Posted by: drracing | December 23, 2016

2017 LMP2 – what’s the story?

Hi everybody!
This is my last post this year and i will try to make good use also of my new Youtube channel (here) to further visually (and not only through data and words) expand about the topic i am going to deal with.

As many of you probably already know, 2017 will mark the start of a new era for the LMP2 class, with new rules coming, a new spec engine built by Gibson and only four FIA mandated chassis manufacturers allowed to sell cars worldwide (Oreca, Ligier, Dallara and Riley-Multimatic).
There have been long debates about the need for a change in a class that seemed to work pretty well, with full grids pretty much in every championship, very good car variety, quick drivers and exciting races.

Anyway, the change is a fact now, so the only thing we can do in this early development stage is try to understand how exactly these new LMP2 machineries will perform.
Technical rules have changed in many aspects: first of all, 2017 cars are some 100 mm narrower than the previous generation ones (from 2000 mm overall width to 1900 mm), following the direction taken already since some years by LMP1; they also use a spec engine (provided by Gibson, as we mentioned already) producing more than 600 hp; they are also aerodynamically different: beside being narrower, they have also a wider rear wing and they are slightly longer than 2016 ones. Finally, because of a late addition of an air conditioning system, they have a slightly higher weight, moving from 900 kg to 930 kg.

All of these changes will surely lead to different performance compared to previous generation cars and there are already both speculations (sometimes pretty solidly-based ones, actually, mainly figures coming from the manufacturers themselves) and first test results suggesting that lap times will probably drop by about 3-4 seconds on a sprint track, assuming same track conditions and even more in Le Mans.

On my side, the excitement of seeing new cars hitting the track was made even higher by being these cars LMP2. Having worked previously on LMP2 vehicle models, I could not help myself but try to gather as many data I could and to build a 2017 LMP2 vehicle model, to see how it performs and behave on track and to get myself a feeling of the performance these cars will achieve this year.
I was lucky enough to be able to collect a pretty big amount of very detailed information about 2017 LMP2s, more or less in every area (engine, aero, suspensions), with the only exception being the gearbox and the tires; the gearbox itself will be this year a sensible area, with only three sets of gear ratios allowed for each chassis (including Le Mans, that will most probably use one of them just for itself), practically meaning only two set for the complete ELMS and WEC calendar; not too bad for this article purpose though, cause I think using the tire model I developed during 2016 could still be a good starting point with some minor changes and I can work out pretty easily some sets of gear ratios, to fit the engine curve and the speeds achievable based on the available data and the track the cars will run.

Analyzing the data I got was already pretty revealing, since this has highlighted immediately some first important points.
The engine has, as we said, about 100 hp more than a 2016 one, with its torque and power curve looking significantly different than, say, an “old” Nissan. The power band has moved sensibly upward, with less torque available at lower RPMs and gearshifts happening at higher revs than before.
The cars are now narrower and that normally doesn’t help handling, reducing a bit the cornering capabilities.
All the manufacturers also went to a slightly longer wheelbase, with values now above 3m, because of a more severe application of a rule about the chassis region immediately behind the driver seat.
On the aerodynamic side, the data I got shows important differences compared to what I have seen till now. Let’s start saying the information I got could well refer to a “x” development stage that is probably not the latest one and are not coming from a 1:1 wind tunnel; according to my experience and to what some engineers with much more experience than me say, this is surely driving some “errors”, although it is difficult to evaluate exactly how big the delta could be. Moreover, some later development and track testing could bring to different numbers in terms of aeromap.
Still, analyzing the available information about 2017 cars performance during testing and the results of my simulations, these data seem to be pretty realistic.
The most significant difference compared to what I have seen previously is a significant step in efficiency, with the new car producing similar level of downforce compared to the ones I worked on before but a lower drag.
For now, I only focused on the “Sprint” package, ignoring what could come out for Le Mans.

The result is what I think being a pretty realistic representation of what 2017 LMP2 cars (or at least one of them) will finally look like in terms of performance and handling.
Basing on this assumption I performed some simulation sessions on several tracks to analyze how quick the new cars will/could be.
Since I didn’t have a driver available to help me, I drove the model myself and that sure left some margin on the final performance that this car (or vehicle model) could achieve. I am pretty sure a good driver could well be up to a second quicker than me, if not more, even in a simulator. Still, comparing the 2017 spec performance to 2016 ones (with both cars driven by who writes) can give a very good indication of what to expect next year.
Beside this, we are going to take a look to the logged data, trying to evaluate how the main metrics look like.

