The National Hot Rod Diesel Association - The largest and longest-running diesel motorsport organization in the world.
NHRDA NO PREP RACE SERIES
REAL STREET TRUCKS. RAW, HEADS-UP COMPETITION.
Built for diesel racers who refuse to ruin a great street truck just to compete. The NHRDA No Prep Race Series highlights real-world, high-performance diesel trucks in a true no prep environment — where setup, driving, and power all matter.
- 2WD, no-prep, street tires — just like you actually drive it
- Non-boosted launches reward quick spool, smart tuning, and driver skill
- Two classes so 90% of diesel street trucks can realistically compete
- $5,000 to win each class — with an escalating purse
STOPLIGHT STREET TRUCK RACING, THE WAY IT SHOULD BE.
2WD. No prep. Street tires. Leaving from a stoplight. Non-boosted launches. Leave from idle. That's how we spend 99% of the time driving in our diesels — and that's exactly what this series is designed to showcase. How well your truck actually drives.
Winning won't be about extreme peak horsepower. It will be about quick-spooling setups, linear and controllable power delivery, solid tuning, and driver skill. The 650–750 hp range is competitive — attainable for a well-built street truck without turning it into a trailer queen.
Average Joe
Drop-In Turbo ClassThe entry point. Built for racers who want to keep things simple, responsive, and street-driven. Factory-style drop-in turbo upgrades only — quick-spooling, fun to drive, highly competitive.
Turbo Allowances
- 6.4L Power Stroke: Stock-size billet wheels only
- Common Rail (Duramax, 6.7 PS, 5.9 & 6.7 Cummins): 64mm drop-in
- 6.0L Power Stroke & 12V/P-Pump Cummins: Up to 68mm drop-in
- 7.3L Power Stroke & VP44 Cummins: Up to 68mm drop-in
VGT-equipped trucks must retain a VGT turbo. No compounds (unless factory), no T4/S300/S400 swap kits. MAP groove must be smaller than 0.200″. No removable plugs or bushings — all welded.
Blue Collar
S300 / S400 / Compound ClassThe next level. Larger single turbos and compound setups for higher horsepower combinations — still rooted in real, functional street truck builds. Faster, harder-hitting, built for those chasing the edge.
Turbo Allowances
- S300 / S400: 72mm max compressor wheel
- Compounds: 64mm HP with 76mm LP
- Factory VGT trucks running compounds must retain the factory VGT
- 6.4L trucks may run compounds OR S300/S400 within sizing
Fire jacket required for all Blue Collar competitors in addition to standard safety gear.
Idle / Launch RPM Rule NEW
At the starting line, the truck must be in Drive and idling at no more than 800 RPM prior to launch. This enforces a true non-boosted, street-style launch. Tech may verify by sound and/or tach — if it sounds excessive, it will be checked. Failure to comply may result in disqualification.
Vehicle Eligibility & Weight
- Diesel vans, trucks, and Excursions only
- Must be a production vehicle that came from the factory with a diesel engine
- No cars or car-based chassis conversions
- Minimum race weight: 7,000 lbs
- Up to 1,500 lbs of ballast — must be securely bolted inside the bed at the very front
Fuel System & Drivetrain
- Single high-pressure injection pump only
- No limitations on lift pump systems
- 2WD only. 4WD trucks must remove the front driveshaft — no exceptions
Chassis & Suspension
- Full factory frame required — no back-half trucks
- No aftermarket rear 4-link systems (factory 4-link OK)
- No rear coil-over conversions
- Front 4-link and coil-over kits permitted
- Allowed: modified stock suspension, lift/lowering kits, CalTracs, traction bars, spring/shock changes
Transmissions & Tires
- Trans swap OK
- Manual valve body OK
- No trans brake, no bump box, no line-lock
- Street tires only — minimum 400 treadwear
- No slicks, no drag radials. M/T, R/T, H/T, A/T all fine if 400+ TW
Power Adders & Electronics
- No water injection
- No methanol injection
- No propane injection
- No nitrous — fuel only
- No aftermarket water-to-air intercoolers (6.7 Power Stroke exception: must retain drop-in OEM-location parts)
- Factory ECU required — OEM ECU swaps allowed. No restrictions on tunes/tuners
- No standalone ECUs, no aftermarket traction control. Foot brake racing only
Race Format
- ⅛ mile, instant green (flashlight start may be used)
- Non-boosted launches — leave from idle
- Cross center — you lose
- Leave early — you lose
- Single burnout — 5 seconds maximum
- First across the finish wins
- Single elimination — no buy-backs
- No time slips issued or displayed
- No prep surface — racing held after the main event
- Hot laps will happen — street trucks should be able to hot lap all day
Protective Equipment
Required for all competitors in either class:
- Helmet
- Long-sleeve shirt
- Pants (jeans)
- Closed-toe shoes
Right to Protest
$500 protest fee. If the protested truck is found illegal, it is disqualified and the protest money is returned. If the truck is found legal, the protested competitor receives the $500.
Frequently Asked Questions
Part of Truckin in Tulsa
The NHRDA No Prep Race Series runs during Truckin in Tulsa at Tulsa Raceway Park.
VIEW MAIN EVENT