Marshfield MO Demo DERBY

Marshfield MO Demo DERBY Welcome to the annual Marshfield Demo derby. On this page we will keep all rules and classes.

05/17/2026

If anyone is looking for a MWFA car, there is a guy selling a running Pontiac g6 that got hit by hailstorm a few weeks back. $350
Located in northwest Springfield.

05/14/2026

Just a few reminders…
No restubbing.
No seam welding.
No creasing.

Feel free to reach out with any other questions. The show is right around the corner!

04/11/2026

2026
MWFA

1. Any 1980 and newer 2 wheel drive passenger car/ mini-van/mini-truck/mid-size suv

2. All vehicles must be stripped of all plastic, glass, headlights, taillights, and anything else that could fall off onto the track during the show.

3. All vehicles must remain stock. ABSOULTY NO WELDING ANYWHERE.

4. Bumpers must remain stock, do not alter bumper in any way. Factory bumper shocks must remain in the factory location. You may remove rear bumpers and shocks. You may weld one single pass on bumper and shock.
Factory stock bumper for your car!

5. Batteries may be left in stock location and spray foam may be added around battery. You may also move the battery to passenger floor or seat. Please make sure the battery is not moving.

6. If the factory gas tank is in front of axle you may leave it there. If it's behind the axle, you must move it to the rear seat area. Factory tanks may be moved inside but completely secured. After market tanks may be used.
All doors may be wired or chained in 6 places max per seam.

7. Trunks, hoods, tailgates, all may be wired or chained in 6 places total. Sheet metal to sheet metal only. Nothing to frame. Bumpers should have #9 wire 2 strands max holding the Bumper from falling off. If you remove trunk< or tailgate or you lose the trunk or tailgate wire or chain.

8. Must have at least a 3 point cage. Passenger door must have bar. 6 in max door bar material. Seat bar 3x3 in max material & dash bar if put in 3x3 max material as well.

9. Drivers’ doors must have a door bar as well as a bar behind the drivers seat. This is for driver safety.

10. DOT tires only. Stock wheels only, all wheel weights must be removed. Only tubes and air are permitted inside of tires.

11. Windshield MANDATORY must have 9wire, chain or something welded in.

12. The airbags must be disabled.

03/20/2026
03/20/2026

Stock Class
Any American made car can run with the following exceptions. Full size cars with the wheelbase of at least 113 in or more. No 4x4s, Imperials, el caminos, ambulances, hearses, trucks, limousines, or su***de Lincoln, no 03's and up.

1 No fresh paint or undercoating on the frame at all. No buffing or grinding frames or bodies except where welded is specifically allowed in the rules.

2 All cars must be stock, unless modification is stated in the rules.

3 All glass, plastic, chrome, and interior must be removed from the car before arriving to the derby.

4 All trailer hitches and braces must be removed.

5. You MUST have a number in bright colors on each front door and may have a sign on the roof of your car with your number on it for recognition of car.

6 Batteries must be moved to the passenger front floorboard. They must be properly secured & covered.

7 All cars must have working brakes. If the car is not able to exhibit the ability to stop, it will not be inspected. You are allowed a pinion brake, must be bolted on style only. NO WELDING what so ever off of pinion brakes to rearend. No bracing.

8 NO welding other than what is mentioned in this set of rules. If your car is found with any weld other than what is allowed and you refuse to fix it to the inspector's satisfaction, you and your car will not run.

BODY

1 Remove all glass, mirrors, and plastic. Remove all decking in wagons. Cars must be swept clean of all debris before you get to the derby.

2 No sedagans fresh or pre-ran, zero crease enhancement, zero sheet metal or frame shaping forming or folding.

3 Deck Lids must be in stock location. You may tuck trunk with a single 90° Bend fast and trunk or tailgate. You may use 2 pcs of 5/8 all thread, you are allowed 3 nuts & 3 washers per piece. Washers no bigger than 4in on top of trunk lids, 2 in elsewhere, or 4- 3/8 in bolts in drip edge or 4 Piece of single strand 9 wire.

4 Anything can be removed; nothing can be added.

5 Hoods get one Hood clip 3 in Long 2x2x3/16 with 1/2 in bolt and nut per side. (2) 5/8" bolts total thru hood in firewall area only and 2- 5/8 core support bolts thru the hood to top of frame only with 5 washers, 5 nuts, washer must be 5/8 store bought, hood washer may be 4 in max. max 3" space for core support. There is no welding of spacers 5 nuts max for all thread.

6 You may weld all other doors 5 on 5 off x 2 in x 1/8 in thick flat. Driver door may be welded solid.

7 Body mounts and spacers to remain stock and in place. IF THEY ARE BROKEN OR RUSTED OUT, A SINGLE PIECE 9 WIRE MAY BE SUBSTITUTED. NO BODY BOLT CHANGING ALLOWED. This excludes 2 core support bolts for all thread.

8 # 9 WIRE, CHAIN, OR BAR REQUIRED IN FRONT WINDSHIELD.

