SoundGuyDave
This Space For Rent
- Joined
- Apr 9, 2007
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First off, I was wondering if anybody has done this successfully before, and if so if they retained the fuel-level signal to the computer.
First off, the application is road-race specific, in an endurance car, and I'm planning on a 22gal cell, with a 3-door center collector, aluminum can, and retaining the STOCK returnless fuel system.
I don't *think* this will be an overly difficult setup to work out... The stock pump, once removed from the carrier assembly (fuel hat and support structure) looks pretty similar to a typical Bosch pump, so the physical mounting in a collector shouldn't be terribly difficult. My real question comes with integrating the fuel level sensors into the mix. Ford runs two circuits for the level in the stock tank... Does anybody know: A) if you leave one open, how that affects the gauge reading, B) if you tie the returns together will a single float then determine the gauge reading? I'm not overly concerned with "true" fuel level, but it would be nice to get an indication in the cockpit when the tank is starting to get low. In other words, I'm most interested in the last 1/4 tank range of the gauge. I could care less if the gauge reads full with a half-load in the cell, but the "low fuel light" would be nice to keep functional for planning pit stops... Has anybody successfully transplanted the level senders into a non-OE tank or cell?
Here's my plan, offered up for comment, discussion, and suggestion:
MOUNTING:
The bulk of the trunk pan will be removed for this, and replaced by a top perimeter frame of 1"x1" square steel stock with nutserts for actually mounting the cell, extending to the rear frame rails. I'd like to run two 1/2x1/2 steel "cradles" down from this frame with an additional tie-bar between the cradles on the underside of the cell. Essentially this would form a fully supporting cradle for the cell's can, and would accept bolts on the top. This entire assembly would be slung as low as possible, with the cradle engineered to stay above ground level even if BOTH rear wheels are stripped off (crash damage and berm clearance). Mounting location will be as far forward as I can get it and still clear the rear swaybar. That will, naturally, also clear the Panhard bar, however if anybody has it, how much clearance would I need to leave between the face of the differential housing and the cell to accommodate a Whiteline or Cortex Watts link bolt for adjustment?
From there, I would build up a floor out of sheet aluminum over the cell, leaving only a latched hatch over the filler neck. This would provide the mandated firewall between the cell and the cockpit compartment. I could, optionally, run a panel down from the rear window to the trunk floor, but I think that would actually use more material and be heavier... It would also restrict airflow for any rear-mounted coolers.
On top of the floor, I would mount the usual trunk-junk (cool-suit cooler, possibly a battery, maybe a diff cooler if I don't mount that under-car).
PLUMBING:
Looking for suggestions on line sizing and how to tie into the stock fuel line... I'm thinking -8 from the cell, but is there a consensus on whether to weld a bung on the stock line, or use an adapter (Push-Lok) to the OE flex line? For the vent, I'm planning on using a -8 line plumbed through a discriminator valve and out of the rear of the trunk pan, right above the bottom-center of the fascia, with a filter clamped over the end. The valve should prevent any siphoning action and only allow (filtered) air in and fumes out to equalize cell pressure from dropping levels and fuel heating.
SAFETY:
Here, I'm on the fence a bit. I'd really like a rear intrusion cage (to protect against rear-impact cell damage), but I don't know how far down to take the bars. Basic design would be a 1.75" main hoop, with the ends angle-cut to lay it down and behind the cell with AT LEAST 3" of clearance, tied directly to the frame at approximately the cell longitudinal midline. Then there would be a pair of 1.75" vertical struts also tying into the frame supporting the bends at the rear of the car. That should provide pretty stout rear and offset-rear impact protection. It'll also make a pretty stout jacking point as well! My real quandry is how far down to take the cage. If I don't take it down far enough, there's a chance that a massive rear shunt could slide a car underneath into the cell (think high-speed punt under a panic-stop vehicle attitude), but I also don't want the cage structure so far down that it smacks the track surface if I straddle a berm, so probably no lower than the bottom of the diff housing?
