25 replies to this topic

[ViMaMo]

Recently i had been on a Roller Coaster ride. It took my breath away. The acceleration, deceleration, g forces through the loops. It was scary to be honest in certain occassions. Especially dropping downhill from 230 feet. Travelling at 80mph and then a sudden loop. Mind blowing.

The max acceleration is 9.81 m/s, equivalent to a free fall. And i don't know how many g's while taking a loop, possibly 3 or 4 g's. Or while going over a crest.

Set me wondering is this the sort of feeling you get driving a F1 car ? Does it knock out the wind out of journalists who sit there waiting to experience a nice fast drive but comeback with a hair-rising experience? Does it feel the same sitting in a F1 car?

[Spunout]

Well, go 370 kph at Monza, brake, 5-6 gs (5.99 gs was the record according to HHFs telemetry). Then go trough corners at 200-300 kph, and so on. Pretty much like supercharged version of rollercoasters

"Set me wondering is this the sort of feeling you get driving a F1 car ? Does it knock out the wind out of journalists who sit there waiting to experience a nice fast drive but comeback with a hair-rising experience?"

Usually it ends up journalists being way too scared to drive fast ;)

"Does it feel the same sitting in a F1 car?"

There is always a big difference between driver/passenger.

[ZoRG]

I recently had the same experience and was wondering the same thing, you tend to spend alot of time fighting the G-Forces, which makes it even more impressive that these guys are doing this lap after lap, Although I think in the car you start to get used to it, but Im sure on your first run out, it would be like a coaster on sterroids. (Except for the 360degree loops of course!)

[crono33]

in a car you experience mainly lateral and longitudinal G. what is really upsetting is vertical G. 3G are very upsetting for an untrained person. -1G are VERY upsetting and if you can keep your last dinner inside you are scoring very well.

i had a friend who was in the military and owned a light plane. when he reached retirement (at 36...) the base commandant took him for a ride on a MB326 and gave him a full combat aerobatic demo.

when they were back took my friend over 1 hour to get out of the cockpit.

Originally posted by ZoRG
I recently had the same experience and was wondering the same thing, you tend to spend alot of time fighting the G-Forces, which makes it even more impressive that these guys are doing this lap after lap, Although I think in the car you start to get used to it, but Im sure on your first run out, it would be like a coaster on sterroids. (Except for the 360degree loops of course!)

[clSD139]

Rollercoasters always pull you in the seat, even when you're upside down. If you hang in the belts it means power is waisted, but when it's connected to a chain the force can be excessive, especially for somthing living. The big difference with F1 are the lateral G's. A driver is pushed to the sides as strong as it's pulled by gravitation somtimes!

Again, in an airplane I think 1G lateral is not possible nor acceleration. But I'm not sure, I'm since I'm not a pilot.

[fester82]

You can check out a similar thread regarding G loadings at this thread:

http://forums.atlasf...&threadid=70189

I discuss some of my experiences at 9.4 gs in military jets towards the end of the thread and the differences between what a pilot feels and a driver.

I recently rode a roller coaster at Hershey Park in Pennsylvania called "Mouse Trap" patterned after the old children's board game that had no banking through the corners. I would guess it gave you a least one lateral G with no seat bolsters to keep you in place so you were either the squishee or the squisher with your seatmate depending on which direction the turn was.

A fully aerobatic airplane is still the ultimate roller coaster ride!

[ViMaMo]

Originally posted by clSD139
Rollercoasters always pull you in the seat, even when you're upside down. If you hang in the belts it means power is waisted, but when it's connected to a chain the force can be excessive, especially for somthing living. The big difference with F1 are the lateral G's. A driver is pushed to the sides as strong as it's pulled by gravitation somtimes!

Again, in an airplane I think 1G lateral is not possible nor acceleration. But I'm not sure, I'm since I'm not a pilot.

how about when going through a corkscrew? i'm sure there is tremendous g's.

i wish someone could provide the g's we do in coasters.

[kober]

Originally posted by vivian


how about when going through a corkscrew? i'm sure there is tremendous g's.

i wish someone could provide the g's we do in coasters.

I was in the Alton Towers park in the UK and I've read somewhere that during the looping on the Nemesis there's 3,5 G vertical.
Edit: source: http://www.towerstim.../fv/nemesis.htm

[clSD139]

3.5G... that's a lot! Probably the first looping it makes, afther a deep fall! It's explosive!

[fester82]

A corkscrew is very minimal G's. You get some lateral G's as the coaster initiates the roll and when it is completed, but that's about it. An aileron roll in an airplane is less than a 2G manuever, regardless of aircraft size, if properly executed. It amazed everyone except the Boeing test pilot, Tex Johnson, when he executed an aileron roll in the predecesor to the Boeing 707 airliner over Seattle in the '50's. When interviewed afterward, he dismissed as no big deal as he stayed well within the aircraft limits.

