https://dirtfish.com/rally/wrc/how-t...ost-will-work/
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Now we know more about how the boost can be deployed, how is it stopped? By hitting the brakes?Quote:
Originally Posted by wwbroe
“That’s correct,” said Fowler. “During normal braking you’re regenerating but if you’re deploying during an acceleration phase and you touch the brakes then you’re required to stop deploying, in a similar way to if you touch the brakes when you have cruise control on on the freeway it might deactivate. It’s effectively the same situation.”
so drivers who use constantly the left foot brake have to change style?
I was thinking that isn’t Ogiers and Tanaks braking style an advantage for generating the energy?
depends on what actually means hitting the brake.Quote:
Originally Posted by dimviii
possibly they can set a bar pressure threshold that activate the interruption, so u can touch the brake until a certain pressure before stopping the boost.
but why lol. they should just put a button to do thatQuote:
Originally Posted by dimviii
Sounds like a brake pedal sensor that cancels deployment with any input, if they're balancing a car already at speed they probably don't want the boost, but that's not energy wasted as it'll be available under acceleration out of the next slow corner, providing they're pointing and travelling the right way.
With energy regen, at first I thought nobody's going to be braking later and harder then they already do and that was it. But regen is active above 5 bar pressure of the front brake and some rear braking comes with the regen capture. To what degree does balancing the regen desire strategy with braking efficacy affect setting brake biases and then standard left footing, in reality and in heads? Maybe it's not so simple, maybe it's not worth the thought. In two weeks I'll find out.
The thing is that with recuperation you can brake harder and later when there is enough grip. The recuperation takes away reasonable part of the energy which would otherwise transform all into heat.
Then why weren't you doing that before? All other factors equal, what changes with just introducing regen?Quote:
Originally Posted by Mirek
If there was only one short braking in the whole stage than the recuperation would make no change but there is a lot of braking. Every braking generates heat. The harder you brake the more heat you produce and the more you need to dissipate. The cooling effeciency is however limited, therefore you can brake only that much that your brake fluid dosn't start to boil or your brake pads don't start to glaze or even burn. When you recuperate energy you create much less heat by braking which means that the same amount of the energy you recuperated during the stage you can also spend on extra braking without overheating the brakes. That may create really big difference especially on stages like in Catalunya.Quote:
Originally Posted by WRCStan
It would be interesting to know what is the maximum regen power they will get and what is the net capacity of the battery in kWh. Maybe it has been provided already somewhere? It would be an interesting thing to show, what is the % of the battery and what is the current regen power and regenerated energy in a sector/braking etc.
In a trip in Norway with a Kona EV I managed to regenerate 5 kWh in around 15 km when descending from 1300 m a.s.l to 9 m a.s.l (the road from Turtagrø to Øvre Årdal). Kona allows a maximum 150 kW charge to battery when recuperating (measured with an OBD dongle), Taycan should allow up to 300 kW if I remember correctly. But as the Rally1 battery is probably quite small I believe their maximum regen power is lower, otherwise the C would be very high and the battery longevity would suffer.
Weighing 84kg, Compact Dynamics’ high-performance P3-topology hybrid system accommodates a motor-generator unit (MGU), control unit and battery in a compact housing, thereby delivering maximum power density. The battery for the hybrid system is supplied by Compact Dynamics’ partner, Kreisel Electric, based in Austria.Quote:
Originally Posted by Tanelv
The unit consists of a 3.9kWh capacity battery pack which is coupled to the MGU, delivering 100kW (134hp) of power and 180Nm of torque during acceleration.
During braking and coasting, the system recuperates energy normally lost and stores it in the battery. If necessary, the battery can also be recharged by an external power supply (plug-in hybrid) during service breaks. To charge from 20 to 80 per cent will take around 20 minutes using the dedicated units.
