I want to add a four point seat belt for my c7 z51, with regular seats, not competition seats.

my local shop told me that my car doesn't have bolt on four point, and I needed a roll bar behind my seats in order to install the seat belt.

(do I really need a bar to install four point? Or there is already one out there like a bolt on?)

My question is, will adding a roll bar decrease the car's overall safety? Compared to not adding one.


thanks a lot for helping out!

 

If you only intend to add the seat belts and don't need the roll cage do a search on Shark Bar I believe it's called. That should get you what you need. There are options without installing a cage.

 

Adding a 4 or 5?point harness without a roll bar or cage is dangerous. In the event of a rollover the harness wont let your body bend down youl stay strait with the seatback

 

That is a myth. In a roll over your body stretches out due to centrifugal force and the most likely thing to happen is for your head to go out the window and contact the ground as the side of the car hits the ground.

Anything that keeps your head in the car is better. Sadly a 6 point, 8 or 9 point belt system will not do that. You need a seat that restrains the head and a window net.

Adding a roll bar may not provide the safety that a lot of people think. First, the Corvette roof halo holds up well in a roll over so a roll bar doesn't provide much benefit; Second, a roll bar can be a detriment when you don't have a helmet on. If the roll bar is in any place where your head can hit it when a rolling or spinning car is flipping your body around it can cause serious injury. A lot of HPDE events require roll bars to have SFI Rated Roll Bar padding located in any place where a head could contact the roll bar.

Roll overs only make up about 1% of track incidents and a smaller percentage in street and highway incidents.

Harness bars provide a solid mount for a race harness. Currently there are three available for the C7. The Shark Bar, BK Bar and Local Motors bar (This is a good design but prevents usage of the stock seat belts, it is used in Bondurant Driving School Corvettes).

OP: Using a 4 point with the GT seats isn't recommended. The slot in the back of the seat isn't wide enough (about 7 inches) to pass belts through and then go around your neck. Running two 3 inch wide belts through that slot leaves 1 inch of extra space that means the belts have to bend around the seat to go out around your neck. In an incident about 3000 lbs of force will be applied to those belts and that bend in the belts will pull straight (breaking the seat and maybe your neck) as the slack from the bend around the seat and your neck snaps straight as an arrow. Putting the belts around the outside of the seat doesn't do any good since as has been found in a number of incidents over the years the belts fall off the occupants shoulders as the body moves back and forth and sideways in an incident. Most HPDE organizers don't permit this type of harness setup anymore.

The only stock seat that works with a 4 point system is the Comp Seat. The only 4 point belt system that will work in the car are the Schroth Profi II ASM belts. ASM stands for anti submarining.

Bill

 

Personally, I wouldn't drive a car with a roll cage without a helmet on.

 

No. Read Bill Dearborn... this is good advice.

Also, go the the PCA Club Racing web site and review their MINIMUM requirements for safety equipment... this is based on 25 years experience racing street cars in highly competitive environment.

Anything less than this is probably either ineffective or dangerous