2017 Class Rules

Classes 
1050 Lb. Stock 
1050 Lb. 250 cc Motorcycle 
1150 Lb. Pro Modified 
1300 Lb. Bike (650cc & 1350 cc)                      
1500 Lb. Mini Rod 4-cyl 
1500 Lb. Modified 4-cyl 
1700 Lb. Econo Modified 8-cyl                       
2000 Lb. Modified 8-cyl 
3500 Lb. 2wd Modified Truck 

1050 Lb. Stock
1.Stock engine only not exceeding 14 HP and 32 cubic inches from     the OEM, Maximum .030" over bore.
2.0.330 Maximum cam lift.
3.Maximum 1" venture carburetor. 
4.Throttle to be run through a working governor, 3600 rpm     maximum.
5.Porting and polishing is not allowed.
6.Gasoline or diesel only.
7.Maximum tractor length shall not exceed 6'6" from center of rear     axle.
8.Tractor must have hood and grill.
9.Maximum drive tire size: 23x10.5x12.
10.Transmission gear ratio changes allowed.
11.Drivers up to 17 years of age and/or High School.

1050 Lb. 250 cc Motorcycle 
1. 250cc maximum stock engine only
2.Single or twin cylinder 2 or 4 stroke
3.Carburetor only, no modifications, no porting and polishing, no     fuel injection, no computer controlled engines.
4.Pump gasoline only
5.OEM Garden Tractor rear ends and transmission- gear ratio     changes allowed, welded or locked rear ends allowed
6.Auxiliary gear boxes allowed
7.Jackshafts allowed
8.Maximum drive tire size: 23x10.5x12.
9.Tractor width shall not exceed 48”. Maximum tractor length     shall not exceed 6’6” from center of rear axle.
10.Modified frame are allowed
11.Must have hood, grill and fenders in place
12.Fenders and seat combination to have side arms and back with     minimum height of 8 inches or tractor to have fall off protection     with sides of seat and rear of seat to have minimum height of 8     inches . (Roll cage or roll bar optional).
13.Fenders to cover minimum 1/4 of tire width and cover front of     tire to frame and return to rear with minimum of 4 inches past     back of seat
14.Drivers up to 17 years of age

1150 Lb. Pro Modified 
1.Any combination of engines allowed, excluding automotive,     motorcycle,  snowmobile or ATV type engines. 
2.Gas, alcohol, or diesel only. Propane injection allowed on diesels     only, see rule # 6 under "Tractor" in General Rules.
3.Turbochargers allowed on diesels only.
4.Maximum tractor length shall not exceed 6'6" from center of     rear axle. 
5.Maximum tire size: 26x12x12.
6.All other modifications allowed.
7. 3/8 safety cable on hitch

1300 Lb. Motorcycle (Small Bike and Super Bike)
Small Bike maximum 650 CC OEM, Super Bike maximum 1350 CC OEM. 
1.Gas or alcohol only.
2.Hood and grill optional.
3.Naturally aspirated motorcycle engines only. 
4.Tractor width shall not exceed 60". Maximum tractor length     shall not exceed 8' from center of rear axle.  
5.Maximum drive tire size: 26x12x12.



1500 Lb. Mini Rod 4-cyl
1.Engine must be OEM block not to exceed 4 cylinders.
2.Gas, alcohol or diesel fuel only. 
3.Tractor width shall not exceed 60". Maximum tractor length     shall not exceed 8’ from center of rear axle.
4.Maximum drive tire size: 26x12x12.
5.Drivers in this class must be at least 14 years old or driver must     be old enough to handle the tractor. To be determined by TMTPA     officials. 


1500 Lb. Modified 4-cyl
1.Engine must be OEM block not to exceed 4 cylinders.
2.Gas, alcohol or diesel fuel only, turbochargers and     superchargers allowed.  
    Superchargers must have adequate restraint to prevent blower     lift off.
3.Diesel engine tractors only may run any combination of propane     injection, methanol/water injection or nitrous oxide injection as     power adders only. For 
    propane injection, see rule # 6 under "Tractor" in General Rules.
4.Tractor width shall not exceed 60". Maximum tractor length     shall not exceed 8’ from center of rear axle.
5.Maximum drive tire size: 26x12x12.
6.Drivers in this class must be at least 14 years old or driver must     be old enough to handle the tractor. To be determined by TMTPA     officials.

1700 Lb. Econo Modified 8-cyl
1.Engine must be OEM block not to exceed 8 cylinders.
2.Naturally aspirated engine only.
3.Gas or alcohol fuel only. 
4.Single carburetor only.
5.No aluminum heads.
6.Tractor width shall not exceed 60”. Maximum tractor length     shall not exceed 8' from center of rear axle.  
7.Drivers in this class must be at least 16 years old or driver must     be old enough to handle the tractor. To be determined by TMTPA     officials.