Most loops in airplanes and coasters can be completed in the 3.5-4G window. More G's than that and one tends to bleed off too much energy on the initial pull. Keep in mind, the G loading changes throughout the loop. The greatest load is on the inital pull up and pull out as one is counteracting "God's G" that we live in on a daily basis and when the vehicle is moving the fastest. When you are inverted, you have the normal gravity G helping and you are going the slowest. That is why, when you look at a loop from the side, it has the shape of an egg. That is also why in aerobatic competion, it is much more difficult for the pilot to execute a perfect circle in a loop as the stick pressure must be constantly changing to avoid the egg shape.

[Ursus]

Originally posted by clSD139
Rollercoasters always pull you in the seat, even when you're upside down. If you hang in the belts it means power is waisted, but when it's connected to a chain the force can be excessive, especially for somthing living.

Idon't quite understand what you mean here but some coasters are designed to pull 'negative Gs'. The restraints are meant to be the only thing that keeps you in car when going over crests. I went on the 'Balder' roller coaster in Gothenburg last year and it puts you in negative Gs 10 times around the lap. With old style cars with low sides and only a bar across the lap to keep you in, it was pretty exciting.

[Spunout]

IMO people tend to underestimate lateral g forces. For example 4 gs F1 pilots experience in some corners is a LOT, especially considering how physically demanding F1 cars are (extremely heavy steering, brake pedal, etc - EDIT *** from earlier thread: "what I remember from F1 test (by Finnish car magazine) years ago, required braking power was around 80 kilos, compared to 15-20 kilos in road cars (and we are talking about maximum braking power here!"). There is a big difference between sitting still and trying to keep F1 car on track! Take a military pilot to centrifuge (WITHOUT g-suit) and I am sure he can tell you 5-6 lateral gs is way, way more than 90% of people believe. And if we are talking about average Joes...

[saudoso]

Originally posted by Ursus


Idon't quite understand what you mean here but some coasters are designed to pull 'negative Gs'. The restraints are meant to be the only thing that keeps you in car when going over crests. I went on the 'Balder' roller coaster in Gothenburg last year and it puts you in negative Gs 10 times around the lap. With old style cars with low sides and only a bar across the lap to keep you in, it was pretty exciting.

I'm not familiar with the ride, but most probably it took you to near zero G. You almos floated. Like the "vomit comets" do (aircrafts used to train 0G with first time astronauts). I really don't believe some theme park manager would dare to have you hanging by a bar on your lap. And if they did, that would for sure hurt.

[Ursus]

Originally posted by saudoso


I'm not familiar with the ride, but most probably it took you to near zero G. You almos floated. Like the "vomit comets" do (aircrafts used to train 0G with first time astronauts). I really don't believe some theme park manager would dare to have you hanging by a bar on your lap. And if they did, that would for sure hurt.

You only experience it briefly as you pass over crests but it is negative g's. Check this graph over g-forces during the ride made by people from Chalmers Univ. of Technology.

[fester82]

Take a military pilot to centrifuge (WITHOUT g-suit) and I am sure he can tell you 5-6 lateral gs is way, way more than 90% of people believe. And if we are talking about average Joes...

Having experienced the joys of a "spin and puke" ride in a centrifuge, pilots do not experience the lateral Gs a driver feels. The gondola pivots to keep the Gs vertically thru the pilot. The only lateral Gs the pilot feels is when sideslipping (pushing on one of the rudder pedals) or initiating a roll. Some of the roll rates can be quite high. The T-38 has one of the highest roll rates approaching 720 deg/sec in certain flight parameters and more than one instructor has had their "bell rung" against the canopy when the student up front initiates a sudden roll. One of the first profiles in a centrifuge is a slow increase of 0.1 G/sec with no G-suit and no straining maneuver (muscle tensing) to find what your individual G tolerance. Once one looses peripheral vision, then straining is allowed. I was good to about 4-5 Gs without straining or G-suit at that slow onset rate.

A better lateral simulator would another amusement ride like the Scrambler where one is spun in a horizontal plane and the outside person is plastered to the side and the inside person is making a sandwich out of you. Strong neck muscles and various head supports such as padded collars and straps are needed for those constant 2-3 G lateral loads drivers experience, especially on American oval races where the Gs are sustained for longer periods.

I haven't experienced an amusement ride yet that simulates the braking power of an F1 car. Some coaster rides are pretty abrupt braking coming into the load/unload station and a "Log Flume" ride isn't even close. The closest may be the GM Test Drive ride at Disney, but I would be surprised if that exceeded 2-3 Gs braking.

