Engine Braking

[zenvision]

KR: "Next year will be completely different without the traction control, without the engine braking and all those things, so I think it will be nice to see. It can be a completely different story"

While on wiki I found

The drivers do not utilise engine or compression braking, although it may seem this way. The only reason they change down gears prior to entering the corner is to be in the correct gear for maximum acceleration on the exit of the corner.

I know that in wiki you don't always find the truth, but I always thought that there never was any engine braking. And if there was, why are they removing it?

[Tifoso]

KR: "Next year will be completely different without the traction control, without the engine braking and all those things, so I think it will be nice to see. It can be a completely different story"

While on wiki I found

The drivers do not utilise engine or compression braking, although it may seem this way. The only reason they change down gears prior to entering the corner is to be in the correct gear for maximum acceleration on the exit of the corner.

I know that in wiki you don't always find the truth, but I always thought that there never was any engine braking. And if there was, why are they removing it?

Maybe Kimi refers to the fact that the TC "cuts" the force transmited from the engine to the wheels so that there is no wheelspin. Maybe that is the brake that Kimi talks about as the TC "brakes" the engine.

[Tom]

Bob Boundrant always said that engine braking does serious damage to racing engines, obviously they're much stronger now though so I wouldn't be surprised if they did use it. I would tend to trust Kimi over Wiki though.

[kimi]

i found this on WIKI..hope it helps

Engine braking is the act of using the energy-requiring compression stroke of the internal combustion engine to dissipate energy and slow down a vehicle.
Compression of gas and vapor requires energy as described by theories in physical chemistry and thermodynamics. Compression in an engine is driven by the forward momentum of the vehicle as well as the angular momentum of the flywheel. When a driver downshifts to spin the engine at high angular velocity (or RPM) without pressing on the gas pedal, the engine converts energy from the vehicle's speed, which is kinetic energy, into a temperature increase in the fuel-air mixture. These hot gases are exhausted from the vehicle and heat is transferred from engine components to the air.

This energy conversion occurs because most four stroke internal combustion engines require compression of the fuel-air mixture before ignition, in order to extract useful mechanical energy from the expansion. Diesel engines are adiabatic and have no spark plugs and use energy transferred to air charge during compression to directly ignite the mixture when the fuel is injected.

well i wonder if this is the case then is it safe to use engine breaking in f1?coz it might exert extra pressure on the engines to run it on higher RPMs in low gears to slow the car down...

[joseff]

I think what KR is referring to is TC-assisted braking. Basically the TC modulating the amount of engine braking at the rear axle, therefore acting as an ABS system of sorts. You can see this on TV, watch the TC indicator flickering under heavy braking.

Next year there will of course be normal engine braking, as they don't declutch the engine during braking.

[Carlos]

Classic engine braking durring manual downshifts and clutching,(I realise this does not have anything to do with TC or current autoshift F1 transmissions and technique) was largely abandoned as a racing technique because of technological advances in tires and brakes. Between 1964 and 1974 tire widths went from 6 inches to over 12+ inches (15cm>30CM+) with a corresponding increase in disc brake size, increased mechanical adhesion/grip advanced surpassing any benefit derived from maunual downshifting/clutching/engine braking.

[redline]

I think what KR is referring to is TC-assisted braking. Basically the TC modulating the amount of engine braking at the rear axle, therefore acting as an ABS system of sorts. You can see this on TV, watch the TC indicator flickering under heavy braking.

Next year there will of course be normal engine braking, as they don't declutch the engine during braking.

Exactly. TC works not only during acceleration. It can be programmed to apply some throttle during braking, thus reducing possibility of locking rear wheels. Onboard videos only show TC cutting down power during hard exit from the corner. I would say it's constantly adjusting throttle/ignition timing either full or off throttle

[Ogami musashi]

The sound of TC is easily distinguishable. You can actually see the TC indicator On during heavy braking on some on board footage.

Last year, during throttle/brakes display view you could see that some drivers and/or TC applied throttle blips during braking to avoid locking the wheels and/or retaining balance ( a major consideration with a formula one car) for the corner.

Next year will be interesting.

On side note, Franck montagny actually explained on his website (in french) that next year TC will be banned but that teams are allowed to work on throttle systems that will ease the work for drivers so that spinning will not occur too often, sadly without any further explanation.

[Belatti]

On side note, Franck montagny actually explained on his website (in french) that next year TC will be banned but that teams are allowed to work on throttle systems that will ease the work for drivers so that spinning will not occur too often, sadly without any further explanation.

Does someone knows how does the accelerator will work now without TC? (mechanical, electronic.... ???)

Tell me how it works and maybe I could guess what can be done...

[riff_raff]

"Bob (Bondurant) always said that engine braking does serious damage to racing engines"

Bob was a pretty good driver and business man, but not much of an engineer. Compression braking puts far less stress on an engine than the engine sees during acceleration. It's high revs that hurt an engine.

The carbon brakes on a modern F1 car can absorb massive amounts of energy without any fade issues, so there is little need to use the engine as an auxiliary braking device. The limiting factor in braking is usually tire grip- you can only brake (or accelerate or corner) as hard as the tires will let you. Most drivers keep one foot on the throttle while they brake to keep the engine revs up. This allows them to put the power down the instant they let up on the brakes.

[Belatti]

...Compression braking puts far less stress on an engine than the engine sees during acceleration. It's high revs that hurt an engine.

True

...The carbon brakes on a modern F1 car can absorb massive amounts of energy without any fade issues, so there is little need to use the engine as an auxiliary braking device. The limiting factor in braking is usually tire grip- you can only brake (or accelerate or corner) as hard as the tires will let you. Most drivers keep one foot on the throttle while they brake to keep the engine revs up. This allows them to put the power down the instant they let up on the brakes...

True again, now here you have got to design a traction shaft (please, help me here with english correct translation) that can handle that braking+acceleration at the same time