Of Roll Cages, Fuel Bladders & Fire Systems

As I winnow down the list of 'things to add' in my conversations with Dennis Olthoff in anticipation of my Mk. I being built and delivered (in mid-June, we hope), a few options have crossed my mind. I'd be interested in what others may think about them.

1. Roll Cage: Dennis says that one may be available as an option, but that it won't be SCCA or FIA approved. Of course, most Mk. I's weren't equipped with roll cages, as were some Mk. II's. So a couple of questions arise: Even if such a roll cage wouldn't make one's car eligible for racing, would the added safety for road use be worthwhile? Particulary given the car's low silouette and high performance. And if it were added, would it steal precious space from the interior that the car can ill afford? Would it impede egress or access? Impact headroom?

2. Fuel Bladders: In much the same with the roll cage, a bladder system may also be an option available for my car. Given the location of fuel under the sills, and the worry of a side-impact rupture, is a bladder system worth installing? It's likely expensive and 'after-market' in that Olthoff will have to install it.

3. Fire Extinguisher System: As an alternative, or perhaps an augmentation, to the fuel bladder system, has anyone installed a racing fire suppression system in their SPF GT40? If so, can you install the cylinder outside of the cockpit? This is something like a $750 option, and likely the cheapest of the three.

Any thoughts?

Kim

I'll put my 2 cents worth in. RE: Roll bar - there is so little room in the cockpit already that I think a roll bar would take up valuable space. However, safety being the most important issue, you have to weigh that against comfort. If you're going racing....get a roll bar. If you're a poser like me (most of us)....... drive safely and don't flip it over.

RE: fuel cells, great idea that I'm still struggling with. To get the tanks out (assuming you already have the car as I do), you have to disassemble the entire front of the car to slide them out past all the spindles, suspension and such...a major undertaking. I would have bought them from the factory had they been an option at the time. I suspect a side impact will be worse than a Pinto experience.

RE: Fire suppression, see photo. This is where I mounted the pull handle. I find (FOR ME) that it does not interfere with my leg or ingress/egress...other will surely disagree. I purchased a Safecraft system from Summit Racing (~$350). It is a HALON system so I have it set up to cover the engine only.

Kim,
I personnaly like the idea of a cage. It makes the whole frame stiffer for one. I even midified my sill framework to give it more strenght. My cage has its front to rear pieces in the center or the framework. I think that the only negative is that the head side to side room is the only thing that tends to get tight, and that is only when you have a helmet on. Given you have a helmet on, you should have a 5 or 6 point harness on and your head then won't hit it then unless you are one that NEEDS a Gutrney buble. I am placing my seat as we speak. I am 5-9 and with an inch or two of seat of the pants to the floor, I have enough room. What you might notice is a little less visibility out the front windscreen(top portion). The cage for me will be a benefit, in that you will find most people who get into one of these cars and have never done so before, will grab the body just above the windscreen at the A or is it B pillar. Unless you have one of Fran's cars or an original(steel spider) that part of the body is fairly weak and will flex rather easily. So my cage gives the passenger something to hold on to on entry or exit. I plan to put a sign on the cage at that point telling them to "GRAB HERE".
You have about three options cocerning roll bars and/or cages.
1. Go for a cage during the build process. It is near impossible to put one in with the spider in place. Trust me I found out how hard.
2. Go for just a roll bar in the engine compartment with either a 2 point or 4 point setup. It can be put in anytime after the build and would be a better chooice as everything is in its place and the bars can be placed where ever they need to be, or things may need a slight rearrangement to fit.
3. Check with KIRK RACING at [email protected]. They build cages for built cars that bolt in place, allowing you to remove it if you don't want it for daily driving. There may be others that do this. Kirk's cages are certified by all the racing associations I believe. They can tell you more than I can. They are located in Mount Olive Alabama. Phone-205-608-1156. They had a display at Road Atlanta during one of the Nasa events. I met one of the owners Mark Stewart. He said his could be put into a 40. I already had mine in by that time or I would have seriously considered his. There are others who have opted for front to rear pieces that intrude in the door way. I am sure they are strong, but at my age I don't like to contort more than I need to just to get in or out. If I had a bad experience at the track, it would take me 4X as long to get out.
With mine the only consideration is that the dash will need to be altered for the cage to fit out of the door way in front. I altered mine as you can see in the photos. The piece cut off the dash will be supported by a bolt and a piece of strap that is hidden in the dash cover(there was enough padding to hide the head of the bolt). I plan to cover the dash in leather and all that should show is a seam where the two pieces come together. The hardest part was making the template for the cut. It wasn't round or straight. Wanted to make it right with the first cut and not have to take more out. I was fortunate in that my car came with a RHD setup and I ordered a LHD dash, so I had a spare to experiment with.

