silly question maybe but....Isnt 1.9 sec kind of harmful?

[Shock-On-T]

I don't see how front-to-back G's could act like a tilt table. The way the tilt table gets some dizzy is you are lying down and they suddenly stand you up. This causes blood to run downward due to gravity and if your arterial system doesn't clamp down fast enough and keep your blood pressure up, there is less blood going to your brain and you black out. The tilt table is more like G's directed from the head down to the feet and not like G's directed front to back.

Yes I agree, it’s a bit of a reach.
I was searching for a mechanism that could cause syncope with rapid lateral acceleration, but nothing stands out. Maybe vasovagal with pressure on carotid sinus. Maybe stress-induced arrhythmia.

 

[Peteski]

I don't think this level of acceleration is a physical problem for most people, especially the kind of people who would be interested in owning a supercar. You are also unlikely to unleash full bore acceleration all the time. The biggest danger by a long shot will be lack of driving talent, as it is with all other supercars. Other cars on the road will also tend to fail to anticipate that kind of acceleration, making collisions more likely. Anyone who drives a supercar or a superbike will know what I mean.

 

[CarlK]

Highest g-force on a roller coaster - Coasterpedia - The Roller Coaster Wiki

 

[busaman]

well i race drag bikes(and have done for the last 30 years) and a 1.1 0-60 has never made me black out or fall off with fright or not being able to hang on my opinion is if you are that scared or feeble DONT buy one..get a nissan micra instead

 

[davidc18]

We just uncorked out 75d and the 0-60 takeoff can make us kind of queasy in the stomach. I cant imagine 1.9 or 1.5 and how that would make me feel. I mean its cool and all but even before uncorking the 75d was very fast to us and faster then the majority of cars on the roads...but after uncorking its even more off the hook but makes us uneasy inside and light headed.

may I suggest that you put the car in "chill" mode to protect yourself from unintended acceleration or perhaps try not pressing the 'go' pedal all the way to the floor.

personally can hardly wait for the roadster to arrive.

 

[brianman]

I wonder what the valet mode 0-60 would be.

I posted a chart of that back for a P85D a year or so ago.

 

[DarthPierce]

I posted a chart of that back for a P85D a year or so ago.

link? I'm interested

 

[VegasBlue]

From a Doctor's perspective, I will try to answer this question in a serious manner.

If you assume the forward force of 1.5 Gs for 4 seconds (assuming you aren't quick enough to slow down as the car passes 60 mph) most people will experience mild discomfort and mild disorientation.

However, there are a few situations where you can do actual damage to your body, and these are the typical warnings you see on roller coaster rides. I will explain some of them briefly.

1) Pregnant patients: The placenta is at risk from tearing away from the uterus forming a bleed called a subchorionic hemorrhage that can starve the baby of blood and oxygen.

2) Arthritis of the neck: The vertebral arteries are small arteries that run along the side of both sides of your neck through little bony tunnels. If you have bad arthritis in your neck or if you have plaque (Atherosclerosis) in these small arteries, you are at risk of either damaging these arteries or breaking off the plaque, both of which can cause a blockage of blood to the brain causing a stroke.

3) Pacemakers: rapid accelerations can decrease the amount of blood returning to the heart. As a result your heart will slow down until it fills with blood. Some pacemakers will perceive this slowdown as a problem and shock your heart to correct the slowdown. This hurts. Bad.

4) Glaucoma: If the pressure in your eyeballs is too high, rapid accelerations can damage the arteries in your eyes, causing bleeds that lead to blind spots in your field of vision.

5) Otitis: Any blockage or infection in the semicircular canals in your ears will result in severe dizziness or "sinus pressure" type of pain in your head.

In my opinion, the danger of this type of acceleration is not from the acceleration itself, but from crashing the car during the period of disorientation and slowing of reflexes that occurs as you try to drive at these acceleration levels. Remember that when you are on a roller coaster, you are a passive rider, "enjoying" the feeling of being thrown about. It takes professional drivers years to learn how to drive a car safely and deliberately while their bodies are undergoing these forces.

