Paul Jeffrey
Premium
Aris has been away from the internet for a while but fear not, he's back - and he's posting blogs about cool cars in Assetto Corsa Competizione once again!
Assetto Corsa Competizione has been out at V1 release status for a little while now, and if you've not yet had the change to try the Porsche 911 GT3 R in game yet, I highly recommend you do.
Seemingly @Aristotelis likes the car too, as he publishes another one of his very interesting and insightful developer blogs about this awesome GT3 machine..
The Porsche 911 has always been a top competitor through the years. The unorthodox architecture with the engine hanging at the rear giving heavy rear weight distribution combined with the short wheelbase, has always been judged as extremely unstable for street use. Yet, in the hands of an experienced professional driver, the extremely fast turn in, the agility in changing direction and the best in class traction, always delivered top performance. Sure everybody would complain of instability at turn in and terminal power on understeer at corner exit. Still professional drivers knew how to deal with such characteristics and adjust their driving style to make good use of the advantages. In a class where the cars were heavy and grip was generally lacking, being able to put the power down and change direction quickly was always an important advantage.
The choice of the word “was” is not casual though. Modern GT racing have brought to the grid cars with big aerodynamic improvements, electronic systems for traction control and ABS are adjusting traction and grip circles and modern tyres provide more grip. Speaking of which, because GT3 racing is “client racing”, in order to keep costs low, the tyres are identical for all cars with tiny dimension changes.
The end result is that the Porsche ended up without being able to make a difference with its architectural advantages, while it become even more unbalanced from the tyre dimension availability that often keeps the front tyres out of the operation range.
Aerodynamic advancements are also limited by the architecture. Much of the aerodynamic downforce gains are made from a big rear diffuser that has to be wide and deep enough. Unfortunately for the Porsche, that’s exactly where the engine sits, so the actual diffuser is very shallow and short. That means the engineers have to work a lot on the front splitter and the rear wing. They manage to create substantial downforce, but it is still not enough. It also generates a lot of drag as it needs the rear wing to work in high angles and most importantly, the resulting aero platform has a very narrow window of operation and a very non linear downforce production that creates unpredictable results. In the paddock, you can often hear the drivers complain that the car works strangely whatever the try to do and the engineers complain that they can make the car “work” in a given circuit or condition. As if things couldn’t get worse, most of the cars have their fuel tank near to their Centre of Gravity, so that the fuel load only affects the weight of the car but not the overall balance and handling. Not the Porsche; 120 litres of fuel hanging under the front bonnet. Which means that even if you manage to make the car work with a good setup, the whole balance is going to change when the fuel load will change. The car needs quite different setups for race and qualifying sessions. Often teams will add more fuel during qualifying, to help the drivers with a more predictable handling. During the race, the car will change handling characteristics and the drivers must be ready for it. It’s not uncommon to see the car being competitive during one part of a stint, and then get slower for the rest of the same stint as the fuel load changes, or vice versa, depending on the setup compromise the team opted for.
Another limiting factor is the engine. This amazing powertrain screams up to 9000 rpm and it is one of the most praised engines in the road car. So how this can be a problem?
Even though the BoP is not very restrictive, it still has to limit the power to around 500bhp, similar value to the other small frontal area cars. Incidentally this is the same outcome of the street engine. Surely race engines could go higher, but when you start analysing the engine capacity, you realise that there’s not much margin available. The flat 6 engine is normally aspirated and has “only” 4 litres capacity. The smallest engine of the grid is the one of the Honda NSX, 3.5lt but twin turbo. All the other normal aspirated engines vary from 5.2lt V10 of the Lamborghini and Audi, up to the massive 6.0lt V12 of the Aston Martin and the gargantuan 6.2lt V8 Mercedes. Which means that those cars can generate similar amount of power but also massive torque from very low revs. The Porsche engine has to climb up to 9000rpm to achieve the same power and obviously the power band is more peaky. Surely the gearbox ratios can cover the problem, but then again the GT3 series demands a single gearbox ratios homologation that then is used on all the circuits. Some serious compromises must be taken.
Seems like the Porsche has serious disadvantages and predictably the performance of the car was not adequate of the name in 2018, with the occasional spark under wet conditions where the traction can make a difference and the top speed is not so important. Porsche focused its efforts on the WEC GTE 991 RSR car which was highly modified with the engine rotated by 180° and practically transformed in a mid engine architecture. The car performed much better and surely the engineers learned a lot from that experience. The 2019 Porsche GT3 R car already won the Monza race and is looking good for the rest of the season. So if you want to win with the Porsche, you need to be a bit patient until we release the 2019 version of the car.
Still, all said and done, when you get to drive the Porsche, the shortest wheelbase of the grid, the scream of the flat 6 at over 9000rpm, the amazing turn in, while the rear starts to rotate, the fast and constant workout needed with the steering wheel to keep the car from over-rotating and the sublime lightness of the front end when you put all the power down and the front raises up, makes you forget the shortcomings in performance. The car keeps you alive and alerted at any moment. Brings back memories of vintage racing cars when the driver could make all the difference. When finally you manage to drive it properly the level of self reward reaches new heights.
Forget about top speed, you know you’ll be the slowest anyway. Add rear wing to get downforce, stiffen the rear end to make it rotate, play with the brake bias that can be set way to the rear and start working that steering wheel. The Porsche won’t forgive lazy drivers, it won’t make it easy for you. It demands your total dedication, yes even if you have to race it for 24 hours and doesn’t care if you’re tired. Show the respect it asks for, and you’ll get a different kind of reward that only special cars can give; and if it rains… you might even have a chance for something special.
Full post can be found HERE.
Screenshot from Kunos forum user Tino66
For more from the world of ACC, why not head over to our Assetto Corsa Competizione sub forum and get yourself into the thick of the action? We have a great and knowledgeable community, plus some pretty epic League and Club Racing events, if I do say so myself. Go on, treat yourself!
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