The car that works best in the demo derby is the 1964-1968 Chrysler Imperial
It works so well, in fact, that in many derby's they have been banned!
The Imperial pictured below has been run in several derbies.
Click here to see an Imperial
Probably the 2nd most wanted car for the derby is the 1971-1976 GM fullsize Station Wagon.
These cars are very heavy and came with strong frames, leaf springs, tough bumpers and good motors.
Wagons in general are sometimes outlawed.
Click here to see a Chevy Wagon
GM fullsize sedans (1971-1976) are probably the 3rd most wanted car for the derby.
They too are sturdy, heavy and have good motors.
Click here to see a Chevy Impala
Pound up or cut out the front/rear fenders for clearance
Why: keeps tires from getting cut
Remove headlights, taillights and all trim
Why: No glass or loose parts are allowed
Remove all windows
Why: No glass is allowed
Cut 24" hole in hood
Why: Easy to put out fires under hood
Cut 12" hole in trunk
Why: So officials can see that you haven't cheated or filled the trunk with trash
Wire trunk and hood down (use threaded rod if allowed)
Why: Threaded rod holds everything together nicely. Run the threaded rod all the way through the frame.
I like wire because it is easier to use, cheaper than chain and you can get it real tight by twisting it
Where possible, replace body mounting bolts with grade 8 bolts and larger washers. Run the bolts all the way through the frame.
Why: Body is less likely to pull apart from the frame
When your replacing the body mounting bolts, toss the rubber bushings
Why: Having the body sitting right on the frame, strengthens both the body and the frame
Cement in the driver's door (local rules)
Why: Protects driver from door hits
Mount bars, chains or wire where windshield used to be. I prefer to use wire for this. I run about 4 strands
through and then twist it nice and tight
Why: If hood comes loose, it doesn't come in and cut your head off
Weld, wire, or chain doors shut
Why: Keeps doors from opening and also strengthens the body
Remove hood latch mechanism
Why: If the front gets really smashed, you may have problems getting the hood open
Kink the trunk and quarter panels (coil spring cars)
Why: The rear end of coil spring (non-GM)cars, tend to bend down. This will help it bend up.
Weld a 3 inch piece of pipe around valve stems
Weld 2 thick bolts before and after valve stems
Why: Protects valve stem from getting sheared off
Mount tallest bias ply truck tires allowed (wider is not better)
Why: The higher the car sits the better. Keeps other cars from going over the top of your front bumper
and smashing your radiator. The vice-versa is true also.
Bias ply tires are tougher than radials
Run inner tubes in all tires
Why: Tires will not loose air if the bead comes off the rim
Remove gas tank and install boat motor tank
Why: Original tanks are in a location that is easily damaged. Since driver's door hits are against the rules,
mounting the gas tank behind the driver's seat is the safest location
Boat motor tanks also sit flat and have secure hose connections
Cover the gas tank with fiberglass insulation and cover that with half of a 55 gallon drum
Why: If the gas tank leaks, the gas cannot splash on the driver. If the car rolls over, all the gas will be trapped
in the 55 gallon drum
Blow out fuel line with compressed air
Why: Removes all the rust and stuff that could plug up a fuel filter.
Replace or remove fuel filter
Why: It may already be partially plugged
Clean carburetor with spray cleaner
Why: Removes any debris and varnish that could cause problems
Turn up idle good and high
Why: When a car hits hard, the fuel in the carburetor sloshes around and floods out the engine.
With the idle up high, the car will keep running
Wire choke wide open
Why: When a car hits hard, the choke may slam shut, causing the engine to stall
Run a solid fan, instead of a clutch type fan
Why: This will ensure that the fan runs all the time and will not stop if it comes into contact with the shroud
Why: Promotes better coolant circulation
Leave the thermostat in just remove all the guts inside of it
Why: If the thermostat locks up, the coolant will not circulate at all. Removing the thermostat all together causes
the coolant to circulate too fast.
Weld radiator brackets/housing
Why: Gives the radiator more protection
Remove battery bracket
Why: Excessive front end damage may cause to come in contact with the radiator
Cut hole in hood over radiator cap
Why: You can easily top off the radiator with coolant
Plug or loop the heater hoses
Why: One less hose that might rupture
Duct tape radiator hoses
Why: Helps prevent ruptures
Unbolt radiator and use gas tank straps or wire to hold it in place
Why: Excessive frame damage may actually cause the radiator to be ripped in two
Secure the radiator overflow hose in the container or route it to the outside of the radiator
Why: If the radiator overheats, you don't want the bypass hose to blow coolant into the aircleaner
Leave the airconditioning radiator in place.
