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20 Jun 2010, 15:56 (Ref:2715113) | #76 | |
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Us outsiders tend to think that the marketing people will influence the technical decisions (e.g., comments like "Peugeot will introduce road cars with HDi hybrid engines"), but in the end it is up to the engineers.
Weight is clearly an important factor. The Porsche 997 GT3 R hybrid system weighs a hefty 125 kg and the system of the Corsa Ginetta-Zytek 09HS 85 kg. However, the system of the Peugeot 908HY weighted 65 kg, but because some other components (e.g., starter and alternator) can be removed the car only weighted 45 kg more than the regular 908; Peugeot hoped that they could get it down to 35 kg (see here). According to simulations by AMR/Prodrive the old hybrid rules with 1000 kJ energy storage (instead of the 500 kJ announced for 2011) are good for 3 sec in Le Mans. So for manufacturers it is definitely worth the investments. |
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20 Jun 2010, 16:27 (Ref:2715127) | #77 | ||
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Moving forward with P-2 rules as P-1 in 2011 the only option of a Twin Turbo diesel is a stock unit, by current rule; Art. 5.1.2c (3). There is no provision for a free disel engine in the rule. Confused? Perhaps, but only in the inconsistent and/or everchanging info coming out. They seem to change in every draft we hear about. And as Mike pointed out, this is just the latest draft (#4) and not the final rules yet, WTF is taking the ACO so long in putting a ruleset together!
L.P. |
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Probae esti in segetem sunt deteriorem datae fruges, tamen ipsae suaptae enitent |
20 Jun 2010, 17:31 (Ref:2715151) | #78 | |
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With the new regs next year to lessen the chance of yaw induced blow over, what do you think the odds of Audi or Peugeot showing up at sebring or le mans with a f-duct system?
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20 Jun 2010, 17:36 (Ref:2715154) | #79 | ||
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Well then, its a good thing that the ACO allowed a grandfather clause for 2010, which may be good news for Audi and others with newer LMP1 machinery and LMP2 cars that in the ALMS/LMS can be bumped to LMP1. However, it'll hurt Peugeot, because they may be stuck with the 908, which is at the end of it's development life, and all four DNF'ed at LM this year.
But I mean, the ACO allowing LMP2s to have larger displacement engines isn't a good sign, as well as Audi having the R18 and Peugeot the 909 at advance stages of design, but not much else because of the ACO's piddling. |
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20 Jun 2010, 17:50 (Ref:2715163) | #80 | ||
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Presumably Peugeot think not if this is their long term plan? |
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20 Jun 2010, 17:58 (Ref:2715164) | #81 | ||
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Isn't this a mistake as the ACO could potentially increase the storage capacity year on year. Ferrari also say their future V12 road car engines are only viable if combined with KERS. |
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20 Jun 2010, 18:56 (Ref:2715192) | #82 | ||
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Porsche are offering it in their 2011 Panamera.
http://www.worldcarfans.com/11006182...y-recuperation |
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20 Jun 2010, 20:10 (Ref:2715230) | #83 | |
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Not very good Ericc. That is strictly prohibited. The fin has to be a certain thickness/thiness and totally flat.
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20 Jun 2010, 21:42 (Ref:2715312) | #84 | |
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The exact description of the fin, at least of a draft version of the rules, can found at http://tentenths.com/forum/showthrea...39#post2708839
So no F-duct as TRuss said. |
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21 Jun 2010, 08:17 (Ref:2715525) | #85 | |||
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Quote:
Quote:
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21 Jun 2010, 12:56 (Ref:2715675) | #86 | |||
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Peugeot have already developed a road and race ready Diesel-Hybrid system (Road will be launched this year in the 3008, and race in the 908Hy). Audi has already thru the A1 shown a Petrol-Hybrid. Peugeot will develop a Petrol-Hybrid too, and probably Audi also a Diesel-Hybrid, but especially Peugeot has spend Development and PR resources on the Diesel-Hybrid system. Which can be seen as the Peugeot Hymotion 4. |
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21 Jun 2010, 13:28 (Ref:2715696) | #87 | ||
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Look at the Audi's press release about the Le Mans victory. They make a big fuzz about how the R15+ used VTG turbos and how this can be transformed to road cars. However, this technology has been used in production diesel engines for many years. BTW VW showed a diesel-hybrid Golf prototype in the past |
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21 Jun 2010, 13:53 (Ref:2715712) | #88 | |||
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The diesel engines I'm sure originates from the PR people, as we have only seen this development from the VAG group and PSA, and no real effort from any other manufacture. |
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21 Jun 2010, 14:13 (Ref:2715719) | #89 | |||
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and since no restrictor regulations have been posted yet there is no way to know witch will have an addvantige, but my guess would be the diesels for some idiotic reason the aco and the fia keep balancing the peak horse power insted of the area below the racing torque curve. and thats why bigger engines, or engines with turbos will have an addvantige over smaler size, or N/A engines |
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To launch a new FIA GT2 category based on strict technical rules, with limited wavers and ‘balance of performance' limited to success ballast. A category where GT manufacturers will prove through competition they can produce the best road going GT car. |
21 Jun 2010, 14:21 (Ref:2715721) | #90 | ||
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If both engine types get the same power, then a diesel engine will always have a torque advantage. So diesels have an advantage in initial acceleration. Potentially they could do with one gear less, like Audi did with the R10 and R15.
