NTPA TechServices logo4webLarry Richwine
Director of Technical Services
6705 E 900 N, Brownsburg, IN 46112
PH 317-852-0630 
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To order a NTPA rulebook, order online, call the NTPA office at 614-436-1761 or mail $6 plus $2 shipping and handling to WPI/NTPA, 6155-B Huntley Rd. Columbus, OH 43229. You may also order by e-mail at: This email address is being protected from spambots. You need JavaScript enabled to view it.  with credit card info.

2018 NTPA Membership Application
2018 Crew Member Application

Items that will go in effect for the 2018 season:

General Rules:

  1. All “Ag type” tractor classes (i.e. DSS, OSS, Pro ST, SF etc.) All replacement blocks used in any Ag type tractor (i.e. DSS, OSS, Pro ST, SF etc.) manufactured after 2016 must meet specs of the OEM block produced before that date and must be approved by NTPA Tech Services. 
  2. Contest Operations: The 330 track length rule will be the same as it was in 2017 with the option for event manager/head official and promoter determining whether or not to use a floating finish with a max distance determined by that event’s insurance application and verified by NTPA.

Modified Rules:

  1.  Add to third note on page 45: A two engine tractor will be allowed to compete with one engine in the event of breakage.

A new class has been added to the 2018 rulebook: Hot Farm Tractors

Note: The Hot Farm Class will run under NTPA Super Farm division rules, plus the following rules.  This class will only be sanctioned at State and Regional level.

  1.  Engines                
    1. 510 cubic inch limit (+ or – 1 percent). Maximum of 8 cylinders permitted.
    2. Engine head must be OEM agriculture-type (no aftermarket head) for that brand engine
    3. No overhead cams allowed. Maximum of 2 valves per cylinder.
    4. Manifolds
      1. Intake manifold may be non-OEM with a maximum inlet size 3.75” measured on the outside diameter. One inlet pipe only. 
      2. No intercooler or aftercooler allowed.  If OEM intercooler manifold is used it must be disconnected from all cooling means.  No CO2 or any other means of cooling the air in the piping or manifold.  No ice filled or ice cooled devices onboard tractor of any kind.  All engine air must enter the inlet of the turbo at ambient air temp and humidity.  Inlet air may not be drawn thru or across any type of cooling device.
      3. Exhaust headers allowed
    5. Turbo restriction:3” inlet X  3½” exhaust outlet, no waste gates. Compressor wheel must protrude into the 3” bore. Intake housing to be no larger than three inches at the face of the wheel. No additional openings in compressor housing outside the 3” opening. The exhaust side to be no larger than 3.5" at the face of the wheel and the wheel should protrude the housing 1/8". MWE groove is allowed a maximum width of .200. MWE groove must be inside neck area where intake covered is measured at 3” 7. 
    6. The Maximum allowed size pump for diesel injection is a P-Pump. (No aftermarket housing) Only one plunger per cylinder allowed.
    7. Diesel fuel only
    8. High pressure water injection is allowed in the crossover pipe and ported water is allowed in the intake manifold only, not in the head. Water only permitted
  2. Competition
    • Hot Farm tractors are only allowed to compete in the Hot Farm class.
  3. Tires
    • Maximum tire size 20.8 X 38 (radials allowed) with a maximum of 56 lugs allowed. Tire can          be no larger than a maximum of 220-inch circumference when inflated to 20 psi.  Tread width to not exceed 21 inches when mounted on a 20 inch wide rim.  Aluminum rims allowed.
  4. Weight. 
    • The class will compete at 9,500 lbs.
  5. Safety
    • All OEM chassis (non-component) Pro Stock rules including shielding, safety and SFI apply to this class.

Tech Questions and Answers

Second hitch


Do I need a second hitch to pull at Cloverdale?


No, NTPA doesn't use a second hitch at anytime, even indoors.

Tech School


Mr. Richwine,
Can anyone attend the tech school or do you have to be one of the "Click" to attend??


The school is open for anyone to set in on but, in order to take the test and become a NTPA licensed official you must be endorsed by either a NTPA member state or by the NTPA itself.

Silly little rules


What’s this Bull Sh_t (silly little rule) that Larry Koester didn’t get a repull when his kill switch was pulled?Was he not on the list of “favored pullers” I would think his sponsor and he would be on your list of “elite”
Asking for a friend.


First, there are no “favored pullers” with me or the officials that worked the event at Bowling Green.

Second, the rule says that if the killswitch tie is not broken they don’t get a repull. As a matter of fact this happened 3 times at BG this weekend (two on North track and one on the south) all in different classes and three different sleds. And the official’s call was the same.

