22 replies to this topic

[wembi]

Every little kid in the world learns early on in his/her life that if you go round and round in circle really, really fast...you get DIZZY! It amazes me that CART officials and drivers didn't know this simple fact until they went to the Texas Motor Speedway...

I LOVE Formula One!!!!

W.

[917k]

What's odd is,when the IRL 1st went to Texas,they turned laps in the 225 range.

They completed a 3 hour race with no complaints.In fact almost all of the IRL races have been incident free.

I realize that the speed differential is the prob. but CART drivers reporting this after just 20 laps.I mean,the way they make it sound,CART just discovered gravity.

You would think that the IRL boys[and girl] would experience some similar effects after extended running.

[JaqFan]

Originally posted by 917k
You would think that the IRL boys[and girl] would experience some similar effects after extended running.

Just like you said earlier, it is all about the speed diff.

[Cociani]

My understanding is that the dizziness came from excessive G forces limiting blood flow to the brain not spinning. Are cart drivers going to have to don pressurized G suits like fighter pilots soon? I find it hard to belive that Cart would even think about putting drivers lives at risk for such a boring spectacle,(high speed oval full course yellow specials). I am glad the canceled the race. If those guys would spend more time on road courses and less time on ovals I would watch the series regularly but roundy round just bores me too tears.

[JJ]

I had a chance to drive in Fontana in Ford L type Prototype.

The car was pulling on average of 3.5 G per turn in that oval track. (Although the top speed of the car was pathetic in comparison to real Champ cars.)


You gotta know that Champ cars can take up to 5G per turn at Texas due to its high banking.

Just imagine getting hit with 5 G of pressure 4 times per 27 seconds for 2 hours.
Texas is by far the toughest track for Champ car racers due to its banking. Some calls it widow-maker already...



What CART drivers need is a gravity suits and oxygen tankers...

[917k]

What is puzzling,though,is that almost ALL the drivers complained of these symptoms and some of these drivers qualified very near the pace of the IRL.

Like I said,I can't see why the IRL drivers did not experience similar symptoms.

[cartfan76]

when you're going that fast, and that close to the theoretical "limit"..only 4-5mph can feel like a world of difference on a track with such high and constant banking. Even from driving that track in Nascar 4 (yes, the cars are much, MUCH slower), but any of those 1.5 mile ovals seem very "mickey mouseish". The limit in this case (in comparason to CART/IRL) is VERY thin.
Regards,
Justin

[GasPed]

Just a small word from an engineer here (sorry ) - the lateral g forces around a constant radius turn (which would apply to enough of TMS to be illustrative) is proportional to the square of the speed around it. In other words, a 10% increase in speed will give you a 21% increase in g forces.

I find it at least plausible that CART's higher speeds could produce a 10-20% (maybe even more in the corners) sustained increase in g forces, and that this could push loads beyond human tolerance limits. It's at least plausible.

Gas

[Blue]

GasPed, I had to check your calculations and it seems....... you are absolutely right

[RJC1]

Another note on the speed differential - IRL and CART use different track calculations. The IRL calulated their speeds based one a ~1.45 mile track and CART used ~1.5. I have no idea why they are not calculated the same, but the result is that the CART cars were in fact travelling around 15mph faster than the IRL cars, which is a quite a difference. So add that to GasPed's note and you can see the drivers were in two different worlds.

[Mosquito]

I also heard that there will be no future CART racing on the Texas Motor Speedway.
Another rumour is that there is also 'some' political thing going on, but that was just a snippet I heard somewhere on CNN sports gossip, wasn't really paying much attention there.

[Pete Stanley]

It wasn't only the lateral g's, it was the vertical g's too.

[Byrellium]

The problem is the vertical g's. They were getting 4-5 g's sustained. This forces the blood out of the brain and into the lower extremities of the body. Fighter pilots wear a g suit that is basically a flight suit with air bladders built in and they pressurize at certain g loads and keep the blood from draining into the lower body. When you lose blood the brain- first you become dizzy, the vision can become impaired, next is a very short grey out and next you pass out. Not a good thing to do at 230+mph.

I really have a problem with anybody that has a problem with the CART drivers refusing to race here. These guys take calculated risks with their lives every time they get in the car. The risk was simply too great at Texas.

