Tech Services

Recent Updates & Announcements


Online Membership Process Migrates to Trackside on March 1

The NTPA’s online digital membership applications and Super/Grand National event registrations are being consolidated into one service. Beginning Friday, March 1, the NTPA will team with Canton, Ohio-based Trackside Systems to provide an all-in-one interface, available via a portal at


2024 Tech Schools

Please register below for the Tech School that you will be attending. These are the last Tech Schools being offered for the 2024 season. March 30, 2024 9:30 a.m. Shelbyville, IN Keith Theobald’s Shop RSVP by March 25 April 6,


Tech Questions & Answers


Mr. Richwine, I bought a new Trick Titanium belhousing for my Mod FWD. I received it in January 2022. It has a current SFI sticker on it and all legal, but, it only has 13 bolts holes around the flange. It also has the 4 big quadrant holes. Do those holes count to meet the 15 bolts requirement? If not, do I need to drill two holes in it to be legal?  I see the rulebook states either 15 or 18 bolts around it to be SFI legal. Please tell me what to do.


 No, don’t drill any holes in it. If they sold it to you as a SFI certified belhousing with only 13 holes it’s legal. If you modify it by drilling extra holes in it won’t be re-certified when you have to send it to Trick Titanium for re-certification because you have modified it.

 Since the rulebook was printed this has come up a couple of times. The bottom line is NTPA wants you to have a “current SFI certified” belhousing properly installed on your vehicle starting January 1, 2023. If Trick Titanium sold you the can as “SFI certified” then NTPA will not tell you to modify it.


Richwine, what’s this I hear about the Scheid injection pump that I’ve been running in the Super Farm class for the past 5 years may not be legal?

How the hell can that be true?


The question was raised at Louisville as to the legality of a “P” pump that wasn’t a P7100 housing in the Super Farm class.

The 2022 NTPA rulebook pg 62 under SF rules states that the pump must be a “P” pump but, doesn’t specify that it has to be “7100 series”.

After research, review and consideration the NTPA exe board has decided that this issue should be reviewed in September of 2022 by the SF division and better clarified at that meeting for the 2023 rulebook.

So, the Scheid pump you’ve been running can continue to run for 2022.


Richwine, I was told at Shipshawanna that the rules had changed and I had to have 1/2 “ bolts instead of 3/8” bolts as close to the exhaust wheel as possible, Is that true?


Yes, the rule changed two years ago. You have to have 2  – 1/2 “ bolts in the horizontal part of the pipe as close to the exhaust wheel as possible.  Also, the turbos that have a cross in the turbo exhaust housing from the manufacture doesn’t count. The exhaust pipe still has to have the cross bolts (1/2”) in the horizontal part of the pipe.


Mr. Richwine

Is BioDiesel legal for NTPA competition in 2022?  I see where you raised the dielectric reading to 150 but I thought that would eliminate B100. Is this not true? There seems to be a debate if Bio is legal or not.


We did raise the dielectric limit to 150 for diesel fuel, but, the rules for BioDiesel did not change. The B100 rules are exactly the same as they have been in the past. So, yes biodiesel is still legal.


Mr. Richwine, my partner and I are coming to Ocala and run the LLSS class. What all do I have to do to pass inspection? We run about all the different groups here in New England, but, we’ve never ran at a NTPA event.


The NTPA rules for all classes will apply to all of the classes that are scheduled at Ocala. This includes all safety rules like inner side shields, cross bolts in the turbo exhaust pipes, rollcage and attachment, firesuit and equipment, etc. Better get there early and get checked ASAP.


Larry I’m getting close to ready to loading and headed Fl.  I’ve been hearing people needing a neutral light on back of tractor ???  Is this a new rule?? A neutral light and neutral safety switch??? Not sure how power it with safety switch being ground. If it needed.  Sending memberships in next week  so I don’t have new rule book thanks


NTPA requires a 2 inch white light on the rear of the vehicle to indicate “reverse” as well as a “neutral” switch to keep it from starting in gear.
The other group requires amber light for neutral.


