McLaren ‘traction control’
Tagged: McLaren TC Traction Control ECU
12th October 2012, 7:14 at 7:14 am #132210
According to Sky’s Ted Kravitz, the strange noise is the engine running only half of the avaible 8 cylinders. As @hohum hinted these kind of devices are banned, but I have an interesting theory, why this could be legal. It might be a silly thing, but I would like to share it with you, and hear your toughts.
I think its operated by steering angle, when the driver turns the wheel fully to either side, the noise kicks in, using only 4 cylinders, reducing the torque output, but maintaining the same rpm, allowing the driver to hit power earlier out of the corner by reducing the wheelspin.
If it works like this, than its driver operated, and not an aerodynamic element, thus IMO legal. Of course it might be something else. Ideas?12th October 2012, 8:46 at 8:46 am #211988
Here is the video:12th October 2012, 9:11 at 9:11 am #211989
I wish I was clever enough to understand this theory. Are we talking about the traction control-esque grinding sound on corner exit?12th October 2012, 9:15 at 9:15 am #211990
Yes we are, I’ve tried to pinpoint the throttle state where it kicks in, but its independent of that, then I tried with RPM, but thats not it, and then I realised it has to be the steering angle, which operates it.12th October 2012, 9:43 at 9:43 am #211991
At first I thought that it was simply in the first 2 gears, but Button does ‘grind’ his way through T8 in 6th gear and a 3rd and 4th gear later in the lap as well.
So steering lock is likely. I tried to look at it, and at T8 mentioned before you can clearly here it, while he is putting in about 45 degrees of steering lock.
But then look at T17. He is going through there at nearly full throttle, and at 45′ish degrees of lock as well but there is no grinding noise.12th October 2012, 10:40 at 10:40 am #211992
You might be onto something, it has to be at around 45 degree. I checked those corners, and there is definetly a 3-4 degree difference.12th October 2012, 11:04 at 11:04 am #211993
Wow thanks for making such an effort. Nicely done!
But looking at it again, I think it also has something to do with the throttle application.
See, it turns on when he is not at 100% throttle and applies over 45 degrees of lock, but then it stay on until he is on full throttle. Look at the exit of T1. Much less then 45 degrees (but he did apply over 45 degrees as he turned into the corner, off throttle) of steering lock in 2nd gear, and just as it reaches full throttle the grinding noise stops.
Same through T8 and some of the 3rd/4th gear turns later in the lap.12th October 2012, 16:10 at 4:10 pm #211994
Maybe, but I dont think so. The drivers never use full throttle in a tight corner, also as you open up the steering angle you apply more throttle simultaneously. When he floors it, the steering angle is less than 45 degree, so IMO this is the reason why it stops at full throttle. But the main question stands, is it legal or not? And why didnt anyone picked up this, apart from a small note by Kravitz?12th October 2012, 16:17 at 4:17 pm #211995
I picked it up last night during a brief onboard shot during FP2. I thought it being 2AM and all I was just hearing things. If it is just cylinder cutting based on steering angle it sounds legal to me. It could also be McLaren have found a creative way to circumvent the exhaust-blowing ban, but I doubt they’d roll something like that out so late in a season.12th October 2012, 17:35 at 5:35 pm #211996
But if you look at T1, you can hear the system as he exits the corner, even when he is in 2nd gear and opens op the steering. So it is still on, while he has less then 45 degree of steering angle. First as he opens the throttle fully it shuts down.13th October 2012, 11:56 at 11:56 am #211997
§9.3. of the Technical Regulations:
‘No car may be equipped with a system or device which is capable of preventing the driven
wheels from spinning under power or of compensating for excessive torque demand
by the driver.’
Would still be illegal.13th October 2012, 12:46 at 12:46 pm #211998
Then the team could argue what is the torque demand, and what is excessive.
The short version:
1) It is not capable of stopping the wheels, nor reducing their speed.
2) The driver changes the torque output, and he is demanding less.
I think the ‘spirit’ of the rule would be, that if the driver pushes the accelerator too early and the wheels get spinning, there should be no device that could prevent it. BUT in the rule there is nothing about the pedals, just the torque demand. The driver knows that he can reduce the torque output by turning the steering-wheel, or lifting off, or doing the two simultaneously, and so he ‘demands’ less torque, than the state of the accelerator pedal suggest.13th October 2012, 13:02 at 1:02 pm #211999
I fail to see how ‘[n]o car may be equipped with a system or device which is capable of preventing the driven wheels from spinning under power’ is a grey area. Even if one were to argue that its primary role is engine-/aerodynamic-related (which there are regulations against as well), it’d still be passively ‘capable’ of preventing the rear wheels from spinning under excessive torque demand.13th October 2012, 13:17 at 1:17 pm #212000
In my interpretation the rule says two different things, and it might have intended to ban one divece, but the rule says:
a)no device which is capable of preventing the driven wheels from spinning under power
b) (capable of) compensating for excessive torque demand by the driver
So a) It is clearly cant stop wheelspin, nor reducing its speed under power, it is not like you hit the power and the car wont let you spin the wheels.
b) there is no excessive torque demand from the driver, as he demands less torque by turning the steering-wheel.
All in all, I think this is a classic example of ‘How to exploit loopholes’.13th October 2012, 13:34 at 1:34 pm #212001
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