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This event is open to Super Lates, Pro-Lates & Limited Lates. All cars must conform to either APC or WESCAR rules except for the weight rules which will be determined by Penticton Speedway to ensure parity between the two rules packages and engine combinations. Penticton Speedway has posted the “Weight & Engine Supplemental Parity Rules”. Additionally, rule changes and additions can be found under “Rules Addendums”. All this information can be found on the Penticton Speedway website. We expect cars from across Canada and the Northwest United States, so we have considered the rules throughout these areas when formulating our rules to allow as many competitors as possible to meet the rules and keep all cars competitive.


General Format


Thursday - May 4th will be open practice for Late Models and Street Stocks.


Friday - afternoon Practice and Qualifying (May 6th). The top 12 will be locked into Saturday’s Western Rattler 300 based on Qualifying times. The next 28 will run a 100 lap Qualifier on Friday night, called “The Baker’s Dozen”, that will allow the top 13 to advance to the Western Rattler 300 (May 7th) locking in the top 25 starting positions.


Saturday – afternoon practice then the night will start off with a 35-lap last chance qualifier called “The 300 Three”. This race will be for the remaining cars after the 25 locked in starting positions and the top three finishers will gain the last remaining starting positions for the Western Rattler 300. The Saturday night 300 lap Western Rattler 300 will start 28 cars minimum and up to 30 as we will have 2 spots reserved for Promotors Choice. Any cars unable to start (maybe blew up in practice) would be replaced by the next car in finishing order from “The 300 Three”. Starting order will be set with the first 12 cars from qualifying, in order with the fastest car on the pole, then the next 13 by finishing order of “The Bakers Dozen”, then the last 3 by finishing position in the “The 300 Three”, then the 2 Promotors Choice.



The WESCAR Series will be utilizing the Baker’s Dozen as their season opener and awarding championship points to eligible cars accordingly, purse payouts will not be affected. Any WESCAR approved entry that qualifies inside the top 12 will have the option to run the Baker’s Dozen without forfeiting their starting position in the Western Rattler 300. These cars will simply start at the front of the Bakers Dozen in their respective qualifying order and start The Western Rattler 300 back in their qualified spot. The same number of cars that drop back from the top 12 will be added to the 28-car field. For example, if three WESCAR legal cars qualify in the top 12 during time trials, then elect to enter The Baker’s Dozen, then the maximum starting positions will grow from 28 spots to 31. The 13th to 28th positions will be assigned by finishing order of the Baker’s Dozen after the ‘drop back’ cars have been removed and placed back in their earned qualifying position.


Some teams own both WESCAR and either a Pro-Late or Super Late and may elect to take advantage of the back up car allowance by running their WESCAR legal car in The Baker’s Dozen then switching to a Super-Late (back-up) for the Western Rattler 300.



General Schedule


Thursday afternoon/evening will be open practice for Street Stock and Late Models. Driver/Crew/Sponsor complimentary BBQ at the track.


Friday night will have ‘A’ & ‘B’ 25 lap Street Stock Heats, then the “Baker’s Dozen 100” Qualifier, then the “Viper 100” Street Stock feature. No Late Model heat races.


Saturday night will have the 35 lap “300 Three” last chance qualifier, then “The Venom 100” Street Stock feature then the Western Rattler 300. No heat races for either class.






Running Rules


Most cars can do approximately 225+ laps on a full load of fuel and re-fueling will be allowed during any yellow. Cars will be allowed to pit under any yellow flag they choose however we will not guarantee that it won’t be a “quicky yellow”. In other words, if a team takes a chance on a simple “spin out yellow” then they may not make it back out before the green comes out and risk going down a lap or more. Teams will have to decide on the severity of the incident and estimate duration of yellow condition accordingly. We will have one competition yellow flag at lap 150 where we will guarantee a 5-minute window before going green again to give adequate time for all teams to change tires and re-fuel. (Any yellow flag condition from lap 140 - 150 will become the competition yellow). No laps will be counted under a yellow flag condition so drivers can pit under any yellow without losing a lap(s), but they will have to start at the end of the line behind cars that didn’t pit.

All cars will re-establish their running order after the competition yellow so there is no need to race out of pit lane but must be ready to rejoin the race when the 5 minutes expires. Any cars involved in the cause of a yellow flag that initiates the competition yellow will start at the rear of the entire field after the 5-minute break. Cars pitting during a non-competition yellow will line up at the back of the field in the order they leave pit exit.


Only one jack may be utilized and only one side of the car can be off the ground at a time for the purpose of a tire change during a non-competition yellow.


A Free Pass Car rule will be used. The first car that is one or more laps down will be given the opportunity to pull immediately behind the pace car during the yellow flag and will be waved by with the one lap to go signal from the flagman. Cars involved in or causing the yellow will be ineligible to receive the Free Pass.


All races except The 300 Three will finish with a maximum of 3 attempts at a Green/White/Checker. The 300 Three is under time constraints so we will only do Green/White/Checker finishes if time allows.





Qualifying order will be by draw.

All cars must be in the qualifying line up by “close of qualifying” time on schedule, any cars arriving late will go to the back of the line and will receive only 1 qualifying lap.

Each car will be given 1 warm up lap and 2 qualifying laps. (1 to go at first pass of flagman then green, white, checkered).

Any car waiving off after entering the track due to a bona fide mechanical issue may pull into the back of the line and attempt to qualify again providing the car did not complete a timed lap (to the white flag) and enters pit lane prior to crossing the start/finish line. The car will remain eligible for 1 warm up lap and 1 timed lap only. In the event the car scores a timed lap regardless of mechanical issues then that lap will be used as a completed qualifying time and no further laps will be granted. Penticton Speedway officials will determine if the car has received repairs that warrant another pass through tech prior to the second qualifying attempt.

