Fire system installation question

[dave harris]

I'm installing the fire system in my GT-40 and in reading the instructions (I know, I know, reading instructions is a bad habit, but I just can't give it up!) they say to mount the cylinder horizontally (see attached pic with mount mock-up). Is there a specific reason for this? I'm assuming that there is a "dip tube" in the cylinder to pick up materials? Or does this mounting differ from Halon to Liquids?

thank for the inputs

[91740Gt]

Dave,

The horizontal position enables the unit to fully exhaust itself. Halons are totally banned for all motorsport use.
Interesting that you are mounting your extinguisher so far forward. You will have very long tube runs to your main heat source problem areas so do make sure you bend carefully, clip well and fit your nozzles on properly.

Regards,

Graham @ GTA RAcing.

[dave harris]

Hi Graham,

Thanks for the reply - I wanted to mount it in the engine compartment, but with an oil accumulator already planned, the rear is simply filling up too fast. I have planned to mount nozzles in each fuel cell nacel, 1 in the passenger compartment and 1 in the engine compartment. The fuel cell nozzles will enter from the front of the nacel, so those should be short. The engine line will travel down the center of the car (with the water pipes) so it should be a very straight line. At least that's the plan for now.

thanks again

[Peter D]

Hi Dave,

Like you, I want to install a "fire bomb" but am struggling with finding a spot to mount it. The DRB's that I have seen with these fitted site them on top of the rear tank cover on the opposite side from the battery - the problem with this approach is that it forces you to put virtually the whole of the fuel system under the tank cover. I thought that was way too tight & hard to get at filters, etc for maintenance, so most of my fuel system sits on top of the tank cover - just where the bomb should sit !

The only places left for the bomb seem to be at the front of the passenger footwell (a bit tight & needs a short, fat bomb (& maybe a short fat passenger !)), or in the front as per your arrangememt - yours looks like much the best choice. I can see how you might fit the front of the bracket to the cross member, but what are your plans for the back of the bracket ?

From what I can gather, most setups involve up to 4 nozzles in the engine bay (the most likely fire source), & some include one under dash & one in the front compartment. I'll probably go with the 4 x engine nozzles, but am a bit wary of gassing myself with CO2 in the cockpit - my (wishful ?) thinking is that if I am able to pull the bomb lever, I should be able to open the door ?

Any further thoughts on nozzle placement ?

Kind Regards,

Peter D.

[dave harris]

Hi Peter,

I too looked at the engine compartment for mounting the bottle (bomb), but the mfg. stated that you should try to keep the bomb from being exposed to temps above 140 c - - and most areas would received (at least from radiated heat) relatively high temps from the headers! I opted away from this (even though it would have been a possible fit as I've sunk my fuel system into the nacel - but it's open for access.

The rear of the mounting bracket forms an "L" down to a cross member at the bottom of the front box. You have to cut a "U" shaped channel for the coolant pipes, but it all fits well.(confused yet?) The only issue is that you have to make one of the "legs" in the back removable in order to fit the bracket in and then re-install that leg. I'll try to take a picture from the reverse angle and post tonight when I get home. I just drilled and tapped holes into both cross members and made the mounting bracked out of .090 aluminum - simple bends.

As for nozzels, I'm planning for 1 in each fuel nacel and 3 in the engine compartment, two under the rear fglass) - one on each side of the engine and one pointing up into the cold air chamber for carb fire supression.

I will have a second extinguisher (hand held) in the drivers compartment with liquid fire suppressent as I too don't want to chance an extremely tight area with gas fire suppressent.

Thanks for the inputs.

cheers

[Iron Sheik]

Put it behind your seat, after all you are so short (what is it 4-2) [img]/ubbthreads/images/graemlins/grin.gif[/img]

Is there any room behind or infront of the passenger seat? That's were mine is in my GTD.... But then again you don't want to do that, Debby would be pissed [img]/ubbthreads/images/graemlins/frown.gif[/img]

Just put it between your legs, there should't be anything there [img]/ubbthreads/images/graemlins/shocked.gif[/img]

[Ron Earp]

I would give careful consideration to capacity and the number of nozzles. As probably one of the few forum members here who have actually been in an in car fire (about 4 weeks ago while racing) and used one of these fire bombs I’d be careful with placement.

I had an 11lb bomb AFFF that had two nozzles. One nozzle was in the engine compartment directed at the carbs and the other nozzle came down the tranny tunnel and pointed at my foot well. When the bomb went off the cockpit nozzle shot stuff at the foot well, where it was not needed, and came out with such force and turbidity my vision was obscured in no time flat. Not only that, the stuff is a horrible throat and eye irritant which made it sort of hard to breathe. I’m a hardy “breather” meaning I don’t have allergies, asthma, or anything like that – I’d imagine someone with these problems would have real difficulty with how much of this stuff actually gets pumped into the cockpit.