The MGU, which operates at up to 12,000rpm, the battery, which operates at up to 750 volts, and the inverter control unit are sealed in a carbon fibre housing to resist possible forces and impacts in the event of an accident. The unit is designed to withstand a 70G impact.
https://www.wrc.com/en/news/2021/wrc...inable-future/
Rally1 hybrid system explained by M-Sport:
https://youtu.be/-mbCJecCDr8
If I count right in a veeeeery simplistic linear scenario a 300 kW recuperation would be able to slow down a WRC car from 150 km/h with a deceleration of 1,5G without using brakes at all.Quote:
Originally Posted by Tanelv
Does anyone know how the cars regen their battery between stages during a loop (not at service). Is this done with the car's ICE ?
Yes of course.Quote:
Originally Posted by Fast Eddie WRC
Great work by WRC Wings comparing the aero of the three new Rally1 cars...
https://www.wrcwings.tech/2022/01/10...2-rally1-cars/
after 3 days we discussed here ,there we are.Quote:
Originally Posted by dimviii
https://dirtfish.com/rally/wrc/will-...e-out-in-2022/
I remember that already in the era of the fully active 2.0 litre WRC they often said that left foot braking isn't needed if you set the diff maps right (at least on asphalt). After all the left foot braking wastes energy and adds heat to the brakes. In pure theory it shall be avoided. The new cars don't have the center diff and shall therefore behave more like an overpowered R5 car. It would be interesting to hear from the drivers how much they actually use it in them.
By the way my eyes bleed reading the first paragraph of the article... of course you launch yourself through the windshield if you do the left foot braking in a stock car because there is the vacuum brake servo which is not present in the WRC car. On the other hand everyone is able to brake by left foot in a go kart and finds it perfectly natural.
There's a difference to using your left foot for braking (while not throttling) and doing the "left-foot-braking" which is used to balance the car to improve turn-in.
From what I've heard from various interviews, Ogier's style is to brake before corner, roll through the corner and apply throttle upon reaching exit angle. Thus there's no simultaneous braking and throttling.
Out of the current drivers Esapekka Lappi seems to be a heavy left-foot-braker, braking lights are alight while turning as well. Remember when he and Ogier were teammates at Citroen, they struggled to find suitable front diff ramps for Esapekka.
Since you mention Citroen...
In 2017 Mikkelsen drove the 3 rallies with them, before the first one (Sardinia) he had some 80 km test. Later there was I believe an official press release where they said that they didn't have any diffsettings ready for a driving style that "didn't use left-foot braking at all" (Mikkelsen copied his style from Ogier at VW).
This even got some attention here with comments about "how can anyone drive like that".
I just wonder what's the disadvantage for the left foot braker. when they use the throttle and the brake at the same time in the 2022 hybrid car??
Quote:
Originally Posted by AnttiL
how much energy can regen when braking for each corner? and how much energy can be use for each second when driver use the extra power ? is the hybrid power control by another button like the kers button in F1Quote:
Originally Posted by sti123
With regards to hybrid deployment? If they cancel the boost under acceleration using any brake pressure when the battery is less than 80% charged, they lose what boost they could've had and must go through a full regen cycle to get another booster shot (let's agree to ban this term). How much energy they get to use per boost and need to recover for a valid regen cycle is different per rally and is set by the FIA, so what they lose on is unknown now. Regen under braking has a throttle pedal input tolerance of 30% and brake pressure must be above 5 bar pressure. According to Google/Quora, a typical road car is at full lock around 70 bar (or 96 bar power assisted), so how much energy can be micro-recovered this way remains to be seen but I guess insignificant. So much depends on the stage and the rally.Quote:
Originally Posted by 1988senna
With regards to handling/approach? Others will have the input here. Lack of the active centre differential may encourage it. Things like suspension setup in terms of pitch/roll and brake biases may play with heads. 10 days or so time we'll see to what extent.
