CARS The BMW M6 GT3

The brand new BMW M6 GT3 made quite an impression in 2018 Blancpain GT3 series.

Following the dimensions of the street car, there is no denying that the race car is also very big, even bigger than the Bentley, especially in length and wheelbase. This same aspect, together with the impressive twin turbo V8, define the handling characteristics of the BMW.

The dimension of the car, results in a very large area of the underbody aerodynamics. The front splitter is impressive and the length of the rear diffuser is massive. Even the exhausts have lateral exits so that they do not interfere with the diffuser aero flow. Many smaller or bigger details can be found all around the long bodywork, achieving impressive amounts of downforce on par with the top of the class, even though the total drag inevitably stays a bit high given the big frontal area.

Nevertheless, the absolute aero numbers tell half the story. The best feature of all this attention to the aerodynamics is the quite stable aero platform. As we have explained in other posts, the main issue for the drivers of modern cars with high aerodynamics, is the stability of the aero platform in terms of aero balance, from the effects of pitch and roll. Often, the higher the downforce, the more sensitive the car becomes to pitch and roll, forcing the engineers to big setup compromises that make the car worse at low speeds, and forcing the drivers to change their driving style at higher speeds, in order to not upset the car. The later is easier to tell than do, especially for amateur gentleman drivers that participate in the Blancpain series.
The long wheelbase and long under tray of the BMW, deliver a much more stable aerodynamic platform, especially under forward pitch (coasting, braking) that permits softer suspension setups and more natural driving techniques to be exploited. At low speed the car offers exceptional turn in and minimal amounts of understeer at power exits. A hint of understeer is present at the apex of slow turns, which is typical for such a big car with a bit of front weight bias, but it adds confidence to attack the corners at entry and can be easily controlled by the drivers. As the speed raises the big amount of stable downforce, result in a very confidence inspiring car that can be pushed at high speeds and if the driver makes the occasional mistake, it can be relatively easily corrected.
The very very fast right hand bend at the end of the long back straight at Paul Ricard is the perfect example of the car’s stability. Even if you overcook the entry going in way too hot, you can confidently raise your foot or even pinch the brakes and the car will correct it’s trajectory without big drama. Not something you can do with the much more pitch sensitive Huracan for example.
Similar situation at the Misano circuit. The very dangerous braking zone for T13 and T14(Carro) turns, must be approached in a very certain and precise way, by practically all cars. The BMW M6 showcases great stability and honest reactions, giving the driver the opportunity to attack and trust the car, without big setup compromises.
Fantastic car then, is this the best of all worlds? Not so fast.
The very very long body and wheelbase, does indeed provide stability, but predictably enough, makes the car sluggish at narrow turns, chicanes and fast direction changes. The car turns in fast but then needs some time to take a set and keep the line. The perception of the limits of the bodywork is also not so good and this is a disadvantage in close racing situations.
Worse of all, the very long overhangs touch the ground easily and they will do often do so at the very worse moment at very high speeds while trying to ride a kerb in a very fast corner. The resulting loss of tyre grip and aerodynamic stalling can bring catastrophic results. This is where compromises have to be made on the setup, by rising the ride height, using stiffer springs and dampers and so on. Drivers must also adapt and find which kerbs should ride and which ones are better to avoid. In such situation the excellent behaviour of the BMW can quickly betray you and make you spin in no time at all. Beware.
All in all, the car forgives some aggressive driving and a bit less precision, but it really shines when the inputs are smooth, both on the steering wheel and on the accelerator pedal. The smoother you drive it, the more speed it gains. The advanced traction control, is finely tuned for safe driving but lowering it to level 3 or less, will permit even more forward acceleration if you are smooth on your inputs. In a way, it is as if the looks of a grand touring coupe are mirrored one to one on its handling behaviour.

The big V8 placed behind the front wheels, produces massive amounts of torque and power. The favourable Balance of Performance, let the engine output around 650Nm of torque and approximately 550bhp. Most importantly the torque curve of the car seems like the great plains, or siberian plains, or Netherlands, or padania… choose whatever fits your definition of flat and infinite. Unfortunately it’s not what I would call an enthusiastic engine. Even though it pulls incredibly from as low as 3000rpm, the party ends at around 6200rpm. It feels a bit like a very big diesel engine and you need to keep changing gears as fast as possible as it arrives to the top end of the power in no time. Occasionally you won’t even be able to hear your own engine sound while changing at around 6000rpm, while an attacking Audi or Lamborghini are screaming besides you at over 8000rpm. Still, after 2nd gear and with the rear tyres finding traction, there not many cars that can beat you in a drag race down the straights.
There is some turbo lag but it is taken care of with an anti-lag feature which makes the exhaust gurgle and our sound engineer happy. All this generous torque can easily result in power oversteer at any speed and gear, which normally would make the tyres unhappy but the very advanced new generation TC, helps both amateur and professional drivers, position the car properly and at the same time results in a big smile in their faces. Don’t overdo it though because after then smooth and gentle initial drift, the long rear end starts to slide and slide and slide even more, raising the heartbeat and destroying the tyres.
Keep it all together and you’ll be rewarded with a best in class acceleration out of the turns. Yes the Huracan has amazing traction and the initial acceleration is great while the TC intervention is minimal… Yes the Ferrari 488 mid turn speed is incredible. Yes the Mercedes GT3 balance is exemplary… but keep them behind you and watch them become smaller and smaller on your rear view mirror as they can’t even keep the slipstream while you roar towards top speed. Which you will hit fast… and hard. As a matter of fact, the car arrive at a high top speed very fast and then it hits a wall. A wall of air resistance as the drag hits and stops the car. This is when the other smaller cars will start closing up to you towards the brake zone and so the play starts again… Overtaking you though, that’s a whole different story.

No surprise then that the car managed to win the 24Hours of Spa, at a track famous for it’s mid to high speed turns and long uphill straights. Look at the narrow bumpy Brands Hatch race though and you’ll get the opposite side of the coin.
That is what the Blancpain series is all about, isn’t it?

 

I just watched Chris Heye's video. Amazing as usual, I enjoy them so much, thanks for the link.
Can't see though how we contradict each other. I think we say more or less the same things. Did I misunderstood something?

All in all, the BMW is a car that you can "trust" and push. The problem is that while you can arrive at the limit sooner with it, and it seems to do what you want, to do Huracan laptimes you need to start driving it way more smoother and with much more self control than what you think at first is normal. And then it starts showcasing some of its limitations. Kerbs handling, understeer, traction problems... But still in a kind way most of the time. You don't feel in danger as often as with the Huracan

Btw, tomorrow Huracan blog...

 

The other dev guys are working their brains out long hours every day. When I have a tiny bit of time, it's the least I can do to support their work and keep you guys busy and entertained. Besides, I really love cars so when I manage to start the text, then everything flows

 

When we are on track sites, he usually wears a t-shirt with "WARNING MAY SPONTANEOUSLY TALK ABOUT CARS".
And it's not a joke

 

Yeah all the girls say that I'm such an interesting guy for chit chat...

 

I doubt you ever noticed a girl at a race track with cars around