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

[canaglia]

Originally Posted by FormulaFox

No... It wouldn't do that at all. First of all, the tub specs are the same between LMP1 and LMP2, so there is zero reason you can't sue the LMP2 tub as a base. Secondly, the DPi concept ITSELF is far more in line with LMP1, and Cadillac has made very clear that the concept makes it possible for a DPi to be made as fast as an LMP1-L without "artificial" assistance.

Disagree, 2018 lmp1-L performances should be much much better than an even dunlop/michelin cadillac dpi.
In the actual status quo, a dunlop/michelin dpi should be barely 1.5 seconds faster than a dunlop ACO lmp2 IMHO.

[Deleted]

If all it took was some minor modifications to base structure, why on Earth do you think Dallara and Oreca would go through such extensive new builds for the new P1 chassis if they could just slap something half-assed together from existing chassis like the (hinted) suggestion here seems to be? It's not just some aesthetic slap-off job some of the fans of DPi would perhaps like to imagine. There are many similarities in LMP1 and LMP2 (which "DPi" still is) regulations, of course there are, but they are still worlds apart.

Even to the point where it - once again - looks like Oreca might have problems in making Paul Ricard and possibly Spa again, after starting the project "only last summer". They also were only being able to commit to just single customer, their effective Swiss works team, while refusing Dragonspeed and possibly others. And Onroak, still, after so many years of talking about it (even as early as 2014), still refuses to commit to P1? Why? Do they not like money? Or would the answer instead be it's not easy.

Besides, even if it was easy to just integrate "DPi" into P1 - or hell even to just P2 - we have already seen in the past that the IMSA teams refuse to bring up their own chassis from the States. Remember the MSR Onroak for example, they leased another identical chassis from the Onroak instead of shipping their car to Sarthe. Do you think these ex Grand-Am DP and ex LMPC teams, already seemingly most of the time either refusing their automatic ACO invites into Le Mans or plain not having the interest in the first place, would go through modifications for their cars in the middle of the championship? No, they'd just expect to be at Le Mans, performance balanced for the [preferably overall] win, because it wouldn't cost them anything and is easy. It doesn't matter to them if P1 would be killed off at the process, because they don't care. There is no technological incentive for them in anything.

As for DPi being able to match nonhybrid (once again "LMP1-L" has not existed since 2014) prototypes - and simultaneously hybrid seeing as they are now theoretically on the same line - without artificial speeding up... yeah right The spec Hoosier tires in IMSA might be useless crap and therefore mask some margin of the potential performance, that is true, but they are not so useless that the cars would magically find million seconds of extra pace out of thin air. The "DPis" are nothing but standard spec ACO LMP2s with non-Zytek engines and aesthetic headlight styling cues, those do not transform them into anything earth shattering. Besides the ACO LMP2s are already running together them with similar pace with same standardized ACO BoP values, save the aero configurations for Daytona or whatever. Why would the ACO P2s - which once again are the same 99,9% exact same cars as "DPis" - would suddenly lack behind them at Le Mans?

[Deleted]

The editing time run out, so just to add one bit to that last paragraph:

Perhaps one would argue that while the standard LMP2 would stay frozen in their tech freeze cost cap nature, the way you could have DPis getting closer-to-P1 performance for Le Mans would naturally be via, you know, performance development. But do you really think these uhm, "manufacturers" and their designated privateer teams who rely entirely on balance of performance in their domestic series to win races, would bother with development for one event in the middle of the year? Especially when the people involved have already hinted at just wanting to run their cars-as-it-is...

[carbsmith]

The irony in a Penske driver complaining about not being able to go to Le Mans is that it's Penske's race that conflicts with the Le Mans test day and makes it impossible to use the same car in IMSA and at Le Mans anyways.

[Deleted]

Originally Posted by carbsmith

The irony in a Penske driver complaining about not being able to go to Le Mans is that it's Penske's race that conflicts with the Le Mans test day and makes it impossible to use the same car in IMSA and at Le Mans anyways.

He probably doesn't even know there is a test day

Anyway, if there was theoretical access to Le Mans, they could probably lobby ACO into handing force majeure waivers, or lobby rescheduling of the test, or lobby IMSA in inserting a "worst result of the season is dropped" regulation so that they could ditch Detroit (it's not like that event matters to anyone except GM anyway) which is something IIRC they talked about in that initial 2012 series fusion press conference

[FormulaFox]

Originally Posted by canaglia

Disagree, 2018 lmp1-L performances should be much much better than an even dunlop/michelin cadillac dpi.
In the actual status quo, a dunlop/michelin dpi should be barely 1.5 seconds faster than a dunlop ACO lmp2 IMHO.

Just how much faster are you expecting the non-hybrid LMP1s to be?

