For fully accurate classification information you should be looking at the CACC Time Attack Regulations. We post this information here as a courtesy, but it is not the official classification document.

NOTE: All Drivers new to running Knox Mountain Hill Climb must class their car according to the CACC Time Attack Regulations 2024. This classification system is based upon the SCCA Time Trials system.

Drivers who participated in a legacy class in 2023 or earlier MAY run in the Legacy Class again in 2024. Legacy classes may only be used when the driver and the car have participated at Knox Mountain Hill Climb in that legacy class in 2023 or prior. A returning driver with a ‘new’ car MUST USE the current CACC Time Attack classification system. A ‘new’ driver with a returning car must use the current CACC Time Attack Classification system.

2024 is the LAST year that the CACC Legacy classes will be allowed to run. Start preparing your car and yourself now for running in the above classes for 2025.

CACC Time Attack Regulations 2024

18.7 Classification and Categories
18.7.1 Time Attack, Time Attack – Passing and Hillclimb
The following classes and categories are the official for all Time Attack, Time Attack – Passing, and Hill Climb* events:

18.7.1.1 Sport (S1, S2, S3, S4, S5, S6)
18.7.1.2 Tuner T1, T2, T3, T4, T5)
18.7.1.3 Max (M1, M2, M3, M4, M5)
NOTE: 18.7.2.7.1 For Hill Climb events, Max class cars which have safety equipment that meets the CACC GCR Roll Cage Specifications will be allowed to run DOT tires from 199TW to 40TW.

18.7.1.4 Unlimited (U1, U2, U3)
18.7.1.4.1 U3 minimum weight:1,750 Lbs. (With Driver.)
18.7.1.4.2 U3 Maximum Displacement, 1.999 Litres corrected displacement.
18.7.1.4.3 U2 minimum weight:1,750 Lbs. (With Driver.)
18.7.1.4.4 U2 Maximum Displacement, 3.0 Liters corrected displacement.
18.7.1.4.5 U1 minimum weight: None

18.7.1.5 Note: U3 is not an SCCA class but a CACC Class. All safety expectations for Unlimited must be met.

Formula/Open Wheel/Sports Racer Classification
18.7.1.5.1 Time Trial Special (TTS)
18.7.1.5.2 Time Trial Atlantic (TTA)
18.7.1.5.3 Time Trial Winged (TTW)
18.7.1.5.4 Time Trial Non-Winged (TTN)
18.7.1.5.5 Time Trial V (TTV)

Legacy Classes

• CACC Legacy Classification applicable for Knox Mountain Hill Climb

Street Prepared

Cars eligible for Stock, SS, or SP classes as per the CACC Time Attack regulations.
Note: Race tires are not permitted in any Street Prepared class. All tires must be DOT approved.
Turbocharged and Supercharged engines are classified according to their actual displacement multiplied by 1.7
SP-1 - Street sedans and sports cars under 1800 cc.
SP-2 - Street sedans and sports cars 1800 - 2500 cc
SP-3 - Street sedans and sports cars 2501 - 4000 cc
SP-4 - Street sedans and sports cars 4001 cc and over.
SPX-1
SPX-2
SPX-3

GT Cars

Cars conforming to current CACC/SCCA GT classifications and legal to race in the appropriate group below.

GT-1
GT-2
GT-3
GT-Lite

Cars prepared beyond GT, IP or CACC Time Attack classes (ie. engine swaps, over-lightening, etc.).
Turbocharged and Supercharged engines are classified according to their actual displacement multiplied by 1.7

GT-U - Under 1800 CC.
GT-X - 1800-2500 CC.
GT-M - 2501-4000 CC.
GT-0 - Over 4001 CC.

Formula and Sports Racing Cars

Cars must conform to current race regulations for respective classes. Cars not conforming to current open wheel regulations will be bumped to Formula Libre class.

FV - FV, F440. F4, and VW powered dune buggies.
FF - FF1600, FF2000, FC.
SR - Sports Racer.
FA - FA, FB, FSV, FSOOO, F Libre, Modified Open wheel.

Specialty Vehicles

We reserve the right to add and/or delete classes to accommodate specially prepared vehicles at the discretion of the Knox Mountain Motor Sport organizers. Please contact the organizer for this class. Examples might be:
Electric vehicle Experimental
Vintage
Legend
4x4,etc