There seems to be no slowdown within the relentless battle of auto producers chasing down Nürburgring laptimes in an effort to achieve a high spot on the ring and show their engineering prowess. With a wide range of vehicles working sub 7 minute laps we requested ourselves which powertrain configuration is essentially quickest across the inexperienced hell; entrance, rear or all wheel drive? Few would gamble on a entrance wheel drive being quickest, significantly on the ridiculous energy stage we’re testing at, so let’s put some numbers to it and discover out. We’ll additionally check out the advantages of including in torque vectoring — a activity which turns into simpler with electrical vehicles as there are higher alternatives to drive the wheels individually.

First, we’d like a mannequin of a robust supercar so let’s make up some specs, and check out to not get too carried away!

• Weight: 1750kg (about the identical as a Porsche 918 with a passenger)
• Powertrain: 1MW/1341bhp (just a little shy of a Bugatti Chiron)
• Downforce: 900kg at 260kph (50% greater than a McLaren P1)

In fact, automobile producers spend years fettling the stability of their automobile, however since that is hypothetical, we’ll follow getting the fundamentals proper, that’s:

• Weight distribution (whereas adjusting spring stiffness to swimsuit).
• Aero stability (whereas matching trip heights).
• Mechanical stability (whereas sustaining complete roll stiffness).
• We’ll permit the automobile to have computerized management over the brake stability.
• For the 4WD automobile we’ll optimise share torque cut up to the entrance/rear.

We ran 10,000 mixtures of the above setups across the Nordschleife — a activity which is simple to say, however even amongst F1 groups, that is solely possible for those utilizing Cover. Listed below are the outcomes:

Let’s check out the laptimes first. At this monitor grip stage, the optimum RWD automobile is 7.6sec faster than FWD. AWD then positive factors us an extra 6.1sec, whereas AWDTV widens the hole to an extra 8.7sec faster than AWD. Whereas we pause on this commentary, I can hear our FWD followers complaining that drivability is vital, and if we had been to enter this automobile right into a gentleman’s driving collection such because the VLN or the 24 Hours of Nürburgring it’s the ease of which we will knock out fast laptimes with metronomic precision that’s extra vital than theoretical final tempo. One factor we may do to verify the drivability is to see what occurs when issues get just a little damp by dropping the monitor grip by 10%.

Luckily, it solely takes just a few clicks and a cup of tea to re-run the ten,000 simulations to search out out. In the event you work at a motorsports crew you’ll know that having the ability to rapidly reply to altering situations on the monitor is essential for racking up these championship factors! With the perfect consumer interface, strongest simulations and cloud computing it’s simple to adapt to trace structure modifications, native grip variations, or wind modifications. With the brand new simulations run we discover the laptimes and optimum setup as follows:

The tempo distinction between the FWD, RWD and AWD configuration is sort of an identical after a drop in grip, nevertheless the fascinating end result right here is that AWDTV performs even higher on a moist monitor relative to the others and has widened the hole by an extra 1.4sec.

If we check out optimum weight distribution, we will see that weight distribution is by far essentially the most delicate parameter, as laptimes deteriorate quickly after we transfer away from the best setup. On the excessive grip stage, the FWD is quickest with 74% of the burden on the entrance axle (which explains why we don’t see many rear engine examples!), whereas Porsche homeowners can be delighted to see that the RWD is quickest with the burden way back to 33%. BMW drivers with their 50:50 weight distribution may use this graph as an excuse to improve to all-wheel drive expertise, as 53–55% is right for AWD efficiency.

The aerobalance optimum seems to be very excessive. FWD and RWD demand very far forwards and rearwards aerobalance respectively. I’ve by no means pushed a automobile with 84% aerobalance round a excessive pace nook within the damp, however the considered it sounds terrifying (perhaps this explains why I make vehicles go faster by way of engineering slightly than driving!) If we impose a stability constraint, the aerobalance remains to be actually far ahead, in all probability as a result of having to steer and drive the identical set of wheels places all of the arduous work on the entrance. If this doesn’t line up with our trackside expertise (of 1MW FWD vehicles!), it’s very easy to regulate the setup. We will do that within the Cover consumer interface by dragging the aerobalance rearwards to what we really feel is a extra acceptable stability after which shifting the burden distribution and mechanical stability to their new optimum.

Mechanical stability has the smallest impact, which is sweet to know because it leaves the race engineer free to regulate this in an effort to tune the stability to driver desire with out having a detrimental impact on final efficiency.

Within the case of the AWD the place we’ve a set % entrance/rear torque cut up we discover that 35% entrance/65% rear is an efficient place to begin, with steep loss in laptime after we begin to transfer away from this level. The final word resolution is to have a dynamic entrance/rear and left/proper cut up, as is the case with AWDTV. Maybe essentially the most vital end result right here is that by choosing torque vectoring, not solely can we depart the opposite vehicles within the mud, however we’re a lot much less delicate to weight distribution, aero stability and mechanical stability. This brings with it two main benefits: 1) it’s a lot simpler to design a automobile after we’re not restricted to protecting the design inside a really slender window 2) it’s in all probability a lot simpler for the motive force to persistently exploit the efficiency if the automobile performs effectively over a wider vary of setups.

Now I can hear our RWD followers complaining that the gear used to run AWDTV with a regular ICE is heavy. By including weight to this automobile, we discover that it takes 680kg to deliver the efficiency all the way down to the extent of the RWD. This partly explains why the Porsche 918 is so fast across the Nordschleife whereas boasting extra most modest headline figures when in comparison with the present crop of hypercars. With so many corners to get proper, drivability must be prioritised right here.

The outcomes appear clear; if you wish to go quick and have a automobile that’s not too delicate to setup, you want all wheel torque vectoring. In actuality that’s simpler stated than executed. Our simulations merely have 4 throttle and brake controls — one for every nook of the automobile; perhaps a practical purpose if we’re making devices for a one man band, however much less sensible after we’re attempting to drive on the restrict for 7minutes at a mean pace of 215kph.

Dynamic lap has no in-built torque vectoring technique; the one goal is to generate an ideal laptime — that is the one strategy to assure optimality. We will look by way of this excellent lap and determine options from Determine 3 which assist us design a method, for instance making use of torque to the wheel with essentially the most grip or offering extra torque to the surface wheels whereas braking the within ones to supply a yawing second.

The problem is to design a system that may take a single throttle & brake pedal then intelligently distribute the torque between the 4 corners. To assist with this we may embed the controller logic inside the Cover platform. In the identical method as we swept by way of setup parameters on this train, we may sweep by way of management parameters for the torque vectoring controller. This might assist us to rapidly develop a system which will get near the right torque distribution. Another strategy to get nearer to excellent torque vectoring could be to take away each the motive force and controller methods altogether and run the automobile autonomously, with our automobile mannequin working dwell in actual time on the ECU. Possibly that may spoil the enjoyable!

In the event you’re a motorsports engineer and also you want to optimise the behaviour of your torque controller; or perhaps you might be uninterested in inefficient work flows and might’t simulate 20,000 laps across the Nordschleife in just a few hours, then we’d love to debate how we may also help. Ship us a message at hello@canopysimulations.com