I think you fail to realize, though, that they wouldn't just be switching the tires and letting it loose. The engine would be tuned more adequately to the purpose. Even when the car first made it's public debut, before IMSA took it's first swing at the car, the Cadillac engine was already running restricted. The engine produces more power in it's roadgoing form than it does in the DPi, and it has a massive amount of performance that can still be reliably squeezed out - I've seen techs squeeze 800+ out of the LT4 and run it at full song on a dyno for HOURS, with a subsequent teardown uncovering no discernible wear.

There's a reason I always turn to the Cadillac when talking about these matters. That engine is capable of more than most realize - GM themselves may not be aware of it's full potential.

Originally Posted by Chiana

If all it took was some minor modifications to base structure, why on Earth do you think Dallara and Oreca would go through such extensive new builds for the new P1 chassis if they could just slap something half-assed together from existing chassis like the (hinted) suggestion here seems to be?

Because the Dallara and Oreca LMP1 cars were both commissioned by third parties that wanted their own unique cars, and as such were not interested in merely tuning up the LMP2 car. Their programs are, as a result, indicative of nothing regarding the potential capabilities of DPi in LMP1.

Despite this, the Oreca at least is reportedly based directly on the 07's tub, even though the rest of the car is expected to be very different.

From a technical side, however, there IS a possible reason why the manufacturers might wish to opt for a new car rather than tuning up an LMP2. The LMP2s are optimized for the Gibson engine(and, in the case of the Dallara, the Caddy engine), and adapting them to fit an engine more suitable to LMP1 could cause issues with chassis rigidity, cooling, etc. Case in point, since the Ligier chassis was not originally developed with the Nissan engine in mind, ESM had a bit of overheating trouble early on in testing. Props to them and Penske for overcoming the limitations caused by the lack of optimization, though it was a fair bit easier since the performance targets were no different than the base car's(or rather, are supposed to be).

Put simply, while a Cadillac DPi should be plenty capable of hitting non-hybrid LMP1 performance(especially if they dropped last year's version of the engine back in), that doesn't mean you would want to use the same car for just any LMP1 application.

But if you had an engine that could fit the LMP2 tub without these concerns, there would be nothing stopping you from building an LMP1 car off of the LMP2 tub.

[canaglia]

Surely cadillac dpi engine can be tuned to rev up to about 10000rpm, achieving >850hp like sprint cup 5.8L V8, but what kind of fuel tank will be required to keep the actual 40-45 mins stint lenght?
everything is possible, just not everything is sustainable.

Anyway I explain better my post:

A DPi is basically a more or less customized bodywork on a ACO lmp2 chassis, powered by different road derived or bespoke engines.
Despite this, the performance window, must remain the same of a ACO lmp2, by rules. Cadillac DPI and turbo DPI are somehow more performant just because have more torque, that's it....

If we take as reference 2017 WEC silverstone qualifying:

best lmp1-h: 1.37.3 - best lmp2: 1.44.4

to me 2018 performances status quo could be something like this:

best lmp1-h: mid 1.36
best private lmp1: about 1.39-1.40
best lmp2: low-mid 1.43

if you ask me, a michelin/dunlop cadillac dpi would be in low 1.42.

Is really unlikely that dpi may have a better aero than new lmp1 like dallara BR1 or ginetta, but is a fact that dpi are about 100kg heavier and not less than 70hp less powerful and no torque advantage this time (at least compared to turbo lmp1).


To cover the performance gap, DPi's chassis/bodywork/hardware etc.... must to be updated or redesigned to make the car lighter (remember that angelelli and scott sharp revealed that cadillac dpi and nissan dpi struggle to reach 930kg). Road derived NA or turbo engines too would need to be heavily updated to reach those powers remaining in the same 40-45 min / 75L rate.
Costs will reach stars.... and original dpi identity will get lost, basically you get a new car comparable to new private lmp1 models, just derived from a different base platform


Don't get me wrong, I'm an big DPi formula fan!
It was a great idea to create a new and cheap prototype class with huge performances.
It's so great that I hope in next years ACO would use a similiar core rules set for the new rumored GTP specs.

To me is just insane to think that actual DPi's could share the same field with lmp1-h and new more performant private lmp1.
Just leave them to their IMSA habitat.

[Coach Ep]

Nothing stopping Action Express or WTR to commission a BR/Dallara P1 and fit last year's Caddy engine in it and go to Le Mans in 2019. It could even been done under the Cadillac banner if the GM executives wish.

But who's gonna foot the bill if GM doesn't wanna jump in? Whelen?

[chernaudi]

One thing is, ACO LMP1 technical regulations. GM would have to redo the engine to run on fuel flow BOP vs air restrictors. That's unless the ACO make an exception or dump fuel flow in favor of going back to air restrictors as a whole.