Before to dive into the data analysis, here is the link to a video I recently did with the vehicle model we are dealing with. It shows some laps in Silverstone. Hope you like it! Again, it is me driving, so don’t expect too much!

The very first test I have done was in Monza, since this was one of the first tracks where new LMP2 cars tested, with some lap times that leaked through the press.
In particular, according to the info I found, these new cars have run in Monza with lap times around 1:36 minutes (Ligier, in particular, who drove in Monza back in October, I think). Interestingly, I was able to drive the model with a best lap time of about 1.37.
First thing to keep in mind here is that I suspect my vehicle model (and hence the data on which it is based) is on the low side of both Downforce and Drag, probably fitting a track like Monza pretty well, since here the straight line speed is crucial in obtaining competitive performances.
Unfortunately, I don’t have any 2016 LMP2 data to compare with on this track, but it could still be interesting to take a look to the logged to have a feeling about 2017 cars performance (please note all the following pictures/plot can also be found in High-Res in my Flickr channel).

 

monza-speed

 

First thing catching the attention here is, of course, the top speed the car achieves, which is about 308 km/h. Keeping in mind this is achieved with a Sprint Aerodynamic setup, it is interesting to think that this top speed is already higher of what most teams could reach in Le Mans last year (at least without any slipstream), with a dedicated low drag configuration.
This is sure the result of the much higher power the engine can produce but, partially, also of the particular low drag that the model has.

For reference, here below the plots of some other important metrics: lateral acceleration, longitudinal acceleration and RPM.

 

monza-lat-g

 

monza-long-g

 

monza-rpm

Monza doesn’t have super quick corners, but still the car is able to reach lateral acceleration marks in the region of 2.4 – 2.5 g in some occasions (see, for example, the two Lesmo corners and the Parabolica).
Not too much to say about the longitudinal acceleration, with very similar values to the ones we saw analyzing LMP1-L cars (the difference being driven mainly by the higher weight of 2017 LMP2 compared to 2016 LMP1-L, about 80 kg).
The RPM plot helps to see how the new engine will most probably be used, with higher power band of previous Nissan motors.

The test has gone forward in Silverstone, using a slightly higher Drag/Downforce configuration and shorter gear ratios, to better fit the English track, requiring probably the highest possible setup on the downforce side.
My best lap time was a 1.46.5, which is, as I said already, surely not even close to the best lap time we could expect next year, if track conditions will be good, but is already comparable to what the LMP1-L cars did in 2016 during the race (Qualifyingtook place in wet conditions).
More interesting, this lap time is some 3-3.2 seconds quicker than what I was able to do with the 2016 LMP2 model I worked on this year (about 0.54 sec/km); it is useful to keep in mind that this vehicle had anyway a higher downforce/drag compared to the 2017 one I am testing, so probably a more suitable setup for this particular track.
The gap between 2016 and 2017 lap times seems to match quite well to what media sources communicated, following indications coming from the manufactures. Also, this is very close to the gap that a lap time simulation would produce for the changes in weight, downforce/drag and engine power (compared to 2016) we are dealing with.

Let’s take a look to the data plots for Silverstone too.

 

silv-speed

 

First thing we can see is that, with this vehicle model and the setup I used for Silverstone, the car can achieve a top speed of about 287 – 288 km/h at the end of the Hangar Straight.
Silverstone is also an interesting track because drivers have to face the challenge posed by several pretty quick corners. The first one is Abbey, where a minimum speed of about 235 km/h was registered (with the corner being driven in 5th gear), while at Copse we can see a minimum speed of about 219-220 km/h (again 5th gear).
This translates to sustained lateral acceleration marks of about 2.7 g for both Abbey and Copse, but with peaks close to 3 g.

 

silv-lat-g

 

Car’s cornering potential (or how many g the car can pull in a certain corner) is driven by some main factors: downforce, tires grip, weight and track width, to name some. We are assuming, in the absence of better data, the same tires as in 2016. Anyway, downforce (which is lower than the 2016 LMP2 I worked on), weight, and track width all plays again achieving better performance.