2017 NTPA rulebook general rules pg 36 reads:

8. Kill switch ring must be secured with a single nylon tie wrap (1/8-inch). The tie wrap must be broken for a repull. Competitor will be responsible for replacing the kill switch mechanism and securing the tie wrap once kill switch is checked by tech official.

9. If vehicle has a kill switch or shutoff located in legal position, and during the pull it is pulled and the nylon strap is broken and the presiding official inspects and finds switch capable of operating properly under normal conditions, the vehicle will be allowed to re-pull immediately or drop six positions. The decision to drop must be made before the vehicle leaves the track. It is the competitor’s responsibility to see that the switch

BTW, this rule has been in place since NTPA required a killswitch in the early days.

While I agree it sucked for these competitors that it happened to, if the tie is fastened "tight" the tie has to break in order to pull the killswitch. The ties we use are not a "Lowes or hardware store" wire tie. They are a "18lb" test wire tie that NTPA uses. They are/have been bought at the same place (10,000 per year) for over 25 years.

Bg Fuel


Are you checking fuel at BG? I need to know how much to put in this weekend.


Yes, we will pre test fuel during the day each day.

Bowling Green Tech and Entry schedule

August 17-19, 2017
National Tractor Pulling Championships
Bowling Green, OH

Wednesday Entry Opens: 12:00 noon
Tech Opens: 12:00 noon
Entry/Tech Close: 5:00 pm

Thursday- Session I
Entry Opens: 8:00 am
Tech Opens: 8:00 am
Drivers Meeting: 4:30 pm (at the entry trailer)
Scales Open: 4:30 am
Entry/Tech Close: 5:00 pm (for session 1)
Drivers Introduction: 6:00 pm (one for all drivers for the weekend)

Friday - Session II
Entry Opens: 8:00 am
Tech Opens: 8:00 am
Drivers Meeting: 9:00 am (Drivers for both sessions)
Scales Open: 9:00 am
Entry Close: 9:30 am (for session 2)

Friday - Session III
Entry / Tech already open
Scales Open: 3:30 pm
Entry/Tech Close: 5:00 pm

Saturday - Session IV
Entry / Tech Open: 8:00 am
Scales Open: 8:00 am
Drivers Meeting: 9:00 am (Drivers for both sessions)
Entry closesI: 9:30 am (for session 2)

Saturday - Session V
Entry / Tech already open
Scales open all day
Entry/Tech close: 5:00 pm

BG times


Hey Richwine,

What time does tech and entry open and when at BG?


Here ya go……..

Entry Opens: 12:00 noon

Tech Opens: 12:00 noon
Entry/Tech Close: 5:00 pm

Session I

Entry Opens: 8:00 am
Tech Opens: 8:00 am
Drivers Meeting: 4:30 pm (at the entry trailer)
Scales Open: 4:30 am
Entry/Tech Close: 5:00 pm (for session 1)

Mr. Happy returns


Hey Dumbass, What’s this stuff you let the new “big tires” run at Tomah? Geezz Can I run a big turbo till I get a chance to change it? What a stupid thing to do. You need to stick to eatin donuts and play with the fuel….At least the fuel keeps the cheaters in the same state. So, come on, what’s your BS excuse this time?


Good to hear from you Mr. Happy, I thought you had a health issue or something. Good to see you’re paying attention. Now, to answer your questions in the order received:
1. Yes, we allowed the “big Tires” (211” and212”) to run for the Tomah weekend. We told everybody they had till the next event to make their tires fit the spec (210” circumference). As a matter of fact the next event we had 24.5 tires was last night at Rockwell, IA and we had a set of tires that was not measured at Tomah (they were in the gravel lot) and they measured 213” and the tires were not allowed to run last night (he borrowed a pair) the tires. So, from now on the tires are either right or wrong.
2. Can you run a big turbo till you get a chance to change it? NO, most of you have a spare or a “selection” of turbos depending on where you are going for the night.
Again, it’s good you’re ok…….I did kinda miss our “chats”……NOT

Tires at Tomah

Question / comment:

What's this I hear that two guys so far can't pull at Tomah cause their tires are too big?
That's B-llsh-t. When did you decide to start doing yer job and measure tires?
I also heard that you're only measuring the ProPuller tires, what about the firstones?


Well, first let me tell you that we are measuring all tires in the Super Farm and Lgt Pro class.
Firestones and all others. The two that have been found not within the rules have been told they can run this weekend but,
have to be corrected before they run again at any NTPA or state event. I told everybody since the "new tires" came out that I would check them for size.

