SuperNats XXVII

209DAYS

2025 Winter Series

2025 TBA

2024 Pro Tour

57DAYS

SKUSA Mexico

36DAYS

2024 PKC

2DAYS

2024 TSRS

15DAYS

California ProKart Challenge

Round 1 - Feb 10-11, 2017 – Buttonwillow

RACE ENTRY

Race pre-entries may be submitted at a “packaged-price” discount through MotorSportReg.com. Our web-challenged friends may use our DOWNLOADABLE entry form at a slightly higher entry price.  If you have any questions, email  This e-mail address is being protected from spambots. You need JavaScript enabled to view it   or call 951-491-0808 for assistance.  NOTE: If you had a SKUSA membership in the past few years you were sent an email from MotorsportReg detailing how to get your new account ready.

Pre-Entry – Enter Before the Cut-Off and Save!
The definition of a “PRE-ENTRY” is an entry received, with payment, at the ProKart Challenge office before midnight on the Monday prior to the event, and will qualify for the pre-entry pricing.  Entries after this cut-off will have to be submitted at the event (starting Friday morning) at walk-up pricing.  See pricing below.  All race pre-entries will be confirmed via email within 2 business day of receipt at the PKC/SKUSA home office.  If you do not receive an email confirmation within 48 hours, please call 951-491-0808 to confirm that your entry has been received and is in process.

Pre-Entry closes at Midnight on Monday, February 6th,  Anyone wanting to register for the race or Friday's practice after that time will have to sign-up at the track on Friday starting at 7:00am or Saturday starting at 6:30am. 

Capped Entries - Enter Early - Don’t Miss Out!
All classes will have a maximum amount of 40 entries per race.  Entries received after a particular class is filled will be placed on a waiting list and held pending cancellation openings.  Entrants will be notified directly of any change in status or availability and offered entry on a first paid, first served basis

Entry Fees
(NOTE: $325 Entry+Tires pricing is available on MotorsportReg.) 

ALL CLASSES (active SKUSA membership required for race days):
  • $75 Practice Day
  • $125 Pre-Entry Race Fees
  • $160 Post-Entry / At Track Race Fees
  • $20 Transponder Rental ( If you don't have your own )
  • $222+tax per set Evinco-M ‘Red’ practice or race tires (for all classes except Mini/Micro Swift). These tires may be re-used from event to event. Practice or race tires for Mini/Micro Swift (Evinco-H ‘Blue’) are $211+tax. All tires can be picked up at the track or shipped ahead of time for $10 Shipping and Handling (within CA) or $15 (outside CA).
    Note: Race Tires MUST have the special PKC stamp to pass tech.
  • $100 SKUSA Annual Membership (must be current member)
  • $35 Reserved Pit Space
  • $50 Overnight Camping
  • $15 for 1-day or $25 for 2-day spectator passes for all guests, including mechanics (purchased ahead of time or at the track at the same price, 5 years old and under are No Charge)
  • NOTE: SKUSA’s Spec Fuel (C12 for all classes) and Spec Oil (Motul 2T Grand Prix) are mandatory at this event, but are not available to purchase from PKC/SKUSA. Please make arrangements to get some from your local kart shop or team for this event. Buttonwillow Raceway will also have the spec fuel and oil for sale at their TIRE/FUEL SHOP on site.

Driver Age
As ALL driver’s ages must be verified, you must email to This e-mail address is being protected from spambots. You need JavaScript enabled to view it or fax to (951) 491-0809 a copy of his/her birth certificate with the application for a SKUSA membership/racing license. Be sure to check the Classes section of this site or sections 15.3 and 20.1.2 of the SKUSA Rulebook for minimum age requirements of each class.