15 replies to this topic

[NinjaMouse]

On the engineering side of things, I know a little more about the aircraft scene, than I do about the car scene........so bare with me...

For a few decades now, the prospect of pilots being removed from the cockpit of combat aircraft has been tossed about, and as we have seen with Predator and Global Hawk UAVs, maybe this time rapidly approaches where true autonomus fighting vehicals do the fighting.........one major advantage of Not having a pilot, is G-Forces.......so by sticking a pilot on a seat behind a desk, the aircraft is free to manouver at whatever G loads it can sustain..maybe 20-30 Gs in the future......more than enough to kill any pilots out there........

So it got me to thinking about F1 cars....currently pulling 5g-ish.........I ask: What would be possible, with No Limits inovation, and a removal of the flesh and bone from the cockpit....how fast Could a 4 wheeled vehical go around a track...using every trick in the book, suck-down-fans, rocket boost on straights, flip up spoilers/air brakes, moveable aero surfaces, ground effects, mega slick tires.......

Could a car be devised that is so capable, that no human could drive it around a lap of a normal F1 track?....what sort of corning g-loads could be sustained?..etc...

[cheapracer]

Look around, this thread has been done but I don't remember the title sorry. Something about if there were no rules etc.

[OfficeLinebacker]

Originally posted by NinjaMouse
Could a car be devised that is so capable, that no human could drive it around a lap of a normal F1 track?....what sort of corning g-loads could be sustained?..etc...

It's already been done on an oval before in AOW. I forget the details but something like 3/4 of the drivers reported dizziness, black spots in their vision, nausea, etc. during practice and the race was cancelled, I believe.

Indeed, if all you did was make a modern version of the fan car with slicks on it, I don't think you'd have any trouble finding tracks where the G-forces would exceed human endurance.

I'd like to see it taken a bit further, and as opposed to RC cars (for which there are already highly competitive leagues), have computer programs drive the cars.

I'd sign up to help write the logic.

Imagine if the engineers could still call the cars in to pit, tell them to back off/push harder, etc. Only the commands were simply causing different code to execute on the machine.

Of course the ultimate would be to disallow all shore-to-ship communication, save perhaps a "turn off everything" command in case of accident.

Sort of like that contest sponsored by the US military with robots navigating a desert course.

[imaginesix]

Never mind making the drivers dizzy, it would make the spectators dizzy and turn the drivers (well, passengers really) to purée!

[Ray Bell]

Originally posted by OfficeLinebacker
It's already been done on an oval before in AOW. I forget the details but something like 3/4 of the drivers reported dizziness, black spots in their vision, nausea, etc. during practice and the race was cancelled, I believe.....

Texas Motor Speedway, 2001?

Texas 2001: CART management failed to listen to widespread concerns and scheduled a race at Texas Motor Speedway. It was canceled two hours prior to the start after G-load related driver blackouts.

From Auto Racing Digest, September 2001:

CART officials cancelled the recent event at Texas Motor Speedway--the circuit's first at the 1.5-mile oval, and the first time since 1985 that one of its races was abandoned due to safety concerns--thanks to worries about the drivers' health and well-being. The combination of speeds topping 235 mph and 24-degree banking on the oval track caused 21 of 25 drivers to report light-headedness and dizziness after spending more than 20 laps in the cockpit. It was feared that these extraordinary gravitational force levels--both horizontal and vertical--could cause drivers to suffer a loss of consciousness, to blackout, and put themselves and others at great risk.

Actually, that article is worth a read, in part it goes on:

Now, just as NASA is struggling to overcome human deficiency in its quest for achievement, so too must CART. The IRL has raced successfully at Texas Motor Speedway for years, but that is because of rules that restrict speeds to the 220 to 225 mph range. In other words, by limiting drivers and teams from performing at their best. CART now faces a similar decision, particularly because the equipment will only continue to improve, maxing-out the limits of driver conditioning and human ability.

I think Buford would love it...

[NinjaMouse]

fking 'ell......lol.....wow........I had no idea the treshold had already been crossed...cheers for the info.

I never really thoguht about it until recently, but it is worse for drivers than fighter jocks???......Fighter pilots may pull more G, but in general, they don't yank it around like that for more than 10 mins if in a dog fight or doing an airshow I geuss.....where as a Car driver has to hold up over a couple of hours....???