Mr. Richwine, I was told I can’t use hex socket head bolts to attach my belhousing to my engine / block plate. Is this true?  Some of the bolt holes are so close to the bell that a normal hex head bolt can’t be used. What the heck should I do?


I understand that this is a problem on some belhousings, so, in this case, you will be allowed to use a hardened hex socket head bolt as long as all the other fasteners are grade 8 bolts and / or studs.


Hey Richwine, what’s this BS that I’ve gota get my steel Lakewood belhousing inspected by Lakewood and have a sticker on it? You guys stamped it so I didn’t have to worry about the sticker or if it was current.


Yes, Starting Jan 1, 2023 all SFI belhousings regardless of material i.e. steel, titanium or aluminum must display a current SFI sticker with a expiration date affixed by the manufacture. The NTPA steel stamp will no longer be acceptable as a replacement for SFI decal after Jan 1, 2023.


Hey Richwine, Did the Mini Rod trans mounting rules change after Bowling Green?


No, nothing changed yet. The number of bolts may change for 2022 but, we will finish the 2021 season same as in the past.


Mr. Richwine,

Will there be pulloffs at BG this year? I’ve noticed that you havent had pulloffs at any events this season.


Yes, there will be pulloffs if they go past 350 feet. The NTPA rulebook allows for a max distance of 350′ I realize we’ve exceeded that distance at several events but there’s not really enough “runoff” room past 350 here at Bowling Green to allow it. The pullers will be red flagged if they go past 350 and will be required to come back for a pulloff. 


Can I run if I don’t have a turbo blanket but have it ordered?
Also, can I build a steel shield around my compressor housing instead of buying a blanket?


No, you are required to have a Kevlar blanket around you “high pressure” or last turbocharger’s compressor housing in a multi turbo setup. 

Also No, a steel cover instead of a blanket will not contain the fragments as well as a properly installed blanket.

If you show up at a NTPA event without a blanket you will have to borrow one or just not pull.

Note: A turbo blanket is only required in classes that allow a turbo inlet larger than 3 inches.


Mr. Richwine, I’m new to NTPA, how do you guys measure the turbo? I say that the wheel where it sticks thru the housing should be 3” and everybody tells me I wrong it’s the housing.


Sorry, they’re correct and you’re wrong. When NTPA first started measuring the Super Farm class and actually made them tear the turbo down to be measured and sealed  we set the president of measuring the bore of the housing at the face of the wheel like the rules state.

We measure several different classes now and they’re all measured the same way. We use a slug or a  “Go /No Go” gauge. Sounds like if measured at a NTPA event that your turbo will not pass.


Mr. Richwine,

Are the LLSS rules set in stone? What about the WTPA tractors that don’t fit the rules you published? Are you gona allow front suspension?


The rules that are posted are final and in place for 2021. I suggest that any changes you or any group wish to make be subbmitted for the September meetings of 2021. If they are adopted, they would be in effect for the 2022 season.


Hey Mr. Larry,

Did the NTPA raise their diesel fuel spec like the other guys did?


No, its still at a max number of 100 for 2021.


Mr. Richwine, My engine builder wants me to run 3-4 cables around my engine after the Light Pro explosion at a non sanctioned event this summer, can I do that?


No, only one cable is required or allowed around in line engines in NTPA competition. I understand your engine builders concern but, years ago when the cables were first required we required two cables. We found that only contained the explosion enough to make smaller pieces fly. The cables job is to flip the assembly away from the driver. Everyone always says “but the cable broke” and thats true, but, before it breakes or pulls out of it clamps it does the job as intended.

If you come to a NTPA event with more than one cable on your engine you will be told to take all the extra ones off before you’re allowed to run unless you have a Moline or case, then they require a cable for each head.


Richwine are you doing “Super Tech” at Ft Recovery?


Yes on Saturday from 11am – 2PM on Mini Rods and Unlimited only


Hey Richwine, I hear that the Super Farm pullers had trouble in Rockwell passing the new water test you have. Is that true? what the heck are you doing?


