Questions for mathematicians / stats experts - fuel saving

[wsn03]

Anyone who's good with numbers:

If you had an LMP1 privateer, not sure what they'd be, but say 5 secs per lap slower than the factory cars?
What happens overall if they're 14% more fuel efficient than everything else - i.e. overall would they be ahead? I don't know the numbers in terms of how long fuel stops take, how many they would save etc.

I guess the same question goes for that privateer vs other similar privateers - ie how far ahead would they be after 24hrs with similar level competition (asking this one because the way things are going there may not be factories LMP1s in the near future)?

Finally, does GTO pro allow mods to fuel systems, or do the cars have to be stock? And can a privateer team enter PRO, or is it just factories?

[eps]

Interesting question...

How many laps per tank? So how long is a 'normal' stint? 8 laps? Maybe more with Hybrid

I guess we're discounting mechanical or driver issues...

Then there's the tyre deg... Would a set of tyres last 1 or 2 more laps per 'stint'... They seem to triple or have even quadruple stinted them.

ETA : Some facts and figures from 2015 https://newsroom.porsche.com/en/motorsports/le-man...

[Mellow Yellow]

Based on the Porsche figures from the link, the private car would do one extra lap per tank, so 14 rather than 13. Over the race distance, the faster LMP car would make 30 stops, the more efficient car only 28. At around 1 minute for a fuel-only stop, that'd save two minutes. But the faster car is gaining 5s per lap, over 395 laps that's half an hour.

[wsn03]

Thank you for the answers. Based on your answers Mellow Yellow the 14% fuel saving isn't going to make much difference unless the car is more or less on a par with the factory cars, my brain is fuzzy but less than a second a lap would have to be achieved. I really thought a 14% fuel saving would have made a substantial difference.


Anyone have an answer to my 2nd question - are GT Pros allowed fuel system changes, or stock only.
Do they have to be factory cars, or can they be private entry?

[FredericRobinson]

Don't know about the fuel systems question, but they can be private entries - like the Risi car

[wsn03]

FredericRobinson said:

Don't know about the fuel systems question, but they can be private entries - like the Risi car

Thanks, I didn't know that, I thought only AM could be private.

So final question - what mods are allowed, does it stretch to fuel systems?

[RL17]

Does seem surprising how fuel efficiency doesn't have more impact. Toyotas in 2016 were on 28 or so stops compared to a 30 stop for Porsches - the 14% margin might get down to 26 or 27.

If you add long run in to pits with chicane and pit lane speed and getting back up to speed it must add 15 seconds or so (1km at 50kmph v say 200kmph (both ave speeds probably low)) it still only saves 5 mins for 4 stops compared to the 30 mins plus the 5 seconds a lap saves.

The LMP1 factory cars also get the acceleration gains (electric motors etc) out of the corners so can overtake much easier after turn exits - looking at the start of the start/finish straight this year they could overtake really easily as all the others were accelerating more slowly and overtake much quicker and back on line. Rather than relying on longer overtakes at higher speeds or into corners/turns which are trickier when more cars involved as shown by some of the LMP2/GTE incidents. Lots of time overtaking 3 or so cars at a time after slower turns.

Reckon that during the race they (LMP1 factory teams) have a practical lap time advantage of more than the 5 seconds or so of the fastest lap or qualifying times might indicate

[rdjohn]

wsn03 said:

So final question - what mods are allowed, does it stretch to fuel systems?

Fuel tank capacity

Mini 50 litres / Maxi 90 litres can be adjusted with BOP

It will be a sanctioned race fuel cell, rather than standard kit

[VladD]

wsn03 said:

FredericRobinson said:

Don't know about the fuel systems question, but they can be private entries - like the Risi car

Thanks, I didn't know that, I thought only AM could be private.

So final question - what mods are allowed, does it stretch to fuel systems?

Modifications wise, Porsche turned the engine round in the 911 to make it mid-engined instead of rear. I'm not a big fan of 911s normally, but the sound of them at Le Mans this year almost changed my mind.

[wsn03]

FredericRobinson said:

Don't know about the fuel systems question, but they can be private entries - like the Risi car

Thanks for the answer on this, that's useful info.

[wsn03]

RL17 said:

Does seem surprising how fuel efficiency doesn't have more impact. Toyotas in 2016 were on 28 or so stops compared to a 30 stop for Porsches - the 14% margin might get down to 26 or 27.

If you add long run in to pits with chicane and pit lane speed and getting back up to speed it must add 15 seconds or so (1km at 50kmph v say 200kmph (both ave speeds probably low)) it still only saves 5 mins for 4 stops compared to the 30 mins plus the 5 seconds a lap saves.

The LMP1 factory cars also get the acceleration gains (electric motors etc) out of the corners so can overtake much easier after turn exits - looking at the start of the start/finish straight this year they could overtake really easily as all the others were accelerating more slowly and overtake much quicker and back on line. Rather than relying on longer overtakes at higher speeds or into corners/turns which are trickier when more cars involved as shown by some of the LMP2/GTE incidents. Lots of time overtaking 3 or so cars at a time after slower turns.

