73 914 V8 roll cage Options

[914junkie]

Ok, so I think I'm ready to install a roll cage in my 73 914 V8. I was thinking about going with an Autopower for an easy install since I lack welding skills. I have friends that could weld the feat in and I can do the rest. Anyone installed an Autopower in their car? And will my harness bar still fit? Any advice would be helpfull. Thanx, Paul. (IMG:style_emoticons/default/beer3.gif)

[GeorgeRud]

I have an Autopower roll cage fitted to my car, and it's OK, but I had to modify the harness bar slightly to make it fit (the upper attachments for the rollbar utilize the upper seatbelt mounts, so it requires the harness bar to be shortened).

The door bars also require some dexterity to get in and out of the car. OK for a racer, but too much for a street driven car in my opinion. I took mine out as I don't drive on the track very much anymore, but left the attachments in place if I change my mind. The bolt-in cage is not all that hard to install or remove.

[rick 918-S]

IMHO a roll bar is a street car is a bad idea. Unless your strapped in a 5 point and wearing a helmet to protect your coco nut it's a suicide mission.

[Solo914]

IMHO a roll bar is a street car is a bad idea. Unless your strapped in a 5 point and wearing a helmet to protect your coco nut it's a suicide mission.

I thought that too. Then I built a race car. That's what high density and medium density foam is for. If you think about it, in any street car you head and body is sometimes only a piece of plastic away from the steel body. So, if I were to build a street car with a cage, I would put foam around all the bars that I could contact.

kyle

[charliew]

I don't have a race car but I have broken a full face bike helmet in three places while I was hitting dirt and grass. The concussion lasted over a month. I couldn't focus on tv or anything and couldn't hear very well. I don't care if it's super dense or soft your head without a helmet can't take much of a blow without serious damage. If you have a cage on the street and the bars can be struck by your head with or without padding it is russian roulette.

[Solo914]

I don't have a race car but I have broken a full face bike helmet in three places while I was hitting dirt and grass. The concussion lasted over a month. I couldn't focus on tv or anything and couldn't hear very well. I don't care if it's super dense or soft your head without a helmet can't take much of a blow without serious damage. If you have a cage on the street and the bars can be struck by your head with or without padding it is russian roulette.

Charlie,

I hear what you are saying but what about your normal honda civic that just has plastic covering the A and B pillars.


Kyle

[carr914]

I've heard the argument against a cage in a street car, but when I had my wild conversion, the fact it had a cage, made me feel very safe. Especially when even a Honda Civic looks big when your hunkered down in a 914. I had my cage padded, I had a Recaro race seat and wore 5 point harnesses all the time.

Solo makes a good point about hitting things covered in plastic in a normal car. Much less things like fire extingishers mounted on A-pillars.

T.C.

[jhadler]

I hear what you are saying but what about your normal honda civic that just has plastic covering the A and B pillars.

Because the bars of a roll cage are much closer to the occupant than the A and B pillars are. Especially in a 914, where there isn't that much room to begin with. The difference my be 5 inches or so, but in a car with such a small passenger compartment, that 5 inches might be the difference between a sore neck, and a concussion (or worse)...

edit: Having witnessed a pretty good injury as a result of side impact on a car with a caged (it was a Z06) it further reinforces the point that a roll bar or cage is incomplete without the rest of the safety gear that goes with it. He had stock seats, and a stock belt, and while the sideways sliding car stopped, he did not, and his ribs met the door bar with significant force. Had he not had the bars, there would have more room for his body to move, and should he have gone up to the door, the impact would have been distributed over a much larger area. Or, on the other side, had he been wearing a harness in a real race seat, it would have been one of those you just walk away from...

For me, cage=harness+lid.

-Josh2

[byndbad914]

(IMG:style_emoticons/default/agree.gif) Josh beat me to it. Sit in your car, centered in the seat, put your belt on and get it locked into place and move your body around trying to hit the A pillar and B pillar... going to have a VERY difficult time pulling that off, or else sell the car it is a death trap. You will typically be able to bust the door window out with your head in a side impact but that should be about it.

Add a cage that is 2-3" closer than those items between gaps and tubing size itself, make it ROUND not flat like a B pillar so you can really crush an area of your skull - do the same thing... won't be hitting the A pillar, the cross bar across the top of the windshield (the hoop)... maybe but probably not, but the B pillar area and the bar immediately behind your head hoop, probably so.

I built the cage in my car custom to tuck everything as tight as possible, moved the seat inboard almost 2" to center up on the wheel (and rotated the steering column to match) and I can't hit the bars with my head and have 1" of clearance in general. WITH the padding, I can just touch the front of the hoop with my thick, top air helmet, so in a big crash I will make contact with the thick SFI padding but not worried.

Keep in mind SA rated helmets v. M rated helmets have the additional testing for hitting roll bars, because the initial contact is a point (sphere on cylinder) and only becomes line contact as the helmet deflects, so force is distributed over very small areas. If that is your skull... hope you enjoy eating your meats and starches with a straw.

So, my point (I am long winded)...

you can do a cage, but relocate your seat and make damn sure you have at least 1" (IMO) of clearance straining against the belts in any direction. I would make sure that is including padding - don't ever "expect" your head hit anything, period - do all you can to avoid contact with your noggin. That SFI padding will kill you just as quickly with no helmet - it only serves to increase the area of contact for your helmet, the force is still brutal.

[Solo914]

(IMG:style_emoticons/default/agree.gif) Josh beat me to it. Sit in your car, centered in the seat, put your belt on and get it locked into place and move your body around trying to hit the A pillar and B pillar... going to have a VERY difficult time pulling that off, or else sell the car it is a death trap. You will typically be able to bust the door window out with your head in a side impact but that should be about it.