NTPA does have a new test but, it’s no different that PPL’s, so if your water will pass there, it will pass here.



Is the MSD 600 CDI unit legal on my mini rod for NTPA competition?


The Msd 600 cdi by definition of the timing control rule is a legal component when used as only an energy provider for individual coil packs. It only becomes illegal if an external controller is used in conjunction with the 600 cdi in order to adjust ignition timing during a competition run.


Mr. Richwine,

Please explain how a “Rain Out” works. When can the promoter call it off where I don’t have to show up to get rain points etc. I’ve heard a bunch of different versions of what should or has happened.


Page 88 of the 2019 NTPA rulebook under letter E Inclement Weather states:

#7. If a session is cancelled more than 24 hours prior to start time
at GN/SN or 8 hours at RN/PN/state level, no points will be given
for that session.
#8. If a session is cancelled prior to start time, competitors will
receive refund of paid entry fees, but no other compensation.

With that said, if the event isn’t canceled within the time period described in #7 then you do have to travel to the event with your pulling vehicle and check in so the entry personnel can record your entry in order to receive rain points. The entry trailer must remain open until scheduled start time of the event in order for you to “check in”.

As to “Why do I have to take my pulling vehicle with me?” page 81 under Event Procedures and Requirements #4 reads:

#4. Vehicle must be present on the ground in running order and
ready to compete before being allowed to enter.



When the rule says exhaust limit 4.5 inch and the wheel must proturde .125 inch into the bore, will the nut count? Its part of the wheel. Or if I have a couple of little fins in front of the regular wheel will they count? Answer:
No, the nut doesnt count. The rule says

  1. Turbo limited to 4.5 inch diameter exhaust to be measured at the face of the wheel.
  2. Exhaust wheel tips of wheel (each blade/fin, nut does not count) must protrude into the 4.5 inch bore by 0.125” minimum.
  3. All exhaust must exit the 4.5 inch bore.
    We are going to measure the turbo just like we have on the Super Farm class’s 3 inch bore since the days when we “sealed” the turbo with a lead seal.

If we question how deep it goes into the bore you will be required to disassemble your turbo so we can measure it.

I included a picture of how / where we will measure the wheel

turbo exhaust


Mr. Larry,
Can I run my 24.5 tires in the Hot Farm class? I dont want to buy 20.8’s but, my tractor fits the hot farm class all but tires.
If not, WHY not.


No, you can’t run the 24.5 tires in the Hot farm class. The reason is that the class needs to and does look different than all the other classes from the grandstand.
You will be surprised how good your tractor hooks up with 20.8 tires on it.


Can I run my tractor with an expired roll cage sticker?


Yes as long as the old sticker is still in place. The Techs know (because they have been told in tech school) that you can run until you find one of the roll cage inspectors.


Mr. Richwine,

What’s the deal with the new “V” hitch I’ve heard about for Mini rods? Are they legal? Are they gona be allowed in all classes? Asking for a friend.


No, they aren’t legal the rulebook states in general rules as well as some class rules that nothing can obstruct the chain or the hooking or unhooking of it. The “V” cut design not only would cause difficulty in hooking (if not straight with the sled) but would also make unhooking harder than it already is. Also, when the hook tries to go from side to side when the vehicle gets sideways it will affect the angle of the hook and change the draft of the chain.

The cross sectional thickness of the point of hook is also spelled out in the rulebook for all classes. This too can affect the hook and the draft of the chain.
Drawbar Design


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.


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.


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


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.


Mr. Richwine,
I’m not a member of NTPA but, would like to run at the upcoming event. 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.

Marvin Epperson
Director of Technical Services

(317) 852-0630

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.


The following people are certified as rollcage inspectors, please contact them to get your rollcage inspected. Rollcages are certified for 5 years.

Scott Doty (MI)734-755-3959
Dale Quamme (MN)952-500-0820
Jay Barrett (NC)​ 315-559-9568
Marvin Epperson (OH)​ ​317-852-0630
Dennis Long (OH)​ ​740-837-0582
Matt Steinmetz (OH)​ ​419-239-3820
Steve Zimmer (OH)* ​​740-525-0639
Mike Griffin (TN)931-629-2244

* Travels a​ ​lot so reach out to see if in your area.