And how is lateral G compared to ...vertcial G?..I have a feeling from some fair ground rides I've been on, that lateral G is less natural to contend with, and quite uncomfortable.....I am familiar with the concepts of red out and gray out/black out and G-loc........but how does that work with lateral G?.....and they say you do different things with differnt sides of the brain, so one might assume that the "racing" (Artistic?) side of the brain could possibly be switched off due to blood loss???? And if on an oval, and a particular direction, one could possibly have the "racing brain" switched off for much of the time......???

Blimey...

[zac510]

I've been thinking about this and I think the answer is: 1 - ∞.

[Ogami musashi]

You have to separate the G-s stresses in two:

-the blood circulation
-the muscular stress

By far the most dangerous vector for G's as far blood circulation is concerned is the vertical one and especially the negative ones.

However the vertical one are not the most difficult to withstand muscularly in fact they are about second behind the longitudinal forward acceleration simply because your have a seat that already provide for the G's compensation so the strength difficulty lies only into the compression of the body.

The least demanding on blood circulation is forward acceleration as blood circulation does not suffer a lot from that; This is not surprising then that the record for sustained G's for a human was done with forward longitudinal G's (i think it's 58G's sustained for several seconds).

Lateral G's are not that hard on blood circulation however they are the hardest in muscular stress because basically you not only have almost nothing to stop you but the muscles working in side motions are quite weak compared to the muscle you can use for compensation of vertical and longitudinal accelerations.

The CART episode was a mix of vertical G's (as you know banked turn provide a component of vertical acceleration) and the fact it was sustained for very long period.

That leads to what influences G's withstanding:

-The rate of increase
-The duration

You can G-lock under 5G's if the rate of grow is something like 18g's/sec, then you can be okay under 10g's if the rate if progressive.
A crude example are accidents; recently in F1 drivers sustained about 25g's in frontal crash and collapsed because the rate was very high (the car was decelerating very fast).


Under normal circumstances however the duration is more important, sustaining 5's for 30 seconds is harder than sustaining 9g's for 2 sec.


So all in one to answer the topic. The first problem is to know what G's would result.

in 2001 CART race, drivers went to experience combined 5,5-6g's and experienced dizziness.
In 2004 F1 cars pulled 6G's at suzuka 130R and no problem.
The reason was of course duration and vector of application.

However F1 drivers had to go through hard fitness to withstand the muscular stresses and prevent any dehydration problem or cramps.

The problems are not the same.

In a current format of F1 race i think the most important problem would be the muscular one; one could imagine providing G's suits to pilots.
This was planned back in 1980 when ground effects let think that soon the drivers would have blood circulation problems.

That said a G's suit doesn't help with muscular stress.

How much a driver could withstand??? i'm not quite sure of the answer thus i'm not quite sure that the theory that the limits are reached holds true.

Another safety concern are reaction times, but quite surprisingly that was never a problem for F1 drivers, but rather for rally ones.

F1 drivers have barely the same reaction times than a sharp person, but they use far less energy to mobilize their capacity. That translates into the possibility of treating at the same speed more complex information.

However rally drivers may have similar demands because their environment may not move as fast, but is more complex.


Well in 2004 studies were done and the conclusion was that on a pure physical side, the limits were not reached, but that definitely the speed was a concern safety wise.

We would need another study maybe; I think a car that would reach 9G's in lateral would be very dangerous.

[Peter Leversedge]

Not For Remote Control Race Cars
When I was involved in racing for me the buzz came from sitting in the car, driving it around the track and being directly in control of it. Mind you I would have missed out on two broken knee caps etc. Was not aways in "control". Still I would not liked to have had to race by "remote control".

[phantom II]