2000 Lb. Modified 8- cyl
1.Naturally aspirated engine only.
2.Gas or alcohol fuel only.
3.Maximum drive tire size: 31x15.50x15.
4.A 4 point frame mount roll cage of round or square tubing with     .090 wall thickness and 1 ½" minimum o.d. recommended. Cage     must enclose the driver and be capable of supporting the     completion weight of the tractor. Minimum 4 pt. safety harness     recommended. Minimum requirement will be a roll bar at least     .125 thick X 2" o.d., and of adequate height and placement to     protect driver in event of a rollover. Lap belt also required.
5.Tractor width shall not exceed 72”. Maximum tractor length     shall not exceed 8' from center of rear axle.  
6.Skid Pad/Plate requirement – minimum size will be 3” wide by 8”     long with at least a 15 degree bend at the front of the skid pad,     1/8" steel or 3/16" aluminum. Skids must be attached to the frame     rail on each side and as close to each front tire as possible     without interfering with wheel travel or turning. Maximum     ground clearance not to exceed 2” with the front tire in normal     operating position. OR x .120" mild steel tubing or same material     as tractor frame rails. Front axle support should connect to each     frame rail inline and extend toward front of tractor. Front     skid/front axle support should have radius to prevent digging     into track. Front axle support frame should be strong enough to     support front end weight of tractor. Support should have a     maximum of 4" ground clearance. Note: Skid plate must be able     to support weight of the front end when checked with a jack.
7.Drivers in this class must be at least 17 years old.

3500 Lb. 2WD Modified Truck Rules 
Frame/Chassis
1. Any type body allowed: Trucks - (Chevy S-10 & Luv, Ford     Ranger, Dodge D-50 and Dakota, etc.), custom trucks - (roadsters,     T buckets, and coupe bodies), custom rail type rods - (big mini     rods), custom compact cars, etc. If vehicle has doors, they must     be kept on and closed. Flip top bodies must have escape passage.
2.Anybody modifications allowed.  
3.Any type frame allowed. 
4.Vehicle may not be any longer than 156" from center of rear axle     forward, including weights. 
5.Maximum width 84".
6.Windows optional. 
7.Rear tires must have cover over tread, extending from top of tire     down to front center and covering min. 2/3 of width.  
8.Nothing may extend past hitch point except for sled bumpers or     wheelie bars.
9.Rear tire 34x18x15 Pullers. Also allow street DOT tires, must have     size clearly marked, and will not exceed 34" tall and 16 ¾" tread     width.
10.Class weight: 3500 Lb.  
11.Wheelie wheels/bars: Must be 2" min. width and designed to     prevent pulling front of vehicle more than a 45 degree angle     from the ground. Wheelie wheels/bars must be built heavy     enough to support weight of vehicle.
12.Sled bumpers bars required. Bumpers 6" tall x 2" wide min.,     must be most rearward point of vehicle, no more than 6" behind     point of hook and no more than 24" from ground to top. Can be     mounted on wheelie bars. Wheelie wheels can serve as bumper     bars if most rearward point. 
Engine
1. Engine size maximum 510 cubic inch.
2.Gas or Alcohol Fuel allowed.
3.Any type engine blocks, cams, heads allowed. 
4.Gas/Alcohol must be naturally aspirated.
5.Exhaust must exit within 45 degrees of vertical. 

Hitch
1.Stationary in all directions, center of rear axle to point of hook     36" max.
2.Hitch height max 15"  
3.2" min. dia. hole ¾" min. material around opening, ¾" min thick.
4.No "L" shaped hitches, i.e. drop hitches.
5.Hitch bar anchor pin may not be less than 7/8" dia. 

Safety Requirements
1.Manual transmissions require SFI bell housing, or a stock bell     housing shielded 360 degree with ¼" steel and covering the     entire clutch/flywheel area, or a properly attached SFI blanket     completely covering the clutch/flywheel area.  
2.Automatic transmissions may either have (1) a properly     attached  SFI safety blanket which completely covers the trans     center section and flex plate/torque converter area, or (2) an SFI     blanket or SFI shield over the trans center section, along with a     SFI flex plate shield over flex plate.
3.Except for SFI approved balancers, 1/8" steel or 3/16 aluminum         shield 360 degrees around the engine balancer, not less than 2"     wide, must have bar across front. 
4.Cooling fans electric only. 
5.Block shields must be .060 steel or aluminum, and must run the     full length of engine block and from bottom of head to the     centerline of the crankshaft, must not be bolted to engine.
6.Top shields over u-joints, wide enough to cover u-joint, long     enough to completely cover side of u-joint, 1/8" steel min.     Driveshafts must have a 360 degree loop within 6" of each     u-joint. 
7.No fuel tanks, fuel lines, radiators, water pumps or coolant hoses     in cab. If batteries are in cab, they must be enclosed. Must have     visible fuel shut off, and visible battery disconnect switch. 
8.Must have rear mounted reverse light.
9.Must have rear mounted breakaway to kill ignition and electric     fuel pump.  
10.Must have working 2 Lb. fire extinguisher
11.Vehicle with OEM type bodies require a lap belt with a braced 2"     x .125 thick roll bar over/behind driver. Open bodies require 4 pt.     frame mount cage of round or square tubing with .090 wall     thickness and 1 ½" minimum o.d. Cage must enclose the driver     and be capable of supporting the competition weight of vehicle.     Minimum 4 point safety harness. SFI approved fire suit and full     face DOT helmet required.
12.Drivers in this class must be a minimum of 18 years old.


TMTPA OFFICIALS DECISIONS AND DIRECTIVES ARE FINAL AND TMTPA OFFICIALS RESERVE THE RIGHT TO REFUSE ENTRY TO ANY PULLER OR VEHICLE.

PULLING WITH US IS MORE THAN JUST A DRAG!









Class Numbers  
100 - 149  
150 - 199  
250 - 299  
300 - 399  
400 - 449
450 - 499
500 - 599  
600 - 699  
700 - 799
Texas Minirod Tractor Pullers Association