I was doing some research regarding buying a harness and rolbar/rollcage in a street driven car. The consensus is that it is unsafe to have a harness in your car in case of an emergency. This seems somewhat odd since some race series make it mandatory for a car to have a harness in the car. Are accidents that much more severe on public roads (I doubt it), is "sub-marine-ing" an issue, or something else. Any info would be helpful.

 

in most car, you can't safely mount a harness bar without a roll bar/cage.(length of shoulder strape, angle of your shoulder height vs. mounting points)

a roll cage in a daily driver is danger because your melon can contact with the hardened steel bar during rollover.

plus for car without rollover protection, you can suffer great neck injury by using a harness, the oem 3 pt are designed so your head can duck out of the harm's way during a rollover. with the car with harness and no roll over protection, the roof can be crushed and the next thing is your melon.


race driver use roll cage, harness instead of 3 pt belt and srs air bag is because they use a helmet.

if you want to wear a helmet to drive around town then it's actually safer.


there's a way to fab and mounting bracket for the s2k, the simple answer is not for street. mounting an harness actually is not as easy as it sounds, there's a difference between a "slap on" job vs. a proper mount job

 

It is not safe to have the harness without:

1) roll bar
2) race seat
3) anti-sub features

This is because:

1) harness will hold you in place *above* the OEM roll hoops
2) harness requires race seat stiffness and shoulder guides
3) normal four point harness will cause internal injury if you submarine below it (use 6-pt or a 4-pt with anti-sub features)

If you have all those, then it is safe to use.

 

It really depends on what you are talking about. If you are talking about just a harness bar, then yes it is dangerous on the street to be strapped in. If you are talking a cage then that is also dangerous but not in the same category. They are apples and oranges.

We will tackle the harness bar first. These are the bars that mount behind your seat and are not the full cage. These are great because you only have to do minor if any modification to your car and still equip you well for the track. However, there are issues with running a harness on the street. Seat belts that are in factory equipped cars are designed to allow you to move. Cars are also designed to crumple. In a roll over, you want to be able to move out of the way. If you strap yourself in, and you can't move out of the way, well think about it.

When you introduce a roll cage it adds rigidity and takes a lot of the flex out of the car. It does make the car safer but it must be a properly designed roll cage. Secondly, the biggest difference here is, you mentioned racing series. There is a huge difference between what you drive on the street and what they drive in racing series.

Do you wear a helmet on the street? That is the difference. You are introducing tons of feet of steel tubing in the car. If you wreck, it is a guarantee that the nice steel bar right above you is going to leave a nice big gash in your forehead.

If you are just wanting to do occasional track days then a harness bar is fine, just don't wear the harness on the street.

 

Thank you guys for the info. What do you guys think about removing the stock roll hoops, adding a roll bar and putting padding on it?

 

I think it really depends on the position of the rollbar. Most rollbars for the s2k (that aren't custom) are designed to clear the factory hoops (so they sit in front of them) and are thus closer to your head. You *might* be ok if the rollbar you're gonna put in is close to or further back than where the factory hoops were.

But you probably shouldn't listen to anything I say because I'm an idiot

 

Fair enough.

 

Why do you want a harness anyway?

 

While I agree that a cage is more dangerous on the street and so on, the sentence I quoted is HORRIBLE advice.

NEVER use a harness bar and harnesses for track days. I won't even let a car on track with such a setup. It's the MOST dangerous setup for a track day (well OK, I guess no seat belt would be worse...).

 

My friend had a race seat with a 4 point harness in his m3, some lady pulled out in front of him and he collided with a light pole head on at 45-50 mph. He walked away with just a couple cuts and bruises and of course a sore chest, the cop said he has never seen anybody walk out of a wreck like that before. He was saved by his harness, so if you do it right it can be safe, maybe safer.