CACC Rule Change Proposal
RCP-2025-4431

Date CreatedSeptember 30, 2025
Name of ProponentGreg Petroski
Short Descriptionremoval of the allowance for sub 200tw race tires at Knox in street tire classes
Applicable Regulatory DocumentTime Attack
Type of Rule ChangeModification
Affected Sectionknox mountain sup regs - section 13
Current Regulation

Summary overview of CACC classes:
Sport (S1, S2, S3, S4, S5, S6)
Tuner (T1, T2, T3, T4, T5)
Max (M1, M2, M3, M4, M5)
Max Classes ONLY: *CACC Time Attack Regulation 18.7.2.7.1 DOT 40 TW tires allowed for having CACC
GCR Roll Cages.
Unlimited (U1, U2, U3)
Formula/Open Wheel/Sports Racer

Proposed Regulation

Summary overview of CACC classes:
Tuner (T1, T2, T3, T4, T5)
Max (M1, M2, M3, M4, M5)
Max Race (MR1, MR2, MR3, MR4, MR5)
Unlimited (U1, U2, U3)
Formula/Open Wheel/Sports Racer
Time Trial Special (TTS); Time Trial Atlantic (TTA); Time Trial Winged (TTW); Time Trial Non-Winged
(TTN); Time Trial V (TTV).

Reason for Rule Change

Max Classes ONLY: *CACC Time Attack Regulation 18.7.2.7.1 DOT 40 TW tires allowed for having CACC
GCR Roll Cages.

Allowing competitors to run without a roll cage and limit the tire selection to run in the exact same class as someone on race tires with a cage is an unfair advantage.

The SCCA time trials rulebook (of which the CACC time attack regs are copied from) specifically requires the use of 200tw tires or higher in max class. This is a "street" class intended for vehicles still suitable for road use without swapping tires. Any deviation from that allowance is purely for safety (ie. removing interior, gutting doors, etc) in allowing a full cage. This is not intended to give a significant performance advantage in terms of tire selection.

I appreciate that the majority of cars competing at Knox are well beyond the realm of a "street class" car even if their overall performance does not match the class they should be in (unlimited) but want to be competitive with what they currently have.

If people do not wish to compete in unlimited yet still use race tires (sub 200tw) then I propose that the MAX class be broken up into two categories. MAX Street and MAX Race. MAX Race would allow competitors to use DOT slicks, lexan windows (of which a significant portion of the field is using in max class currently, illegally but overlooked) and additional weight reduction without moving to unlimited. MAX Street would remain for people that have built their cars in accordance with the SCCA time trials rules.

This would allow competitors currently stuck in unlimited due to a minor change to their car to drop back down to the more competitive max race and have a spot for basically all of the SP cars currently still running in the legacy classes without modification to their cars to be compliant.

This change would allow the complete removal of the legacy classes reducing the enormous amount of classes currently run at Knox. I believe a significant number of the GT cars would also fit in MAX Race.

To further reduce the classes, I think that Sport should be removed from the classing options. Given the minimum safety requirements for Knox, it is very rare that someone goes to the effort of the safety level without also some modifications to the car, likely pushing them out of Sport. Since adding the SCCA classing system to CACC time attack, the entries in Sport at Knox have been extremely minimal.

Additionally numerous cars currently competing in Tuner class should actually be in Max. Hood vents, aero, engine modifications, etc push them out of tuner. This was overlooked during classing likely due to the performance differential between cars competing in Max and those in Tuner. This new class would allow them to move up to their correct class while not having to directly compete against heavily modified vehicles with slicks.

Looking at last years results, by my quick calculation, you'd be adding 5 classes for MR but would be removing about 10 others that would not need to exist (in that it does not force people into unlimited). There were 20 classes last year so my proposal would consolidate it to 15 and would better represent the performance levels of each class.

The knox mountain website is down. I have attached the sup regs from last year.

Status/DispositionRejected
      The Confederation of Autosport Car Clubs
      BC's FIA/ASN Canada Motorsport Sanctioning Authority