently mean that the petrol guys would have to work harder on saving weight in other areas in order to reach the minimum car weight but - ultimately - there would be no impact on overall engine efficiency as such.

Besides, getting rid of the KTF altogether (and imposing an "engine overweight compensation ballast") would mean a less favorable fuel allocation to the diesel cars forcing them to improve fuel efficiency even further.

[GasperG]

Well, at least we agree to disagree

Two things to consider:
- Engine efficiency - diesel has 6.6% advantage
- Car efficiency - diesel has only ~2.7% advantage because of weight and consequently lower ERS energy.

With ballast you would lower petrol car efficiency by at least ~3%. No one will take the rules in that direction even if it means simplifying or better understanding to general public.

[MyNameIsNigel]

Originally Posted by GasperG

Well, at least we agree to disagree

Two things to consider:
- Engine efficiency - diesel has 6.6% advantage
- Car efficiency - diesel has only ~2.7% advantage because of weight and consequently lower ERS energy.

With ballast you would lower petrol car efficiency by at least ~3%. No one will take the rules in that direction even if it means simplifying or better understanding to general public.

As far as fuel efficiency is concerned, I trust that we agree that the FTF properly takes that into account.

As regards what you call "car efficiency" I suspect that you are looking at the current Appendix B figures, aren't you ?

The current Appendix B figures are in essence flawed because the balance of technology is artificially created between the 8MJ petrol and the 6MJ diesel classes. Nothing would be prevent a readjustment of the Appendix B figures so as to create a proper balance between the same ERS classes in both fuel categories. That would evidently imply a further reduction of the current fuel allocation awarded to diesel cars. What would be wrong with that ?

I don't see why both fuel categories shouldn't be allowed to rely upon the same amount of energy retrieved by the hybrid system. Why is it that the diesel guys (i.e. Audi) have to use a 6MJ ERS to compete with the petrol guys running in the highest ERS class ? In effect, Audi currently have to rely upon a comparatively greater fuel allocation to compensate for the 2MJ deficit in hybrid energy. That ultimately makes Audi more exposed to further reductions in fuel energy allocations when they will come (which is inevitable).

It is just a question of redefining where the balance/equivalence of technology should be.

[GasperG]

FTF is the only measurable factor that tells you exactly where you are (BSFC measurement). All other factors are just some estimates so we can watch an interesting racing. Weight ballast for petrol would also be just that some estimate to keep thing equal under practical conditions, when conditions change we get adjustments.

I hope the rulemakers are targeting:
- same min weight
- roughly the same fuel energy (adjusted so that it stays entertaining)
- ERS power limitation (something like 400 kW)
- unlimited ERS energy - No more ERS classes

It's then your decision what will work out better, heavier more efficient engine and lighter ERS or lighter less efficient engine and heavier ERS. It's hard to pick the right concept, so with ERS classes it's a little lighter decision, but ultimately there is no need for any ERS classes, min weight defines how much ERS can you afford.

[MyNameIsNigel]

Originally Posted by GasperG

FTF is the only measurable factor that tells you exactly where you are (BSFC measurement). All other factors are just some estimates so we can watch an interesting racing. Weight ballast for petrol would also be just that some estimate to keep thing equal under practical conditions, when conditions change we get adjustments.

I hope the rulemakers are targeting:
- same min weight
- roughly the same fuel energy (adjusted so that it stays entertaining)
- ERS power limitation (something like 400 kW)
- unlimited ERS energy - No more ERS classes

It's then your decision what will work out better, heavier more efficient engine and lighter ERS or lighter less efficient engine and heavier ERS. It's hard to pick the right concept, so with ERS classes it's a little lighter decision, but ultimately there is no need for any ERS classes, min weight defines how much ERS can you afford.

I would fully agree with you if the ACO-FIA ultimately opt to ditch the current "ERS incentive" that artificially favors big hybrid systems over small hybrid systems. With the current ERS incentive in place, competitors all have to move to the highest possible (and optimal) ERS option, namely 8MJ for petrol and 6MJ for diesel.

[Deleted]

With ERS classes gone they should then also remove the artificial request for manufacturers to have hybrids in the first place. If the privateers can choose whether or not they want 'em, why cannot the works teams...

[chernaudi]

I'd argue that for all the intentions of making interesting racing and tech relevance to road cars, on one end the ERS incentive/KTF/FTF figures are meaningless. This is simply because this is a race, and the goal is to win, not have the most efficient car. Winning is what pays points and prize money, the green challenges is just a bonus.

I've never been a big fan of the fuel flow sensors. They're expensive, the Gill units are of questionable accuracy, and they're doing the same thing that air restrictors and torque sensors can do for cheaper.

Here's how I'd do things: use air restrictors to keep the cars roughly equal in top end power, use torque sensors in lower gears to keep diesel and forced induction gasoline engines from far out performing NA gasoline engines, bring back a max engine displacement limit for all fuel/induction categories. I'd also drop the fuel flow, make each ERS class roughly equal in performance to get the true pros and cons of everything.

And we all know why Audi, Porsche and Toyota are pushing for the most powerful ERS classes that they see as worth while. It's not nothing to do with efficiency, it's all about performance. Part of that is the ERS incentive, the other is that while you take a bit of a hit on fuel energy, you gain more energy and power overall in the higher classes.

As far as I'm concerned, if car makers can tie in with their road car programs in terms of tech or R&D, then good for them. But this stuff in the WEC is called racing, not an economy run.

[chernaudi]

I'm not totally against what the ACO and FIA are trying to get at, but I do think that there's better, cheaper and easier ways to do it. Improving the road car is how auto racing began, and I'm aghast at how it's often been totally turned into a pure sports entertainment spectacle, like in NASCAR and F1.

But there's always areas for improvement. I wish for 2018 that the ACO/FIA would ditch the ERS incentive, use air restrictors/torque sensors on the forced induction/diesel/hybrid cars to determine BOP (without going to the ridiculous, race to race lengths that IMSA has resorted to), make the LMP1 cars back to a max 2000mm width with the 14.5 inch wide front and rear tires, and come up with more visually appealing ways to come up with cockpit height regs.