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CptTripps
While talking with my uncle about the build I have underway, he asked a question that I hadn't spent a lot of time considering...what if I roll the thing?

Fair point. I'm going to be well north of 300HP, and while I've upgraded the suspension, chassis and brakes...I haven't put a lot of thought into the cabin.

Is there a way to do a roll-bar that would still maintain the "street-ability" of the car, while adding some protection for my noggin?

I was thinking about something like the attached photo, with additional tubing added where I have the green.

Being able to use the stock seats and seat-belts is important.

Does someone make something like this, or am I finding someone local to build me one? I'd be welding it into the car, and on top of the Engman stiffening kit.
Steve
The built in roll bar, should be fine if you roll it, unless you have major rust issues. In the early 80's one of my friends went off the mountain side to avoid hitting a truck passing in his lane. The 914 rolled at least five times and the built in roll bar did not collapse. It was a little rounded on the sides and the windshield hoop was also bent. Both the occupants survived with only scratches and bruises. For track use, you might be required to put in a roll bar anyway. For the street and my 3.2, flairs etc, I just went with the Engman kit to strengthen the car.
stugray
agree.gif You already have a rollbar.

I would consider the stock bar to be better than most cars with roofs.
r_towle
if you do not plan on wearing a helmet, a stock car is correct.

The issue with a rollbar (at least something to think about) is there is documentation out there that shows you can do more damage to the occupant with the rollbar (hitting your head in a roll over against the roll bar) then any potential savings it might deliver.

Abel, my son (Rocket here) rolled his, the roll bar was fine, windshield held up fine...the rest of the car did its job and collapsed, but the passenger compartment is pretty solid if you have no rust.

If you are working with an early chassis, I would suggest you upgrade to the 73 or newer doors that do have side impact bars welded in....or modify yours.

I looked long and hard before I gave my son that car,,,,cause I figured it might happen.
I did not find one wreck that the occupant compartment could not sustain a person....
All of the typical wrecks took the hit fairly well.

Now, if you go do a carrera GT type thing....well even the best protection wont help you.

Rich
CptTripps
Great info guys. I'll skip the extra roll-bar then.

I've got a 75 chassis and was planning on double-checking the welds inside the doors to make sure everything was still solid. I'd rather have a car that was 100lb heavy...and safe.
r_towle
seems like the common opinion is its less safe without a helmet.

RIch
Dave_Darling
I wonder if adding a doubler to the stock Targa bar would do any good? Sort of like the Engman long kit, but for the Targa bar.

--DD
SirAndy
I'm surprised the "you're going to die!" crowd isn't out in force yet.

According to them, a rollbar in a street car is certain death, might as well shoot yourself now ...
rolleyes.gif

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Steve
QUOTE(SirAndy @ Jan 29 2014, 02:02 PM) *

I'm surprised the "you're going to die!" crowd isn't out in force yet.

According to them, a rollbar in a street car is certain death, might as well shoot yourself now ...
rolleyes.gif

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A properly padded cage is a diferent story. He only asked about a roll bar, regarding rollovers. In the case of a car accident or running into a rock like that other guy did I would rather have your properly padded cage.
ThePaintedMan
... along with appropriately adjusted 5 point harnesses to keep your body and skull from flying into said rollbar.
stugray
As someone who has personally rolled a car, I refuse to buy a car without roll protection.
i.e: Boxster, Solstice, miata, etc....

However I know for a fact that the flimsy looking roof on a 71 Ghia is plenty strong to support the entire weight of the car and two occupants....
jeff
I'm not against using a roll bar/cage for the street,
-Use padding on the tubes near your body
-have at least 2" of clearance from your Helmet to the bar( this will be about 4" without helmet)
Make sure your bar/cage tube are welded in compression& shear..
Be sure your confident about your welding ability,
If you have large gaps in your coped tube ends your cage/ bar will be weak
Reconsider stock seat belts, if you have a good cage I'd wear harnesses and snug them up good
Don't put the dash bar where your knees will hit it ...
I can't think of anything else...
CptTripps
I'd thought about maybe working on a reinforcement for the targa bar. Maybe a rectangular piece across the top, contoured to the body. Then two pieces up the sides from inside the targa bar. I'd have to draw it out, but it'd likely be more work than it's worth.
gryphon68
What about tucking a one piece main hoop in under the targa bar outside the passenger compartment? Run it down to the rear rails and brace forward and rearward. . . .
carr914
QUOTE(Dave_Darling @ Jan 29 2014, 04:46 PM) *

