The National Hot Rod Diesel Association - The largest and longest-running diesel motorsport organization in the world.
S300 / S400 / Compound Class
Blue Collar
The next level. Larger singles and compounds for street trucks chasing the edge.
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.
At A Glance
- Purse: $5,000 to win
- Surface: No prep, 1/8 mile
- Launch: Non-boosted, idle in Drive ≤ 800 RPM
- Tires: Street only, 400+ treadwear
- Min Weight: 7,000 lbs
- Safety: Fire jacket required
Turbo Allowances
| Platform | Allowance |
|---|---|
| S300 / S400 | 72mm max compressor wheel |
| Compounds | 64mm HP with 76mm LP |
| Factory VGT w/ Compounds | Must retain the factory VGT |
| 6.4L Power Stroke | May run compounds OR S300/S400 within sizing |
Class-Specific Notes
- Fire jacket required in addition to standard safety gear
- Factory VGT trucks running compounds must retain the factory VGT on the manifold — applies to 6.0L PS, 6.7L PS, VGT Cummins, and VGT Duramax
- S467 Cummins is welcome
Shared Series Rules
Applies to both Average Joe and Blue Collar classes. See the full rules page for complete details.
Launch
- At the starting line, the truck must be in Drive and idling at no more than 800 RPM prior to launch. Tech may verify by sound and/or tach. Failure to comply may result in disqualification.
Vehicle
- Diesel vans, trucks, and Excursions only
- Must be a production truck that came from the factory with a diesel engine
- No cars or car-based chassis conversions
Fuel / Drivetrain
- Single high-pressure injection pump only
- No limitations on lift pump systems
- 2WD only. 4WD trucks must remove the front driveshaft — no exceptions
Tires
- Street tires only — minimum 400 treadwear
- No slicks, no drag radials. M/T, R/T, H/T, A/T all fine if 400+ TW
Race Format
- 1/8 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
Run this Class at These Events
February 27-28, 2026
Diesels in the Desert
Firebird Motorsports Park · Chandler, AZ