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12 Jan 2018, 10:35 (Ref:3792242) | #5351 | |
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Forgive my ignorance, but what does actually mean "stint fuel"?
There will be mandatory refuel pit stop after consumed a dictated amount of fuel or basiclly toyota will get an smaller fuel tank? |
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12 Jan 2018, 11:51 (Ref:3792253) | #5352 | |
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As far as I know there is certain small amount of fuel that has to be present in fuel tank at all times. So "stint fuel" + reserve = tank size.
So yeah Toyota will have much smaller tank size. And from that fuel flow if a privater gets to the same engine efficiency they will have around 700 HP, where Toyota will have 900 HP (300 kW LeMans limit) for 26s at LeMans lap and only 500 HP the rest of the time. So they will have power advantage for only 13% of total lap time. I can see why that many privateers are in for the win tis year, but I doubt they will show consistency through the whole 24 hours, that is IMO the only advantage that Toyota has. |
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12 Jan 2018, 16:07 (Ref:3792303) | #5353 | |
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I see, it makes sense indeed:
53kg = about 71L petrol for a 75L fuel tank 44.1kg = about 59L petrol for a 62L fuel tank for porsche and toyota in 2017 35.2kg = about 47L for toyota in 2018, that let me guess that eot will give them a 50L fuel tank. Well, a considerable stint lenght cut. In a yellowless 6h race, there would be required 8 refuel at least. Anyway, as far I know, fuel for LMP1 is spec, basically the same type and same supplier for everyone.... why ACO is using "kg" as unit of measure? it's not like f1 where each engine manufacturer along to oil companies partners developes its confidential petrol mixture. In that case is logical to use kg and not liters, because 1L of petrol is much heavier than standard 0,75kg |
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12 Jan 2018, 17:06 (Ref:3792314) | #5354 | |
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That's a decent sized cut in stint length if this is true through the season. They'll (Toyota) be lucky to get 12 lap stints before refueling.
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12 Jan 2018, 17:10 (Ref:3792316) | #5355 | ||
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there is any change on the refuel time? if cars have a different tank size, refueling must the adjusted too.
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12 Jan 2018, 17:33 (Ref:3792322) | #5356 | ||
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I think that the ACO might be trying to make Toyota play the game that Audi played against Toyota in 2013 (and vice versa the year before) by trying to get Toyota to basically go faster to make up for reduced stint length. And I have little doubt right now that Toyota might still have something of a pace advantage over a stint.
That hybrid power will probably still be like the diesel power and torque and also like packing big engine or a good forced induction engine relative to the opposition in traffic. And that mapping will still give the options. One thing that this reduction in fuel tank size (since it seems to be across the board) is that it seems to make it so that everyone in a 6 hour race might have to for sure do 8 fuel stops. I can see the ACO trying to do one of two things, either let Toyota keep a pace advantage but make them have to take on more fuel later in a race to make it to the end, or roughly equalize pace and stint length. However, I don't think we can draw definitive conclusions until testing gets under way and we get info on the performance of the newer cars. We also have to think about tire use. LMP1 tires might be the same size on all the cars, but Toyota the past couple of years at least has been running 13x18" wheels, while Porsche and Audi in '16 ran 14x18", the max currently allowed. Hence, Toyota have been getting pretty good tire wear (especially Shanghai and Bahrain) with up to an inch less rubber on the road due to running narrower wheels than the other factory teams did. |
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12 Jan 2018, 20:50 (Ref:3792349) | #5357 | ||
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Looking back though the figures, it'd seem that Toyota will likely run 11-12 laps per stint with about 20% less fuel in the tank. On paper, that seems (at Le Mans, where I'm basing these figures) that the LMP1 privateers will be able to run roughly similar stint lengths at LM, as they'll lose only .1kg of fuel per stint vs Toyota's near 20% deduction that will likely cost them two laps around LM.
I know that one theory about doing tires and fuel at the same time may've been to see if the distance record could be under threat. I don't think so, not just because of how the ACO now use local yellows (slow zones) and FCYs at Le Mans, but with the increased fuel consumption for privateers and Toyota's reduced fuel tankage, we'll probably be seeing 11-12 lap stints like in 2011. Compared to 13-14 lap stints, I'm thinking at for the LM24 that teams will be seeing (notably Toyota as the benchmark example here) probably 3-4 extra stops, and doing tires and fuel with two wheel guns (vs up to now with separate fueling and tire changes and one wheel gun at a time) since tire usage restrictions will be essentially the same, I don't think much time will be saved in the pits with the extra stops and having to triple/quadruple stint by default. We'll probably see a bigger impact in the sprint races, where you'll have 8 stops (I don't know yet 8 full fuel stops or 7 stops and a splash), teams probably using their full tire allotment, and the shorter race times/distances. |
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12 Jan 2018, 21:42 (Ref:3792356) | #5358 | |
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This take into account the gains Toyota makes in efficiency yet or no? Because they will definitely improve on that year on year. Not enough to negate the loss of fuel, but achieving 11 laps shouldn't be an issue, so will they push and do 11 or ease up and make 12?