Could you legibly sign your name on a piece of paper on a roller coaster? Could you successfully avoid a person texting on their phone who inadvertently walks into a crosswalk while you are undergoing roller coaster type forces as your car speeds across a busy intersection?

 

[brianman]

link? I'm interested

Chassis CAN Logging To ASCII Text Plus Graphing

 

[roblab]

From a Doctor's perspective

In my opinion...

It takes professional drivers years to learn how to drive a car safely and deliberately while their bodies are undergoing these forces.

Personal opinion of one who has worked in medicine for years -- but not a real doctor (which is not the golden wonder many think it is, ie: There are dumb doctors), most of these worries are too rare to worry about. Oh, sure, a plaque might tear off and might block something, but that can happen for many reasons. Etc.

What I'd like to suggest, though, is that it takes ordinary drivers only a few launches to start figuring out how to do it safely "while... undergoing these forces." I can't imagine sane people launching through a traffic-filled intersection.

 

[VegasBlue]

Sadly, all it takes for sanity to flee most P100D owners, is for a Hellcat to pull up next to them while they are first in line at the red light.

I once had a patient who was an old lady in her nineties. I asked her what the secret to her longevity was. I expected her to say half a glass of wine or something. Her response was poignant for those of us who live in the crazy town of Las Vegas:

"Never be the first car into an intersection"

 

[Uncle Paul]

On a car with this much power, Tesla should be mandated that they install a driver controllable lever that allows the driver to be in constant charge of how much acceleration the car will achieve...oh wait...

 

[Formeremployee]

Should be exciting to see!

 

[SSedan]

Talk of harmful effects is kind of silly when we are talking 2 seconds worth. This isn't like a fighter pilot who can hold much higher g-loads a LOT LONGER.
Seem to remember motor trend or someone saying the P100D was the first car they tested that managed 0-60 as quickly as 60-0. Most cars can brake harder than accelerate, but when do we hear people worry about the g-force of slowing too quickly withOUT hitting something. Nobody claims cars stop too fast.

 

[bga]

FYI
A carrier launch goes from 0 to 165 MPH in about 2 seconds.

I have read about issues with disorientation in fighter pilots, particularly at night. Not a good thing when you have to keep the plane out of the sea in the seconds after it clears the catapult.

It may pay to practise some lower acceleration roadster launches so the 1.9 second effort isn't surprising and good control is maintained.

 

[GTKAZ]

I've taken a fighter pilot for a ride in my Model S, and he said that even though in my P85 it's less than 1g the straight-line g-force acceleration phases him. When you're in a jet fighter the g-forces are pushing you down, not back.

Just one anecdotal point of data. Add salt.

You're absolutely right. Also the initial acceleration forces of a high performance aircraft/fighter is not anywhere near what the new Roadster will produce. In general in race cars the intense Gs are lateral from the tires and aero gripping in the turns. This is very different from the longitudinal Gs pilots experience. I personally prefer the lateral Gs and acceleration Gs for a rush, and can't wait for the Roadster to become available.

For all of you concerned about not being able to handle the Roadster's acceleration the Roadster probably isn't the car for you.

If you happen to still want/purchase a Roadster use common sense and ease into the acceleration. Then don't take it past your personal limit

 

[Phillip L]

There is a reason that fighter pilots are young persons in top physical condition. So some of the comparisons in this discussion may not be valid. Do you want a 70 year old, overweight, diabetic with angina accelerating at those speeds? If you are in an ICU with a heart condition you get stool softeners because the stress of having to push down taking a constipated crap can be dangerous. There is a reason for warnings on different gadgets we use. Cannot turn on my son’s PS3 to watch Netflix on the tv without seeing the warning screen saying to read the owner’s manual before using. Tesla lawyers might insist they have a warning screen appear before using; like cars have now, where a warning pops up to advise of the risk of being distracted when you go to use their GPS navigation.

