[WEC] LMP Future Regulations (was Le Mans EVO rules - now hypercar rules)

[TF110]

Originally Posted by Spyderman

775Kg was only in the beginning. The ACO quickly and steadily increased the weight of the RS Spyder until by 2008 the car weighed 825KG. After that (2009) the ACO introduced new restrictor rules that reduced the power ot 440 hp (from original 503). A real shame.

Yes, I know. That's why I said a few years ago. And mentioned the R10 in ALMS. The point I'm making is it's not unfathomable that the new LMP1's could go below 850kg, especially seeing as how back in 2007 there were LMP2 cars below the 800kg mark.

[deggis]

RS Spyder had only one source of power though. (Not disagreeing that the 2014 weight could have been kept lower.)

[Fogelhund]

Originally Posted by TF110

A little power help? How do you not understand what I'm saying? They aren't quite as powerful now as they were.

Ok, your previous post made it sound like the Spyders had some special BoP help to allow them to keep up with the R10s, which was absolutely not the case.

[TF110]

I don't see how you came to that conclusion. It wasn't just the Porsche that was as fast as the Audi. The P2 HPD (Acura) was up there with it. If they want LMP's to be more efficient, lessening the weight is the easiest route. Oh well.

[Fogelhund]

Originally Posted by TF110

I don't see how you came to that conclusion. It wasn't just the Porsche that was as fast as the Audi. The P2 HPD (Acura) was up there with it. If they want LMP's to be more efficient, lessening the weight is the easiest route. Oh well.

I don't know if perhaps you weren't around at the time, of have forgotten the sequence of events.

The ACO built the LMP1 and LMP2 rules and Porsche took a look at them, and realized that at most circuits, a LMP2 car was as quick as a LMP1 car. Acura realized this as well. When Porsche went to the ALMS to enter, the ALMS agreed to keep rules stability for a few years. The ACO realized after a year of the Porsche Spyder competing very well against the R10, that they had made an error in the rules, and subsequently penalized the LMP2 category to prevent this from happening in the future. The ALMS had an agreement with Porsche, and did not implement these changes until one or two more seasons. The ALMS followed the original ACO rules to the T, it's just that the ACO screwed them up, and Porsche realized this and took advantage. Efficiency wasn't as important then.

[TF110]

I got the ALMS past in memory, there's no need to discuss it.

The talk is pointless, I'm just disappointed with the direction the ACO took with the future cars weight. 850kg is IMO 'heavy' for non hybrid cars, and the P2's from those days give an indication that an even lower weight can be done. I'm speaking nothing about their efficiency. Just making a little note that lesser weight goes in hand with improved fuel economy.

[deggis]

Likely it was the manufacturers who wanted to raise the weight. So, actually we shouldn't blame ACO for raising the weight but bending over once again infront of the manufacturers.

Altought ACO might like more weight so that it's easier to keep speeds down and might be cheaper for privateers (if privateers are going to exist at all).

[Fogelhund]

I can recall some discussion about the difficult of getting the Diesels down to weight, which could have contributed to the increases of weights. I agree that lower weights should have been the direction.

[joeb]

Originally Posted by Fogelhund

I can recall some discussion about the difficult of getting the Diesels down to weight, which could have contributed to the increases of weights. I agree that lower weights should have been the direction.

I thought the Etron has an unballasted weight around 800kg, can't seem to find the link though.

[Fogelhund]

Originally Posted by joeb

I thought the Etron has an unballasted weight around 800kg, can't seem to find the link though.

I'm thinking back to the R10 and the first Pug.

[deggis]

Yes, iirc "coincidentally" the min weight increased to 925 kg and then was eventually later reduced back to 900 kg.

[gregtummer]

I think the Audi R18 Ultra weighed 750kgs without ballast. I don't know how much of that extra weight they would need to balance the car.

[TF110]

Originally Posted by gregtummer

I think the Audi R18 Ultra weighed 750kgs without ballast. I don't know how much of that extra weight they would need to balance the car.

