Datsun Roadster Forum-311s.org

Hey everyone. As my car gets closer to being a driver, I am starting to look to the future where the car will be prepped to race in VARA. For a decent amount of time though, the car will still be a road legal car. That being said, my car currently has a rollbar already installed, though Im not sure what type it is. I do know it will need to be modified to accept the harness, so Im wondering since it will get modifed is there anything else I should do?

Heres what I already plan on adding:
-Crossbar going from above the drivers head area to the bottom "b-pillar" area of the roll bar.
-a straight across bar to accept harnesses. will initially add the one for me, maybe a pass one later

this is a maybe
-from that same above driver head area, another cross bar going to the rear pass side mounting point to triangulate it all
-spreader plates with the nuts welded on that will be underneath where the roll bar mounts to spread the load

Is there anything else I should do while its all getting fabricated? It will all get powdercoated when its done so I want it done right the first time

I attached the pics of Wills rollbar upgrades as an idea of basically where I plan to start the upgrades

You might want to check with them for the requirements for racing just to make sure. Most of the roll bars you see on roadsters are considered 'street bars'

Check with Will, he has track experience

I'd be surprised if you were allowed to run a bar that was not mounted to the frame instead of just bolted to the body....at least in wheel to wheel racing.

Read the VARA rules first.

Usually you want to start with all new material. The height requirement is usually the fly.



H.18 ROLL BAR Roll bars are required on all postwar cars. (Roll bar requirements for specific historic cars may be waived by application to the Technical Committee.) The roll bar shall be higher than the driver's helmet when seated in the car. Roll bar design and construction is the entrant's responsibility, but it is strongly recommended they be designed and constructed to current SCCA or equivalent standards. The Chief Technical Inspector and/or Tech Chairman may deem a roll bar or rollover structure unfit for competition. There must be a padded head restraint within 6 inches behind the drivers head.

SCCA SOLO

1. The basic purpose of the roll bar is to protect the driver in case the vehicle rolls over. This purpose should not be forgotten. 2. The top of the roll bar shall not be below the top of the driver’s helmet when the driver is in normal driving position, and shall not be more than 6 inches behind the driver. Exception: For Modified Category Specials (Section 18.4), the bar must extend at least 2.0” (50.8 mm) above the driver’s helmet in the normal seated position and a head restraint keeping the driver’s head from going under or behind the roll bar is required. It is strongly suggested that all roll bars extend at least 3.0” (76.2 mm) above the driver’s helmet. In case of two-driver cars, both drivers must be within the roll bar height requirement, however only one (1) driver must be within 6.0” (152.4 mm) of the roll bar.

2. The roll bar must be designed to withstand compression forces resulting from the weight of the car coming down on the roll structure, and to take fore-and-aft loads resulting from the car skidding along the ground on the roll structure. 4. The two (2) vertical members forming the sides of the hoop shall not be less than 15.0” (381 mm) apart (inside dimension). It is desirable that the roll bar extend the full width of the cockpit to provide maximum bearing area in all soil conditions during rollovers. The roll bar vertical members on formula cars and other single seat cars with a center driver position must be not less than fifteen inches apart, inside dimension, at their attachment points to the uppermost main chassis member. 5. An inspection hole of at least 3/16" (0.1875”, 4.75 mm) diameter must be drilled in a non-critical area of a roll bar member to facilitate verification of wall thickness. This should be at least 3.0” (76.2 mm) from any weld or bend.





