CR21 and CR22 aluminium fuel tank.
Superseded by the composite cell from CR25 onward. The CF against aluminium comparison was run before the change.
No part-specific design process is documented. The Fuel subsystem design process applies: 1. Set tank volume from endurance consumption plus margin, with the HydraMat area and the tank CG as constraints. CR26: 1.4 gal cell, 1.56 gal effective system. 2. Design the sump to the acceleration cases: 1.42 g at 45 deg from vertical under acceleration against a rear wall 30 deg from vertical, and 2.51 g at 66.5 deg from vertical under braking against a vertical front wall. 3. Lay up the sump: 1 layer of Kevlar over 5 layers of stitched carbon twill on HIPS dissolvable molds, bonded with 3M DP420, sealed with Caswell epoxy gas tank sealer. 4. Design the top plate: -4 AN weld bungs instead of fittings, stud bulkhead terminals so no fuel path runs through wire, an aluminium terminal block for proper bulkhead seating. 5. Leak test the assembled system before it goes in the car.
Welded from sheet or tube.
Aluminium. From the cost report drawings and CAD: From the cost report drawings: Carbon Fiber + Aluminum (CR25 Fuel Tank Assem); Carbon Fiber (CR25 Fuel Tank Drawing).
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
CAD mass, CR26I master assembly: 1.368 lb (0.620 kg). CG at X 56.84 in, Y -2.79 in, Z 5.14 in in vehicle coordinates. (CAD component: CR25 fuel tank) CAD mass, CR25 master assembly: 1.368 lb (0.620 kg). CG at X 56.84 in, Y -2.79 in, Z 5.14 in in vehicle coordinates. (CAD component: CR25 fuel tank) Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. CR25 Fuel Tank Assem (as drawn): 396.90, 39.69, 115.90, 11.59, 224.5722.46, 38.10, 3.81, 142.75, 14.27, 11.18 CR25 Fuel Tank Drawing (as drawn): 115.90, 11.59, 396.90, 39.69, 136.09, 13.61, 92.35, 9.23, 19.05, R1.91 Source: SolidWorks mass model exports: CR22 (5 May 2024), CR25 (4 Jul 2025), CR26I (30 Jul 2025), CR26E (22 Mar 2026) | Cost report drawings: CR25/Powertrain/Design/Y - Cost Report Drawings/Fuel/CR25 Fuel Tank Assem.pdf; CR25/Powertrain/Design/Y - Cost Report Drawings/Fuel/CR25 Fuel Tank Drawing.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Fuel/CR25 Fuel Tank Assem.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Fuel/CR25 Fuel Tank Drawing.pdf and 2 more Quantity per car, as costed: 1
Nothing in CrimsonStorage covers these yet.