It was a manufacturer that suggested the low weight of below 800kg. Peugeot I think it was! And yes the R18 Ultra can go very low in weight. So with a smaller slimmer car, lighter is not unreasonable. I think it was Audi that may have been the one to reject that low weight. It was discussed in this very thread.

[gwyllion]

In a nutshell. At first Aston Martin and Audi were in favour of lowering the minimum weight as a means to improve the efficiency, but Peugeot was against this choice. However, in the end Audi changed their mind and they chose the heavier, hybrid route.

[hondafan37]

Originally Posted by TF110

It was a manufacturer that suggested the low weight of below 800kg. Peugeot I think it was! And yes the R18 Ultra can go very low in weight. So with a smaller slimmer car, lighter is not unreasonable. I think it was Audi that may have been the one to reject that low weight. It was discussed in this very thread.

Carlsson made a Mercedes SLK with 780 kg. so this weight does not appear to be a problem for a prototype.
http://www.racecar-engineering.com/n...off-in-geveva/
I think this car is faster than LMP2 and GT500. I would like to see in the ALMS in a special class.

[MyNameIsNigel]

Just read the article about fuel flow sensors ("Let it flow") in the latest issue of Racecar Engineering. Very interesting stuff. No wonder the 2014 rules have yet to be finalized.

Interesting comment about Audi "complaining" that the size of the fuel flow sensor compromises the work already undertaken in the monocoque of its 2014 car. Audi apparently have concerns with the size and overall package of the three sensors (and three connectors) that are stipulated by the regulations.

Also interesting to note that Gill Sensors apparently still have some work to do to ensure the same level of sensor accuracy for diesel fuel as they can apparently achieve with petrol (+/- 0.25% according to Gill Sensors).

[gwyllion]

Judging from the comment of Litjens in the April 2013 edition of RCE, Toyota was really against a lower minimum weight for 2014:

If you make it too light, with the pick up and dirt during the race, you throw away the bodywork at the end of the race.
For 2014 it will be far more critical with the 870 kg weight limit. It was very early in the discussion to go to 750 kg minimum weight, but if you do that, you say goodbye to hybrid systems. We are still at the bottom of the curve with hybrid systems, so it was too early.

source: http://gb.zinio.com/reader.jsp?issn=0961-1096&p=30

[TF110]

With hybrid sytems... The whole thing is about efficiency, they don't need a huge hybrid system. The rules of having them is just for manufacturers to tout they have a hybrid racing. That's why he says "you can say goodbye to the hybrid systems". IMO it's sad and kind of gimmicky, but that's what the road relevance is about- hybrid power and efficiency of the fuel.

[hondafan37]

A question for the experts in aerodynamics.
Suppose you want to run with a Ferrari 458, Porsche 918, McLaren MP4/12 or some similar mid engine car into LMP1. Then make a carbon fiber chassis to be 900 kg or less. Also put tires and suspensions of P1 cars and we also made an engine with the power of this category. Then the difference would be only the aerodynamic.
How much time we lose in 1 lap over a real P1?
How much time is lost in Le Mans? and how much on other tracks with more curves?
What extra power is needed to recover this time?

[Machin]

Suppose you want to run with a Ferrari 458, Porsche 918, McLaren MP4/12 or some similar mid engine car into LMP1. Then make a carbon fiber chassis to be 900 kg or less. Also put tires and suspensions of P1 cars and we also made an engine with the power of this category. Then the difference would be only the aerodynamic.
How much time we lose in 1 lap over a real P1?
How much time is lost in Le Mans? and how much on other tracks with more curves?
What extra power is needed to recover this time?

Interesting question; and just the sort of thing that caused me to write my "Virtual Stopwatch" program which I've put online for others to use (HERE).