It is the competitor’s responsibility to notify a certified inspector and arrange an inspection prior to the deadline indicated on the NTPA-issued rollcage certification decal. (Re-)certification inspections may be requested at the entry trailer or during standard on-site tech inspection.

For rollcage inspections at a site other than an NTPA event, contact NTPA Tech Services to make an appointment.

Please note: Inspection dates do not necessarily coincide with event dates. Check the Schedule page at for event dates and session start times.

Rollcage inspections have been completed for 2022.

All Updates & Announcements

Online Membership Process Migrates to Trackside on March 1

The NTPA’s online digital membership applications and Super/Grand National event registrations are being consolidated into one service.

Beginning Friday, March 1, the NTPA will team with Canton, Ohio-based Trackside Systems to provide an all-in-one interface, available via a portal at, for Competition License, Crewperson License, and Vehicle Registration applications.

Trackside to Collect All Applications; Prefill URLs Deactivated

On that date, the Trackside interface will replace all existing license and registration application forms. Teams who wish to use the prefilled URLs provided in the membership email of November 19-20 for expedited completion of those forms are advised to complete this process on or before Thursday, February 29. The URLs will be disabled once registration is open in Trackside. To request a re-send of the URL email for use with the current forms, contact Jon Dunlap (

GN Class Entry Conducted Via Trackside

Then, beginning this spring and summer, participants in Super and Grand National events and in Grand National classes at Regional National events will return to the Trackside portal to enter these events.

Registration for GN classes at SN, GN, or RN events must be completed at least 48 hours prior to the advertised start times of the events’ first sessions. For example, competitor and vehicle entry into either 7 p.m. session of Benson, North Carolina’s Mule City 300 on Friday and Saturday, May 31-June 1 will close at 7 p.m. on Wednesday, May 29. Registration materials will then be available for pickup at the NTPA Entry Services trailer on-site. Entries into GN classes will not be accepted on-site at these events or after the 48-hour deadline has passed.

Though online entry will remain open for these events up to the 48-hour deadline, it will be possible for competitors to enter every SN/GN event all at once via the Trackside portal.

New System Provides Ticketing Options for Promoters

The NTPA and Trackside will also partner to provide online ticketing services to several sanctioned events including the North Iowa Nationals and the Enderle Pull-Off. Promoters who are interested in online ticketing are encouraged to contact Matt Steinmetz (

2024 Tech Schools

Please register below for the Tech School that you will be attending. These are the last Tech Schools being offered for the 2024 season.

March 30, 20249:30 a.m.Shelbyville, INKeith Theobald's ShopRSVP by March 25
April 6, 20249:30 a.m.Bowling Green, OHNWOTPA OfficeRSVP by April 1

2024 Turbo, Bellhousing Rules to Be in Effect at Upcoming Louisville, Green Cove Springs Events

Attention, Green Cove Springs competitors: The NTPA’s new turbocharger containment and bellhousing certification rules will be enforced at all sanctioned events in 2024. These include the upcoming invitational MAC Trailer NTPA Winter Nationals in Louisville Kentucky on March 23 and the Region VI/Mid-Florida Tractor Pullers Association Clay County Fair Pull in Green Cove Springs, Florida on April 13-14.

Competitors in all affected divisions, including state-level divisions in Green Cove Springs, are urged to consult the Tech Services page at to make sure that their vehicles are in compliance with these rules.

NFMS to Enforce Turbo Containment Rules; Pre-Inspection Photos Requested

2024 National Farm Machinery Show
Attention NFMS Competitors: In light of the adoption of new turbocharger containment rules and device specifications by the NTPA and other national pulling organizations, the National Farm Machinery Show’s Championship Tractor Pull will require such devices on all turbochargers on competition vehicles in the 2024 event, which runs from Wednesday-Saturday, February 14-17. The following is a release prepared by the NFMS CTP. (Click here for the NTPA’s specifications.)

