1M Fan Posted May 1, 2014 Share Posted May 1, 2014 I had a major malfunction with my fuel tank last race and I'd like to replace it with a fuel cell. The problem is I don't see an affordable way to do it within the requirements of the CCR and the 944 Spec rules. The one option I see is to cut the spare tire well out and install it there, however; I have an early car and it says I can't cut the spare tire well unless I have a plastic tank. has anyone put one in or know where to put it? I only need 8 - 10 gallons. Quote Link to comment Share on other sites More sharing options...
Sterling Doc Posted May 1, 2014 Share Posted May 1, 2014 Read a little further down the rules 17.3.14 The spare tire well and rear cargo deck may be removed or modified to allow for a fuel cell installation conforming to section 12.6.1 and the NASA CCR’s. Underbody panels may need to be added to ensure a similar to stock airflow under the back of the car. Consult the series director for guidance. From a weight perspective, putting the fuel there will change the balance and the handling of the car more than one in the stock location, and this will change as the fuel drains. Also, I'm not convinced it is safer mounted that far back, than the well protected OEM fuel tank. Quote Link to comment Share on other sites More sharing options...
1M Fan Posted May 1, 2014 Author Share Posted May 1, 2014 Read a little further down the rules 17.3.14 The spare tire well and rear cargo deck may be removed or modified to allow for a fuel cell installation conforming to section 12.6.1 and the NASA CCR’s. Underbody panels may need to be added to ensure a similar to stock airflow under the back of the car. Consult the series director for guidance. From a weight perspective, putting the fuel there will change the balance and the handling of the car more than one in the stock location, and this will change as the fuel drains. Also, I'm not convinced it is safer mounted that far back, than the well protected OEM fuel tank. My preference is to mount it in the stock tank location. However, your reference above is part of the problem. First, section 12.6.1 of the CCR doesn't exist. Section 5.14.1 states "There should be a solid bulkhead completely separating the fuel tank, fuel pump, fuel cell, filler neck hoses, and/or vent lines, from the driver compartment." I can't think of a practical way of making the bulkhead without violating other 944 rules. I'd need to close off the back hatch. The only practical solution I can think of is to put it below the floor and let the floor be my bulk head. I can cut the floor and get a small tank in front of the spare tire well, but I'm at a loss on the bulkhead. Is it allowable to build a new floor higher up? The 944 rules require the tank fill point must be the factory fill point. Is this true for a fuel cell? It can be done, but it adds considerably to the cost. Quote Link to comment Share on other sites More sharing options...
Sterling Doc Posted May 2, 2014 Share Posted May 2, 2014 I can't think of a practical way of making the bulkhead without violating other 944 rules. I'd need to close off the back hatch. The only practical solution I can think of is to put it below the floor and let the floor be my bulk head. I can cut the floor and get a small tank in front of the spare tire well, but I'm at a loss on the bulkhead. Is it allowable to build a new floor higher up? The 944 rules require the tank fill point must be the factory fill point. Is this true for a fuel cell? It can be done, but it adds considerably to the cost. "Modify" gives you pretty broad leeway on fuel cell installation. You can rebuild the floor higher up to create a bulkhead. As the rules are written, a fuel cell must be filled through the OEM location. I have seen custom fuel cells that mimic the stock 944's saddle tank, but are $$$. I've seen very few issues with the late plastic tanks, other than some venting issues from old tubing. Quote Link to comment Share on other sites More sharing options...
1M Fan Posted May 2, 2014 Author Share Posted May 2, 2014 I can't think of a practical way of making the bulkhead without violating other 944 rules. I'd need to close off the back hatch. The only practical solution I can think of is to put it below the floor and let the floor be my bulk head. I can cut the floor and get a small tank in front of the spare tire well, but I'm at a loss on the bulkhead. Is it allowable to build a new floor higher up? The 944 rules require the tank fill point must be the factory fill point. Is this true for a fuel cell? It can be done, but it adds considerably to the cost. "Modify" gives you pretty broad leeway on fuel cell installation. You can rebuild the floor higher up to create a bulkhead. As the rules are written, a fuel cell must be filled through the OEM location. I have seen custom fuel cells that mimic the stock 944's saddle tank, but are $$$. I've seen very few issues with the late plastic tanks, other than some venting issues from old tubing. Thanks, I didn't realize I could rebuild the floor a little higher. It only needs four or five inches. That would make it pretty straight forward. The old steel tank pressurized so bad it bent the transmission crossmember and creased the floor. It'll take a couple of hundred dollars to replace the valves and lines as well as putting another tank in. I do have a spare steel tank. I need to weight all my options. Quote Link to comment Share on other sites More sharing options...
Sterling Doc Posted May 2, 2014 Share Posted May 2, 2014 Well, at least it wasn't cracked. The vent lines can be an issue! Quote Link to comment Share on other sites More sharing options...
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