I wonder if adding a doubler to the stock Targa bar would do any good? Sort of like the Engman long kit, but for the Targa bar.

--DD


The Stock Targa Bar is Strong enough to do anything that is coming it's way
damesandhotrods
Maybe I’m putting too much faith in Porsche’s engineers, but if the windshield alone can hold up a sedan delivery I am confident the Targa would support the weight of the 914…
jeff
http://m.youtube.com/watch?v=QQh56geU0X8

CptTripps
QUOTE(jeff @ Jan 29 2014, 09:14 PM) *


One of my favorite episodes.
TeenerTim
http://tangerineracing.com/rollcages.htm
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larryM
just buy a bolt-in AutoPower

- add the gurney brace if you think you want to be scca legal

it significantly stiffens the chassis - you will not regret it

or - if you do - it is easy to unbolt & sell

.
CptTripps
That tangerine one is about exactly what I'd be looking for.

Need to ponder this a bit though. Not sure it's needed after seeing some of the comments.
Mike Bellis
I have a double hoop roll cage. It's tied into the rear suspension and soon will be tied to the front.

I have pads on the bar above the side windows. I have never hit my head on any part of the bar except getting in the car a few times. I have good clearance from my dome most of the time.

I have removable door bars that are almost never on the car. I actually find it easire to get in/out of the car using the roll cage as a handle. It also make a good handle for the passenger during spirited drives.

I do feel safer with the cage and maybe it gives me false courage but I like it.
914forme
I run a single hoop roll bar, with a petty bar. Petty bar is only in if I don't have any passengers. I'm 6'2" with stock seats and cushion, my head is petty high in the car. I run full FIA spec padding. If I pull the seat cushion like I do when I race, I have plenty of clearance. But I have to do that to get my helmet in the car with out a bubble. I need to find a different seats and mounts. Do I worry about it, nope, not worried at all.

To me the most important part of the cage/roll bar is its mounts. The bolt in cage / roll bar mounts are pretty small. I built my own to tie into 4 different planes on the floor mounts. Spread the forces out. Added a bar at the bottom that runs across the floor area and picks up the seat belt mounts in the center tunnel. Also keeps things from crushing crushing that section of the car in a side impact. At least thats the design theory hopefully I never test it. I have begun to think about a cage, my problem has always been the cutting in of the leg room with the cage. I have bad knees, and that flexibility and room really make my ingress / egress a whole lot better. So for my design, I would have to push the front legs as far forward as I could.

My roll bar was added as chassis stiffening. It attaches at 7 points, In my class rules 8 points would have added points to the car. I could remove a the two in the center tunnel. And have a full cage. with the two front drops. In this rebuild, I am planning on adding the front mounts for the cage, so I can add it when I need to. Again, it will tie into at least three planes if not four. Its hard to do, but worth it
tomeric914
QUOTE(damesandhotrods @ Jan 29 2014, 08:58 PM) *

Maybe I’m putting too much faith in Porsche’s engineers, but if the windshield alone can hold up a sedan delivery I am confident the Targa would support the weight of the 914…

The windshield isn't holding up the front drive, front engine sedan delivery. The front of the 914 is. dry.gif

Click to view attachment
carr914
QUOTE(larryM @ Jan 31 2014, 11:35 PM) *

just buy a bolt-in AutoPower

- add the gurney brace if you think you want to be scca legal

it significantly stiffens the chassis - you will not regret it

or - if you do - it is easy to unbolt & sell

.


WTF is a Gurney Brace - Dan Gurney had nothing to do with any 914
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