Fire Suppression System installation - Best Practices?

That's exactly why I wanted this thread.

I read somewhere about following manufacturer's direction.

I've seen discussion about the foot well, because you don't want crispy feet - I totally understand that.

I think mounting point is critical, and the graphics I saw on cursory review showed mounting along the tunnel.

Also, I've seen discussion about the number of nozzles, and the reasons for having either more, or fewer.

Also, instructions specifically state vehicles differ, and they don't pretend to give directions for every case; having said that, I'm looking for best practices, and most importantly, WHY.

There's so much knowledge here, and people have been doing this so long, I want to tap into that.

Thanks for your input!

The type of suppressant you use will dictate where nozzles need to be located and that will be dictated by the equipment manufacturer.  The application of foam or gas suppressants will be different.  There is a reason most rule books are written very general as to not take on liability where it conflicts with manufacturer directions. 

The two current options of AFFF (foam) and Novec 1230 (fluorinated ketone and gaseous) are classified as PFAS chemicals and are being heavily regulated starting this year by the EPA.  AFFF ends up in water and is difficult to decompose so it wont be around long.  Novec 1230 ends up in the atmosphere and will degrade from UV exposure...eventually.  I believe gaseous fluorinated ketones like Novec 1230 will miss this current phase out, but 3M is voluntarily stopping production of Novec 1230.  There are other manufacturers that make an identical product now that the 3M patent has run out so you will likely see other chemical names coming from fire suppression systems in the future.  I find it a little weird that 3M claims Novec 1230 is "harmless" but is voluntarily stopping production.

Hopefully we see new solutions coming out in the next few years as the EPA crackdown continues on PFAS chemicals.  Oxygen displacement is obviously not good for an occupied situation and would be difficult to maintain in an open condition like a vehicle.  The other option I have seen in buildings right now is a very fine water mist system.  I don't see how this can be adapted to a car easily and would be another item for me to forget to winterize. 

I completely understand why people say don't put a suppression head at the fuel tank as it wouldn't do much if the fuel storage is on fire. I do think there is an aspect that gets overlooked in that area with wiring or other materials and equipment near the fuel tank that could create a fire near the fuel system.  A suppression system could prevent the fire from reaching the tank and creating a bigger issue.  Best option would be to mitigate these potential sources when you are building but some cannot be avoided.

All cars should be looked at from a holistic view and a risk assessment taken during the build.  The more nozzles the faster the suppression tank will empty.  Some manufacturer have heads with temperature sensitive disks to prevent discharge if there is not a fire in that part of the vehicle.  Obviously #1 importance is the cockpit to buy the driver time to get out of the vehicle.  #2 most fires will start in the engine bay.  That's why those two are required in the rules.

OK I found the instructions from lifeline for the 2020 (and others)

For cockpit:
"2 nozzles under the dashboard
pointed downwards into the footwell
or driver’s midriff in open cars.
Do not point at occupant’s head"

Under engine compartment:
"Carefully consider
the position of the 3 engine
compartment nozzles to cover the
most likely source of ignition:
induction, exhaust, fuel pump,
injector rail, carburettors etc. Two
nozzles should be placed on
opposite sides of the engine, with
the third at one end."

Just to be clear that's from a lifeline manual, other systems may vary.

There are pics and whatnot and more info ect https://www.google.com/url?sa=t&sou … DjAaF5z6-8

I found one of the Lifeline installation documents to recommend mounting high - potentially on the cage (not where there's padding), and aimed toward the firewall, so that the horizontal spray settles to the floor over the legs and feet.

I note your summary specifies "open" cars; is that what you're running? It was your interpretation of "open" to be a convertible? Or just that there are no front windows?

Does anyone have any pictures of cars that burned?

I'm almost completely focused on the cockpit rather than the engine compartment.

But there's always going to be a driver and seat; and here, most will be on the left.

As others have mentioned, there is a trade off with spray time and placement of nozzles. I think 4 nozzles/2 in the engine bay is fine. Please see my post #6 above, I've had 3 cars go through tech with flying colors with 2 nozzles in the engine bay.

This team decided to test their bottle before sending it in for refill:

https://youtu.be/gSdet6Yp5Y0?si=y0t2gSDx1EBUNfAJ

I would want to point the nozzles away from the drivers face so they can see to get out.

We run six nozzles. One each at the driver and passenger footwell aimed aft as to create a "wall" of suppression. In the engine compartment (E36 BMW), one nozzle at each aimed at potential sources of fire - brake booster n brake lines, intake/head area, PS pump and nearby oil lines, and exhaust header.

The SPA bottles we run only have 4 nozzles and specify 2 in the cockpit and 2 in the engine bay.  They say to mount the inside ones up high (we used the roll bar), aimed down at the driver's (or driver & passenger's lap. They spray in about a 45 degree pattern, so aiming at the lap covers a driver from chest down but allows them to see enough to get out, at least in theory.

LNM: I couldn't find any of my graphics or instructions, either, but they were pretty clear.  Probably tossed them right after installing. 

It makes sense, and made me think about it some since I was initially going to aim one at the lap/legs and one at the head/chest.  Reading that made me realize that if aimed at the head, the driver would be blinded by foam and that might slow down an exit, when the intent was really just to buy 15-20 seconds while he/she gets the hell out.

And you could get similar coverage with nozzles mounted to a dashbar (or in the dashboard area) with one aimed at the chest and one aimed at the lap/knees, but not knowing the exact spray pattern it might be harder to avoid spraying the driver's face.

And I don't recall SPA what SPA said about the underhood nozzles. We aimed one at the fuel rail and one at the turbo, with enough angle and separation that much/most of the engine bay should get sprayed.

Like you, we're more worried about the driver than the car.  Driver is a "must-save", car is a "try-to-save".