Also, why aren't LMP2 cars being upgraded to LMP1? One, they'd have to cut 4 inches/100mm out of the wheel base get them down to the 4650mm max length allowed in LMP1 (front and rear overhangs are identical in max dimensions between LMP1 and LMP2). And two, even though the chassis regs and crash test regs are the same between both classes, there's clearly enough bureaucratic red tape involved as far as homolgation goes to discourage such a practice nowadays.

[EffectiveSprinkles]

Did something change in the LMP1 regulations? As far as I knew previously the only thing a DPi car had to change to race in LMP1 would be electronics. And of course adhering to the fuel flow regulations. Did the dimensions for LMP1 change for this year?

[EffectiveSprinkles]

Originally Posted by tomerswayler

If Le Mans wants to attract the IMSA teams, the cheapest solution surely would be to just let them race in their current configuration and adjust the rules on fuel flow and aero for LMP1(H) to match the speed. Maybe give LMP1(H) a small theoretical advantage of half a second according to ACO's simulations.

Make sure LMP2 is five to ten seconds behind the level of P1 and then go racing. Too simple?

That does not sound simple at all to me You would need to completely rewrite both regulations for LMP1 and LMP2 and make both immensely slower. Sounds like a lot of effort, and unnecessary too since the entry list for Le Mans is oversubscribed as is!

[Akrapovic]

Originally Posted by Coach Ep

Nothing stopping Action Express or WTR to commission a BR/Dallara P1 and fit last year's Caddy engine in it and go to Le Mans in 2019. It could even been done under the Cadillac banner if the GM executives wish.

But who's gonna foot the bill if GM doesn't wanna jump in? Whelen?

The chances of getting a one-off Le Mans entry in LMP1 is pretty small. And you'd have to spend a fair bit of money on that one off. Toyota were told they were to run the whole season, so I don't see anyone else getting away with it.

[chernaudi]

Originally Posted by EffectiveSprinkles

Did something change in the LMP1 regulations? As far as I knew previously the only thing a DPi car had to change to race in LMP1 would be electronics. And of course adhering to the fuel flow regulations. Did the dimensions for LMP1 change for this year?

LMP1 has always been 4650mm, going back to the LMP900 days as far as max length. For some reason, the 2017-present LMP2s (and DPIs based off of them) got their length increased to 4750mm, all of which is probably in the wheelbase since max overhangs (fore and aft the wheelbase) are the same between LMP1 and LMP2.

[carbsmith]

Originally Posted by FormulaFox

Just how much faster are you expecting the non-hybrid LMP1s to be?

Expecting? They're already 4 seconds faster on a short track.

[TF110]

Originally Posted by carbsmith

Expecting? They're already 4 seconds faster on a short track.

Very fast! Doing times close to if not matching Toyota's times at Aragon. I think it'll be close this year.

[FormulaFox]

Originally Posted by canaglia

Surely cadillac dpi engine can be tuned to rev up to about 10000rpm, achieving >850hp like sprint cup 5.8L V8, but what kind of fuel tank will be required to keep the actual 40-45 mins stint lenght?
everything is possible, just not everything is sustainable.

Nowhere near as much as you'd think. You don't need to get the engine revving that high to produce the needed power, and the 800+ I pointed out is actually a fair bit higher than the engine would likely need to hit, and took far less fuel than was expected when running the test(less than half of what was expected, IIRC).

A DPi is basically a more or less customized bodywork on a ACO lmp2 chassis, powered by different road derived or bespoke engines.
Despite this, the performance window, must remain the same of a ACO lmp2, by rules. Cadillac DPI and turbo DPI are somehow more performant just because have more torque, that's it....

That's not the entire story.

If we take as reference 2017 WEC silverstone qualifying:

best lmp1-h: 1.37.3 - best lmp2: 1.44.4

to me 2018 performances status quo could be something like this:

best lmp1-h: mid 1.36
best private lmp1: about 1.39-1.40
best lmp2: low-mid 1.43

if you ask me, a michelin/dunlop cadillac dpi would be in low 1.42.

And without seeing it unrestricted, you have no way of knowing that.

Is really unlikely that dpi may have a better aero than new lmp1 like dallara BR1 or ginetta, but is a fact that dpi are about 100kg heavier and not less than 70hp less powerful and no torque advantage this time (at least compared to turbo lmp1).

The aero rules between the two classes are pretty much identical now. Additionally, if you were to bring a DPi to Le Mans there'd be nothing stopping you from tweaking the aero if you felt some improvement was needed.

To cover the performance gap, DPi's chassis/bodywork/hardware etc.... must to be updated or redesigned to make the car lighter (remember that angelelli and scott sharp revealed that cadillac dpi and nissan dpi struggle to reach 930kg). Road derived NA or turbo engines too would need to be heavily updated to reach those powers remaining in the same 40-45 min / 75L rate.
Costs will reach stars.... and original dpi identity will get lost, basically you get a new car comparable to new private lmp1 models, just derived from a different base platform

And getting there would still likely cost less than building a whole new car.