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12 Jan 2018, 21:47 (Ref:3792360) | #5359 | |||
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13 Jan 2018, 06:35 (Ref:3792412) | #5360 | ||
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edit: also I'm still not seeing how the privateers could be anywhere near the Toyotas. The non hybrids will have around 700hp, while the Toyotas will be boosting out of corners with 900-1000hp. They'll be long gone halfway throgh the straight. At LM it will be a bit closer. On top of having a massive acceleration advantage, the Toyotas will always be faster around the corners. I don't think that 45kg will negate the advantage they get from better tyres, aero and mechanical grip. So how are we supposed to see the privateers race the Toyotas? What am I missing here? Last edited by TzeiTzei; 13 Jan 2018 at 06:45. |
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13 Jan 2018, 10:51 (Ref:3792433) | #5361 | |
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Thanks for the link. If the fuel flow is actually decreased from 115 to 110 instead of raised from 100.9kg/h, than my hopes for a significant improvement in laptime for the non hybrid cars might disappear and there should be a clear gap between the Toyotas and the others. A 9% increase in fuel flow would have been worth several seconds I believe, maybe similar to what LMP2 gained from 2016 to 2017.
Now I can only hope that one if the new non hybrids uses a more efficient engine than last year's Kolles as that would still mean more power with the capped fuel flow. The cut in the stint length for the Hybrids seems to remain. |
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13 Jan 2018, 12:02 (Ref:3792444) | #5362 | |
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Are the Toyota's allowed to have more than one position on the podium?
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13 Jan 2018, 13:32 (Ref:3792460) | #5363 | ||
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As I've mentioned and one or two others have mentioned, since the EOT and performance balancing is based off of what Toyota (only current extant factory team) and Kolles (then the only existent private team in LMP1) did last year, I'd argue that there's not much incentive for Toyota to do any serious R&D work beyond making their car more user friendly or easier to drive.
EOT right now is being based off of last season's figures as the ACO were able to collect them. Which probably means though Le Mans since Kolles didn't run beyond Nurburgring last year. With that said, it's easy to assume that privateer data is limited due to only one car doing only a partial season last year. Thing also is that I doubt that Toyota are going to be able to milk enough efficiency gains to make up for any significant portion of losing 20% of their fuel tankage. Even if they make up 5%, they're still out about 15% on range, which means still probably 2 laps short around Le Mans compared to this year. And then we have hybrid power vs engine power. Combined, Toyota might have between 1000-1100 bhp between engine and hybrid. But we have to remember that nearly half of that is hybrid, and such power is temporary. The LMP1 privateers are supposed to have at least 700bhp. It'll be acceleration vs top speed, especially since the LMP1 privateers are also supposed to be a good bit lighter. |
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13 Jan 2018, 13:37 (Ref:3792463) | #5364 | ||
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About weight, I've always had concerns about private lmp1's <840kg min weight. To me none private lmp1's will reach it. And I'm not even putting in the equation aero development and michelin confidential compounds. Equivalence is pure utopy. If you ask me, this year at le mans, best lmp2 will be in low 3.24; toyota's it's about how much they wanna push.... guess they will stay in a comfortable 3.18-3.19. Don't expect anything lower but 3.22 at best for private lmp1. Happy to be wrong about last line. |
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13 Jan 2018, 14:15 (Ref:3792469) | #5365 | ||
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It's easy to forget that the Kolles car is based on a vehicle designed in 2013. It's been updated constantly, especially the last couple of years, but it's still of that vintage as far as the tub.
The newer cars have been developed seeing how the know-how and technology has developed and knowing that customers expect. As far as minimum weight, the privateers have a better opportunity to reach that than Toyota would since they don't have to lug around a hybrid system. Just the battery pack along for the Toyota weighs I don't know what, but they need a hoist to help them get it in and out of the car under normal conditions. We also have to remember that LMP1 cars in the ALMS in 2006 were ultimately allowed to weigh 860kg to try and allow them to run lap times similar to what the Audi R10s were capable of. If any of those cars were able to meet 860kg or not, I don't know conclusively, but the ACO are playing a similar game here, hoping that lighter weight will mean better cornering and quicker acceleration and matching what a factory car is capable of. And if we go back further, the Audi R8 needed nearly 130+lbs of ballast to meet 900kg when it was brand new, which is nearly 60 kg. That's 900kg minus 60, but that'd take the R8 down to 840kg, not too far away from the current 830kg of the private LMP1s. And the R8 didn't have integrated monocoque and bodywork, and several other things have have allowed teams to shave off the kilos. The Audi R10 did, but it took them until just before LM in '06 to meet 925kg with ballast, and until '08 to get well below 900kg without ballast. I don't think it's far fetched to think that at least in qualifying that the privateers can give Toyota something to think about, but we'll have to wait until the Paul Ricard Prologue before we can make accurate guesses or testing times get leaked. Also, privateers do have several concessions, such as massively relaxed limits on private testing, engine use, and wind tunnel time, among others, compared to Toyota. |
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13 Jan 2018, 14:27 (Ref:3792472) | #5366 | |
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I looked at Le Mans qualifying last year. Sector 2 is pretty handy as it's just a long straight cut with two chicanes. The ByKolles with it's wonderful Nismo engine and large fuel flow lost 3,4 seconds on that sector alone. I'm having hard time believing they lost all that time in two chicanes. The point is, while people go bananas watching the speed trap data and not seeing the hybrids on top, the fact is that the hybrids are still faster even on the straights. Weight has very little effect on straight line speeds, as that is mostly about power vs. drag at the speeds we're talking about.