Bill

The new fuel cell option isn't a factory-installed option????? Why the hell not???

And if a roll cage "may be available as an option" why can't Hi-Tech make it to satisfy SCCA and FIA rules??? (At least for under SCCA purveyance, where they're probably going to sell the vast majority of their cars.)


Bill: Nice job. Does your installation meet (not to belabor the issue) SCCA spec's?


If you are going to drive aggresively, IMO a roll cage would be a wise addition. Walt Hangsen was killed at the Le Mans trials in 1966 in a Mark II he flipped. There isn't nearly the structural integrity in the stock design to protect you in such an incident.

Alan - You may want to check out this thread for more discussion on making the cars legal for competition:
http://www.gt40s.com/forum/all-gt40/18592-us-sanctioned-club-racing-gt40.html

Alan in Nevada said:

And if a roll cage "may be available as an option" why can't Hi-Tech make it to satisfy SCCA and FIA rules??? (At least for under SCCA purveyance, where they're probably going to sell the vast majority of their cars.)

Click to expand...

As Bigfoot says, have a look on the roll cage thread. I and lots of other board folks have researched this and have plans for making their cars SCCA legal. In fact I'm putting mine on the trailer in two weekends to take it to my cage guy. We're doing an SPO (GT) rules cage on the Lola.

If you are planning on taking your car racing then a SCCA or FIA cage makes sense, but that is only part of the puzzle. There are other things that are actually a bit more difficult to make SCCA legal with GT40s and Lolas. For instance, the fuel being stored in the side sponsons is a slight challenge. The rules indicate that there must be a bulk head between you and the fuel cell of a certain thickness, and that bulk head cannot be the cell container. So effectively to you the built in GT40 sponson tanks you'll need to "double skin" the entire sponson areas into the cockpit.

A SCCA cage is a challenge in the Lola, but it'll be even more so in the GT40. You've got main and front hoop requirements to meet (not that hard) but you'll also have rear hoop supports, side bars, and front bars that will be hard to fit into the car. It'll be possible, but you'll need some holes through the bulkhead back to the rear area.

If you aren't planning on racing then it makes sense to use some sort of well-constructed cage that might not meet SCCA or FIA specs. You'll still get some protection without the hassle and limitations of a fully compliant cage.

As far as a fire system I think that is a 100% must have in a GT40. Speaking from experience of one who was in a race car fire a bit over a year ago, there is no way I'd track a 40 without it. They are small, cramped, and not easy to get out of when all the stuff works as it should. After a serious off or accident you can probably bet not every thing is going to work as it did before the accident. Doors might not open easily, you might be block from escape, etc. A fire bomb might buy you some time to leave through the other door, the windshield area, or via some other means. Also, remember that after this accident you might not function that well too and the fire bomb could buy you a bit of time to become coherent. Fire bad.

I just got back from a race weekend that involved a fair amount of carnage - Formula Atlantic doing a 7' end over end, lots of IT cars piled up in some serious log jams, and a few other things. But nobody was hurt, thankfully, and I made in through in the Z with no damage either. If you plan to be on track, even if just for a simple track day, the various means of protection discussed in this thread (and some other threads) is a really good idea.