Also, I'm considering adding an automatic temp-driven dedicated 5lb fire bottle for the cell area, plumbed under the firewall.
First off, the application is road-race specific, in an endurance car, and I'm planning on a 22gal cell, with a 3-door center collector, aluminum can, and retaining the STOCK returnless fuel system.
I don't *think* this will be an overly difficult setup to work out... The stock pump, once removed from the carrier assembly (fuel hat and support structure) looks pretty similar to a typical Bosch pump, so the physical mounting in a collector shouldn't be terribly difficult. My real question comes with integrating the fuel level sensors into the mix. Ford runs two circuits for the level in the stock tank... Does anybody know: A) if you leave one open, how that affects the gauge reading, B) if you tie the returns together will a single float then determine the gauge reading? I'm not overly concerned with "true" fuel level, but it would be nice to get an indication in the cockpit when the tank is starting to get low. In other words, I'm most interested in the last 1/4 tank range of the gauge. I could care less if the gauge reads full with a half-load in the cell, but the "low fuel light" would be nice to keep functional for planning pit stops... Has anybody successfully transplanted the level senders into a non-OE tank or cell?
Here's my plan, offered up for comment, discussion, and suggestion:
MOUNTING:
The bulk of the trunk pan will be removed for this, and replaced by a top perimeter frame of 1"x1" square steel stock with nutserts for actually mounting the cell, extending to the rear frame rails. I'd like to run two 1/2x1/2 steel "cradles" down from this frame with an additional tie-bar between the cradles on the underside of the cell. Essentially this would form a fully supporting cradle for the cell's can, and would accept bolts on the top. This entire assembly would be slung as low as possible, with the cradle engineered to stay above ground level even if BOTH rear wheels are stripped off (crash damage and berm clearance). Mounting location will be as far forward as I can get it and still clear the rear swaybar. That will, naturally, also clear the Panhard bar, however if anybody has it, how much clearance would I need to leave between the face of the differential housing and the cell to accommodate a Whiteline or Cortex Watts link bolt for adjustment?
From there, I would build up a floor out of sheet aluminum over the cell, leaving only a latched hatch over the filler neck. This would provide the mandated firewall between the cell and the cockpit compartment. I could, optionally, run a panel down from the rear window to the trunk floor, but I think that would actually use more material and be heavier... It would also restrict airflow for any rear-mounted coolers.
On top of the floor, I would mount the usual trunk-junk (cool-suit cooler, possibly a battery, maybe a diff cooler if I don't mount that under-car).
PLUMBING:
Looking for suggestions on line sizing and how to tie into the stock fuel line... I'm thinking -8 from the cell, but is there a consensus on whether to weld a bung on the stock line, or use an adapter (Push-Lok) to the OE flex line? For the vent, I'm planning on using a -8 line plumbed through a discriminator valve and out of the rear of the trunk pan, right above the bottom-center of the fascia, with a filter clamped over the end. The valve should prevent any siphoning action and only allow (filtered) air in and fumes out to equalize cell pressure from dropping levels and fuel heating.
SAFETY:
Here, I'm on the fence a bit. I'd really like a rear intrusion cage (to protect against rear-impact cell damage), but I don't know how far down to take the bars. Basic design would be a 1.75" main hoop, with the ends angle-cut to lay it down and behind the cell with AT LEAST 3" of clearance, tied directly to the frame at approximately the cell longitudinal midline. Then there would be a pair of 1.75" vertical struts also tying into the frame supporting the bends at the rear of the car. That should provide pretty stout rear and offset-rear impact protection. It'll also make a pretty stout jacking point as well! My real quandry is how far down to take the cage. If I don't take it down far enough, there's a chance that a massive rear shunt could slide a car underneath into the cell (think high-speed punt under a panic-stop vehicle attitude), but I also don't want the cage structure so far down that it smacks the track surface if I straddle a berm, so probably no lower than the bottom of the diff housing?
Also, I'm considering adding an automatic temp-driven dedicated 5lb fire bottle for the cell area, plumbed under the firewall.