As for acceleration, Hershey Park has a new ride where the cars are accelerated from 0-72mph in 1.5sec before starting a vertical climb. It is quite a rush if you have never experienced acceleration like that and approximates an F1 car, but pales in comparison to an aircraft carrier launch (0-130kts <3sec) or a top fuel dragster (0-320mph <4.5sec).

[Spunout]

Good post!

"Strong neck muscles and various head supports such as padded collars and straps are needed for those constant 2-3 G lateral loads drivers experience, especially on American oval races where the Gs are sustained for longer periods."

Actually, according to Da Matta and several others F1 cars cause bigger problems for neck. Not only top g forces are higher but you have a combination of left, right, brake, accelerate...

[ViMaMo]

Nitro

This one goes up 230 feet. And then it drops to the bottom at an amazing rate, reaching 80mph. Its like you are sitting in a rocket. I think it nears 1G in acceleration.... almost free fall.

[clSD139]

Originally posted by saudoso


I'm not familiar with the ride, but most probably it took you to near zero G. You almos floated. Like the "vomit comets" do (aircrafts used to train 0G with first time astronauts). I really don't believe some theme park manager would dare to have you hanging by a bar on your lap. And if they did, that would for sure hurt.

You only experience it briefly as you pass over crests but it is negative g's. Check this graph over g-forces during the ride made by people from Chalmers Univ. of Technology.

If you'd take the average you're closer to the real feeling. The wheels under the rails are always much lighter than those on the rails, it's obvious the train has to be kept on the rail while manouvering. In statistics those extreme moments are called outliers, but when inertia, residual acceleration, other movements,... are included, it can feel pretty heavy. But in such attractions lateral g's are very rare. And I don't mean lateral on gravity but on the body.

[BRIAN GLOVER]

Howdy Dennis,

Ah yes; The art of rolling. A corkscrew is a barrel roll which should be a positive g maneuver. I often rolled passengers in a Lear 35 D without them knowing it. A spiral dive is the most stable maneuver in any plane and if not arrested will eventually load the wings beyond their design limitations.
Aileron rolls require some planning. During the roll the wing is loaded at less than 1g except for the initial pull back entry which does not have to be severe. Depending on the roll rate of the plane and how many rolls you wish to achieve without descending below entry altitude, a trajectory must be determined. I would imagine in the T38 in a 300' trajectory would complete about 6 to 8 rolls at 400kts with a 50kts energy loss. A F4 would start out at 450kts and end up at 350kts with two rolls during the same elapsed time. While Inverted, you would have to push the stick far forward for each roll to prevent dishing out. The T38 would require only pull backs for entry and exit and neutral during the rolls.
A victory roll in a P51 would be a coordinated roll with the ball in the middle which requires even more planning. A yawing victory roll is not nice. I hope to speak from experience pretty soon but I would imagine a 270'/sec roll rate and one roll at 250kts.
The nicest plane ever made is the Pitts S2B. With 4 ailerons it rolls so fast especially to the left you would get maybe 10 rolls in 300'. The roll rate will drop off drastically as the plane slows. Lots and lots of drag unless 100hp is added to the engine. An Extra would get 10 rolls at a near constant roll rate with slight left rudder.
A snap roll in these two planes is even faster. A snap roll or as the English say, whip stall, is a spin. A hard pull back to stall at 130kts with a simultaneous power back and hard rudder will snap you so fast with a recovery all within in 360' is really something to behold.
Loops performed to IAC standards in an Extra or a SU35 would be 11gs at exit and 8 at entry with 2 positive on top. This is for the perfect circle ARESTI and I mean perfect. I would never do that.
No G suits in aerobatic planes because of short durations.
A loop in a Cessna 152 Aerobat is limited to 105 kts and the plane is limited to 6gs with zero over the top. A loop is not possible in a C172 , but you can perform a pear shaped maneuver with zero g at the top and you can exit to level flight at 2 G. Remember carb heat in these things.
The beauty of non competition aerobatics is that you can unload the plane at anytime, whereas a roller coaster, you have to hang in there till the end. The worst roller coaster in the world is Magic Mountain at Disney World Florida. It is an indoor affair and done in the dark with no visual reference. You will **** yourself.

Originally posted by fester82
A corkscrew is very minimal G's. You get some lateral G's as the coaster initiates the roll and when it is completed, but that's about it. An aileron roll in an airplane is less than a 2G manuever, regardless of aircraft size, if properly executed. It amazed everyone except the Boeing test pilot, Tex Johnson, when he executed an aileron roll in the predecesor to the Boeing 707 airliner over Seattle in the '50's. When interviewed afterward, he dismissed as no big deal as he stayed well within the aircraft limits.