9 No 9 wire except where mentioned.

FRAMES

1 No welding on frames allowed, no pre bending on Fresh cars, you are allowed to strap your upper control arms with 1 2x2x1/4 in. Top control arms only. You are allowed lower cradle with front plate with Stock OEM motor mounts only.

2. You may use 2 twists in Spring spacers per side (store-bought no homemade).

3 You may use a single strand 9 wire to hold coil spring to rear end and leaf sprung cars may use 4 single strands of 9 wire as leaf clamps.

4 A-arm maybe swapped with no modifications. Must be direct bolt in.

TIRES/WHEELS

1 Tires no bigger than 16 in, no split rims, no studded tires, double tires are okay no foam filled.

2 Small wheel center only 3/8 max, no bead locks, no full wheel centers.

DRIVETRAIN

1 You may use 1/2 in thick lower cradle with front pulley & pulley protect or allowed. No bracing off of front plate anywhere. Must run stock motor mounts only. Only the lower engine mounts may be welded to the crossmember. You may use 2 1/2 in thick spacers to raise engine to clear steering components, may not exceed rubber mount area. You may extend off back of crossmember but nothing excessive half inch flat plate only. (Ex SBC in caddy, mopar, Ford).

2 No tr**ny protectors, no Ultra Bell stock mounts only, stock cross members passenger car OEM only. Maybe mounted with 1 piece of 2X X2 X3 angle iron welded to frame and bolted with 2 -3/8 bolt per side.

3 Rearend swaps allowed: no bracing, no welding, no reinforcement. Max axle size 31 spline. Subject to be pulled. Must be a direct bolt in gears may be welded. You are allowed to run Ford 9in rearend, but you must have stock lower brackets off of 8.8 read end. Upper you may run 1 inch ear no gussets what so ever.
On the rear end you are allowed a stock car type 5 lug only.31 spline max !!!

4 You may run 2 strands of 9 wire or chain from rearend to frame, nothing through the body, nothing through the frame. ( 9 wire 2 loops, 4 strands together). Must be vertical around frame only.

5 Floor shifters allowed, gas/brake pedals allowed, headers allowed. (none may strengthen the car).

6 No fuel cradles, protectors, skid plate, and no aftermarket parts of this nature at all.

7 You May swap engine (ex. Chevy in a Ford)

8 Slider driveshafts are allowed.

9 Aftermarket steering column okay, no hydro steering, aftermarket pedal and shifter okay.

10 Rear control arms must be stock to the car you are running.

DRIVERS COMPARTMENT

1 4 point square cage 6-in Max material. 6 in away from firewall inside of car not inside of door skins. Side bars not to exceed 62 in total length, with 1 2X3 down tube to sheet metal only per side, down tube must be located in center of the front door. Halo Bar allowed to backseat bar or floor sheet metal. Nothing from Halo to tank protector.


2 Gas tank protector is allowed no wider than 24 in. Must be at least 4in away from the rear package tray. Must run straight back from the center of the cage and must be a minimum of 4 in off the trans tunnel.

3 driver door must be padded.

4 Gas tank must be removed cannot us the factory tank. Battery must be moved and secured to passenger side floorboard.

5 Trans coolers allowed, must be mounted inside of cage area.

BUMPERS
1 You May weld on any OEM stock car bumper, you can stuff OEM stock car bumper, or you run a fab bumper. If you run a pointy, it must conform to a stock Chrysler bumper. (will be enforced) you are allowed 1-4x4x1/4in. bumper bracket MUST be on the inside of the frame & MUST touch the bumper.

2 Shocks can be collapsed and welded, all shocks and brackets in stock location and extended 1 in in front of frame.

3 All bumper brackets and shocks must be in stock location or you may shorten to 1in in front of the core support space and hard nose with no shocks or brackets on car or you may chain 1 piece of chain per side bolted from the mount to mount to hold on the bumper.

PRE-RANS
1 You may have 2 4X4x1/4 in plates per side where visibly bent- if it's determined that's its not bent you will cut entire plate off.

2 Plates must have a 1 in hole in center for inspection purposes.

3 Plates are to be welded around single 1/2 in pass only no plug welding in the center area.

4 cutting & tilting of a z box car and putting a plate over is prohibited.

5 if a tab on a z box car is tampered with and not in factory location you will be loaded.

02/27/2026

Ladies and gents, the derby will be on July 4th this year. We will have rules and payouts posted soon!

07/05/2025

It’s Derby day Folks!!! Let’s see some cars. Safe travels and remember that inspection closes at 6.

07/02/2025

Inspection will be 2-6 Saturday. You must pass inspection by 6. This show will start at 7.
We will try to do one and done but as always, be prepared for heats if there is a high car count.

06/26/2025
04/30/2025

July 5th is right around the corner. If anyone out there wants to do a sponsorship for Maddog, reach out to one of us or the Marshfield fairboard.

Address

Webster County Fairgrounds
Marshfield, MO
65706

Website

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