Again no big surprises looking at the longitudinal acceleration trace, showing similar maximum values compared to Monza.

 

silv-long-g

 

The RPM trace shows instead the shorter gear ratios I used in Silverstone, to better suite a slower track where a slightly higher downforce/drag setup was also used.

 

silv-rpm

 

First gear is used only once, at the Loop. The engine works below 5000 RPM only once, at the left corner after Vale (before Club corner), where second gear is used.
This shows anyway how the power band is mainly located on the higher side, also compared to previous generation Nissan engines, which confirms some of the feedback given by some drivers during development which suggested that new cars, even if having so much power, should be relatively easy to drive also for gentlemen drivers.
The latest track where I tested the model on was Spa, to have again a reference against previous simulations I did with a 2016 LMP2.
The final lap time (again, with me driving, so most probably not the best lap time achievable with this particular vehicle model) was a 2.03.6. Again, more important is the gap between this lap time and the best lap time I could achieve with a 2016 LMP2 vehicle model; the difference between the two is close to 3.8 seconds, again about 0.54 sec/km; as I already told about Silverstone, I would expect the best real lap times to be lower than this, above all if the track will be in good conditions.
In any case, the gap between 2016 and 2017 LMP2 performance seems to match well with the media communicated 3-4 seconds difference between the two.

Let´s take a look to the simulation results. First to come is speed plot.

 

spa-speed

 

Again, first thing catching attention is the overall top speed of about 304-305 km/h, at the end of the Kemmel straight. Even more suggesting, though, is a minimum speed in excess of 270 km/h inside Eau Rouge, with the car literally flying through this iconic corner.
Very interesting is also the minimum speed at Pouhon, another very quick and grip limited corner, very interesting to evaluate the cornering potential of the car in a high speed condition.
The data shows here a minimum speed of about 206 km/h and a maximum lateral acceleration of about 2.7 gs, as shown by the following plot.
spa-lat-g

 

The same plot shows a maximum lateral acceleration in excess of 3 g at Blanchimont, although at such a high speed we are not really in a grip limited condition.

Again no big surprises in the longitudinal acceleration plot, with peaks always in the same region of what seen in the other two circuits and highest values achieved at the bus stop braking, where some bumps on the tarmac contributes to create higher peaks in the reading.

 

spa-long-g

 

Finally, we can take a look to the RPM trace, where we can see how the car (here using the same gear ratios as in Monza) doesn’t reach the 8500 mark at the end of the kemmel straight in sixth gear and operates significantly below 5000 rpm only once, at the bus stop, where first gear is engaged.

 

spa-rpm

 

It would now be interesting to let a quick driver to test this vehicle model to fully explore the performance potential of these cars, at least taking for granted that all my assumptions are correct.

Anyone interested?

It would be cool to work on this model and on such an analysis with a real LMP2 driver.

This article, together with the video I linked above (car driven in Silverstone), should anyway give a feeling of the level of performance to expect in 2017 in the LMP2 class.
The cars will be, as we could already expect, much quicker than the old spec ones and, probably close to or quicker than 2016 LMP1-L in many occasions. It will be interesting to see how far the performance will be pushed, also considering that many teams seem to be able to include very fast professional drivers in their lineups.

Our findings seem to generally confirms what communicated to media by the manufacturers, expecting a gap between 3 and 4 seconds between 2016 and 2017 lap times, but can show more in detail how and where these gap can be built and can give a more detailed idea about 2017 LMP2 performance.

Here again a link to Silverstone’s video.

It will definitely be a very exciting season.

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Responses

  1. Interesting article! Very excited about the new cars. I did a quick model of a 2017 car as well (though lacking direct data I used other similar cars to help fill the gaps) – for AC. Will see how our telemetry compares and let you know.

  2. Small lap times update, based on some refinements of the model (i received some more data recently and i also improved a bit car’s setup) and a real driver testing:

    Monza 1.36.3

    Silverstone 1.45.5

    Will be interesting to see how this compares to the real lap times, as soon as the car will officially hit the track in Monza (Prologue) and in Silverstone (first race).


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