To me is just insane to think that actual DPi's could share the same field with lmp1-h and new more performant private lmp1.
Just leave them to their IMSA habitat.

You'd be surprised what can be done when you start with a base as insanely potent as what Dallara and GM have pumped out.

[EffectiveSprinkles]

Question, why do you think the GM variant of the Dallara LMP2 is suddenly that much faster than even an Oreca LMP2? Remember the engine is not allowed to run unrestriced in LMP1 either.

Also the aero rules between P2 and P1 have vast differences, they are not equal at all.

[canaglia]

Originally Posted by EffectiveSprinkles

Question, why do you think the GM variant of the Dallara LMP2 is suddenly that much faster than even an Oreca LMP2? Remember the engine is not allowed to run unrestriced in LMP1 either.

Also the aero rules between P2 and P1 have vast differences, they are not equal at all.

Torque. Last year cadillac dpi was likely about 700Nm range in low-mid rpm, oreca 07 is powered by gibson that has a torque peak of 550-560Nm at about 6000rpm; low-mid rpm torque release is much lower than nissan-acura-cadilacc dpi.

[TF110]

Lmp1 aero rules are a lot more free than lmp2. They make significantly more downforce not to mention are around 100kg lighter. That's a lot of weight difference. If you put that GM engine in a Dallara lmp1, it still would need work to be on pace of the new cars. I'm sure it can produce over 600hp reliably, but fuel efficiency would be of concern too since that's the name of the game in lmp1, efficiency!

[Coach Ep]

Originally Posted by Akrapovic

The chances of getting a one-off Le Mans entry in LMP1 is pretty small. And you'd have to spend a fair bit of money on that one off. Toyota were told they were to run the whole season, so I don't see anyone else getting away with it.

Could be covered by an auto-invite if IMSA were to bend their own concept on it a bit.

[FormulaFox]

Originally Posted by EffectiveSprinkles

Question, why do you think the GM variant of the Dallara LMP2 is suddenly that much faster than even an Oreca LMP2? Remember the engine is not allowed to run unrestriced in LMP1 either.

No, but they're allowed a lot more freedom than the Caddy engine has been able to run.

Also the aero rules between P2 and P1 have vast differences, they are not equal at all.

They're closer than you and TF110 seem to think. They're not the same, but it would not be difficult to adapt if GM really wanted to do so.

Originally Posted by TF110

If you put that GM engine in a Dallara lmp1, it still would need work to be on pace of the new cars. I'm sure it can produce over 600hp reliably,

There is no doubt of that; The roadgoing version of the engine already does so.

but fuel efficiency would be of concern too since that's the name of the game in lmp1, efficiency!

LMP1 cars produce an estimated 4 MPG(US). The LT4 roadgoing version managed 14 city. This is obviously not under heavy load, but it is unlikely to be under 4 MPG at the limit. Especially if running a lighter car like an LMP1.

Something often forgotten about the LS line is that it's not ONLY power that has led to it being so well-regarded. Most entries in the line have been far more economical than one would expect, and this is the primary detail that keeps it alive in this era of small displacement turbos.

[EffectiveSprinkles]

Well that, and BoP

Shedding 100kg and completely redesigning the aero seems to me not very worth it though. Might as well build a new car.

[TF110]

Originally Posted by FormulaFox

No, but they're allowed a lot more freedom than the Caddy engine has been able to run.



They're closer than you and TF110 seem to think. They're not the same, but it would not be difficult to adapt if GM really wanted to do so.



There is no doubt of that; The roadgoing version of the engine already does so.



LMP1 cars produce an estimated 4 MPG(US). The LT4 roadgoing version managed 14 city. This is obviously not under heavy load, but it is unlikely to be under 4 MPG at the limit. Especially if running a lighter car like an LMP1.

Something often forgotten about the LS line is that it's not ONLY power that has led to it being so well-regarded. Most entries in the line have been far more economical than one would expect, and this is the primary detail that keeps it alive in this era of small displacement turbos.

While it may have good mileage right now it's not running near 700+hp, so to get it there with the fuel flow allowance, I'm sure the fuel usage will go up some. It'd be cool to see what that engine would be capable of if it did run in lmp1.

[FormulaFox]

Originally Posted by TF110

While it may have good mileage right now it's not running near 700+hp, so to get it there with the fuel flow allowance, I'm sure the fuel usage will go up some. It'd be cool to see what that engine would be capable of if it did run in lmp1.

I'm 100% positive the LT4 could run an LMP1 at sufficient economy, power, and reliability.

It is also the only roadcar-derived engine I think is capable of such. It's so close to what it would need to do already that I can't see it needing much work.

[Adam43]

Only road car engine? Do you mean only road car engine being used in something LMPish? Or at all?