best locations for fire system nozzles?

[tom91ita]

now many might think the cockpit is a given and then it is a toss-up of the other two. but i would also like some input from corner workers on if they think the most likely places for a fire (due to oil/gas at the motor or gas at the fuel tank) is the best place to stop the fire and its spreading.

i have not really seen anything gcr wise that has said the two locations that are be required.

this is for a mostly ITB CRX that will also be running some G Production (will cross post at the prod board as well).

tia, tom

p.s., it is a two nozzle AFFF system

[lateapex911]

I know enough about this to tell you that i don't know enough to answer, LOL, but IIRC Kirk Knestis has some real life experience or better than average knowledge in this area...if he doesn't check in, PM him. Of course, I also predict you'll get some other good answers...

[JoshS]

Since I've had an engine compartment fire, I vote engine compartment. I always put one in the passenger compartment and one or two in the engine compartment.

[Speed Raycer]

The system I'm getting ready to install suggests 3 in the engine bay (basically one on each shock tower and one pointing back from the radiator) and two in the cockpit, one pointed at the drivers footwell the other pointed basically in the crotch area (not near the face). The injectors spray pretty close to 90 degrees and about 1 meter in coverage. I'm tossing a third one pointed at the fuel pump/cell area.

On a side note, check your instructions on how to mount the bottle. I've noticed a lot of pics on the net with the same system I'm installing mounted side to side when the instructions say fore/aft.

[CaptainWho]

I'm a corner worker as well as a driver, but I am not an expert on this in any way. That said, my personal preference would be engine compartment and cab, because the main goal of the system is suppression long enough for escape ... if it can completely stop the fire, that's just gravy. I'm more worried about getting my flabby ass out of there with as little cooking as possible. If you're moving, and you probably will be when the problem starts, it seems to me a fire under the hood has a greater chance of interfering with me getting the car safely stopped and getting out of it than one aft of the rear bulkhead.

When the worker gets to your car, he'll have an extinguisher, probably a ten pounder. If he's trained right, the first thing he'll do is figure out if he needs to suppress the fire in the cab to get you out. If that's not an issue, and you're getting out on your own, he'll probably try to suppress the fire a bit until the truck gets there. But you've gotta remember, he's only got a ten pounder and the truck could be more than two minutes away by the time it gets dispatched and everything.

If you plan things right, have a great big fire streaming out the back of the car when you go by the tower, then stop at the closest fire truck on-call station. :D

Edit: FYI, at Road Atlanta, that'd be turns one and seven.

[Knestis]

First, understand that I operate from the assumption that since a fire system isn't required in an IT car, I'm free to install the optional system as I see fit, rather than how the GCR defines for required installations.

Second, I think there is one reagent that is right for the job: Halon 1211. When the military starts using AFF or some other junk, THEN I'll think about it.

Third (and reasonable people will differ here), I think the fire system is for saving my skin, not saving the car. I have a handheld halon extinguisher that I generally have in the car for underhood fires, (not that it's likely with a modern FI car), or other non-life-threatening issues. I put all of the bottle in the cockpit, using a "curtain" effect tube system to spread the reagent out around ME. It has multiple holes that measure the same total area as the original two directional nozzles that came with the system. I swiped this idea from the Porsche 962 GTP cars, since it seemed so elegant.

Thanks, Jake for the vote of confidence but warning: Just because my opinions on this topic are strong doesn't make them right. You need to do what you think makes you the safest.

K

[tom_sprecher]

Immediately after the wreck there was funny smell and looking in the rear view mirror and I could see flames coming out of the spare tire well like somebody had just lit a charcoal grill in the back of my car. The rivets holding the cover on it had sheared and my ass was on fire. I had a Safecraft, Halon, 10# system with 3 nozzles that once pulled I had more than enough time to get out of the car even with the door pinned shut against the wall in the esses at Road Atlanta. Plus, it’s amazing how motivated you can get when you’re on fire, hence the term “light a fire under his ass.” As I hustled toward the corner worker (a comforting sight) who was running with an extinguisher I could still hear the hissing of the nozzles.