E. MOUNTING PLATES
1. Roll bars and braces must be attached to the frame of the car wherever possible. Mounting plates may be used for this purpose where desired. 2. In the case of cars with unitized or frameless construction, mounting plates may be used to secure the roll bar structure to the floor of the car. The important consideration is that the load be distributed over as large an area as possible. A backup plate of equal size and thickness must be used on the opposite side of the panel with the plates through-bolted together. F. REMOVABLE ROLL BARS Removable roll bars and braces must be very carefully designed and constructed to be at least as strong as a permanent installation. If one tube fits inside another tube to facilitate removal, the removable portion must bottom on the permanent mounting, and at least two bolts must be used to secure each such joint. The telescope section must be at least eight inches in length. G. INSTALLATION ON CARS OF SPACE FRAME AND FRAMELESS DESIGN It is important that roll bar structures be attached to cars in such a way as to spread the loads over a wide area. It is not sufficient to simply attach the roll bar to a single tube or junction of tubes. The roll bar must be designed in such a way as to be an extension of the frame itself, not simply an attachment to the frame. Considerable care must be used to add as necessary to the frame structure itself in such a way as to properly distribute the loads. It is not true that a roll bar can only be as strong as any single tube in the frame. H. ROLL CAGES It is recommended but not mandatory that all cars utilize a roll cage as defined in the current Club Racing GCR Section 9.4, Roll Cages For GT And Production Based Cars, or Section 9.4.5, Roll Cages For Formula Cars and Sports Racing Cars. I. ROLL BAR PADDING Braces and portions of the main hoop subject to contact by the driver’s or passenger’s helmet, as seated normally and restrained by seat belt and harness, must be padded with a non-resilient material such as Ethafoam® or Ensolite®

Where are the typical frame mounting points that people use ? Any other pics?

Simon,
It's a tough line to balance between street and dedicated race car. Especially if you want to take passengers on the street. I can help with pictures, but your best bet is too follow Will's build. I know you don't want it to be "someone else's build" but he's actually raced with VARA with that roll bar.

A good point that was brought up (and a definite pass/no pass at inspection) :

"The roll bar shall be higher than the driver's helmet when seated in the car."

Keep this in mind when you build your roll bar. Do you plan on running a hard/softop? Will your racing seat make you sit lower/higher?

Autopower sells a similar bar to Will's, but mounts against parcel shelf/trunk wall in rear:




Other VARA racing roadster roll bar setups
Follow Brian Zana's build he's been racing this year with VARA!
http://www.311s.org/phpBB3/viewtopic.php?f=27&t=13757





DP-prepped roadsters:

Thanks for those pics Alvin! I feel like my height might finally benefit me as I was looking at some older pics I have of Will racing his car and Im a good foot shorter than him so I should be able to avoid having a huge rollbar like most of the dedicated cars have, though I know one reason they have them so tall is because without the windshield frame you have to have the extra height to protect the driver in the event of a rollover.

2 things here..

If you actually want to be safe, it absolutely has to go to the frame, right through the body. It absolutely has to have door bars, to keep the other cars out. And it absolutely cannot plan on the windshield pillars as part of the safety structure. And with that, you will have killed the usability as a street car.

If you want a fun car to go play on the track but are not planning for wheel to wheel action, what you are looking at looks fine. Make sure the harness bar is high enough. And drive on tthe track with reserves, and knowing that you are not exactly safe, so leave yourself a way out..

a much better view of the Autopower roll bar:

This is my old '65 1500 I used to race with VARA. As others have said, you gotta know you're rule book before building anything for a race car. Bolt-ins are for track days and parking lots, and then they are still really just a harness mount.

troyt wrote: Bolt-ins are for track days and parking lots, and then they are still really just a harness mount.

FINALLY someone who gets it! Well said Troy.

Bumping this back up.

Im curious if my current rollbar is remotely near spec. I know that wall thickness is important and I remember my E30s rollbar having a hole drilled in it, presumably for inspection. My question is about this hole. Is there a specific location on the bar that this hole should be drilled, or size? Id like to see if there is any value to the current rollbar in my car right now

Almost all clubs use the SCCA GCR sections on roll cages as their guideline. GCR is very detailed and available online. Height, thickness, inspection holes, bracing, attachment points, all discussed in there.

Thanks Troy, I will take a closer look at SCCA

May not be worth trying to use the old one with required / desired modifications. Check out his gallery...
http://jakenethome.dynu.com/Roadster/20 ... index.html
Also the car next to,the roadster above with the teepee style. Door bars out into the door are highly desireable as is a dash bar or two. Just sayin. I had a great cage save unknown personal injury in a front end collision that totaled the car. Ya never know. Sorry to be macabre, but what are your legs, body, life worth?