Tires, Turbos and stuff


Hey Richwine,
Have you measured anything on super farm yet? Turbos, tires or wheelbase what's the word?


As luck would have it, the officials and I will be measuring some vehicles at Benson on Saturday morning at 9:00 am.

Rollcage in NC


Mr Larry,
I need to get a cage inspected, will you be at Pinetops?


Yes, There will be two of us at Pinetops and Benson.

New SF turbo 3"charger


Mr. Richwine,

I hear that Hart has a new 3" charger that measures a fuzz over 3 inches.It was allowed to run last weekend in NC at a non NTPA event. Will that be allowed to run at a UPOC event? If so what's the limit?


I heard about the new turbo and have had a couple of calls already. I can assure you that NTPA won't allow that and if they are found to be on a tractor at a NTPA event, they won't be allowed to run or if they are found to have run after the fact the tractor will be DQ'd.As luck would have it, I will be at Pinetops and Benson and will make sure the SF chargers are checked.

Mounting OEM Rollcage


Hey Richwine,
I’m new to NTPA and I can’t find the rollcage mounting spec anywhere in the rulebook. I have a D-21 and need to mount an AccuFeed cage to it. Where is it and what do I need to do?


The Rollcage spec is a SFI 47.1, that’s all that’s listed in the book. The mounting to a OEM chassis is as follows:

Mounting must use at least 3 axle housing bolts on each side as well as 1 bolt before and after the axle housing. There bolts must be in sheer (horizontal ) with a total of 2 9/16” bolt material. 
mounting cage



What does WFO stand for?

There are many schools of thought on that. The Bauer Team are the ones to really ask.

Here are some of the meanings that I've heard:

1. Whole Family Operation
2. World Family Out reach
3. Wide Friggin Open

Rollcage Webbing

Mr. Richwine,

I am building a Mini Rod and have a question about the webbing between the upright tubes? Can they be lightened? If so, how much? I have included a photo of the chassis that is available and they look like they have been lightened a lot.

Yes the shear webbing that goes between the up tubes can be lightened by 40%.
The Spec says: shear web may have lightening holes but must retain 60% material and must have a minimum of 1 inch around the perimeter of the web on all four sides. This applies to both Mini Rods and Big Tractor rollcages.
After looking at the photo you are correct this will not pass the SFI / NTPA inspection and will have to be corrected before they are allowed to compete with NTPA.

New tires

Richwine, How big can of a tire can I use in the Super farm class? These new tires that are out are pretty big.
What if I buy a pair and they measure 212-214 inches?
The guy selling them that they are ok but, I don’t wanta get throw out if I show up with them.

The rule reads:
24.5 x 32 with a maximum of 210-inch circumference, when inflated to 10 psi. Tread width not to exceed 25 inches.

I realize that after hardening, over inflation and use they will stretch some but, if we measure your tires when they are relatively new and they’re to big, you would be allowed to run that day but told not to come back till you have tires that fit the rule…….

Bottom line is make sure you get tires that are legal.

Rollcages in New York


Mr. Richwine,
I'm not a mamber of NTPA but, would like to run at the upcoming event in New York. I need to get my cage inspected, is there a charge for that?

Here's the program that's been in place since 1999 when the cage was implemented.
All vehicles that compete at a NTPA event must have the rollcage inspected and display a NTPA/SFI certification sticker or the vehicle will not be allowed to hook.

1. Upon passing inspection and paying the fee of $75.00 per cage to NTPA on vehicles that have a paid NTPA membership. The rollcage will have a certification sticker applied to it that denotes the inspection date, it will be valid for a period of five (5) years before being required to have their rollcage reinspected. Unless an accident occurs that involves the rollcage.
2. A service fee of $100.00 will be added to a cage that is on a non NTPA member vehicle. This $100.00 fee will be applied to a regular membership (not per hook) if the vehicle joins NTPA within a 60 day period from the date of inspection.
As for dates other than the April 8th date that has been scheduled in NY the next available dates would be at Millers Tavern, VA May 13 or Pinetops, NC on May 19-20
This is not something that can be done at the event because there will not be a "rollcage inspector" there due to scheduling conflicts.

Murray KY


Mr. Larry,
Are you comin to Murray KY?  I need to get my cage inspected.


Yes, I'll be there a few hours before it starts to inspect rollcages and measure tires.

Contact Info

National Tractor Pullers Association
6155-B Huntley Road,
Columbus, OH 43229

PHONE: (614) 436-1761

FAX: (614) 436-0964