Happy New Year and Congratulations to your acceptance to the 2024 Farm Machinery Show Championship Tractor Pull-

We understand the fluidity of the newest safety rules regarding turbocharger exhaust.

All of the options already spelled out by PPL and NTPA will be accepted for 2024 CTP.

We would like to receive a photo(s) via email of the exhaust side of your turbocharger AND exhaust pipe inlet from the turbocharger with a manufactured ejection prevention system by Feb 1st for APPROVAL.  If not received, a more indepth tech review by officials will occur and could result in further adaptation to meet compliance. We will have 100% cooperation with these rules

Email your photo(s) to the Championship Tractor Pull Committee (

2024 CTP Turbo Exhaust:

A manufactured exhaust wheel cage assembly must be used in and/or fastened to the exhaust housing with one set of ½ inch bolts installed 90 degrees of each other immediately (may be in pipe) as close to the cage as possible.

Please understand we will work with each of you for an acceptable solution those not already spelled out by the PPL & NTPA specifications.

Thanks for your cooperation-
Championship Tractor Pull Committee

Note: Do not email photos to NTPA Technical Services for approval to pull at the Farm Show. The NFMS Tractor Pull Committee is the sole arbiter of the legality of a containment device at the Championship Tractor Pull.

SFI Approves New Bellhousing Specification with Five-Year Certification

Columbus, Ohio—NTPA Technical Services has successfully petitioned the SFI Foundation to add a bellhousing certification that specifically addresses truck and tractor pulling applications and extends certification period to five years for steel and titanium bell housings. This new certification was approved by SFI on July 24, 2023.

SFI Specification 6.4, “Puller and Diesel Drag Racing Bellhousing,” was jointly pursued by the NTPA and National Hot Rod Association, which joined the effort initiated by the NTPA in January 2021. The SFI 6.4 specification contains a five-year certification period for steel or titanium bell housings specifically used in pulling and drag racing competition. A two-year certification limit still exists for aluminum bellhousings and remain as SFI 6.3 certification only.

Existing SFI 6.3 certified steel and titanium bellhousings automatically meet SFI 6.4 requirements in an automotive application since there is no change in the construction of the bellhousing required. Such certification can be applied by the manufacturer with no additional testing required. Competitors are encouraged to request their bellhousing manufacturer to apply the new SFI 6.4 certification decal and 5-year certification period to their steel or titanium bellhousing.

Modified Mini – Driver Compartment and Foot Placement

The following are new rules approved by the joint WPI/NTPA Executive Board of Directors that are being added to the 2024 NTPA Pulling Rules for Modified Mini division. These rules will be found under F. General Rules, section 19.Safety, sub-section c. Driver Compartment, new 2) Modified Mini – all levels

2) Modified Mini – all levels

  1. Both driver’s feet must rest inside the main frame rails and even with or behind rear of bellhousing while seated inside roll cage with 5pt. restraint harness fastened.
  2. Brake pedals must be mounted directly ahead of foot rest and inside the main frame rails.
  3. Feet and brake pedals must remain inside the main frame rails and behind the engine block plate during brake pedal application.

2024 Turbo Exhaust Containment

Turbo Exhaust Wheel Containment

  1. Any turbocharger used in NTPA competition where exhaust exits to atmosphere must have an approved exhaust wheel containment device installed.
  2. Containment device and any attaching components or hardware must be supplied by a NTPA approved manufacturer.
  3. Containment device cannot be placed in any part of exhaust pipe. If containment device is attached to turbo exhaust housing flange by use of a clamp, then the exhaust pipe must be welded to the containment device.
  4. Containment device must be installed as designed by manufacturer. No modifications or alterations of any kind allowed.
  5. Manufacturer may identify each component or assembly by engraving part numbers or some type of identification into each part.