Windtunnel data from Racecar Engineering magazine suggests that the F458 with a GT3 bodykit has a similar drag coefficient to an LMP1 car.. so the main difference is the downforce; an LMP1 being much higher, so high speed cornering speeds will be higher in the real LMP1... A quick and dirty simulation suggests that the difference in downforce would account for about 8 to 10 seconds per lap at Le Mans.

Looking back over last year's Le Mans results this would seem to be about right; the fastest GTE-Pro cars were losing about 5 seconds through the Porsche curves, but only a few tenths through the slower T6, T7 and the Ford Chicane (qualifying times HERE, page 15 for the cornering speeds/times).

How much power is needed to make up for this? Well to make up for the time in the corners you need to reach a higher top speed on the straights, but because power absorbed is related to speed^3, you need a lot more power to make up for that time.... my calculations suggest an engine output somewhere in the region of 600 to 640bhp would be required (compared to the privateer LMP1's power output in the region of 520bhp) to get the same overall lap time...

[TF110]

You could do something like the Super GT route. They're already faster than LMP2 cars with the aero freedom they have. But they're 200kg heavier.

[hondafan37]

Originally Posted by Machin

Interesting question; and just the sort of thing that caused me to write my "Virtual Stopwatch" program which I've put online for others to use (HERE).

Windtunnel data from Racecar Engineering magazine suggests that the F458 with a GT3 bodykit has a similar drag coefficient to an LMP1 car.. so the main difference is the downforce; an LMP1 being much higher, so high speed cornering speeds will be higher in the real LMP1... A quick and dirty simulation suggests that the difference in downforce would account for about 8 to 10 seconds per lap at Le Mans.

Looking back over last year's Le Mans results this would seem to be about right; the fastest GTE-Pro cars were losing about 5 seconds through the Porsche curves, but only a few tenths through the slower T6, T7 and the Ford Chicane (qualifying times HERE, page 15 for the cornering speeds/times).

How much power is needed to make up for this? Well to make up for the time in the corners you need to reach a higher top speed on the straights, but because power absorbed is related to speed^3, you need a lot more power to make up for that time.... my calculations suggest an engine output somewhere in the region of 600 to 640bhp would be required (compared to the privateer LMP1's power output in the region of 520bhp) to get the same overall lap time...

Thank you very much for your reply. So you believe that a GT with LMP1 settings will be 8 to 10 seconds slower in Le Mans.
According to the qualifying times, there were 33 seconds gap between LMP1 and GTE. Therefore a GT with LMP1 settings should be 23 to 25 seconds faster than a GTE

[hondafan37]

Originally Posted by TF110

You could do something like the Super GT route. They're already faster than LMP2 cars with the aero freedom they have. But they're 200kg heavier.

It is very interesting topic of SuperGT because besides the 200 kg overweight I believe they also have 100 HP less.
Then what would happen if we equate the terms with LMP1?

[chernaudi]

Super GT run roughly the same power as most LMP1s, because they run the same basic engines (the Honda uses the HPD LMP1 engine and the Lexus uses the same basic engine that TMG sells to Rebellion), just that the ACO spec engines use air restrictors to limit power vs rev limiters in Super GT, but that's the only notable difference.

That extra 100+bhp allows the Super GT GT500 cars to be faster down the straights than LMP2s, and it showed at Fuji last year, where the Super GT pole and LMP2 pole and race laps were very similar.

[TF110]

Originally Posted by chernaudi

Super GT run roughly the same power as most LMP1s, because they run the same basic engines (the Honda uses the HPD LMP1 engine and the Lexus uses the same basic engine that TMG sells to Rebellion), just that the ACO spec engines use air restrictors to limit power vs rev limiters in Super GT, but that's the only notable difference.

That extra 100+bhp allows the Super GT GT500 cars to be faster down the straights than LMP2s, and it showed at Fuji last year, where the Super GT pole and LMP2 pole and race laps were very similar.

You're wrong. The GT500 cars use air restrictors as well. Super GT just has better aero, and according to Nakajima they run softer tires.