There's no button - they either have it or don't. Probably best to read the previous pages and links to understand why the other questions can't be answered.Quote:
Originally Posted by 1988senna
Quote:
Originally Posted by AnttiL
the drive can't manually control the hybrid boost right?it's the teams set the maps before the stage and so when driver use the throttle the .the hybrid boost will active automatically?Quote:
Originally Posted by WRCStan
I'm not clear by this video for 2 pointQuote:
Originally Posted by Fast Eddie WRC
1.if there have 80 kilometre with 4 stages to go and no service between the stage. how can the driver make the regen if the 100 KW used out
2.why the driver must use the EV mode .is that mean they will use more electrical energy from the battery? how can they have the advantage
1. The car can regen the battery during the liaison or during the stage through brakingQuote:
Originally Posted by 1988senna
2. EV mode is shutting off the ICE engine in city sections and service park. Advantage? It's positive image.
Essentially yes. You are always entitled to hybrid boost on the start line. Subsequently you need to brake to regenerate power and recharge the battery to then deploy a new boost.Quote:
Originally Posted by 1988senna
And the driver can only switch off the hybrid boost for example on an icy section on a Monte stage with slicks.
So will small dabs of (left-foot) braking to adjust the car be enough to stop the hybrid boost and require another regen cycle or not ?
Likely yesQuote:
Originally Posted by Fast Eddie WRC
Quote:
Originally Posted by Mirek
Left-foot breaking is used for many reasons, as mentioned above. Third reason is the time it takes to move right foot from throttle and back just for breaking. So left-foot breaking I guess is used by every (fast) driver. Even driving RWD rallycars you perfectly can use left-foot breaking, if car has dogbox gerabox. However not at same time throttling in corners... :)Quote:
Originally Posted by AnttiL
I tried to explain that these are two different thingsQuote:
Originally Posted by Rallyper
1. Using left foot to brake, but never braking and throttling at the same timebecause the cars don't need the clutch (your #3 falls into this same category).
2. "Left-foot braking" as Rauno Aaltonen invented it in the 50's, to make the car shift weight to the front wheels and thus increasing grip and helping turn-in, and also on FWD cars it would make the rear wheels possibly lock and slide while the front wheels would still have torque. Also useful for early turbo engines to keep turbo rolling but still drive at slower speed
#1 will still be useful for Rally1 cars. #2 is be a technique that will likely be used less.
#2 Also giving FWD cars with no difflock getting both wheels work in corners (on winter and gravel conditions) by breaking same time as throttling. Maybe that was more of Aaltonen advantages than weight shifting...Quote:
Originally Posted by AnttiL
Breen off on PET.
So for the video as also mentioned that the boost lenth depend on the lenth of of stage ,The total energy have only 100KW, Is there have the boost difference for each boost by the ECU?Quote:
Originally Posted by AnttiL
For 4KM stage, each boost have 130 HP,But for 40KM stage ,each boost have only 13 HP to saving more energy for the rest of the stage ??
Aaltonen explained this in a podcast last year. When he got into rallying (after circuit racing) he was told to use the handbrake to get the car turned in. He found this inconvenient, since his both arms were occupied by steering wheel and gear shift. But he noticed his left foot was unoccupied, and thought about using the brake, and it worked. The main effect in those days was to lock the rear wheels and get them sliding.Quote:
Originally Posted by Rallyper
Other effect described was most important driving Saabs in 70´s... however getting them locking rear breaks was also important, especially with very slippery conditions.Quote:
Originally Posted by AnttiL
So no concerns that changes in diff set up and simpler suspension in the new cars will influence things?Quote:
Originally Posted by AnttiL
Might be worth being clear for anyone new to this that left-foot weight balancing happens even where there's no obvious left or right bend in the road or need to slow down. In XYZ axes through the car steering only takes care of Z. Roads go up/downhill, have cambers, ditches, subsidence and potholes, jumps and crests, variable traction, are infinitely describable and generally want to throw a moving car about, but is more pronounced on jacked and soft suspension.
Within the context of the hybrid package it's irrelevant if you use left or right foot to slow the car. The biggest unknown is how often and how much the boost is available. We don't know if it's 150m or 5km per 15km stage, or 150m or 5km on the next 15km stage, or if there's enough to still be in use at speeds where lfb is mostly used following an acceleration assisted boost. Driving style talk may be insignificant!
Loeb hasn't had much testing in the Puma hybrid. But he may remember driving this car from 2008 !
https://www.motorauthority.com/news/...ly-car-concept
I meant only simultaneous braking and pushing the throttle. Sorry if I was not clear.Quote:
Originally Posted by Rallyper