The source of the fire was a torn AN line at the electric fuel pump outlet. Fortunately, the fuel cell itself did not catch fire, but the can was scorched and blistered due in part to getting hosed with burning fuel and also the 8' diameter grass fire that was burning under and behind the car. A 10# system might seem like overkill on an RX-7 but it easily extinguished the fire except for some of the back edge of the grass fire and I am here to tell about it (bonus!). The nozzle placement was at the carb/regulator, at me and Bobo and thankfully at the fuel pump/filter/fill plate. The nozzles have roughly 120 degrees of arc in both dimensions which, if you take the time to think about their exact placement and aim, they can and do cover a lot of ground.

The line broke due to the location of the fuel pump/filter being behind the rear wheel, up inside the well, where the majority of the force and damage occurred. That location will change during the current rebuild (The Phoenix Project). There will be NO lines or wires (except that for marker lights) outside of the frame rails, period. Also, after any wreck turn off the car immediately and do not think “I’m OK, so I’ll start her back up and limp it back to the pits”. That’s advice I did not follow and firmly believe it added fuel to the fire, pun intended.

My wife and both my children highly recommend this system and I plan to use it again. If anybody knows were to get a bottle refilled in the Southeast let me know.

[DavidM]

I have one pointed at the intake side of the motor, one up under the dash, and one pointed at the fuel cell. It's a 10 lb system. I have pointed the nozzles at where I think the fire would be burning.

David

[Bill Miller]

I've seen the system in Kirk's car, and it is indeed elegant. I'd have to give that one a long hard look if I was re-doing my system. Interestingly, when I got my Prod car, it had a fire system in it. 5# halon w/ 2 nozzles. One going to the fuel cell compartment, and one pointing at the floor behind the driver's seat! :blink: :( :018:

That got changed to one going to the engine bay, pointing at the carb, and the other up under the dash, pointing towards me (spray would cover feet/waist area).

Scott, the thing I'd caution you about w/ so many nozzles is not getting enough agent to any one spot. I was on a VFD for several years, and we used AFFF for car fires. Good stuff, but I don't know if there's enough agent in a car-sized bottle to give you the same extinguising efficiency as Halon. Knock on wood that I never have to test mine.

/hijack/

I'll throw this out to the ITAC folks (and anyone else that wants to comment). When do you think that we'll see required fuel cells in IT cars? While most of the tank placements/construction on newer cars is pretty safe, we've got some pretty fast IT cars (ITS and now ITR) who's designs may be not so good. Do we need to start requiring fuel cells in IT cars? I'm almost wondering if that's something we shouldn't have addressed w/ ITR, ahead of time. Thoughts?

[tom_sprecher]

Scott, the thing I'd caution you about w/ so many nozzles is not getting enough agent to any one spot. [/b]

Excellent advice to consider. When I was researching which type and size to put in my car I came across a statement that IIRC you really should not use anything less that a 10# system if you plan to use 3 nozzles. So that's the route I went. Also, I wanted a fire put out no matter where it is in the car and felt it would take 3 nozzles to do that.

The situation where suppose there's a wreck, I'm unconscious, any fire that was in the drivers compartment has been extinguished but the fuel cell is still on fire was not too comforting. Think long and hard on this subject as it can save your life.

[tom91ita]

i have not looked at the line size vs. the effective orifice diameter of the nozzles but the supply line could end up being the weak link so to speak. adding more nozzles may not take away since the supply would be the limit. e.g., 6 nozzles under the hood may not rob the driver compartment if the it is on a separate line. the bottle has two connection points.

after reading the instructions and several posts, i am leaning towards two at the motor compartment and one under the dash towards me. in the prod forum there was a reference to the GCR. i need to look that up. let the fuel cell be its own device so to speak.

part of my thought process has been do you spray you to protect you or do you fight the fire at its origins. well there is time over the winter to get this sorted out. i am also looking at the fuel pump shutoff that is related to the number of g's for an impact as a means to mitigate a fire. i know the kill switch shuts it off but it can be a bit of time until that gets off if the driver is out of it.

with regards to the hijack, i think that fuel cells are only a matter of time and in fact, some of this just does not make sense unless they are thinking that the Prod cars are more likely to break and catch fire.

there are ITA cars that will lap faster than most HP cars.

perhaps they will take a note from the NHRA, if you turn these types of times, you need this level of safety gear. the speeds i can impact a tire barrier in my ITB car are not the same as the formula atlantics yet we may need the same H&N restraints. just asking/thinking out loud on that one.