Most loops in airplanes and coasters can be completed in the 3.5-4G window. More G's than that and one tends to bleed off too much energy on the initial pull. Keep in mind, the G loading changes throughout the loop. The greatest load is on the inital pull up and pull out as one is counteracting "God's G" that we live in on a daily basis and when the vehicle is moving the fastest. When you are inverted, you have the normal gravity G helping and you are going the slowest. That is why, when you look at a loop from the side, it has the shape of an egg. That is also why in aerobatic competion, it is much more difficult for the pilot to execute a perfect circle in a loop as the stick pressure must be constantly changing to avoid the egg shape.

[ZoRG]

The one here by us at Gold Reef city pulls the most G's in the world at 5.7G's I think I should go there one day and take a ride.

[Greg Locock]

and a g meter.

[ZoRG]

lol, sure!

Found this site... 120mph, thats extreme!
http://www.coasterfo...nfo/records.php

[Christiaan]

A couple of years ago HHF had actually talked about drivers blacking out for a split second in chichanes coz of the G-Forces. I believe MS worked quite closely with the racetracks to bring about the horrendous changes that befell tracks like Imola and Hockenheim between 1999 and 2003

[BRIAN GLOVER]

I don't think that's right, Christiaan. The G's in a car are a lot different to an airplane. For instance, I own an Extra 300 and I routinely pull 6 Gs positive and 6 negative, even though when I set out, I only intend to go to 4. I am always surprised to see the needles so high after my fight. If I held 6 positive for 2 seconds, without squeezing my chest, I would probably get very dizzy and experience tunnel vision. Another second I would be out. If I squeeze my chest, I could probably hold it for 4 seconds . It's duration that counts. In a negative maneuver, 6 Gs for 4 seconds would give you red out and a nice pair of bloodshot eyes. It varies from person to person and also your condition at the time. Even one beer the night before will reduce your blood pressure. If you smoke, forget it. Even if you eat fatty foods, you will have problems. One must acclimatize oneself to these forces, IE: get fit, and even then, some days you can find yourself getting very sick with the most mild maneuvers. My daughter can go out and peg the thing at 10 and 8 without flinching. She never gets sick. It is not unusual to crap in your shorts because of pressure. Continued aerobatics will cause hemorrhoid problems. You do this for fun.
The only F1 track that the driver will experience positive and negative Gs, is thru Eau Rouge at Spa. Thru the right hander and the dip, the driver will experience a combination of 4 positive and 6 lateral. In the left hander at entry, the driver will experience 2 negative and 3 lateral but the car will always be positive except for oil and fuel systems because of downforce.
The duration is so small that recovery from any disorientation, would be instantaneous if any is experienced at all. If the car had no wings, the car will lift of the ground at entry and would not be able to make the turn at current speeds and the driver and car will experience 0 G and as the car goes thru the dip, a positive g will still be experienced. Lateral Gs are not obtainable in an airplane unless you exit a hammer head stall and keep the rudder deflected into a knife edge and since the G meter does not register lateral Gs, I can only guess that it would be 2 or maybe 3 Gs.
( Incidentally, I asked my mechanic how they calibrate the G meter, and he said that in all of the 20 years that he has worked on aerobatic aircraft, he has never done it and he wouldnt know how. Maybe in a F1car, this is required because of vibrations.)
The duration of the positive G force thru Eua Rouge would not be sufficient to cause a black out.
I know at some of those state fairs that some over enthusiastic motor cyclists black out in their centrifuge.(Wall of Death.)(Positive G)
Braking and acceleration and cornering are longitudinal and lateral Gs and wont cause drainage of blood from the brain so a G suit in a race car wont help at all. The dizziness experienced by IRL drivers at Texas Motor Speedway was caused by blood actually moving from one side of the brain to the other and confusion and depth perception problems occurred because the left eye lost oxygen and the left half of the brain lost blood. IE: They began to feel like females. .
I was taken around Kyalami(near you) in a F40 for 5 laps. I had to plead with the owner to stop, because I nearly thru up. I think fitness, diet and general well being has a lot to do with how a driver feels during a race. Remember Nigel? I have been driving a shifter cart lately and after 20 laps, I'm ready for the EMT. At 59, I've got to stop this type of behavior.

A couple of years ago HHF had actually talked about drivers blacking out for a split second in chichanes coz of the G-Forces. I believe MS worked quite closely with the racetracks to bring about the horrendous changes that befell tracks like Imola and Hockenheim between 1999 and 2003 [/QUOTE]

[clSD139]

6 lateral in F1? I thought is was around one, but that will probably be in rally then. So a pilot could pass out if it was driving in a big circle?

For airplanes: same reasoning as rollercoasters: the vertical wingsurface is much less than the horizontal (and there are also structural limits). So if a wing would crack off in an sudden attempt to elevate at 10g the lateral potential would be around 3g -- g's not to be confused with enginethrust.

[Spunout]

6 (or 5.99) was longitunal gs (HHF/Monza). Max lateral gs are around 4, I believe.