Roll bar for Convertible

[mwest300zx]

I participated in my first HPDE events this summer and I am hooked. But, I sold my car and now want to use my Nissan 300zx convertible.My questions are:

1-Do I need a roll bar ?

2-The Z convertible has a factory roll bar that gives it structural strength, but is it also a functioning roll bar?(I've contacted various sources regarding this and have not gotten a definitive answer)

3-A prefab bar does not exist for this car, I have to have one made. I met with a builder/fabricator that builds race cars. He suggested due to the limited space in this car to install a roll bar directly beneath the factory roll bar. this would reinforce the factory bar and give it the additional strength to be the equivilant of a roll bar. Would this set up be acceptable for HPDE?

4-Are there standards for the bar and its installation I could give to the fabricator?

Any and all help would be greatly appreciated. Thank you.

MWest

[jl1]

Did you ever get an answer to your question?

 

I'm also curious about which convertibles are acceptable in stock form and which require a retrofit rollbar. For example, are the stock rollover hoops on a Z4 adequate, or would one need a rollbar in addition? (Not that I have a Z4.)

[Voodoo]

I don't know if the rollbar in a Z4 are adequate or not because I don't know how thick the bars are and how they are attached, but the ones in a S2000 do meet the requirements because the bars are .125 in. thick and are mounted directly to the chassis.

[Ryan F.]

MWest- Is there any data from Nissan that states that bar is for the purpose of roll protection? The bars in the Z3, Boxster, etc attach directly to the bulkhead and are designed for that purpose. Many hoops are "style" bars such as the one in the Saleen Mustang and wont do the job. The CCR states that the roll bar must have the rear kicker bars to keep the hoop from folding forward or backward. Since the Z3 and Boxster have a dual hoop design, attach to the rear bulkhead and is stated to protect from rollover protection the insurance company allows it. The BMW M3 Pop up bars are also stated to provide roll protection so that is allowed as well. The best thing would be to have a NASA tech inspector look at the design and check with Nissan to determine its designed function. If it looks like it will hold the weight of the car and not fold then you should be fine.