Roll Cage Information for GT40 Please

ragrod · 12-19-07, 12:49 PM

Could some of the guys using 6 pt. cages post pictures? What tube dia. and thickness are you using etc. ? What are track officials looking for? I am assuming they are non-removeable, how do they affect entry @exit from car?
From most of the build pics. I see most cages follow door line thru top section, is this acceptable? In looking at CAV's GTR I think the cage cuts across door opening, how do you get in? That link must be remaovable?
I did track days in my Pantera without a cage, are cages being asked for in track-days in 40's?
Thanks ,I guess you can tell I am getting excited about the track!

Randy

Russ Noble · 12-19-07, 01:28 PM

Randy,

There are photos on the last two pages of my build thread of my cage which complies with MSNZ requirements. Kiwi scratchbuilt

The cage goes through the door opening. Unlike Aussie, they won't approve any that follow the shape of the top of the door unless you have an engineer design it and certify that it will withstand the design loads that MSNZ specify. Tube size is 1.5"x.100".

It makes getting in and out a bit ungainly, but hell, that doesn't matter . You could still get out superquick if you had flames licking all around you!

Ross Nicol · 12-19-07, 07:19 PM

Quote:

Originally Posted by Russ Noble

You could still get out superquick if you had flames licking all around you!

As long as you can get the door open Russ.

Ross

Russ Noble · 12-19-07, 07:57 PM

Too true Ross.

Less chance of it getting jammed though with a brace directly across the top of the door opening. IMHO.

And it's all welded up solid, we are not allowed removable sections in that part of the structure. I find I can either swing out underneath it or step out over the top of it. Pretty easy really...

ragrod · 12-19-07, 08:35 PM

Wow this is a bummer,as I would like a duel purpuse road /track car. With bars across doors, how am I going to convince the wife it's OK it go for a sunday drive?
I might as well paint it gulf colors and put numbers on the side, Oh ya that what a lot of you do. I get it its a race car!! But part of the fun is driving a race car on the street.
I don't want to make a dedicated race car yet! Just really want to do track days.
Again what is being asked at these type of track day events, Are roll bars even talked about by tech guys?

Fran Hall RCR · 12-19-07, 08:40 PM

Randy,

I have done a few swing out upper door bars..
Dean Lampe has run his...he is a tall chap like you....

Maye he will share his thoughts....

We make the cage from 1 1/5 inch .120 wall DOM as an RCR is under 2500lbs as specified by SCCA.....obviously for a full SCCA legal cage we need to add more tubes and change the config. but for open track/lapping days no upper bar is required.
Depending upon car weight larger diameter tubing may well be required..

Ross Nicol · 12-19-07, 08:55 PM

Randy
The best advice I can give you is to check with the motorsport governing body, who control the vehicle safety requirements, for the level of track work you intend to do.In some cases no roll cage is required but for pose value you could fit a 1/2 cage, which is the hoop behind your head with rear braces.This would add a measure of safety, give the look of a race car with no need for braces across the doors.I have an 8 point cage and the pipes from rear follow the contour of the door opening.I have had this cage homologated for Racing my car in Australia.The design required an engineer to provide documentation proving it's up to the job if the car rolls over.A back yard welder (read myself) is not allowed to fabricate a cage from chrome Moly but is allowed to use CDS cold drawn steel.

Ross

David Briggs · 12-19-07, 08:59 PM

The car is suitable for most track days without a roll cage.
I have done track days with Pantera/Ferrari and Shelby groups w/out a cage.
Racing is a different story.
Dave

ragrod · 12-19-07, 09:02 PM

Fran. can you post a pic. love the small tube idea, Options, I better find out what my car wieghs,
Thanks
randy

ragrod · 12-19-07, 09:05 PM

David, Geat news ,
thanks.
randy

Dutton · 12-19-07, 09:47 PM

Randy,

Ross nailed it.

