PossumJr

I'm sorry if this is the wrong place for this, but I was wondering if anyone knew how safe FBs are in a crash, just normal speed like 50-65 mph. I'm assuming not very, but thought I would ask anyway. Searched everywhere and couldn't find any answers.

bbreidhaupt

well i wouldn't say it would fare well. it depends on whether you hit something stationary or a moving object aswell. you may be going 60 and get hit by someone one else going 60, thats like hitting a tree at 120. plus these cars only weigh 2200lbs. all you have in front of you to stop whatever is a 250lb engine, some sheet metal, the steering components, and the cooling system. best advice is take the ditch if someone is gonna hit you head on and hope you dont hit a tree. also wear that seat belt, no airbags+collision+all metal steering wheel=missing teeth or worse.

Bryan Davenport

I out my 81 in a ditch and walked away. only dented the fender. I kicked it and it popped back out.

C&C

This isn't correct. If an RX-7 going 60 mph hits another RX-7 going 60 mph head on the impact will be equivalent to a 60 mph impact into a stationary object for both cars. It isn't like hitting a stationary object at 120 mph.

If it was like hitting a stationary object at 120 mph for one car then there would have to be an equal and opposite force to the other car. Which means both vehicles would have an impact force significantly higher than there speed of travel would warrant. This would be creating energy and would violate the laws of thermodynamics.

Looking at it another way if two equal cars hit head on they both decelerate to zero, not to -60 mph (120 mph difference).

Now if the car the RX-7 hits has more mass than the RX-7 (which is likely), the result would be that the RX-7 driver may experience a more severe impact than hitting a stationary object at 60 mph, but it won't be equivalent to 120 mph.

That doesn't really answer the original question of how safe an FB is though. My guess is if it were tested with today's test methods it would be shown to be far more dangerous than any vehicle currently sold new in the USA.

bbreidhaupt

simple physics dictates other wise. you have the kinetic energy of both vehicles impacting. a rx7 traveling at 60mph with a weight of 2200lbs has 132000lbs of force. and the other car has 132000lbs of force. thus 264000 lbs of force to cancel out. then go hit a stationary car with 132000lbs of force only. you come back and tell me which impact had more damage. think of it like cherry bombing a baseball and then hitting one coming at you at 90mph. your gonna knock the cherry bomb further, because you had less energy to overcome.

diabolical1

iTrader: (3)

welcome to the board.

my thoughts are this:

as asked, your question still leaves too many variables open to give a definitive answer. the mass of the opposing object, the angle of impact, the location (on the Rx-7) of the impact, etc. will all have an effect on the driver's ultimate safety. also, i will define safe as anything short of being put on life support.

you have to be fair when thinking about this. the Rx-7 passed all it's priod-correct crash tests and i've seen many of them tragically go down and the driver came out of it hurt, but not gravely so. this includes seeing one get damn near cut in two after it hit a support for the "el" (train). for something that's mostly glass on top, they are much sturdier than the average person might give them credit for.

a significant crash at the speed you mentioned is a crap-shoot at best, (as i said, you need to consider all variables). it definitely would NOT pass the crash critieria for today, but a Smart car can. however, i'd personally rather take my chances in the Rx-7.

C&C

A car traveling at a speed does not have lbs of force, it has kinetic energy (which has units like Joule, BTU, etc). The energy is not found by multiplying the speed in mph by the weight of the car in lb. It is 0.5*mass*velocity^2.

If we ignore this error in the example you made, you have to consider that the sum of energy is dissipated between both cars in a head on collision. If both cars are equal, the end result will be like each car hitting a stationary object at the speed they are going.

In your example each car would dissipate half of the "264000 lbs of force" resulting in "132000lbs of force" for each, or the same as hitting a stationary object.

PossumJr

Wow you guys put a lot more thought into that than I thought someone would. I guess I should of asked if you thought you could limp away alive, or be dead. I guess it's up in the air.

Coltdaddy47

Simple. Metal vs plastic. Ill take a metal car even if it is weaker jap metal. A lot of 1st gen rx7's have been in a crash or fender bender or something and there still kickin well on the road today.

PossumJr

Thats a good way to put it. Get in a fender bender in a new car and they fall apart.

sbeers

Lol my car got ran over and smacked in the back fender still going strong

C&C

The car falling apart or crushing is what protects the driver. A car that gets in a accident and still looks good is probably not very safe for the driver.

Something in the crash has to absorb the energy to prevent the occupants from experiencing very large accelerations which lead to injury. Newer cars are designed to absorb this energy by deforming. A simple way to think about it is something in a crash is going to give. Would you rather it be the car or the occupants?

New cars may be more expensive to repair after an accident because of this, but if you factor in the medical "repair" bills of the occupants I would guess they are cheaper.

sevens4me

iTrader: (1)

If worried about safety, make SURE you have the proper shear pins in the steering column so it collapses as it should...I've bought a few fb's where the PO did some work in this area and made the two pcs one pc(steering column). Also, NEVER allow anyone else in the car besides the passenger while driving.
I was in an '85 that got totalled from front impact and I was really surprised how well it and I held up. I was fine, passenger split her forehead open somehow on the side(above door window?). I've got pics somewhere...

PossumJr

I know thats why they fall apart, but even in some slow impact situations the bumper is all kinds of messed up even if there was little chance of injury. It's a good thing for bigger impacts, but in a fender bender I'll take a metal bumper and some whiplash

C&C

Unless you have rear seats.

PossumJr

Even in a 2+2 I wouldn't fit anyone else in a 7.