F1technical.net

I think I read somewhere that an F1 car's aerial resistance from 300 km/h is so high as lifting off results in more than 1g?

It results in approximately 1g. Xpensive once gave us that wonderful calculation where engine power would approximately equal 1g, and since at top speed all your engine power is going into resistant forces (mostly aero drag), that implies ~1g of braking from aero alone. Which is 1g of braking that is not available for harvesting. That was 2010 regulations, current cars probably have a tad less power, less drag and more mass, so it might work out to a bit below 1g these days.

Edit: found the actual quote:

xpensive wrote:If you give Cv times cross-section area the value of 1.5, it should not be that far off.
This makes for simple calculations, when aerodynamic drag becomes 0.75 times density times speed squared.
Conclusively, an F1 car at 320 km/h (200 mph), has to overcome a force equal to 6700 N. That force, if acting on a 700 kg object means an acceleration of almost 10 m/s^2.
In popular wording, if an F1 car loses all power at 200 mph, it will accelerate with one g from air-resistance alone. Think about it.

Tommy Cookers wrote:but where will there be 2g braking down to such a slow speed ?
typically at the slower speeds the driver is braking and turning ie the braking element is much less than 2g
and at this time the driver would find regen intrusive anyway ?

100 kph to standstill = 15m -> average decel = 2.6g. Some is aero drag, most is front brakes, but it would be safe to say rear braking contribution is about 1G.

Obviously, I am only throwing these numbers out there as an absolute limit for MGUK regen.

hollus wrote:It results in approximately 1g. Xpensive once gave us that wonderful calculation where engine power would approximately equal 1g, and since at top speed all your engine power is going into resistant forces (mostly aero drag), that implies ~1g of braking from aero alone. Which is 1g of braking that is not available for harvesting. That was 2010 regulations, current cars probably have a tad less power, less drag and more mass, so it might work out to a bit below 1g these days.

Edit: found the actual quote:

xpensive wrote:If you give Cv times cross-section area the value of 1.5, it should not be that far off.
This makes for simple calculations, when aerodynamic drag becomes 0.75 times density times speed squared.
Conclusively, an F1 car at 320 km/h (200 mph), has to overcome a force equal to 6700 N. That force, if acting on a 700 kg object means an acceleration of almost 10 m/s^2.
In popular wording, if an F1 car loses all power at 200 mph, it will accelerate with one g from air-resistance alone. Think about it.

Interesting, I tried to recalculate that and it seems to figure, but the decelleraiton will rapidly go down from 200 mph.

Abarth wrote: LMP cars are allowed to harvest with front axle too AFAIK.

That's incorrect. LMP1 are limited to two harvesting electrical units (the regs define them as ESRH's or something from memory). The TS040 has regenerative braking from the front and rear axles (and thus deployment as well) while the 918 and R18 only have front axle regeneration. The 918 has a secondary recovery source as a secondary GU-H unit (separate to the main turbo I believe) while from reports the 2015 R18 was meant to feature exhaust recovery but they removed it at some point before competition.

The 918's front axle motor is in the realms of 700+ hp, presumably it's not overly heavy.

Cold Fussion wrote:

Abarth wrote: LMP cars are allowed to harvest with front axle too AFAIK.

That's incorrect. LMP1 are limited to two harvesting electrical units (the regs define them as ESRH's or something from memory). The TS040 has regenerative braking from the front and rear axles (and thus deployment as well) while the 918 and R18 only have front axle regeneration. The 918 has a secondary recovery source as a secondary GU-H unit (separate to the main turbo I believe) while from reports the 2015 R18 was meant to feature exhaust recovery but they removed it at some point before competition.

The 918's front axle motor is in the realms of 700+ hp, presumably it's not overly heavy.

Thanks for the clarification, albeit I don't know what's incorrect saying that they are allowed to harvest at the front axle?
They obviously are, as per your explication?

Aparently they will make another engine change for tomorrow (so they will have a quite fresh spare engine), because they already have 25 and 30 grid penalties for sunday and they cant start any lower.

I think that's a pretty good plan from McHonda, take a massive hit in penalties at one of your worst tracks. I don't expect them to run too much in Q1 when they are starting from the back no matter how high they get

At the moment it looks they don't even need penalties to start at the back

Really patetic the Honda update.........

PABLOEING wrote:Really patetic the Honda update.........

IIRC they're taking these engines that were run today back for analysis - to see if the combustion updates are working as expected, so whilst they may be doing full recovery in bursts to load up the engine/turbine, that doesn't mean they're running near max power mode yet, in fact I doubt we'll see full power until P3 tommorow, and only then if they don't see any issues from today's data.

Abarth wrote:

Cold Fussion wrote:

Abarth wrote: LMP cars are allowed to harvest with front axle too AFAIK.

That's incorrect. LMP1 are limited to two harvesting electrical units (the regs define them as ESRH's or something from memory). The TS040 has regenerative braking from the front and rear axles (and thus deployment as well) while the 918 and R18 only have front axle regeneration. The 918 has a secondary recovery source as a secondary GU-H unit (separate to the main turbo I believe) while from reports the 2015 R18 was meant to feature exhaust recovery but they removed it at some point before competition.

The 918's front axle motor is in the realms of 700+ hp, presumably it's not overly heavy.

Thanks for the clarification, albeit I don't know what's incorrect saying that they are allowed to harvest at the front axle?
They obviously are, as per your explication?

Sorry I miss-read your post, I thought you said they can only harvest from the front axle.

autosport has a very good article with qoutes from eb about the honda pu problems

How many times is it this season we see new engine components fitted to the car and they can't run due to a technical error?
Is it finger trouble or poor quality from honda?

I just followed FP3 and in my opinion the Honda engine is making a very different sound compared to the other cars. A very strange roar which does not "feel" correct and powerfull.

Btw, they are nowhere near the power of the Ferrari engine during last practice sessions, or the McLaren is even worse then the Sauber...