 

[D.E.]

The online calculator I found suggested that the acceleration to go from 0 to 60 in 1.9 seconds is about 14.1 m/sec^2. That is not even 1.5 G's (one G is about 9.8 m/sec^2). We pull up to 9 G's in F-16's, and even 3 G's don't phase most people (seat is slightly tilted back to ameliorate the downward vector). I don't think it sounds like that much in comparison). Also, in the F-16, the G forces tend to be pushing down from your head into your abdomen/butt, which is what makes people black out. Most don't black out at 3 G's even with the G's directed in the optimal direction to promote blacking out. So I don't think 1.44 G's pressing you straight back into your seat should come anywhere close to causing a blackout.

Your discussion is fine for a young healthy pilot. A lot of the people who can afford to put a couple of hundred thousand dollars into a car are older. Their kids are out of college, their houses paid, they're comfortaby retired. Many older people are taking medications, specifically blood pressure medications. Many of those medications interfere with normal mechanisms of the way we deal with local blood pressures in various regions of the body. The 25 year old healthy pilot's homeostatic mechanisms will react almost instantly. Not so the guy taking a couple of meds for blood pressure. Some people get lightheaded with postural changes. That person may well get lightheaded with accelerations in excess of 1g.

There are many conditions that alter one's homeostasis. Consider a pregnant woman. The gravid uterus can compress the vena cava reducing blood returning to the heart. That characteristically happens supine but it is a risk with her seated and under hard acceleration. She undergoes numerous pregnancy related physiologic changes, changes that have been finely honed over many many thousands of years of evolution. None of those changes have prepared her for multiple gravity accelerations.

Dehydration can do it. Hangovers. Drug use. Some people have dysrhythmias. A fib interferes with the heart's ability to pump. Previous heart damage, unrecognized heart disease, uncontrolled blood pressure elevation, some lung problems, electrolyte imbalances, anatomic differences, and on and on.

It is fine to figure a healthy person can withstand 3g acceleration. These cars for the most part aren't going to pilots. Many will go to those of us who have spent our youth and now are just a bit less tolerant of the enormous internal fluid shifts associated with sudden violent acceleration.

I can floor the acclerator on a P100D, and for me it is downright scary. And if my passengers just knew just how lightheaded I got during that acceleration, they'd be frightened as well. Damn frightened.

 

[ViperDoc]

Your discussion is fine for a young healthy pilot. A lot of the people who can afford to put a couple of hundred thousand dollars into a car are older. Their kids are out of college, their houses paid, they're comfortaby retired. Many older people are taking medications, specifically blood pressure medications. Many of those medications interfere with normal mechanisms of the way we deal with local blood pressures in various regions of the body. The 25 year old healthy pilot's homeostatic mechanisms will react almost instantly. Not so the guy taking a couple of meds for blood pressure. Some people get lightheaded with postural changes. That person may well get lightheaded with accelerations in excess of 1g.

There are many conditions that alter one's homeostasis. Consider a pregnant woman. The gravid uterus can compress the vena cava reducing blood returning to the heart. That characteristically happens supine but it is a risk with her seated and under hard acceleration. She undergoes numerous pregnancy related physiologic changes, changes that have been finely honed over many many thousands of years of evolution. None of those changes have prepared her for multiple gravity accelerations.

Dehydration can do it. Hangovers. Drug use. Some people have dysrhythmias. A fib interferes with the heart's ability to pump. Previous heart damage, unrecognized heart disease, uncontrolled blood pressure elevation, some lung problems, electrolyte imbalances, anatomic differences, and on and on.

It is fine to figure a healthy person can withstand 3g acceleration. These cars for the most part aren't going to pilots. Many will go to those of us who have spent our youth and now are just a bit less tolerant of the enormous internal fluid shifts associated with sudden violent acceleration.