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13 Jan 2018, 15:47 (Ref:3792486) | #5367 | ||
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13 Jan 2018, 15:56 (Ref:3792488) | #5368 | ||
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These are the changes from last year to this year:
LMP1H 8MJ 2017 878kg___124,9MJ/lap fuel___80,2kg/h fuel___44,1kg/stint fuel 2018 878kg___124,9MJ/lap fuel___80,2kg/h fuel___35,2kg/stint fuel LMP1 2017 833kg___157,2MJ/lap fuel___100,9kg/h fuel___53,0kg/stint fuel 2018 833kg___210,9MJ/lap fuel___110,0kg/h fuel___52,9kg/stint fuel Basically, the highlights are: *Toyota stay as is with minimum weight, MJ per lap and per hour of fuel. *Toyota will get approx. 20% smaller fuel tank for '18. *LMP1 privateer will be allowed to weight 45kgs less than the Toyota hybrids, get over 9kg/h more fuel to burn per hour, and will get a huge jump in MJ per lap for fuel. Basically, Toyota's performance numbers are the same as last year, but their stints will be almost 20% shorter (approx 2 laps around Le Mans), while LMP1 privateer get a lot more fuel to burn to try and make more engine power to try and offset Toyota's hybrid advantage. |
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13 Jan 2018, 18:09 (Ref:3792502) | #5369 | |
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That's what I thought based on the Technical Regulations I found, but tzeitzei linked a pdf ( 2017: https://www.fia.com/file/57775/download?token=zegn4sKK ) that showed different figures. I also found this file on the EoT for 2016 https://www.fia.com/file/42774/download?token=e5SiIEGz
The limits over the years from these files are: LMP1H 8MJ 2016 878kg___124,9MJ/lap fuel___80,6kg/h fuel___62,5l/stint fuel 2017 878kg___124,9MJ/lap fuel___80,2kg/h fuel___44,1kg/stint fuel 2018 878kg___124,9MJ/lap fuel___80,2kg/h fuel___35,2kg/stint fuel LMP1 2016 858kg___204,4MJ/lap fuel___110,0kg/h fuel___75,0l/stint fuel 2017 833kg___204,4MJ/lap fuel___115,0kg/h fuel___53,2kg/stint fuel 2018 833kg___210,9MJ/lap fuel___110,0kg/h fuel___52,9kg/stint fuel In 2016, the best Rebellion did a 3:26 with similar limits as in 2018, the car however was 25kg heavier. How much is that worth around Le Mans? 2 seconds just from the weight? |
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13 Jan 2018, 18:23 (Ref:3792508) | #5370 | ||
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One thing that I don't really understand is the stint deal, not what the ACO or trying to do, but the measurements. Normally, isn't fuel measured by volume rather than weight?
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13 Jan 2018, 19:34 (Ref:3792518) | #5371 | |
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Defining the stint consumption in kg is a more precise way to do it. The rules want to limit the energy from the fuel and the energy in one kg doesn't change with temperature while the energy per volume does.
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14 Jan 2018, 00:41 (Ref:3792572) | #5372 | |
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The privateers have significantly more favourable aerodynamic regulations with a lower splitter, larger diffuser, larger diveplanes, and larger rear wing so I wouldn't assume Toyota has an advantage there.
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14 Jan 2018, 04:34 (Ref:3792609) | #5373 | ||
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It's pretty logical to drop some fuel allowance for the Toyota because they're much more efficient. So they will try their best to improve there to make a possible 12 lap stint. That should be around what the private teams do. Kolles was capable of doing a 3:21 but didn't get a clear lap. This will be their second year with the new Nismo engine so it should be much more familiar to them. The only piece of the puzzle left is Rebellion. |
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14 Jan 2018, 05:16 (Ref:3792613) | #5374 | |
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14 Jan 2018, 11:53 (Ref:3792644) | #5375 | |
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What's the fastest laptime of a non hybrid car around Le Mans in the last ten years and under what set of regulations (weight, fuel limits) was it set?
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