NTPA Approved Containment Devices

1) Option 1 – Cross Bolts in Turbo Exhaust Housing – installed by turbo manufacturer

  1. Qty. 2 (two) .500-inch diameter, grade 5 or greater bolts installed by drilling qty. 4 (four) holes into turbo exhaust housing and welded in place.
  2. Bolts must be installed at 90 degrees from each other and no more than .0625-inch (1/16-inch) between the two bolts.
  3. Cross bolts must be located as close to the center of exhaust wheel as possible.

2) Option 2: Containment Adapter – supplied by turbo manufacturer

  1. Containment device supplied by turbo manufacturer must be approved by NTPA Tech Services and installed as supplied by manufacturer.
  2. Containment device must be located as close to exhaust wheel as possible.
  3. Containment device and components supplied for attachment to turbo housing must contain the manufacturer’s name or logo identification.

3) Option 3: Containment Adapter – supplied by NTPA approved manufacturer

  1. Exhaust adapter must be fabricated using two interlocking pieces of .250-inch x 1.000-inch flat steel notched .250-inch x .500-inch at center creating a single interlocking assembly and fully welded into a cross pattern.
  2. Round steel containment adapter must be a minimum .175-inch wall thickness and contain cross assembly fully welded inside the adapter, not in exhaust pipe.
  3. Leading edge of cross assembly can be sharpened a maximum of .250-inch back from leading edge facing the exhaust wheel. Any tapered or sharpened edge is in addition to 1-inch minimum width.
  4. Location of leading edge of cross assembly not to exceed .125-inch behind face of adapter flange on turbo side.
  5. Adapter mounting flange must be a minimum .140-inch wide at base of flange and a minimum .125-inch wide at narrowest point of taper.
  6. Adapter must be attached to turbo exhaust housing flange using clamp supplied by adapter manufacturer. Since this containment device is attached to turbo exhaust housing flange by use of a clamp, the exhaust pipe must be welded to the containment device. Adapter and attaching clamp must be clearly identified with manufacturer name or logo.

Exhaust Wheel Cage

Note: Exhaust Wheel Cage is a containment device bolted to exhaust housing by turbo manufacturer. Same rule as adopted in 2023.

  1. Billet steel cage made from 304 stainless bolted and fastened to exhaust housing as supplied by the turbo manufacturer.
  2. Exhaust wheel cage must be fastened using bolts, a minimum qty. 8 (eight) – 5/16-inch diameter, grade 8 or greater bolts required or wheel cage fastened as designed by turbo manufacturer.
  3. Turbo exhaust wheel cage must be manufactured by sane turbo manufacturer on which it is installed.
  4. Exhaust wheel cage must be installed as supplied. No modifications allowed.
  5. NTPA Technical Services to determine any additional dimension or specifications required.

Anyone intending to install a device like the one pictured in your exhaust pipe or flange, this is not an approved device and will not be accepted as a turbo containment device for NTPA. If you do not use one of the Turbo Manufacturers devices, (APEX DIESEL, APEX TURBO, WIMER, Hart’s etc.) then you must have a device and clamp per the drawing on this Tech Page.

WPI/NTPA Competition and Safety Rules to Be Implemented in 2024

The following rules were approved by the WPI/NTPA Joint Executive Board on Friday, September 15, 2023.

2024 NTPA Pulling Rules – NEW RULES!!

Additions and corrections effective for 2024 season

Light Limited Super Stock

  • Besides corrections to 2023 rules for LLSS previously posted to NTPA Tech Page in early 2023, the following rule was adopted
  • Light Limited Super Stock – limit all diesel engines to 3.4 x 4-inch smooth bore turbo including those engine sizes that allow two turbos. Use of a 3.0 x 4-inch turbo with MAP ring is no longer allowed

Pro Stock – 5.0

  • Approved PS 5.0 for competition at Regional National level (no longer on trial basis)
  • Removed Wimer as only supplier of PS 5.0 turbocharger to this class. Retained the same turbocharger size limits as stated in 2023 rule book

Hot Farm

  • Engine cylinder head must be OEM style (recast cylinder heads allowed). OEM stock dimensions (ie height, width, and length) must be retained. No billet heads allowed

