I'm in the process of building a car for Texas HC H2. I've been to a few events since I got the car together, and I've ironed out a few wrinkles. The car is almost done, but I have a few questions I'm hoping you guys can help me with.

A few weekends ago at Hallett, I had a pretty ugly car fire.
Before:


After:



I'm pulling the tank this weekend to inspect it to ensure that the fire didn't damage the tank itself. I'm also replacing all the rubber fuel line bits around the tank.

From looking underneath, it appears that the fire was concentrated in the area underneath the filler neck. Almost all the plastic pieces in that area were melted. The bumper it melted in that area, the tail light is melted on the inside, the trunk vent on that side is melted, the cover for the tank fill tube and vent is completely melted, and the plastic gas tank cover is melted. Amazingly enough, the tire shows no damage, neither do any of the ball joint boots or rubber suspension pieces. I'd estimate that the fire was going for about 2 minutes, maybe a little less. The staff at Hallett did an OUTSTANDING job.

A friend whose father was there to see him race said that as I came around T9 (long sweeping right hander), he saw clear fluid pouring out the gas flap. That makes me think it was the gas cap, but I can't be sure. I never checked to see if it was loose before I tightened it after the incident.

Can you guys think of anything else I can check? Is there a way to pressure test the system?

Interesting thing is the area behind the gas tank flap is pristine. No soot or fire damage. The area around the gas cap is also pristine.

I'm fairly certain that the fire was started by my exhaust, as it backfires during downshifts, and it terminates just in front of the gas tank. The new exhaust is going to go around the tank and dump by the rear control arm.

It was tuned by Tony Palo and runs like a bat outta hell, so at least that's one good thing.

On to my other questions:
I didn't have my fire system installed at that time since I was in an HPDE group, but I'm planning to install it before I take my license exam in Nov. I have a SPA 3.75 liter AFFF system. It comes with what looks like a mounting bracket with two bands, but the "bracket" itself is plastic, and doesn't look very sturdy. There's not much of a flange around this bracket to bolt it to the chassis. Has anyone installed one of these before? Is this plastic mounting piece supposed to be used, or is it only for shipping, and maybe I'm supposed to fabricate my own bracket? Would a picture help?

What did you guys do about your EVAP system? I'm running a Neptune system so I removed the EVAP canister, sensors, and purge valves. I have the vent tube that runs from the tank (and usually goes into the EVAP canister) plumbed into the vent tube that came out of the EVAP canister. I basically just bypassed the EVAP canister. I just had to machine a small adapter to connect the two hoses as they were different sizes. Would this suffice? As I was draining the tank the other night, it drained without "gulping" so it appears that the vent is working fine. It drained faster when I removed the gas cap, but even with the gas cap, the stream was nice and steady. I don't think this is part of my problem that caused the fire, but I thought I'd ask.

Also, any advice for one's first race? I certainly don't want to be "that guy" when I get out there.

 

I'm not familiar with the systems you mention but I would also run a small hand held fire bottle in the car.

 

Might I suggest that you consider a 5 pound AFFF system from Firefox Industries for your primary suppression device. It is approved for use by both NASA and SCCA. It is unique in that there is a bladder inside the bottle that holds the agent. This means you can mount the system in any location or position you desire. I would use that along with a 2.5lb Purple K handheld. That is what we did with the CRX. Want pictures of our setup-drop me an e-mail.
I need to note that the majority of Top Fuel type cars use the equipment I have as do several SCCA pro teams. They ALL concentrate the suppression in the engine bay and use an auxilliary bottle for the trunk-fuel cell area. The latter is the way several NASCAR teams are doing it and that body requires a system just for that part of the car now. You can use a 10 pound Firefox and cover both the engine bay and driver area but it will be bulky compared to other approaches.

 

Does your exhaust exit directly point to the gas tank or is there a turn down??

A student a couple years back in a first gen CRX Si had his exhaust stop just in front of the gas tank and pointing at the tank. During a session, the hot exhaust would heat the tank and gas in said tank and cause a lot of overflow out of the gas filler neck.

He later added a turn down section so the exhaust is not pointing at the tank and fixed the problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITC Racer &raquo;</TD></TR><TR><TD CLASS="quote">Does your exhaust exit directly point to the gas tank or is there a turn down??

A student a couple years back in a first gen CRX Si had his exhaust stop just in front of the gas tank and pointing at the tank. During a session, the hot exhaust would heat the tank and gas in said tank and cause a lot of overflow out of the gas filler neck.

He later added a turn down section so the exhaust is not pointing at the tank and fixed the problem. </TD></TR></TABLE>

Bingo! I had this problem as well. I was boiling my gasoline and it would shoot out past the filler cap. All it took was a turn down and it was fine.

You might want to think about replacing things like your brake lines back there, even though they look fine in the pic. I would hate to see a weakened part fail on you later.

 

Hmm...going points. I have a 45 degree turn down, but it was catching on the trailer because the car is so low. I decided to turn the turn down to the side a bit to allow for more clearance (I used a v-band clamp, so I could rotate the turn down), so it was mostly pointing downward, but not directly downward. This might be at least part of the problem.

I did two events prior to this one with the turndown facing directly downwards with no problems, so maybe rotating it just a bit was enough to actually cause problems.

The new exhaust will go around the tank, so maybe this will be an even better fix.

Good point about the brake lines. I'll order those this week. I'd hate to see them fail too!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 117 &raquo;</TD></TR><TR><TD CLASS="quote">Good point about the brake lines. I'll order those this week. I'd hate to see them fail too!!!</TD></TR></TABLE>

yeah, take it from someone who had a front brake line catastrophically fail on him braking hard for turn 1 at Summit: it ain't fun. New underwear required, as well as a tow truck...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SJR &raquo;</TD></TR><TR><TD CLASS="quote">

yeah, take it from someone who had a front brake line catastrophically fail on him braking hard for turn 1 at Summit: it ain't fun. New underwear required, as well as a tow truck...</TD></TR></TABLE>

I got you beat, I've had TWO complete brake failures going into that turn. Strangely enough, I've never had a brake failure anywhere else, but two in turn 1 at Summit. The first time the gravel basically stopped me with the car coming to rest on the thin strip of grass between the gravel and tire wall, the second time, I did a full 720 before I hit the gravel, so I had bled off a lot of energy and the car stopped pretty close to the track.