Darren,

I looked at your pics. Biggest problem I see is that the 68 seats are shorter than later years so there is more clearance between the back of the seats and the deck lid. My stock 75 seats almost touched my deck lid and the 80 seats I have now have maybe 1/2" inch of space between them and the deck lid. There is no way that your "roll bar" will fit between my seats and the deck lid. You have a nice piece there but I dont think it will fit the majority of C3 verts.

 

If you choose to use aftermarket restraint systems, it is very important to recognize the disadvantages as well as the benefits as compared to the stock system.

During a crash, the main goal of your restraint system is to spread deceleration forces over as wide an area as possible, to prevent you from being ejected from the vehicle, and keep you from moving around in the cabin. The factory restraint system achieves these goals very well, with its main drawback of not holding the body in position when driving hard. A properly installed aftermarket harness system achieves this latter goal, and should achieve the former ones, but is difficult to install and wear properly.

There are 2 types of harnesses in the market. Harnesses designed for use in racecars that meet the standards of various race organizations (e.g. FIA, SCCA), and those that are designed for "street use". In my opinion, even if the belt is designed for use in street cars, they can be lethal if installed improperly and/or without rollover clearance.

The correct installation of an aftermarket harness system REQUIRES sufficient rollover protection. Since the 3-point factory seatbelts allow the occupant to move to the side in the event of a rollover it is possible for an occupant to avoid head injury with relatively little clearance. However, when a 4, 5 or 6 point aftermarket system is installed properly, this is no longer possible and thus requires a roll structure high enough to allow clearance above your head (or helmet) while sitting upright.

Another important consideration is the secure mounting of the harness. The mounting points are subjected to extreme loads during an accident and must not fail. The only way I know of to correctly mount shoulder straps is with a aftermarket rollbar that allows the attachment of the shoulder strap mounts high enough. Since we sit relatively upright in our car, it is important for the shoulder straps to extend rearward at no more than a 15 degree downward angle from the horizontal. If the shoulder straps are mounted improperly you greatly increase the risk of severe injury from spinal compression. Submarining is also a concern with a 4-point harness system for 2 reasons. 1) Since the shoulder straps pull up on the lapbelt, it is possible to raise the lap belt above the pelvic crest bones and onto the abdomen. If the lap belt is too high, serious injury can occur to internal organs. That's why 5 and 6-point systems are used in racecar restraint systems. However, it is not possible to use these anti-submarine straps without the installation of an aftermarket seat that allows the straps to pass directly down to the floor. It is not safe to loop the anti-submarine belt over the front of the seat because it does not provide the correct downward force and still allows submarining. 2) A 3-point system allows some chest rotation. The right side of the chest moves forward in an accident, decreasing the tendency to slide under the lapbelt.

Here are 2 scenarios to consider before slapping on those cool 5 point belts:
Rollover
In a rollover, the A-pillar is designed to leave some room between the passenger compartment and the ground. Obviously, if your body stays in driving position it is possible that your head will hit the ground. However, the stock 3-point system allows lateral movement that has been reported to prevent head injury in these types of accidents. If you were wearing a 4-point harness, lateral movement would be limited, increasing risk of severe injury to the head and neck in a rollover accident. That is why 4-, 5-, and 6-point harnesses should only be mounted in cars that have a roll structure that extends above the head (or helmet).

Frontal Impact
In this scenario, the primary OEM restraint is the 3-point seatbelt. It, combined with the airbag (if your car has one), is designed to distribute the energy of the impact to the strongest parts of your body and over a wide area. A 3-point belt also has belt pre-tensioners that reduce forward movement. A properly installed 4-point harness will distribute crash forces over a larger surface area of the body, but you lose the pre-tensioning benefit. There is also the increased risk of submarining as compared to the stock seatbelt system (see above). Using a 5 or 6-point harness that has the anti-submarine straps routed downward through the seat to secure mounting points on the floor can greatly reduce submarine risk.

I hope I don't seem like a party pooper here - that is not my intention.
I just think some people might buy these harness bars and 5 point belts thinking they will be safer, when in fact the opposite is more likely. However, if they do stop annoying squeaks and rattles, I suppose they are of some use.

 

You do have some good points here but most of the early C3 cars are only lap belts. I don't think in a C3 vert in a roll over you are going to get much protection with any of the belts described. Good points to consider though. It must be mounted properly to work correctly.

 

non of us have air bags either...

 

Yes, I know that. My '71 coupe doesn't have one either. It isn't about airbags. What I posted could be applied to any car, not just a C3....

 

My '79 came without the shoulder belts - upgrading to a 4-point harness is one of my winter projects (it's a mild winter here in FL)

A few years ago I had an accident on the German Autobahn, I was in the left lane (about 110mp/h) when somebody in the middle lane tried to pass another car... long story short: that car hit my front passenger side fender and wheel - it pushed me on the median and hit the center barrier ... my car spun a few times, hit another car, spun a few more times..and finally came to a stop... thank god, most of the cars behind me saw what was going on and slowed down and gave me some room ...

At that time I had a '90 Honda CRX without airbags - I had bucket seats and 4-point harnesses installed. During this accident I did not move in my seat... these harnesses are the safest seatbelt system there is IMO.... of course it must be installed correctly

 

SteveG75,

The C3R harness bar will fit. The only thing is that you may loose a little bit of the sitting position seat angle when the seat is slid all the way back. I am 5'11" and I have my sets slid all the way back and the seat angle with the harness bar install isn't bad at all. In my opinion, it is a small price to pay to have a good looking harness bar that doesn’t hinder the movement of the convertible top and requires no C3 modifications to install.

 

The Shark Bar Series 3 for convertibles will not hinder seating position and uses the factory seat belt anchors to mount the Bar. Currently it will not come roll bar hoops.


When autocrossing the Shark Bar will really makes a difference keeping you secure while aggressively driving a winding course. Before the Shark Bar, I used my elbow against the door to help keep me positioned in the seat. I really hated bruising my arm from the door trim and I didn’t like the having the feeling of the only thing from the pavement was a door. When driving normally I usually use the factory seat belts or only use the part of the part of the 5-pt belts. I also feel the Aftermarket buckles (camlock or lever) are much better than the factory seat belts buckles to escape from. Many C3 seat belts are over 20 years old and have worn out webbing (rust, water damage, etc). How they perform in a bad accident is questionable. The Shark Bar anti-submarine bracket, which is supplied with the harness bar kit, can come with a mount for a (double strapped) 2.5LBS Amerex fire extinguisher. Having a fire extinguisher mounted at your feet for very quick access can be Vidal in an accident. Remember having a 5-8 LBS fire extinguisher mounted near your head is crazy. This can become a dangerous projectile in an accident. Also if you plan on racing in autocross or road racing you maybe required to have a minimum of a 5LBS BC UL rating on the extinguisher.
Dan

 

The C3R Harness Bar uses the factory seat belt anchors as well.

 

Awesome.

Dtengle--does your C3R bar work in coupes?

 

Just had a look at their website again and saw the price.... .... Budget does not allow this right now (wife won't either).....

It's basically two plates bolted to the frame and a 1.5" pipe welded to them.... I'll start this 'project' tomorrow and will post results.... should only be $50 in parts.....