Pro Farm

  • Amend current rule to require turbo intake and exhaust wheels to enter the 3-inch smooth bore restriction by 1/8-inch, same as required of other restricted turbochargers

Diesel Super Stock

  • Engines using a steel oil pan are exempt from pressure burst / relief device requirement in Diesel Super Stock division once final device type and specs are implemented

Modified Mini

  • Front skid plate to be configured according to dimensions and drawings as follows:
    • Skid plate must be made from 1/8-inch steel and extend across under front of chassis – rail to rail and solidly attached
    • Skid plate formed at 90 degrees with a minimum 2.500-inch radius at bottom front of skid
    • Tow hitch placed minimum 7.500 inches from ground
    • Skid to extend rearward to center of front axle
    • Bottom of skid plate to be bellow bottom of front rim
  • Driver’s feet must be placed inside the main frame rails while competing under green flag in Mini division at all levels


  • Rear weight boxes behind hook point must have a minimum 7-inch wide, open space centered behind the hook point so sled chain can be hooked into drawbar without interference from weight boxes

GN Modified – Turbine Engines

  • Allow turbine engines up to a combined maximum 9,450 horsepower as rated in NTPA Pulling Rules

Light Super Stock

  • Maximum weight limit increased to 6,300 lbs.
  • Request to increase weight made by division committee in 2022
  • No action taken due to SFI 47.2 Rollcage spec limited to 6,000 lbs.
  • SFI 47.2 Rollcage spec updated to 6,300 lbs. in July, 2023 now allows weight increase

Light Pro Stock

  • Approved proposal as submitted by committee
    • Limit turbocharger intake compressor wheel opening to 5 inches and retain existing 4.500-inch exhaust wheel limit – wheels must protrude in restricted openings by minimum 1/8-inch
    • No recast aftermarket injection pump housings. OEM P7100 or P3000 housings only
    • Retain current maximum of 48 lug tire rule – no Mitas tires
    • Lock in rules for Light Pro Stock class for 3 years
    • Follow all other class rules as currently written

Pro Street Diesel 4X4 Trucks – 2.6 turbo

  • Pro Street Diesel 4X4 Truck – 2.6 turbo class accepted as a Regional National division based on rules submitted by WTPA
  • Adjustments to safety related rules may be necessary to align with existing Diesel 4X4 requirements

Tires – Semi

  • Add the following rule omitted from 2023 NTPA Pulling Rules
  • Limited to standard 8.250-inch maximum rim width. No chains or cables permitted. No cutting of tires permitted.

Tires – Mini

  • All tires in division, at all levels, limited to maximum 17.5-inch tread width and maximum 30 lugs after cutting as tire is used in competition

Tires – General

  • Existing specs and procedures used by Technical Services to measure tires out-of-mold will remain in effect for all tire sizes listed in NTPA Pulling Rules
  • Approved Tech Services to establish specs and measuring procedure for tire width and circumference in ready-to-pull condition on vehicles at the track

Points / Competition

  • A. Points – pg.20 – amend 4. vehicle license level
    • Purpose is to eliminate disruption to division points chase
    • System (not finalized) to be implemented to limit negative impact to those chasing a points championship at GN level where entries exceed 25 or more in a division
    • Group GN points competitors to minimize negative effect from changes in track conditions
    • Divisions affected most – TWD, FWD, MINI, and PS
    • Procedure will be adopted to begin the first GN points event(s) after Chapel Hill, TN

Entry Procedures

  • Approved to limit all divisions of competition from jumping up more than one level at GN/SN events.
  • Example: PS 4.1 can register to compete in RN PS 5.0 competition but not GN Heavy Pro Stock

Contest Procedures

  • Kill Switch
    • Amend existing rule in 2. Contest Procedures – pg.30 – f.
    • While under green flag conditions, if kill switch is inadvertently pulled by sled cable (ie. cable caught in chain), and plastic tie is broken, competitor may be granted, at the discretion of the head official, to drop to last and have up to six (6) minutes to repair or replace failed or damaged kill switch and make another attempt.
    • Kill switch operation must be confirmed by a NTPA Tech Official before another attempt is made.
    • If incident occurs during first pull attempt, competitor will be granted two (2) attempts to make a measurable pull.