Once you determine which groups you want to run with, pick up a copy of their regulations and start reading. No matter what anyone else tells you, when you get to the track you'll want to know that you AND your car will be welcome at the event.

How incredibly disappointing it will be to discover the car isn't ready when you arrive...

Be safe out there,

T.

Ross Nicol · 12-19-07, 10:14 PM

Hi David
Just as I thought no cage required for track days.It would be helpful for Randy and others to add a location to their profile so questions like this can be answered by experts in the appropriate country.Saw your car on a Pantera site with a very collapsed right rear suspension David.I presume the lower control arm has been improved on your car now.

Ross

Dean Lampe · 12-19-07, 10:41 PM

Here are some pictures. It is not about what the track will let you get away with but what will save my life if I crash during an open track day.

accesshole.jpg

DSC00069.JPG

Howard Jones · 12-19-07, 11:23 PM

I think that I wouldn't race one of these cars with side windows on the car. I hate to think about a fire and a pileup with other cars, in a tire wall, etc. where you can't open the door(s). I have taken my driver-side window off at one track-day for this reason but I have not been doing so thereafter. I do know that I am taking a gamble however. Full on racing is quite another thing. Other cars are much closer and there are more of them such as at the start/1st turn.

Full on race car GT40s should be built with window nets AND a fuel cell from the inception.

There just isn't much room inside to work yourself out of the car by kicking out the side window or something like that.

Every time I get onto this subject I remind everyone to PUT IN A FIRE SYSTEM!!!! Put them into every GT40 built no matter what you are planning to do with it. They are very cheap and easy to install. AND bring along a small fire bottle. One or both could turn a compete loss, or much worse, into a little paint repair.

Picture yourself standing along side the highway with a carb fuel line leak/fire. You smell something burning, pull over safely, jump out and just stand there and watch it burn because you can't do a damn thing but watch. How easy it woiuld have been to pull that lever.

Dean's removable bars are the solution for a track/street car in my opinion. All full on race cars should be built with a complete rules complaint cage regardless of whatever the access issue might be. Very nice job.

Ross Nicol · 12-19-07, 11:44 PM

The powers that be over here probably wouldn't accept those rear stays with the kink in them.

Ross

Fran Hall RCR · 12-20-07, 12:23 AM

Ross...as I mentioned earlier that is a track day cage not a full race spec cage.....see Ron Earps Lola for a full race SCCA cage...not a small undertaking thats for sure.....
Dean has HUGE headers and originally required the kink to clear them.......our standard 6 point has straight rear legs..as can be seen on many cars on the RCR forum..

Russ Noble · 12-20-07, 12:53 AM

Nor here either Ross, unless you can get an engineer to certify that it will handle the required forces.

Either way bent tubes in any load bearing structure, be it chassis or roll cage, are a definite no-no.

I am unhappy about the unavoidable bend in the lateral roll bar at the top of the screen and wanted to put a lightweight diagonal in from there back to the base of the main hoop. More to improve chassis stiffness than for rollover protection, although it would improve that as well, but was unable to do so as it would have intruded into the mandatory door space egress area. Notwithstanding, that you can hop out the top in a GT40! The regs weren't written with GT40's in mind!

I agree with much of what Howard says also, but to me light weight and stiffness are the holy grail. I will be fitting the minimum roll protection and minimum extinguisher system that I can get away with. Otherwise you can go on, ad infinitum, adding weight on a "what if" basis. If shit happens, shit happens!

Cheers,

Fran Hall RCR · 12-20-07, 01:00 AM

Shit does happen but having a wife and children tends to make the shit happen mentaility become refocused.....

If I recall original GT40's had no cage at all ,so does that make it right.....hell no it doesn't....
Any protection is better than no protection...but light is right only goes so far...in my world.
F1 world championship maybe....making it to work on Monday morning after a fun day at the track and hugging the kids every evening is way more **cking important in my life.....sorry Russ ...thinking out loud there.
Russ is your block aluminium???...does your trans have the lighter mag. casing??