Quick Fire Questions for 24h Le Mans cars..??

[jj.]

Do they change oil during the 24h race..?
Do they use special oil or readily available products..?
Do they change Brake Pads/Discs..? (I remember seeing an old race where they changed pads, must have been 25/30 years ago though)..?


Longer questions:
Seeing that occasionally a corner gets ripped off, and they drive back to the pits on 3 wheels/suspension legs. What happens to the brake fluid…?
Is some special system in place to stop all the fluid being pushed out of a single corner. Do they run multiple redundant reservoirs…?

I’m sure I have others…? Just interested really, that a car can run at high temps for this period. Always amazed me.
jj

[LukeBrown66]

The Cadillac team reckoned they could have challenged closer in the race but oil refreshes cost them around a couple of minutes as it is all added to the pit stops.

Not sure if other teams add oil buy they sure do.,

I n some races like N24 there is a rule that teams HAVE to changed discs, I am not sure if they do in any class at Le Mans, you have to understand that GT3 use ABS whereas I am not sure GTAm do, this obviously puts more pressure on brakes.

AS for brake lines etc, most of the cars use snap type connectors, with several break points in them to enable slick changing should incidents occur. the teams are very well p[practiced at making such changes and if you watch they will be bringing stuff into the box as son as an incident happens to hopefully pre-empt the repairs.

Another thing to point out is that these cars are designed to be as easy to work on as possible, if they only had to be fast they would be more complex and less strong, they are designed for easy access where possible and quick changes of simple stuff like dampers, springs, brakes, certain body parts. #

And this is only stuff I know from listening to pods and coverage, there must be more and I think if more people knew about this it would make the sport even more appealing, when you look at F1 and the stupid pit stops they do there that take 2 seconds, when you consider what a LM team does for 24 hours it makes them look like amateurs sadly.

Edited by LukeBrown66 on Wednesday 14th June 18:27

[richhead]

jj. said:

Do they change oil during the 24h race..?
Do they use special oil or readily available products..?
Do they change Brake Pads/Discs..? (I remember seeing an old race where they changed pads, must have been 25/30 years ago though)..?


Longer questions:
Seeing that occasionally a corner gets ripped off, and they drive back to the pits on 3 wheels/suspension legs. What happens to the brake fluid…?
Is some special system in place to stop all the fluid being pushed out of a single corner. Do they run multiple redundant reservoirs…?

I’m sure I have others…? Just interested really, that a car can run at high temps for this period. Always amazed me.
jj

I feel somewhat qualified to comment here, having run various classes of car at lemans over the last 20 odd years.
Oil, well never changed unless for another reason, however the level is monitered and top ups are done with a pressurised bottle via a quick release conector in pit stops, takes a second or to per litre, same for coolant if needed, but thats rare unless a problem.
Brakes, it depends on the class, not sure about modern gt cars, as have only run prototypes for the last decade or so, and they run carbon carbon, and will do 24 hrs ok, The older gt cars, we would tend to change discs at 12 hours, but not pads, the pads would last, if you had the right ones, but discs would crack, hot cold over and over isnt good for them.
Qiuck disconects on brake lines arent legal, as they are prone to small leaks, but if changing pads, and sometimes it is needed, you would work both sides at the same time, but one side pushes back pistons first and shouts out to the other side when new pads are in, they would then push back their side etc, the pasd are only held in by a spring clip normaly, so take seconds, just dont do what i once did and put the used ones in your plastic tool tray, and wander why they are still sitting in the pit lane after the car has gone, and your nice new tray has two pad shaped holes in it lol

[Truckosaurus]

When Radio Le Mans used to run infomercials for Mobil1 they claimed the race teams all used off-the-shelf oil rather than a bespoke blend.

[jj.]

'the pads would last' - Wow didn't realise that...? Assumed it would be some Carbon on Carbon - but assumed they would need to be changed.

Lights..? Do they run full beam all of the time, or do they have some sort of LED matrix type front lighting. They seem amazing bright, especially on the prototype cars, but never seem to put the car in front in a dark box. So assume just blasting out Main Beam...?

Must be hard for the car in front to really see how many cars and where they are behind, even with the car locator indicators they have.
jj

[LukeBrown66]

Interesting to see as per regulations a few bits and bobs have been removed from class winning cars and podium cars from the weekend, it is nothing to be too worried about.

But the InterEuropol car was constantly being done with penalties last few hours, nothing seemed to come of it.

I am sure everything will be fine and it would be awful a week or so after the event for results to change!!

[GlobalRacer]

richhead said:

Qiuck disconects on brake lines arent legal, as they are prone to small leaks, l

Is that an old rule/Le Mans rule as I've 100% seen them used in GT and other series.

[entropy]

Chevy NASCAR needed regular fluid top ups.

Just heard the Autosport podcast and Gary Watkins said a Cadillac lost 20s altogether over the 24hrs with fluid top ups.

[richhead]

GlobalRacer said:

richhead said:

Qiuck disconects on brake lines arent legal, as they are prone to small leaks, l

Is that an old rule/Le Mans rule as I've 100% seen them used in GT and other series.

As far as im aware they have been illegal in sportcars for years, not sure if it was due to a failure, or to prevent quick caliper changing, could be either, but not seen them used since the 90,s in elms/wec etc.
Not 100% about gt's but not seen any used there either, but my experiance of gt is only fia or aco stuff, so rules may be different, anyway most gt races arent really long enough for it to be an advantage, apart from things like creventic etc, and have done that and still never seen them.