Paul Werchan, a research physiologist at Brooks Air Force Base's Air Force Research Laboratory said that pilots can experience a wide variety of symptoms at 3Gs including dizziness and can loose consciousness at < 5Gs.
Werchan was contacted by CART's medical team to help analyze the G-forces on the drivers practicing for the race in Texas. To determine the total G-forces acting on a driver it is necessary to take into account the speed, and the position of the driver. Other crucial factors include the radius, length, and banking angle of the turns of the speedway. The Texas Motor Speedway's track has longer turns with higher banks at each corner than the Indianapolis 500 track. This affects the G-forces on the driver and how long they are acting on them. According to Beckman, at 230mph drivers at Texas Motor Speedway would feel G -forces of almost 5Gs for about 6 seconds, but in Indianapolis the drives would only feel G-forces of about 3Gs for about 4 seconds.
Drivers feel the G-forces longer in the turns at Texas Motor Speedway than at the Indianapolis 500 track according to Brian Beckman, physicist and member of the No Bucks Racing Club. This might explain why the drivers had a harder time handling the turns even though their speeds were comparable to what they would drive at Indianapolis.
According to Hewko, the drivers head position also plays a role in how drivers handle turns. The banking of the turns confuses the relationship between your eye, brain, and inner ear. The inner ear tells the driver which way the G-forces are acting, but the force is not the typical down force of gravity that the human brain is calibrated for. The disorientation is not quite the same as vertigo which is what you experience with motion without visual reference. Left and right sides of the brain functions are not altered drastically with sustained 6 second lateral loads but sufficient to miscalculate track position together with impaired decision making which varies from driver to driver.



The US Air Force at Holloman Air Force Base, NM operates a human centrifuge. It is operated by the aerospace physiology department for the purpose of training and evaluating prospective fighter pilots for high-g flight.
The centrifuge is unrealistic in that it is far more difficult for a pilot to tolerate the high-g environment in the centrifuge than in actual flight in a real fighter aircraft.
It is used to determine the individual pilots tolerance for sustained vertical G forces and a tailored AGSM (Anti G straining maneuver) and PBG ( pressure breathing training to increase tolerance thresholds. The average tolerance for a relaxed fighter pilot without a G suit is less than 4.5 Gs for 10 seconds. It is possible to take that to 8Gs after training which is required for fighter pilots. When joining the Air force, you are subjected to a pretty grueling medical which requires 3 solid days of testing and further testing to verify and exploit individual physiological properties.. 5’10” was the shut off pilots height. The taller you are the less tolerance you have for vertical Gs. Negative loads can cause aneurisms. Red out is very uncomfortable during recovery and aerobatic pilots often have bloodshot eyes.
The G spikes in this form of flight will exceed 13g. These aviators don’t have G suits. I thought that the one RH turn in the last race in Detroit was pushing it at two seconds at 13Gs. G suits won’t help in lateral G conditions.
When gravitational stress is applied well above tolerance, there is a short time period during which normal brain function persists, despite loss of adequate blood flow. At the end of this period, consciousness is lost, and the gravitational stress is reduced back to normal conditions. The length of the unconsciousness averages 12 seconds with a -5 to +5 standard deviation and a range of 2 to 38 seconds. The estimated average length of time blood flow to the central nervous system is altered during the loss and recovery of consciousness and is approximately 15 to 20 seconds.
Convulsive activity is observed in 70% of the G-LOC episodes. The convulsive activity began on the average 7.7 seconds after the onset of unconsciousness and lasted 3.9 seconds. The convulsions would cease with the return of consciousness. Upon recovery of consciousness, there is a period of relative incapacitation that lasts on the average about 12 seconds, in which there exists confusion/disorientation. Some pilots experienced near death hallucinations.

Originally posted by NinjaMouse


fking 'ell......lol.....wow........I had no idea the treshold had already been crossed...cheers for the info.

I never really thoguht about it until recently, but it is worse for drivers than fighter jocks???......Fighter pilots may pull more G, but in general, they don't yank it around like that for more than 10 mins if in a dog fight or doing an airshow I geuss.....where as a Car driver has to hold up over a couple of hours....???

And how is lateral G compared to ...vertcial G?..I have a feeling from some fair ground rides I've been on, that lateral G is less natural to contend with, and quite uncomfortable.....I am familiar with the concepts of red out and gray out/black out and G-loc........but how does that work with lateral G?.....and they say you do different things with differnt sides of the brain, so one might assume that the "racing" (Artistic?) side of the brain could possibly be switched off due to blood loss???? And if on an oval, and a particular direction, one could possibly have the "racing brain" switched off for much of the time......???

Blimey...

[OfficeLinebacker]

Originally posted by Peter Leversedge
Not For Remote Control Race Cars
When I was involved in racing for me the buzz came from sitting in the car, driving it around the track and being directly in control of it. Mind you I would have missed out on two broken knee caps etc. Was not aways in "control". Still I would not liked to have had to race by "remote control".

Of course it's way more fun for the drivers to be in the car--that's the whole point of racing up to this point!

