Weight Reduction
Home | Free Mods | Intake | Ported Heads & Manifold | Exhaust | Gears | Transmission | Brakes | Parasitic HP | Fuelling | Interior | Weight | Performance | HP Gains | PartsAcceleration is inversely proportional to the weight/power ratio so you can reduce that ratio by removing weight from the vehicle as well as by adding horsepower/torque. Each 3% reduction in curb weight results in a 1% reduction in 1/4 mile ET and a 1% increase in 1/4 mile trap speed.
With optimized traction and gearing, the weight/rwhp ratio (with driver) required to reach your target 1/4 mile ET is roughly as follows:
16.0 secs: 23.8lb/rwhp
15.0 secs: 19.6lb/rwhp
14.0 secs: 16.0lb/rwhp
13.0 secs: 12.8lb/rwhp
12.0 secs: 10.0lb/rwhp
11.0 secs: 7.7lb/rwhp
10.0 secs: 5.8lb/rwhp
Some items can be removed altogether from the vehicle at no cost while others can be replaced by lighter items.
Items Removed
Stock front seats (without tracks): 72lb
Stock upper/lower intake manifold: 35lb
Rear seat back: 28lb
Stock single-piston front brake calipers, brackets, hoses, & pads: 25lb
Stock 10.8" front brake rotors: 22lb
Stock rear driveshaft: 20lb
Power driver's seat track: 13lb
Rear seat cushion: 12lb
Stock rear lower control arms: 11lb
Smog pump & EGR assemblies: 10lb
Rear differential "dogbone": 8lb
Rear spoiler: 7lb
Strut tower brace: 6lb
Stock rear upper control arms: 6lb
Fog lights & mounting brackets: 5lb
Rear quad shocks & mounting brackets: 5lb
Rear seat headrest: 3lb
Heater tube assembly & hoses (with coolant): 3lb
Smog pump mounting bracket: 2lb
Knee bolster reinforcement plate: 2lb
Radiator core support plastic shield: 1lb
Rubber blocks behind rear wheels: 1lb
TOTAL: 297lb
Items Added
Modified '01 Jeep Cherokee front seats: 48lb
Edelbrock Performer upper/lower intake manifold with Trick Flow adapter elbow: 38lb
'94-'98 Cobra 13" front brake rotors: 33lb
'94-'98 Cobra PBR dual-piston front brake calipers, brackets, hoses, & pads: 16lb
Maximum Motorsports HD rear lower control arms: 13lb
Custom rear seat delete kit: 13lb
Ford Racing aluminium driveshaft: 11lb
Manual seat track: 7lb
Edelbrock rear upper control arms: 6lb Hayden HD transmission oil cooler: 1lb
TOTAL: 186lb
Overall weight saving: 111lb
Underhood Clean Up
Removal of the following items from the passenger side of the engine compartment has considerably increased underhood space and made servicing of other items much easier:
Smog pump & pipes/valves
Smog pump mounting bracket (cut from alternator mounting bracket)
EGR valve & pipe
Heater tube assembly & hoses
Alternator/Smog Pump Mounting Bracket
Since I'd already removed the smog pump assembly, I also had the smog pump mounting bracket component cut off from the main bracket at the line that I drew. This saved 2lb and gained some underhood space.