[richhead]

jj. said:

'the pads would last' - Wow didn't realise that...? Assumed it would be some Carbon on Carbon - but assumed they would need to be changed.

Lights..? Do they run full beam all of the time, or do they have some sort of LED matrix type front lighting. They seem amazing bright, especially on the prototype cars, but never seem to put the car in front in a dark box. So assume just blasting out Main Beam...?

Must be hard for the car in front to really see how many cars and where they are behind, even with the car locator indicators they have.
jj

Brakes, the prototypes all have carbon carbon, and they will do 24hrs ok, the gt classes uses steel discs, hence the cracking, carbon brakes are fairly bomb proof as long as used in the right temp window, but the steel discs dont like the huge temp changes you get, especialy at places like lemans, long highspeed cooling, then glow in the dark heat in the big braking zones, but modern pads are normaly good for 24 hrs, some last better than others tho.
I will add ive only really done the long races with prototypes in the last few years, so the gt brakes may have improved.

Lights, yes always full beam, as to what they are varies from car to car, alot of funky new tech now, and also lots of different lights pointing in different directions in either headlight, so they shine into turns aswell as straight ahead, dont forget the gt cars have yellow lights, prototypes are clear, this is so the drivers know who is behind., and dont forget the enginners have live data of all cars track position, so tell the driver if a car behind is for position, why radios are very usefull.

As for the poster who asked about oil, it is abit different to road stuff, as the engine will be toast after 24hrs anyway, so longevity isnt a huge concern, it can normaly take a higher temp aswell, tbh we dont really get that involved with the engine, we use the oil the engine builder wants mainly, and only really change it for new with a fresh engine for leman. we usualy change it after every short race, like the rest of the wec year, but more just because. And dont forget a 24hr race isnt really that many miles.

[generationx]

I’ve been fortunate to work in an LMP1/Hybrid Team for the last ten years I can answer this with regards to the top class.

jj. said:

Do they change oil during the 24h race..? No, but sometimes a top-up is required in case of a technical issue
Do they use special oil or readily available products..? No stone is left unturned, the oils are not “off the shelf”
Do they change Brake Pads/Discs..? (I remember seeing an old race where they changed pads, must have been 25/30 years ago though)..?Not unless absolutely necessary. I don’t recall one instance


Longer questions:
Seeing that occasionally a corner gets ripped off, and they drive back to the pits on 3 wheels/suspension legs. What happens to the brake fluid…? Brakes would be bled on a corner change, but I wasn’t very involved in hydraulics so take this with a pinch of salt
Is some special system in place to stop all the fluid being pushed out of a single corner. Do they run multiple redundant reservoirs…? 2 circuits are run - front and rear - with a brake balance bar

I’m sure I have others…? Just interested really, that a car can run at high temps for this period. Always amazed me.
jj

Cheers!

Edited by generationx on Thursday 15th June 22:43

[freedman]

richhead said:

I feel somewhat qualified to comment here, having run various classes of car at lemans over the last 20 odd years.
Oil, well never changed unless for another reason, however the level is monitered and top ups are done with a pressurised bottle via a quick release conector in pit stops, takes a second or to per litre, same for coolant if needed, but thats rare unless a problem.
Brakes, it depends on the class, not sure about modern gt cars, as have only run prototypes for the last decade or so, and they run carbon carbon, and will do 24 hrs ok, The older gt cars, we would tend to change discs at 12 hours, but not pads, the pads would last, if you had the right ones, but discs would crack, hot cold over and over isnt good for them.
Qiuck disconects on brake lines arent legal, as they are prone to small leaks, but if changing pads, and sometimes it is needed, you would work both sides at the same time, but one side pushes back pistons first and shouts out to the other side when new pads are in, they would then push back their side etc, the pasd are only held in by a spring clip normaly, so take seconds, just dont do what i once did and put the used ones in your plastic tool tray, and wander why they are still sitting in the pit lane after the car has gone, and your nice new tray has two pad shaped holes in it lol

When were quick disconnects made illegal then?

GTE cars have been using them, and change the brake disc, calliper and pads as a single unit in a few seconds

Porsche, Ford and Corvette all using dry breaks

https://youtu.be/haolm5D2YBg

https://youtu.be/HJqo7ftR-vE

https://youtu.be/0cBpMas109g

[richhead]

freedman said:

When were quick disconnects made illegal then?

GTE cars have been using them, and change the brake disc, calliper and pads as a single unit in a few seconds

Porsche, Ford and Corvette all using dry breaks

https://youtu.be/haolm5D2YBg

https://youtu.be/HJqo7ftR-vE

https://youtu.be/0cBpMas109g

like i said ive only worked endurance in prototype classes for a while now, so may be out of date, i do know they are used in imsa, but never used them under fia regs, ive not watched your clips,

[freedman]

richhead said:

like i said ive only worked endurance in prototype classes for a while now, so may be out of date, i do know they are used in imsa, but never used them under fia regs, ive not watched your clips,

All of the clips are from Le Mans, under the FIA

[richhead]

freedman said:

All of the clips are from Le Mans, under the FIA

Ive now watched them, and your right, like i said, ive not done gt in endurance for a decade or so, so the rules may have changed now, they certainly didnt used to be legal, but ive not read the regs for gt in a long time, so obviously am out of date with them.