Chopping and channeling is a form of automobilecustomization in the"kustom kulture" and amonghot rodders. The procedures are often combined, but can be performed separately. While chopping takes in only a car'spillars and windows, the more involved work ofsectioning a car is carried out on the entire lower body.
Chopping a car, known more fully as "chopping the top," goes back to the early days of hot rodding and is an attempt to reduce the frontal profile of a car and increase its speed potential. To chop a roof, a shop cuts down the pillars and windows, lowering the overall roofline. Some racers on thedry lakes chopped the tops of their cars so severely that the windows were only a few inches tall, and sometimes called "mail slot" windows.[1] Roof chopping became popular withdrag racers for much the same reasons as it did for lakes racers, and was applied also tocustom cars,kustoms, andlead sleds. The first roof chopper is considered to be Sam Barris (brother of auto customizerGeorge Barris), who chopped and customized his brand new1949 Mercury.[2] Barris also pioneered a more advanced form, removing theB-pillar and turning the car into apillarless hardtop in the process.[3]
Automakers themselves may lower the roofs ofconcept cars based onproduction models, asAMC did with itsAMX-GT, to make them look sleeker and "racy", even if impractical for normal use.[4]
Channeling is a modification that can be applied to cars withbody-on-frame construction. To channel a car, a shop lifts its body temporarily off of itsladder or perimeter frame, cuts loose the floor and refastens it higher inside the body, and then lowers the body back over the frame. Thus, the entire body rests closer to the ground without alterations to the suspension, giving the car a lower profile.[5][6] In some instances, shops must also modify chassis components, and so may be constrained by local laws as well as safety considerations. Channeling is popular among hot rod, lead sled, andminitruck enthusiasts, the last calling itbody drop.
Sectioning a car is removing a horizontal section from its lower body, lowering the remaining top section onto the bottom one, andwelding the result back together, reducing the body's and thus the car's overall height.[7] Like a top chop, it has the advantage of reducing a car's frontal area andwind resistance. This sort of bodywork is popular on minitrucks, race cars, customs, and lead sleds.[8]