  • Turbocharger Exhaust Wheel Cage
    • Technical Services is evaluating wheel cage designs from turbo manufacturers.
    • Exhaust wheel cages submitted by turbo manufacturers will be sent to SFI for testing
    • Containment device between intake compressor wheel and guillotine will also be studied
    • Recommendations will be used to craft new rules necessary to ensure turbo safety for 2024 season
  • SSFWD Trucks
    • All trucks competing in SS FWD division only are required to use a SFI certified steel or titanium bellhousing
    • No aluminum bellhousings allowed in this division.

Bellhousing Certification

  • Adopted for 2024 – per 2023 NTPA Pulling Rules – pg.40 d. Bellhousing Certification / Renewal
    • 1) All divisions, SFI 6.3 aluminum bellhousings must display a valid and current SFI sticker from the manufacturer before being allowed to compete in any NTPA sanctioned event. This applies to all aluminum bellhousings in divisions where use is permitted.
    • 2) Starting Jan.1, 2024, all SFI bellhousings regardless of material (ie. steel, titanium, or aluminum) must display a current SFI certification sticker with an expiration date affixed by the manufacture. Any bellhousing previously stamped with a NTPA shield stamp will no longer be acceptable as a replacement for the SFI decal after Jan.1, 2024.
  • SFI 6.4 Puller and Diesel Drag Racing Spec Approved
    • NEW SFI 6.4 bellhousing spec approved by SFI Board of Directors in July 2023, spec is now available for manufactures to implement
    • 5-year certification for steel and titanium bellhousings available – aluminum not included
    • SFI 6.4 is applied at manufacturers discretion
    • Current SFI 6.3 steel or titanium bellhousings will meet SFI 6.4 spec
    • Pullers can request bellhousing manufacturer apply the SFI 6.4 – 5-year certification to a SFI 6.3 steel or titanium bellhousing

Definitions – pg.45 – d. Cubic Inch Formula

  • Approved the addition of + or – 1% cubic inch measuring tolerance to this rule to cover all engines in all divisions

Exhaust Headers – pg.58 – a. General Requirements – 2)

  • Approved standard 8-inch dimension from bottom of bend to top of header pipe in all divisions
  • Exceptions currently found in TWD and FWD will be removed.

5pt. Harness

  • Approved any application where a 5pt. harness is required, the harness must meet SFI 16.1 and such SFI identification tag must be affixed to harness.

Attention Competitors: Effective Immediately 6/6/2023

  1. Effective immediately, the Limited Pro Stock will be allowed to enter the 5.0 Regional Pro stock class for this 2023 season. Providing they meet all competition rules and safety regulations.  Still no Light Pro Stock or Super Farm.
  2. Any class requiring an SFI  – 4.2 Blanket must have them installed correctly and will be held to the same criteria as the bellhousing in competition. If you have the proper blanket installed but it has and out of date tag,( outside of the 5 year window) you will be able to run but you must make the effort to either get them recertified or replaced and by January 1.2024 they must display an up to date certification on the SFI Tag.

Effective Immediately 3/16/2023

1. GN Light Modified division weight limit is now 6200 lbs. for 2023 season.

2. Super Farm, Light Pro Stock, and Limited Pro Stock divisions cannot enter the new RN Heavy Pro Stock 5.0 class. Entering of stated vehicles in divisions other than RN Heavy Pro Stock 5.0 as permitted by 2023 NTPA Pulling rules is still allowed. 

3. The WPI Executive Board moved to limit Mini division at all levels to any current 18.4×16.1 – 6 ply tires already in competition from 2022 season (Pioneer, Cepek, Mayhill). No changes to construction or dimensions of these tires will be allowed for the 2023 season. Limiting Mini division to these tires will maintain current vehicle dimensions and weight limit while keeping competition at an already high level.

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