Engine Braking

[Belatti]

ECU/TC acted as a rear axle ABS, engine braking its just engine adding "negative" torque cause of internal friction and air compression as mahesh248 said.

The first thing to do would be to send a bit foward brake bias and then teach this drivers to downshift at proper rpm´s so that the big increase of "negative" torque (if you allow me) due to more air compression at higher rpm don´t lock the rears.

To achieve this purpose they have those racing simulators.

If I can downshift perfectly in GP4 and any stock car racing drivers can do it without electronics then they can!

[Mikey_s]

yup they are fly by wire, im sure.

I imagine pedal adjustment was one of the first things drivers did when testign without TC.

I was reading the tender document for the FIA spec ECU and indeed there are 2 inputs for; analogue and LVDT input for throttle pedal travel... QED the throttle pedal is fly by wire...

[riff_raff]

2008 F1 reg's:

"5.5 Engine throttles :

5.5.1 The only means by which the driver may control the engine throttle positions is via a single chassis mounted foot pedal.

9.3 Traction control:

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 throttle demand by the driver. Any device or system which notifies the driver of the onset of wheel spin is not permitted.

11.1 Brake circuits and pressure distribution :

11.1.4 Any change to, or modulation of, the brake system whilst the car is moving must be made by the driver's direct physical input, may not be pre-set and must be under his complete control at all times.

11.5.1 No braking system may be designed to prevent wheels from locking when the driver applies pressure to the brake pedal.

What the rules say is no drive-by-wire, no traction control and no ABS.

[Mikey_s]

Riff raff,

I do not interpret the rules you have quoted as stating no "drive by wire".

The throttle is controlled by the throttle pedal irrespective of whether there is a direct link between the two. My understanding of drive by wire is that the old fashioned physical link between the pdal and the throttle body is no longer there. In place we have an LVDT which senses the pedal position, relays that to the ECU, which then relays the information to a servo in the throttle body (also connected to an lvdt) so that the movement of the throttle is "controlled" by the pedal movement, but virtually, rather than directly...

I do not believe that this "drive by wire" system contravenes the TC ban, this would onl happen if the teams managed to find a way to get the ECU to intervene if wheelspin was detected. However, I would be astonished if any of the teams were using a throttle cable any more...

[alelanza]

Please excuse my ced ampoing here but i didn't find any more recent topics with this subject.
I found this FA video interesting, it's in spanish but mainly he describes the 2009 changes on the steering wheel (KERS and front wing angle)and then he goes on to talk about the engine brake control (multimap dial on the upper left side around min 3:42)

[youtube]http://www.youtube.com/watch?v=dMprvHaQgSo[/youtube]

Personally i was unaware they had this option to adjust how much the engine affects rear axle braking, in my head it had been eliminated altogether, now i realize it was only the electronics automatically controlling it being eliminated. Once you mix it up with the KERS recharge rate and forward/rear brake balancing it seems like a fairly complex system, but Fernando says simply that the kers recharge rate is given to him by the engineers and that engine braking is simply determined in practice by whether or not you blocked the rears, in which case he tones it down one notch.
So i guess a lot of you knew this, nice video anyways.