Ron

I put a Safecraft system in the passenger footwell of my CAV, it is out of the way and an easy install.

First, Roll cage, Do it on the first built. Very hard to retro. The main issue with a sanction body complainant cage is the side bars. You can see from the above pictures that they are not there. I did mine this way also. The guy who did mine told me that the front hoop would be fine if upside down unless I hit the wall VERY hard on the front top corner, now the bottom front corner. Expect it to fold over. It will however absorb a lot of energy. The main thing is it will keep another car or large object out of the drivers compartment. Picture side impact with a minivan.

Second, Fire-system. If you save money on this you are stupid! For 400 bucks you can save you 100K car. AND maybe yourself. Put one discharge low under the dash and aim it at the drivers chest. Put the other one in the engine room below the rear hatch. Aim it at the carb. Place the bottle so that it will survive any hit that you will. Not in the front behind the radiator. Behind the rear bulkhead in the engine room seams to be the best place or it the foot-well up against the passenger seat.

Third, note what I said about upside down. My worst fear! The old style gas fill pipe covers are really BAD. The newer style screw in caps under the flip open covers are much better. Fuel cells would be a lot better but so far I haven't seen a off the shelf product that will fit into the sponsons. I run on track with only the passenger side tank with gas in it. At least I have taken away 50% of the risk. It would be hard to hit both sides of the car in one wreck. Well maybe a little harder.

Thanks to all. This is exactly the kind of information I'm looking for.

Alan's right. The quality and quantity of information that has been provided by our fellow members of this Board, coupled with very helpful photographs in many cases, is precisely why GT40s.com has become one of the first sites I read whenever I logon.

When I first posed my questions only a few days ago, I never imagined that I would be so well educated in so short a time. I now have a very clear course of action on moving forward on these three issues. Thanks to everyone!

Kim

A grim reminder

wbmusarra said:

Kim,
I personnaly like the idea of a cage. you should have a 5 or 6 point harness on
Bill

Click to expand...

Hi Bill. You and I spoke briefly by phone on this subject and perhaps it is covered in the forum. I haven't had time to read all the posts so I will post this here.

If you lose a tire at 150MPH or above, you might get to die instead of just having fun. The onboard air pressure and tire temp monitors are some kind of wonderful.

At speeds of 170MPH and above, the air is NOT your friend.

DC

my understanding is that roll cages in a street car are ill advised since you will not be wearing a helmet and striking the cage in a crash is a certainty. I certainly understand the benefits in a rollover which I suspect is far less likely than an upright crash in these cars. A fire system is a must and you should not use Halon in the interior since it displaces oxygen. One of the new water soluble foams is a better alternative in a 40. Fuel bladder would also be a welcomed addition, pricey though. But cheap if it saves your butt.

chuck 1 said:

my understanding is that roll cages in a street car are ill advised since you will not be wearing a helmet and striking the cage in a crash is a certainty.

Click to expand...

Generally this issue is minimized by padding the roll cage. In fact, any cage that passes SCCA tech will be required to have FIA padding in ANY area that your body might remotely come in contact with. I've had oversealous tech inspectors ding me for not having padding in some obscure areas.

"You don't have padding over there"

"But my head would have to come off to hit that"

"I'm not signing the logbook until you fix it. Are you going to fix it?"

"Yes sir"

So, even if you don't have a FIA or SCCA cage and aren't looking for a tech sticker I think you should pad them. That FIA foam is a bit hard, I'd choose a bit softer stuff in a "street" car. A well done roll cage will take away very little interior space and shouldn't be that much closer to your head than the roof or A pillars.

Ron

Ron Earp said:

Generally this issue is minimized by padding the roll cage. In fact, any cage that passes SCCA tech will be required to have FIA padding in ANY area that your body might remotely come in contact with. I've had oversealous tech inspectors ding me for not having padding in some obscure areas.

"You don't have padding over there"

"But my head would have to come off to hit that"

"I'm not signing the logbook until you fix it. Are you going to fix it?"

