The National Hot Rod Diesel Association - The largest and longest-running diesel motorsport organization in the world.
Drop-In Turbo Class
Average Joe
The entry point. Keep it simple, street-driven, quick-spooling.
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.
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
Turbo Allowances
| Platform | Allowance |
|---|---|
| 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 |
Class-Specific Notes
- Single turbo only
- VGT-equipped trucks must retain a VGT turbo
- No compounds (unless factory), no T4 swap kits, no S300 or S400 swap kits
- Turbo must be a readily available drop-in style purchasable via online retailer — no custom one-off turbos
- MAP groove must be smaller than 0.200″
- No removable plugs or bushings — all welded
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