The other nozzle in the engine bay got defeated somewhat. I had a carb fire that burned undetected for probably about 30 seconds. The lines that these companies give you for running throughout the car are aluminum hard lines with a plastic coating. In the 30 seconds the fire burned it melted the plastic coating off the lines and did something to the ally tube – what ended up happening was that the AFFF came out all along the length of the tube and only a small bit through the nozzle. When I wrote the company about this they immediately requested the line for analysis and it has been sent to them. We suspect that a small piece of plastic or ally got trapped in the nozzle during assembly and the pressure/heat split the line once it became sealed. Could be other things too, I am awaiting their answer.

So, while the engine nozzle did put the fire out, mostly, it could have done a lot better with more accurate placement of the nozzle. Don’t put it anywhere the flames from a likely source might reach it – these things spray plenty and can be located far away from the fire they are to put out. The other thing I’d be concerned about is number of outlets.

If the bomb weighs X lbs with Y pressure drop per nozzle, then hooking up pressure drops (nozzles) to the bomb will obviously decrease the amount of time it can effectively spray. I’d check with the company, but Dave your plan with 2 for fuel tanks and 3 for the engine might be too much, but I don’t know. I’d prefer to keep them to a minimum or use two systems wired in parallel as we’ve done on our Enduro car. After that car fire, on my first competition race I might add, I am quite paranoid about fires and build accordingly!!!!

In the end I got out of my fire okay but the corner workers at the station I drove to while the car was on fire had a lot to do with how it ended up. 40s are hard to get out of, almost as hard as a race car with all the restraints, harnesses, nets etc, and you need something to kill fire in a 40. I'm younger than a lot of folks on here and can get out of one pretty quick, but fire is fast too. On the other hand, having a fire in a car really makes you move!!!!!!

Ron

[dave harris]

Farhad, If you have time to harass me during the middle of the day, I'm going to tell your wife that you're NOT out looking for a job - ya lazy bum!!

Peter - I've changed the mount to lower the bomb in the car and simplify the bends/assy necessary. I've PM'd you with pictures.

Ron, Was your fire system liquid or gas based? When I talked to the Mfg. of my system, he stated that you needed 2x to 3x the volume of liquid materials to do the same job as the gas based units. I asked him about 5 nozzels on the current system and he felt it would be sufficient in volumen and would last for a sufficient ammount of time - As I think that I have pleanty of nozzels in this application I did, however, get the nozzels with the lower flow volume (smaller holes) and that should give some more "time" to the discharge.

thanks everyone for the inputs - - Hopefully I'll never be able to let you know how it works - I'l like to let Ron continue to be our "test platform" (sorry Ron).

cheers

[Ron Earp]

Dave, don't you know, Farhad lives in "The People's Republic of Kalifornia". They do not have to work there, all they have to do is enjoy the weather and collect dole checks!

[dave harris]

Ron, The really scary thing about Farhad is that I ORIGINALLY HIRED HIM at the company I work for!! And it sure has taken me a long time for me to make up for that!!!

I'm still going to tell his wife on him!!

[Iron Sheik]

Mr Harris, Mr. Moderator,

Thank you for your kind words. [img]/ubbthreads/images/graemlins/grin.gif[/img]
Dave you forgot to mention you hired me a second time 4 years ago (will there be a third?! Don't do it) BTW, I should be getting my third "dole Check" this Friday, all $820 of it [img]/ubbthreads/images/graemlins/crazy.gif[/img] WORK is UNISLAMIC, don't you know?!! [img]/ubbthreads/images/graemlins/shocked.gif[/img]

[SpyderMike]

You might consider firesleeve on the exposed lines to the nozzles. A great source is at www.firesleeve.com - about $2 per foot. This will buy you some time in the event of a fire.

In airplanes we tend to use a lot of firesleeve - it is not unusual to see it on all fuel and fuel vapor lines (vents and dumps) and all oil and oil vapor lines (breather vents and dump).

It's hard to pull over at 10,000 feet.

Mike

[Ron Earp]

Hi Mike,

I am a pilot as well and learned about this stuff at our last 100 hr maintenence meeting. Guess what I ordered a bunch of for our race car prep business??

R

[Howard Jones]

The directions that came with my system said that for a 5 pound bottle to use only 2 nozzles. They also said to place the driver compartment nozzle at least 36 inches from the drivers head and aimed at the drivers chest. That required me to place that nossil near the top of the gas peddle in a line of sight to my chest. It is interesting and somewhat comforting to note that the dashboard blocks the line of sight to my head.

The other nozzle is installed near the distributor facing rearward. The hope here is that much of the expended volume of gas will be directed towards the carb. Some of that will invelope the top of the motor and the rest will remain bellow the rear hatch and in the engine room.

I would not confine the the discharge to the side pod. If you have a ruptured tank and a large volume of fuel in the car and on the ground around it you will want to give youself a few moments to get out of the car. The gas plume will be most effective if it is not contained in a side pod.

Anyway thats my 2 cents.

[40 Bud]

Unislamic - is that anything like Unisex?

[SpyderMike]

Ron,

I am firesleeving just about everything on the engine side of my homebuilt. If it buys me an extra ten seconds I will be happy.

Mike

[Ron Earp]

Mike, I hope it never has to be used, as I am sure you do as well!!!