"Yes sir"

So, even if you don't have a FIA or SCCA cage and aren't looking for a tech sticker I think you should pad them. That FIA foam is a bit hard, I'd choose a bit softer stuff in a "street" car. A well done roll cage will take away very little interior space and shouldn't be that much closer to your head than the roof or A pillars.

Ron

Click to expand...

Man alive - I've had those very same conversations with Chiefs of Tech over the years.. What's really difficult is to tactfully school them in something they are supposed to be experts at. Ultimately they do wear the badge that either says you get to play or get to go home early...

On Halon, It is true that you can not breathe it but if the fire is in the cockpit with you, you had better not breathe anyway.

The fire system will give you a good 30 sec chance to get the hell out of there or it will put the fire out completely. Either way you can hold your breath that long. You had better! 800 degree air inside your lungs and your gonna die anyway.

The real reason for a halon or halon replacement is that it leaves no residue. This is a very big deal if you have ever seen a car that has been put out with dry chemical.

These systems real worth is that you have the means to put out a fire that CAN be put out before it kills you or burns the car to the ground. It you dump 15 gal of fuel onto the ground under the car and set it off the car is gonna be done anyway. Its the little carb fire that if put right out that saves the car. Or the ability to put out the first flash and reduce the cockpit heat to near normal for a few seconds so that you can get out that is what we are talking about here.

A word about track work. I really think that the drivers side window, maybe both, should be removed when on track. It's just a good idea. Pinning the car against the wall on the drivers side or jamming the door will really f&*k you up if it lights off.

The roll cage should be padded no matter what you do. The main reason for one in my opinion is to keep things out of the car from the front in a impact such as a pile of tires or a bumper of a pickup.

These cars are not SUV's and you really are not safe in them. Kinda like riding a motorcycle. If fact if you think like a smart bike rider it will go a long way towards preventing a wreck. Nobody sees them either!

Comments pls re a fire system that would use an electrically activated nozzel vs pull or push operation...Actuation automatic via air bag type switch ( anyone have ideas re best mfg/ switch) with a push button wired in parallel that would allow manual activation if desired ( idea here that the elex push button used if carb fire or fuel pump fire detected and the automatic actuation by air bag switch if in accident)....Disch nozzels to carb base, swirl pot cavity and into both sponsoons ( if all that done to cockpit too???)...Any idea of capacity required ( would 10# total by sufficient)?....Pls advise thoughts....Tx Steve

From what I recall (please contact the manufacturers for better information) the 5# bottle had a 30 second discharge through 2 nozzles and the 10# bottle was twice that (60 seconds).

I'm an advocate for Halon for one very simple reason - I can still see through it if I'm still moving while it's being discharged. Yes the powder types leave a caustic (or acidic - I don't remember which) residue that eats up finishes and corrodes metals.

I typically mount one nozzle above the driver's feet and another one by the fuel line to the fuel injection system or carb(s). I don't generally want one back by the fuel cell in the rear of the car because it is pretty well protected and I don't want to waste the discharge time. Remember that every nozzle you add to the system reduces the total discharge time.

One other thing - Not that they aren't good, but I've never learned to trust the electrically controlled systems. I prefer a cable. I also replace the plastic / nylon / aluminum tubing with steel.. Call me funny but like the electronics, I don't trust anything less than steel to move the contents of the bottle..

I recently had some fuel bladders made for me (In the US) and if I can work out how to I will post some pictures

Iain

One last thought. This is one that I haven't taken my own advice but I still think its a good one. Buy a 2.5 Lb hand held halon and mount it in the cockpit. They are perfect for putting out that carb fire or coming to someone else's rescue. Saves the big system for when you need it.

I think a 5lb system is fine. 30 sec of discharge into the cockpit of a GT40 will really fill it up. Same with the engine room. The 10 pound system tanks are pretty big and room is limited.

I have a manual system with the pull handle mounted right next to the gear selector.

Oh and don't forget a main battery switch and a tow/recovery hook point!