I can floor the acclerator on a P100D, and for me it is downright scary. And if my passengers just knew just how lightheaded I got during that acceleration, they'd be frightened as well. Damn frightened.

Perhaps, but the issue here is that the 3G's I was referring to was 3G's pushing straight down through your body from your head to your butt. That is how we test fighter pilots. We spin them in a centrifuge to get up to 9 G's (or more) in the axis that pushes the blood out of your brain and towards your feet. Not 3 G's from front to back, which is primarily what a car does. The reason even 3G's from your head to your feet can cause the issue is that all the blood runs out of your head into your lower abdomen, buttocks, etc and away from your brain. There really isn't the same sort of reservoir for blood to run to and lower brain perfusion with a front to back acceleration, and there isn't a tendency for G's of acceleration along that axis to directly push the blood down away from your head. Even for pregnant women (I am a maternal-fetal medicine physician as well as an Air Guard flight surgeon, so I do frequently consider pregnant women as you suggested), the issue is primarily when that the physiologic pressure of the uterus on the IVC and the slowed reaction of the arterioles to react to a drop in BP and less blood going to their brain. Same for people sensitive to postural changes. That is something causing your BP to drop because you stood up or sat up, and the change leads to blood dropping away from your head and your BP not keeping the pressure up—not a change in front to back movement of blood. Also, for the record, both myself and others who fly in high-G fighters manage into our 50's and 60's and even on high blood pressure meds. So I am still a bit skeptical and just don't see how 1.5 G's directed from front to back can really cause that much of a drop in BP in anyone but the most frail, but perhaps there is some biologic variation or people living right on the edge.

I am willing to postulate that maybe any dizziness felt is more related to the acceleration in your semi-circular canals just making some people feel a little dizzy, especially if the acceleration produces a slightly turning of the head and you induce motion in another axis. Maybe my calculations are wrong somehow, and it really is more than 1.5 G's.

I guess we will just have to see what the accident rate is when it rolls out!

 

[buttershrimp]

Your discussion is fine for a young healthy pilot. A lot of the people who can afford to put a couple of hundred thousand dollars into a car are older. Their kids are out of college, their houses paid, they're comfortaby retired. Many older people are taking medications, specifically blood pressure medications. Many of those medications interfere with normal mechanisms of the way we deal with local blood pressures in various regions of the body. The 25 year old healthy pilot's homeostatic mechanisms will react almost instantly. Not so the guy taking a couple of meds for blood pressure. Some people get lightheaded with postural changes. That person may well get lightheaded with accelerations in excess of 1g.

There are many conditions that alter one's homeostasis. Consider a pregnant woman. The gravid uterus can compress the vena cava reducing blood returning to the heart. That characteristically happens supine but it is a risk with her seated and under hard acceleration. She undergoes numerous pregnancy related physiologic changes, changes that have been finely honed over many many thousands of years of evolution. None of those changes have prepared her for multiple gravity accelerations.

Dehydration can do it. Hangovers. Drug use. Some people have dysrhythmias. A fib interferes with the heart's ability to pump. Previous heart damage, unrecognized heart disease, uncontrolled blood pressure elevation, some lung problems, electrolyte imbalances, anatomic differences, and on and on.

It is fine to figure a healthy person can withstand 3g acceleration. These cars for the most part aren't going to pilots. Many will go to those of us who have spent our youth and now are just a bit less tolerant of the enormous internal fluid shifts associated with sudden violent acceleration.

I can floor the acclerator on a P100D, and for me it is downright scary. And if my passengers just knew just how lightheaded I got during that acceleration, they'd be frightened as well. Damn frightened.

I think you simply must adjust the shoulder strap downward and off your neck so you stop asphyxiating yourself during the launch. Or perhaps this is part of the thrill? You 50 shades of grey types always confuse me.

Jokes aside. The aircraft carrier launch is the best example I've seen that makes the roadster look slow. I think it's 0-150mph or faster in 2 seconds?