All cars must deliver the qualifying tires to tire impound no later than 30 minutes after receiving the checkered flag in qualifying. Any cars not delivering tires to impound within the allotted time will start at the back of the field for the first race they qualified for.



Chassis & Engine Rules


Cars, less engines, must conform to APC or WESCAR Rule Books. These are the Penticton Speedway Late Model Rules as well.

Engines must conform to APC (Crate), WESCAR (Crate or Built), or Prior Approved SLM Built.

All SLM built motors must run a stock, tool legal, 2 bbl. 500 CFM Holley 4412. Alternatively, a tool legal, 4 bbl. Holley 750 CFM p/n 4779 or 80528 combined with “The Governor” 1” adjustable base plate p/n ALL26060 with 0.95” base plate inserts p/n 26061 as supplied by Allstar Performance. No modifications to inserts of any kind will be allowed.

Entrants must declare which rule package and engine combination they are running prior to the start of the event and must maintain that package throughout the event.

Engines may not be changed after the start of the event unless a failure occurs, and the engine swap is approved.

If an approved engine swap changes the Rules Package/Engine combination, then the new rules package must be adopted, and the car must pass through tech.

No frame height rule, however, any car continually bottoming out will be black flagged to save the racing surface.


The use of a backup car is allowed, providing the back up car meets all rules as outlined and is passed by tech. Back up cars replacing a primary car after Qualifying, The Baker’s Dozen or The 300 Three, will be considered qualified to start if the primary car earned a starting spot, but in all cases will start at the rear of the field. Tires will be transferred to the backup car. Any change from a primary to a backup car must be approved by Penticton Speedway.




Minimum weights will be as per car/engine combination



➢ PRO LM 602 CRATE 2800

➢ PRO LM 604 CRATE 2825 (Factory GM Seals)

➢ PRO LM 604 CRATE 2875 (Rebuilt Seals)







Maximum 58% Left Side Weight

Maximum 50% Rear Weight





Only American Racer EC-84 purchased from Penticton Speedway will be approved for this event.

All pre-registered cars will be approved an allotment of 12 tires for the event and 4 more for the Thursday Practice. Cars missing pre-registration will be allotted tires on a first come first serve basis and may be restricted to 12 tires based on availability.

All tires sold by Penticton Speedway will be recorded and marked. 8 tires will be marked as Race Tires and up to 8 will be marked as Practice Tires. Teams will have an opportunity to measure and group their allotted tires prior to being officially marked.

All teams must designate a maximum of 8 new Race Tires that will remain impounded prior to being released for qualifying. Up to 8 tires will be designated as Practice Tires and will not be impounded until after the completion of all practice sessions. A total of 2 Practice Tires can be designated emergency tires and placed in impound prior to the start of the Western Rattler 300. The emergency tires can only be used in the event that the Race Tires have been destroyed. During the western Rattler 300, a bona fide failed Race Tire can be exchanged for an Emergency Tire at the tire impound. No Emergency Tires will be exchanged for Race Tires that are holding air. The failed tire will remain in impound for the duration of the race and until tech is cleared to give the officials an opportunity to inspect the failed tire and determine the cause of the failure. Any attempt to purposely destroy a tire to achieve an exchange will result in disqualification from the event. Only Race Tires will be released from impound prior to the start of the race and each team will be in possession of 8 tires only, at any given time during the race, at their pit box.

All cars starting the Western Rattler 300 must start on the 4 tires they qualified on.

Cars that qualify into the top 12 will only be allowed 8 Race Tires total for the weekend. All 8 must be impound tires.

Cars having to run the “Baker’s Dozen” Qualifier will be allowed 8 Race Tires all weekend. All 8 must be impound tires. The Baker’s Dozen may be run on designated Practice Tires, Race Tires, or a combination. Race Tires must be returned to impound a maximum of 30 minutes after the conclusion of the Baker’s Dozen.

Tires used in qualifying will not be eligible for races other than the Western Rattler 300.

Cars having to run the “300 Three” Last Chance Qualifier will be allowed 8 Race Tires all weekend and may elect to run the “300 Three” on designated Practice Tires that were purchased from Penticton Speedway or any of the Race Tires. Race Tires that are not part of the qualifying set must be returned to impound. Race Tires that are part of the Qualifying Set must remain on the car for The Western Rattler 300.

Designated Practice Tires (2) may be used during the Western Rattler 300 in case of emergency, after they’ve been released from tire impound, by exchanging with a bona fide flat Race Tire that gets placed in impound.

No tire softeners or modifiers of any kind are permitted. Any team caught modifying tires will be disqualified from competition.

Only one designated crew member will be granted access to the tire impound area during scheduled times to adjust tire pressures, measure sizes and group sets.

All wheels must be clearly marked with the car number. A decal must be used for marking the numbers, no jiffy markers, paint pens etc.



Rules Addendums

1. Shocks – Single adjustable, no canisters or reservoirs. Only one shock per wheel, no electronics of any kind.

2. Drive Shafts – Aluminum drive shafts permitted

3. Starters – Reverse mount starters and aluminum bell housings permitted

4. Transmissions – 4 speed transmissions allowed, all gears must be functional

5. Rear Ends – Cambered rear end permitted; 25 lbs. added to minimum combination weight

6. Differentials – Mechanical locker type differentials allowed; 25 lbs. added to minimum combination weight.

For all tech-related questions please email

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