what is the difference between fuel cell and gas tank?

[Guest Anonymous]

this may be a stupid question, TIA

Michael

[Guest Anonymous]

I believe fuel cells have a rubber bladder to contain the fuel in an event where the metal housing is cracked or leaking, like in a crash. There are a couple different kinds, in the summit catalog or racer parts wholesale, they list ones that are approved for different classes of racing, fia, scca etc. These differ in bladder material and thickness.

HTH

-Dave

[Guest Anonymous]

There are a lot of varieties of 'fuel cel' style tanks. The top of the line is very high-tech, meant for high-speed racing: usually there is a polyethylene or kevlar-composite main tank, often surrounded by a metal shell, there will be some sort of flexible, puncture resistant bladder, and inside there are foam chunks that prevent aeration and sloshing of the fuel. The filler mechanism and hoses are all heavy-duty pieces. The main idea in a fuel cel is to prevent punctures, explosions, leaks, etc.

If you buy a 'real' SCCA-approved racing cel for sanctioned races, it's only good for a few years before it must be replaced--not that they fall apart or anything, but race sanctioning bodies require new equipment for serious duty.

I wanted to improve the safety of my 2002 relative to the stock tank, which is really just a wimpy piece of sheetmetal that forms part of the trunk floor. I bought a 16 gallon fuel cel from Summit. It's not the type approved for real SCCA racing events, but it's overkill for driver's school, autocross and street use. Mine is a heavy polyethylene tank in a steel shell, with foam baffling inside. About the only thing that separates it from a 'real' cel is the lack of a bladder. If I ever decide to try my hand at real competition (unlikely) it will be easy to drop in an approved cel. Mine cost about $180 including tax; an SCCA-approved bladdered cel would cost over $500 easy.

I'm mounting mine between the rear shock towers. I've replaced the stock tank area and spare tire well with sheet metal, and I've welded in some bracing and supports for the cel. Straps will hold the cel tight against the rear bulkhead and the trunk floor. I'll have to open the trunk to fill the tank, but to me that's kinda cool. It'll remind me of my '67 Beetle. ;->

On formula cars, the fuel cels themselves can be structural members of the chassis, and they protect the driver from side impacts.

Mike

[Guest Anonymous]

I like your fuel cell setup. I'm about to move my battery to the trunk, but it does not seem very wise. Every time I open the trunk I get a strong whiff of gasoline. Putting a battery back there that can generate sparks and whatnot is asking for trouble.

Did you put your battery under the rear seat? I think I am going to see if I can make that work. Then I'm figuring out where the gas smell is coming from.

[Guest Anonymous]

thanks guys for the explanation, I would love to see

a picture of your set up, if I may copy it (this is the

best form of flatter) it would eliminate several

problems on Bacchus: the strong smell of gas, the

inherently unsafe nature of the 02 gas tank, and

spilling half a gallon every time I fill up.

Michael

72 tii

[Guest Anonymous]

The rubber filler neck usualy cracks with age. You cant see them but they are there. Try replaceing that. It should help.

Andy Rattley

[Guest Anonymous]

I've always had concerns about moving the battery to the trunk, given a stock tank setup. I know that a lot of old-time cars had worse setups, but if I'm moving things around to make life better, I don't see anything wrong with keeping safety in mind.

I might not bother with having a back seat at all. My car is going to have a rather stripped interior, mostly painted steel. I'm going to buy a decent roll bar; I don't think a full cage is necessary at this point, but I'd like a good bar and harness setup. I'll build some sort of a battery mount/cover setup, and I'm probably going to put a lot of the wiring crap under the back seat--relays, etc.

Oh, and I opted for the fuel cel that has no provision for a gas gauge. I can keep track of how much is in there, I'm sure. For an extra $50, you get the gas gauge sender for a GM-style gauge.

Mike

[Guest Anonymous]

I'm just making this stuff up as I go along. Check out any decent 2002 IT car for an 'official' fuel cel setup. My system will reduce trunk space by a good amount, but I don't care. My car will be mostly for play.

Mike

[Guest Anonymous]

URL: http://www.geocities.com/mestumm/76BMW2002.html

...you may want to reconsider the Optima. I tried it and it did not

fit well under my back seat. I opted for a hawker as suggested by

Mark on the other board. Way smaller and it costs less. I love it.

Cranks very well. Maybe not for very cold starts but that's not a

toy car anyway. I am also going the fuel cell route and considered

the same tank you have. Unless I can find one that will fit in the

existing fuel "hole" I'm going with the same summit unit.

[Guest Anonymous]

(nt)

[Guest Anonymous]

If you built a sheet metal box to replace the fuel tank, it would be pretty easy to put a lid on it and get hidden (even lockable) storage and/or build in a sealed / vented to the outside battery box for a pair of 6 volt Optima's laid on their sides and wired in series.....

[Guest Anonymous]

Only pressurized gas will explode, the worst I could ever imagine would be a flash flame and the chances that there will be enough vapor in the compartment and the a random spark will occur is slim to none. If it really freaks you out just put it in a marine battery box. I wouldn't worry though.

[Guest Anonymous]

I love it too. where I am living it hovers around freezing most of the day in winter and at night it drops about 10 degrees- No problems starting the beast at all. Also the post design is really nice. Bolt or clamp with brass posts. Nice stuff.

[Guest Anonymous]

from the angled neck outside, to a straight down-into tank neck in the trunk. This does not eliminate trunk odor problems, nor does it improve gas tank safety, but it makes it easier for the guy ( it is an A4 tii also) to fill up without spillage.I dont remember if he has a trunk mounted battery- but I suspect that he does. Of course, he now has a cylinder sticking up in the middle of his trunk floor! But, that is the only space sacrifice in the trunk, other than a repositioned battery. I like what the others have done with fuel cells up against the rear bulkhead in between the strut towers: great placement, but i would like the weight lower in the car.Ideally, I would like a bladder that fits in the OEM fuel tank area. I am committed to rear mounted battery within a welded TEP brace in the Sahara, but I still have options for the A4. It just has a battery box around the trunk mounted battery right now (pictured). Let me know what you decide to do.

[Guest Anonymous]

I though about doing something like that. I'm building a tool tray into the space between the new trunk sheetmetal, which is even with the bottom of the box sections that make up the rear trunk structure, and the top of the box sections; for now I'll use the original plywood covers, but they'll be replaced with hinged aluminum lids at some point. I wanted the battery closer toward the center of the car, and I'm trying to reduce protrusions from the bottom rear of the car, to prevent bottoming out, and also to improve access to the differential, etc., when the car isn't jacked up.

Mike