However perhaps for fans or science, for the sake of finding the limits of performance of a ground-based vehicle, you simply cannot have a human inside it.

[OfficeLinebacker]

Originally posted by phantom II
When gravitational stress is applied well above tolerance, there is a short time period during which normal brain function persists, despite loss of adequate blood flow. At the end of this period, consciousness is lost, and the gravitational stress is reduced back to normal conditions. The length of the unconsciousness averages 12 seconds with a -5 to +5 standard deviation and a range of 2 to 38 seconds. The estimated average length of time blood flow to the central nervous system is altered during the loss and recovery of consciousness and is approximately 15 to 20 seconds.
Convulsive activity is observed in 70% of the G-LOC episodes. The convulsive activity began on the average 7.7 seconds after the onset of unconsciousness and lasted 3.9 seconds. The convulsions would cease with the return of consciousness. Upon recovery of consciousness, there is a period of relative incapacitation that lasts on the average about 12 seconds, in which there exists confusion/disorientation. Some pilots experienced near death hallucinations.
[/B]

Isn't there a famous episode involving Chuck Yeager where he somehow regained control on a test flight despite experiencing extreme G-forces in all kinds of directions as his plane effectively tumbled for several seconds?

[OfficeLinebacker]

From Wikipedia:

'the Air Force started a series of tests with the X-1A, which the test pilot of the series, Chuck Yeager, named "Operation NACA Weep". These culminated on 12 December 1953, when Yeager achieved an altitude of 74,700 feet (22,770 m) and a new air speed record of Mach 2.44 (equal to 1620 mph, 724.5 m/s, 2608 km/h at that altitude). Unlike Crossfield in the Skyrocket, Yeager achieved that in level flight. Shortly after, the plane spun out of control, due to the then not yet understood phenomenon of inertia coupling. The plane dropped from maximum altitude to 25,000 feet (7,620 m), exposing the pilot to accelerations of up to 8g, during which Yeager broke the canopy with his helmet before regaining control.'

Here's a great PDF from the USAF I believe. Nice racing reference in the beginning.

http://www.af.mil/sh...-080107-018.pdf

excerpt:

'During his vicious—”snapping and rolling and spinning”—descent, he plummeted approximately 50,000 feet in 70 seconds and was subject to accelerations of plus 8g’s, minus 1.3g and side loads of 2 g’s. A glance at the time histories for g forces, yaw, roll, and pitch during the
first 50 seconds of his tumble dramatically revealed the extraordinary rates at which he experienced these events while being thrown about in the wildly gyrating airplane. At one point, for example, the airplane went from 0.5 negative g to 8 positive g to 1.5 negative g, all within a span of less than 3 seconds.'

[MikeTekRacing]

I don't think you can compare fighter pilots with drivers...one have to resist HUGE forces but for shorter periods and the others resist a lot more stress/changes/vibration and need a lot more precision in their reactions
really, it's very different...

[Ogami musashi]

I think, back to my previous post that G's rating means very little.

As i said the vertical G's in a fighter plane (or whatever you seat in) are very hard on breathing, blood circulation and many other senses but muscularly not as hard a lateral G's.

Also noted is the duration, of course. The rate is very important if the plane/car pulls a given number of G's very fast, your reaction will be delayed that is you'll be under a more important stress when you start to counter it.

That's why drivers usually bend their neck prior the entry of the turn.

On the rates, as far as cornering G's are concerned i think the F1 acceleration build up slower than a vertical load on a plane.


That said the vector of application of G's in an F1 car is indeed changing every time and except for vertical and backward acceleration almost nothing helps you to retain your body.

That's indeed different, and even inside motorsports that's different, i don't think we can really compare superspeedways loads to road track ones.

Several pilots when they first tried F1 cars noted that braking forces (first) and cornering ones (in second) were the most impressive differences between an F1 car and the rest (even coming from GP2).

So imagine a full 5g's braking translating into a 3,5g turn is surely very hard.

[Paolo]

In order to achieve maximum performance the spectators' flesh should be removed also...
Many current technical limitations stem from the need of containing the results of accidents and avoid a new Le Mans disaster.

About G induced unconsciouness, it depends a lot on training. I remember reading complaints of momentary black outs from drivers in 1982, and the cars were doing no more than 3g (lateral) at the time. Of course, they had almost no physical training, back then.