The CART management definitely screwed up here by not testing properly before they went to race, but the blame is not with the drivers.

[Blue]

I’m not sure about vertical Gs to be so big problem. Surely they have good suspension

[Chris G.]

With regard to driver safety, no one has expressed the least bit of a "problem" with the race stoppage. All here seem to agree that it was too dangerous.

However, GasPed states "In other words, a 10% increase in speed will give you a 21% increase in g forces."

According to reports, IRL was going at 225 and only some of the CART drivers were as fast as 230 - about a 2.2% difference. So, double that for the g-force calc and we get a 5% increase in g's. Not a huge difference on paper, but seems to cross the line on the human limit scale.

I suppose it's possible that 225 is the human limit and even a fraction beyond is bad at that track. I suppose my calculations could be flawed too. But, it does seem a bit strange...

[BogotanWarrior]

Cart made a mistake here. Clear enough.

Still I disagree with most of you about ovals being boring.

Not that I prefer them to circuits, but I like them: ovals are pure speed, there you have a lot of overtaking chances, and the machines and the pilots are taken to the limits, and that is what the sport is about, isn´t it?

I know it won´t happen, but I would like to see two oval races in F1, one of them 500 miles long.

[Laphroaig]

Still I don't see (as a spectator) the fun of oval racing...
The only thing you can look for are crashes, most overtaking is pure slipstreaming or 'fuel economy' by the driver being overtaken.

Maybe there is some excitement in the gamble in who gets to pit at the right moment during a yellow, and maybe... MAYBE 'ohh' they make a mistake during a pitstop...

Nahh... even CART has outgrown ovals...

[tony]

Champ cars are considerably faster than IRL cars. The top speeds for the CART cars at Texas were probably about 20-25 mph faster. However, there is one important fact about physics that's important here. The g's felt when cornering are from centripetal acceleration, C.A. C.A. = v^2/R, where v is the speed and R is the radius of curvature. Since the C.A. increases with the square of the speed even a small change increases in speed have a larger effect than you may think. Example: Let's say that the IRL cars can go 180 mph on the corners, and the CART cars can go 205 mph on the corners. 205/180 = 1.14, thus that's a 14 % increase in speed. HOWEVER, (205/180)^2 = 1.30. Therefore the drivers of the Champ cars would feel a 30% more G's just by going 14 % faster. Are we going to see G suits in CART?

[Thank-U]

For you calculation purists there, please remember to convert figures to the metric system for the formulas to be applicable

so speed should be in m/s (meters per second) so that g can be in m/s2

btw: the percentages remain the same, so the calculations above stand.

[tony]

Thank-You,

I am a physicist, I prefer MKS units as you mentioned, but most people don't like to hear speeds in m/s. And by the way g's have units of m/(s^2), or in words meters per second per second, or meters per (second)^2.

[markzed]

I was a physics student at uni and I've tried to forget as much of that crap as possible. Now you've brought all those horrible memories flooding back.

Couldn't a G-suit that supports one side of the body be developed to prevent these problems.

Although, I'm quite partial to the occasional fainting driver enlivening a dull oval track race (zzzzzzzzz).

[Thank-U]

Tony,

Absolutely right, I mistyped it acceleration is certainly in s^2.

My physics teacher would kill me for this that is if he is still alive (already 25 years passed , sh!t)

[GasPed]

Hey guys! Engineer here again:drunk: Anyhow, thought we should be clear here - a person can use any units they want in any of the formulae, just so long as they are consistent.

So, take for instance a hypothetical calculation for the TMS lateral g forces. Let's say I calculate lateral acceleration as v^2/r, and use v = 230 mi/hr, and r as 0.15 miles (who knows what it really is - this is just an example). So then I get a lateral acceleration of 352700 and the units are (miles)/(hr)^2. The gravitational constant g in those units is approx. 79040. I take my lateral acc and divide by the g constant (i.e. 352700/79040), and voila, I get 4.46 g's as the lateral acceleration expressed as a mulitple of the earth's gravitational constant.

It doesn't matter what units you use (SI vs. Imperial vs. MKS), you'll get the same result as long as you're consistent.

Gas (geek trying to impress )