Reckon that during the race they (LMP1 factory teams) have a practical lap time advantage of more than the 5 seconds or so of the fastest lap or qualifying times might indicate

Thanks for the answer, again I've learned something new.
I did wonder how come the LMP1s were lapping faster than the LMP2s with the latter being quicker down the straights.
Like you I remain surprised at the small difference such a fuel efficiency saving could make.

[wsn03]

rdjohn said:

Fuel tank capacity

Mini 50 litres / Maxi 90 litres can be adjusted with BOP

It will be a sanctioned race fuel cell, rather than standard kit

Thank you for answering this, much appreciated.

[wsn03]

VladD said:

Modifications wise, Porsche turned the engine round in the 911 to make it mid-engined instead of rear. I'm not a big fan of 911s normally, but the sound of them at Le Mans this year almost changed my mind.

Thanks for the answer, didn't realise they could make such large modifications, I thought it was a mostly stock class. As for the 911s, best sounding cars there I think, and I'm no fan of them either.

[wsn03]

Thanks for all the answers - there is a little more than a passing interest, I'm finding out some headline details for an entity who might be interested in looking at endurance racing at some point in the future, but from a "have money and technology, now what to do with it?" point of view, rather than experienced with any type of racing.

A very distant sketch on the back of a fag packet atm, could go in any direction, but no harm in getting some headline answers for them, you never know!

I may be back with a couple of questions in a few months time, I'll post on this thread if so.

[VladD]

wsn03 said:

Thanks for all the answers - there is a little more than a passing interest, I'm finding out some headline details for an entity who might be interested in looking at endurance racing at some point in the future, but from a "have money and technology, now what to do with it?" point of view, rather than experienced with any type of racing.

A very distant sketch on the back of a fag packet atm, could go in any direction, but no harm in getting some headline answers for them, you never know!

I may be back with a couple of questions in a few months time, I'll post on this thread if so.

Intriguing. I'd love to see a Lotus at Le Mans. Not that I'm trying to suggest anything about somebody taking a Lotus to Le Mans. But if someone took a Lotus to Le Mans, it would be very cool. Have I said Lotus and Le Mans enough yet?

[wsn03]

VladD said:

wsn03 said:

Thanks for all the answers - there is a little more than a passing interest, I'm finding out some headline details for an entity who might be interested in looking at endurance racing at some point in the future, but from a "have money and technology, now what to do with it?" point of view, rather than experienced with any type of racing.

A very distant sketch on the back of a fag packet atm, could go in any direction, but no harm in getting some headline answers for them, you never know!

I may be back with a couple of questions in a few months time, I'll post on this thread if so.

Intriguing. I'd love to see a Lotus at Le Mans. Not that I'm trying to suggest anything about somebody taking a Lotus to Le Mans. But if someone took a Lotus to Le Mans, it would be very cool. Have I said Lotus and Le Mans enough yet?

There's a thought, what a good idea. I was thinking the only British car in that sort of class is probably Aston, but of course, Lotus. Do they make Lotus's with big enough engines (I don't even know what cc Lotus cars are anymore)? Is the Lotus a reliable car these days? Are they still in business (I remember reading the doors were about to close on them at one point), alive and kicking and likely to have a future?

EDIT- I've just educated myself, the Evora. Seems the business make a sizeable engined car, and seemingly they are in business, but I could be wrong, I've only skimmed a couple of items on the internet. Looks nice though, and labelled as the best car they've ever made in one article.

Edited by wsn03 on Thursday 27th July 11:12

Edited by wsn03 on Thursday 27th July 11:13

[VladD]

wsn03 said:

There's a thought, what a good idea. I was thinking the only British car in that sort of class is probably Aston, but of course, Lotus. Do they make Lotus's with big enough engines (I don't even know what cc Lotus cars are anymore)? Is the Lotus a reliable car these days? Are they still in business (I remember reading the doors were about to close on them at one point), alive and kicking and likely to have a future?

EDIT- I've just educated myself, the Evora. Seems the business make a sizeable engined car, and seemingly they are in business, but I could be wrong, I've only skimmed a couple of items on the internet. Looks nice though, and labelled as the best car they've ever made in one article.

The Evora or the new Exige would do the job. 3.5 litre Toyota engine, normally aspirated or supercharged to various states of tune. Lovely. It would have to be BRG with a yellow stripe or two naturally.

[wsn03]

VladD said:

wsn03 said:

There's a thought, what a good idea. I was thinking the only British car in that sort of class is probably Aston, but of course, Lotus. Do they make Lotus's with big enough engines (I don't even know what cc Lotus cars are anymore)? Is the Lotus a reliable car these days? Are they still in business (I remember reading the doors were about to close on them at one point), alive and kicking and likely to have a future?

EDIT- I've just educated myself, the Evora. Seems the business make a sizeable engined car, and seemingly they are in business, but I could be wrong, I've only skimmed a couple of items on the internet. Looks nice though, and labelled as the best car they've ever made in one article.

The Evora or the new Exige would do the job. 3.5 litre Toyota engine, normally aspirated or supercharged to various states of tune. Lovely. It would have to be BRG with a yellow stripe or two naturally.

Obviously...
Either car would certainly be a good starting point to look at, in a hypothetical theoretical back of a fag packet sketched out ideas sort of a way.
Budget wise would certainly fit within the realms of possibility to run at level based on what I know of the costs vs the budget available.