And as Paul Truswell said, there is still a lot of development potential in diesel technology. Quote:
Or maybe we have already seen the full potential of the diesel engine. This year the Audi and Peugeot were producing a lot more soot, so the engines were running closer to the limit. We just don't know... Last edited by gwyllion; 21 Jun 2010 at 14:29. |
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21 Jun 2010, 14:41 (Ref:2715726) | #91 | |||
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I can't see any advantages for Peugeot to make a switch (neither PR or performance). What i base the equal state of Petrol-Hybrid vs. Diesel-Hybrid on, is the fact that there even is talk about a Petrol-Hybrid. If a manufacture knew that there was a performance advantage in Diesel-Hybrid, a Petrol-Hybrid would be out of the question. Instead there is talk about both systems, therefor they must be seen as equal (performance wise). |
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21 Jun 2010, 14:50 (Ref:2715735) | #92 | |||
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a 5.5l petrol TwinTurbo with VTG vs a 5.5l Diesel twinTurbo with VTG and under same restrictors the petrol would eat the dieasel for breakfest and ask or more, even if the max hp were the same, although i cnt see that happening |
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To launch a new FIA GT2 category based on strict technical rules, with limited wavers and ‘balance of performance' limited to success ballast. A category where GT manufacturers will prove through competition they can produce the best road going GT car. |
21 Jun 2010, 15:14 (Ref:2715761) | #93 | |
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Sorry, but this is elementary physics: power = speed (~torque) x speed (~revs). Diesel engines don't rev. So in order to produce the same power as a petrol engine, a diesel engine needs more torque. Just look at production cars:
Also the ACO has already the highlights of the 2011 engine rules: petrol 2 liter single turbo vs diesel 3.7 liter twin turbo. So clearly diesels will retain their torque advantage. |
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21 Jun 2010, 16:06 (Ref:2715789) | #94 | |
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Here's the funny part. While the air restrictors keep engines from breathing well on the top end they do increase velocity of the intake charge increasing low end power. And as Gwyllion mentioned hp is just a number. Torque is the true measure of work. And peak hp and peak torque will never coincide. They will never happen at the same time. This is why the ACO struggles so much. Then you may ask; Why do the diesel have such high top speed as well? Well they are turbo diesels. Diesels work great with turbos because you don't have to worry about detonation. Diesels practically run on detonation. So they can really lean out the fuel mixtures, making for a much hotter exhaust which will spin those turbos even faster, making more power. I have a feeling that the Peugeots were really pushing and found the limits of that during LeMans.
I think if I were building the R18 going by my limited knowledge I would chose petrol/hybrid. I just think that it will be simpler and easier to package and make lighter weight. Which will be crucial in the early years of this. Again the extreme effeciency and torque of the electric motors will more than make up for what a diesel could produce. As the years go on the cars will become increasingly electric and the engines smaller and more effecient finally being reduced to powerful onboard generators making it even more crucial for their weight to remain low. I think a petrol engine would be best suited. But who's to say that far down the road. I will say that I'm sticking with my projection of a mostly electric car winning LeMans by 2020, maybe 2022. As far as the R18 is concerned. Only Audi and probably the ACO know what they are planning. The speculation is fun though. |
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21 Jun 2010, 16:24 (Ref:2715801) | #95 | |
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Here is how hot rodding/racing great Barney Navarro explained it to the young hot rodding masses back in the day.
http://www.jalopyjournal.com/?p=9064 |
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21 Jun 2010, 16:36 (Ref:2715817) | #96 | |||
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I know what power is and what torque is, torque by itself is mening less, more torque doesent mean a car will accelerate fasster its more complicated then that, as you put it elimentary physics, example car 1 diesel 700nm at 2500rpm, and 5000 redline, car2 gass 500nm at 4250rpm 8500 redline ***numbers quoted above are max torque, for the sake of this exmple it is asumed both cars have te same curve(proportionaly adjused for their revanges) car 2 will accelrate faster then car1 in every example, because compared to the car 1s gearing car 2 has 850 NM, so higher NM is only directly comparable if the cars havve the same gearing, and higher reving cars have a better gear ratio, simple bycicle physisce |
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To launch a new FIA GT2 category based on strict technical rules, with limited wavers and ‘balance of performance' limited to success ballast. A category where GT manufacturers will prove through competition they can produce the best road going GT car. |
21 Jun 2010, 16:52 (Ref:2715834) | #97 | ||
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Actually, the 335i is a single turbo (for 2010) and twin turbo for earlier iterations. However these figures are all bad comparisons to race cars because these road cars are limited electronically. Their boost pressure is kept down and can be turned up via ECU reflash. For example the BMW 335si makes 30 more horsepower than a regular 335i becuase of different engine mapping. |
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21 Jun 2010, 17:01 (Ref:2715840) | #98 | ||
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21 Jun 2010, 17:54 (Ref:2715891) | #99 | ||
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excelent example of my point is the 335i and 335d
even hough the diesel has 180nm more and only 20hp less it is slower to accelerate 335d accel numbers Acceleration 0 - 100 km/h (in s) 5.9 Acceleration 0 - 1,000 m (in s) 25.1 335i accel numbers Acceleration 0 - 100 km/h (in s) 5.5 Acceleration 0 - 1,000 m (in s) 24.5 reason ---it has a 3000rpm lower redline thus the petrol has more performance |
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To launch a new FIA GT2 category based on strict technical rules, with limited wavers and ‘balance of performance' limited to success ballast. A category where GT manufacturers will prove through competition they can produce the best road going GT car. |
21 Jun 2010, 18:39 (Ref:2715920) | #100 | |||
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However, the huge peak torque of diesels is good indication that they have better low end power, which is good for initial acceleration out of slow corners. That is also evident from the fact that Audi uses a 5 speed gearbox, so they loose less time shifting. Henri Pescarolo pointed out the torque advantage of diesel engines in 2006: see his open letter. Quote:
Last edited by gwyllion; 21 Jun 2010 at 18:46. |
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