Top Doorslammer
- Heads-up, 1/4 mile drag racing for Naturally Aspirated and Nitrous entries
- Automatic Transmissions only, may be manually shifted - no clutches or converter drive systems permitted
- Lock-up Converters permitted
- Reaction Time Delay Box permitted
- 4/10 Pro Tree
- No nitro
- No dial in
- No break outs
- Deep staging permitted
- No limit on tire size
- Naturally Aspirated, up to 599 cu in, NO MINIMUM WEIGHT LIMITS
- Naturally Aspirated, 600 cu in or more, but no more than 800 cu in, 3.75 lbs per cubic inch
- Single Kit Nitrous Injected, 640 cu in maximum displacement, 4.10 lbs per cubic inch, maximum 36 jet
- Multiple Kit Nitrous Injected, 640 cu in maximum displacement, 4.60 lbs per cubic inch
Unlimited Doorslammer
- Heads-up, 1/8 mile drag racing
- 4/10 Pro Tree
- No nitro
- No dial in
- No break outs
- Deep staging permitted
- No limit on power adders
- No limit on tire size
Heads-up Index Classes:
- Pro Street (10.60 - 10.90)
- Pro Gas (9.60 - 9.90)
- Pro Comp (8.60 - 8.90)
- Pro Eliminator (7.60 - 7.90)
- Pro Extreme (6.60 - 6.90)
(More Details Coming Soon)
NHRA technical and safety rules apply to all classes.