Add a cage that is 2-3" closer than those items between gaps and tubing size itself, make it ROUND not flat like a B pillar so you can really crush an area of your skull - do the same thing... won't be hitting the A pillar, the cross bar across the top of the windshield (the hoop)... maybe but probably not, but the B pillar area and the bar immediately behind your head hoop, probably so.

I built the cage in my car custom to tuck everything as tight as possible, moved the seat inboard almost 2" to center up on the wheel (and rotated the steering column to match) and I can't hit the bars with my head and have 1" of clearance in general. WITH the padding, I can just touch the front of the hoop with my thick, top air helmet, so in a big crash I will make contact with the thick SFI padding but not worried.

Keep in mind SA rated helmets v. M rated helmets have the additional testing for hitting roll bars, because the initial contact is a point (sphere on cylinder) and only becomes line contact as the helmet deflects, so force is distributed over very small areas. If that is your skull... hope you enjoy eating your meats and starches with a straw.

So, my point (I am long winded)...

you can do a cage, but relocate your seat and make damn sure you have at least 1" (IMO) of clearance straining against the belts in any direction. I would make sure that is including padding - don't ever "expect" your head hit anything, period - do all you can to avoid contact with your noggin. That SFI padding will kill you just as quickly with no helmet - it only serves to increase the area of contact for your helmet, the force is still brutal.

Guess I never sat in a caged 914. After moving the seat and steering column you are still only an inch away... that is close. I am that way in my SM and thats with the SFI padding but I wish my A pillar tube was even tighter to the top. We have talked about this at length locally because we have some guys that drive their track cars to the track and the sentiment is that you shouldn't drive a fully caged car on the street, and if you HAVE to, make sure that you pad the shit out of the cage and where your 5 point harness.

Kyle

[Brett W]

Roll bar is the most I ever recommend for my customers in a street car. It will save you in more ways than one. Steel tubes and you head do not work well together. Leave the roll cages to the race cars.

BTW Autopower and Kirk bolt in cages fit so bad you are almost guaranteed to knock yourself out just trying to get in the car one day. Don't run them on the street.

[Aaron Cox]

Is there any way to do a 'halo' type cage, keeping steel bars farther from your noggin?

[jhadler]

Is there any way to do a 'halo' type cage, keeping steel bars farther from your noggin?

In a 914?? Not really, there's no room. Not unless you re-build the car to be center-drive...

-Josh2

[charliew]

I think the op should just do a exoskeleton cage like the rock crawlers. I bet he would be the only one to have one. Paint the car red and chrome plate the skeleton. Probably get more looks than a gt40.

[914junkie]

Hey guys, thanx for all the replies. Lots of good advice and arguments on both sides. I'm thinking I won't put a full cage in the car now. I do have 5pt belts and I always have them on when I'm driving. That and I have a Momo T-frame seat bolted straight to the floor and slightly towards the center so I do have pretty good clearance for my melon from a top bar even with padding. But my primary reason for wanting a cage in the car (other than safety of course) is to make the thing as stiff and solid as possible. I've been driving the car for 15 years but every time I'm standing there looking at it with the doors open I look at that little floor and hate to think thats the only thing holding the front and back together! Especialy with a V8 8" behind my back! I think what I really need is a custom built cage with roll hoops and everything else below the beltline. Similar to what Dana designed in his turbo suby 914 (that thing is gonna be sweet). With some tubes going through the firewall to the rear sections of frame in the engine bay. Think I need to get with one of the local race car builder guys and come up with a good design. Thanx again for the input. See ya, Paul. (IMG:style_emoticons/default/idea.gif)

[Brett W]

If you are really short you can get away with a cage in the 914, But you pretty much have to sit on the floor. But I really wouldn't advise it.

Now you could do what I did on a Vette I just built. I ran the upper A-pillar bar almost outside the window frame and then duck back into the main hoop. Looks funny and the window is useless, but that was a race car.

[J P Stein]

Stiffness is gud, but there are compromises with livability for a street car.....entry & egress being the main problems.

At one point I had a 10 point cage (with halo) in my car. I was not impressed by the resulting stiffness. I was impressed by the shot the side bar put on my head....with bar padding & helmet on.

I got rid of the halo and redid the cage for chassis stiffness.....shoulda done it years ago.

Come on by & take a look. I'm sure the guys here are tired of my pics.

[Randal]

The other point about "livability" with a cage is that you have to have your 5 point belts tight (tight) to make sure you don't move more than you did in your "test."

Now if you run around with that cage and the belts tightened where they should be for (head) safety, you're going to be one uncomfortable guy. Imagine getting stuck in traffic....

I always wonder why I'm sore after a track day... duh.

[Wilhelm]

This thread make me wonder if it might be possible (or scca legal) or practical to run a roll bar behind the rear window, ie outside of the car, but just beneath the factory roll bar. Otherwise might it be completely irrational (or impractical) to cut into the factory roll bar and tuck a replacement roll bar up into it on the inside so that the original head to roll bar clearances would remain?

[Aaron Cox]

Stiffness is gud, but there are compromises with livability for a street car.....entry & egress being the main problems.

At one point I had a 10 point cage (with halo) in my car. I was not impressed by the resulting stiffness. I was impressed by the shot the side bar put on my head....with bar padding & helmet on.

I got rid of the halo and redid the cage for chassis stiffness.....shoulda done it years ago.

Come on by & take a look. I'm sure the guys here are tired of my pics.

Post em anyway (IMG:style_emoticons/default/smile.gif)