Why: It helps protect the radiator from flying mud and rocks
Re-enforce drivers seat with chain, pipe or seat belt
Why: Hard hits can sometimes break the back of the seat off
Remove dash and all wiring
Why: Prevents electrical shorts, fires and promotes easier driver access
Why: The less flammable material in the car, the better
Remove door upholstery (except driver's door - local rules)
Why: Bits of plastic may come loose and fly around the car
Lock door and remove doorlock stems
Why: You want the doors to stay shut. The doorlock stems tend to rip your pants when entering/exiting the car
Remove outside door handles
Why: They may get knocked off by another car and hurt someone
Remove rear seat
Why: It's a fire hazard. It may come loose. You're better off mounting your gas tank lower to the ground and on solid metal
Remove sun visors
Why: Just another think that may come loose and poke your eye out
Why: Another fire hazard
Change Oil - use 1 quart Slick 50 (or equivalent)
Why: You want to most protection possible. Friction causes heat. Heat kills engines.
Install new/clean sparkplugs, distributor cap and wires.
Why: Lessens the chance of electrical problems.
Duct tape wires on distributor cap.
Why: Hard hits may actually knock the wires off of the distributor cap.
Cutoff exhaust pipe, flip manifolds if possible.
Why: You can hear and tell how the engine is running. Running the exhaust through the hood keeps heat away from the engine,
If you keep the exhaust in the stock location, make sure that you don't cut if off to short and it blows on the starter or transmission
Tie plug wires away from exhaust manifold.
Why: Keeps them from burning or melting.
Weld or chain motor mounts.
Why: If a motor mount breaks, the engine doesn't jump around under the hood.
Remove all unused vacuum lines.
Why: Just something else in the way or could catch fire or go wrong.
Clean engine/transmission with gunk off.
Why: Clean engines/transmissions dissipate heat better and are less likely to catch fire.
Re-route battery cables to passenger side floorboards and mount battery securely there.
Why: This will keep the battery our of harms way.
Run all electrical cables through a section of heater/radiator hose where they pass through the floorboards.
Why: Chaffing can cause electrical shorts and fires.
Run battery ground to intake manifold bolt.
Why: Promotes a better ground than the frame of the car. The stock cable will usually reach the battery inside the car.
Cut hole in firewall behind distributor (if needed).
Why: Excessive front end damage can cause the distributor to contact the firewall and crack or break.
Wire up starter, coil and battery to toggle switches.
Why: The less electrical connections the better.
Here's a diagram on how to do the wiring
Solder and use electrical tape on all connections.
Why: You want to secure all the connections and keep them from coming apart.
Remove all extra wiring.
Why: It's more stuff that's in the way and could catch fire.
Weld spider gears together.
Why: Both tires will still turn when flat. Promotes better traction and maneuverability.
Jack up car and stuff rags into shocks (repeat several times).
Why: Makes the car sit up higher.
Loosen bumper mounting bolts and relocate bumper as high as possible.
Why: Protects the radiator better.
Replace bumper mounting bolts with grade 8 ones and large washers
Why: Keeps the bumper from falling off
Wire or chain the bumper to the frame
Why: Keeps the bumper from falling off
Drill holes in bumper shocks, compress, and weld in place (front and rear).
Why: Strenghthens them and keeps them from falling off.
Cutoff bumper ends and leave them good and sharp.
Why: Keeps you from getting stuck up on other cars. You can use the sharp ends to puncture tires.
Notch frame behind real axle if car is a non-gm and has coil springs.
Why: The read end will bend up, instead of down.
Run chains through hood, in front of radiator, around bumper and back up (if allowed).
Why: Protects the radiator.
Remove the front sway bar if equipted.
Why: Frontend damage may push it into the fan.
Hook up threaded rod shifter.
Why: The stock linkage is easily broken.
Chain or wire transmission to mount.
Why: Broken transmission mounts are not good.
Change transmission fluid and filter after every derby.
Why: Transmissions get hot and burn the fluid and sometimes even melt the plastic filter.
Connect the 2 lines at the transmission using rubber transmission hose (not rubber gasline).
Why: Rusty metal lines break or crack easily.
Why: Broken u-joints are a show stopper.
If you have any addition tips you want to share, Please email me at firstname.lastname@example.org