As a follow-up to our post about Daigo Saito and Ryan Tuerck not making weight in Seattle, we sought out some additional information about the tire-to-weight rule to better clarify how everything works.
After our initial post went live, we got the official weight class list back from FD Technical Manager Kevin Wells. In case you missed our update to the original post, here are the weight classes for 2013:
Weight and Tire Classes-
2100-2399lbs up to 240mm
2400-2699lbs up to 250mm
2700-2799lbs up to 260mm
2800-2899lbs up to 270mm
2900-2999lbs up to 280mm
3000-3099lbs up to 290mm
3100-3199lbs up to 300mm
3200-3299lbs up to 310mm
Per the rulebook, here is the exact classification process:
Cars are limited to the size of the rear tire that can be used, depending on the weight of the vehicle.
A car must be track-ready and running when it is weighed and registered to a weight
class. A car will be weighed WITH the driver
Once the car is registered to a weight class, it will be recorded, and issued a class specific sticker that must be displayed prominently on the windshield. A car’s weight may fluctuate within the limits of its weight class, but it can never weigh less than the minimum weight for its registered class.
Tire sizes are AS MEASURED in mm with the official Formula Drift tire tool, across the span of the contact patch. The Formula Drift tire tool will determine class compliance regardlessof the advertised sidewall size.
Tires will be measured on the rim, while on the car, while the car is on the ground.
Tire size must not exceed the maximum size dictated by class at any time on track.
Tire size will be measured and verified on track before the start of every tandem round and qualifying. A FORMULA DRIFT official may also check tire size at any time during the event.
Here are some additional parameters of the Weight Class rules:
● Cars will be weighed WITH driver, complete with all required bodywork and safety equipment installed.
● Drivers must be fully suited with helmets during the weigh-in process. Cars may only be weighed and registered upon passing their annual safety and technical inspection.
● A car can only be weighed and registered before the official start of a FORMULA DRIFT event. Cars may be weighed before any event and only during the regular technical inspection hours provided.
● The vehicle may not change weight classes at any time during an event. It is required of each competitor to inform the TECHNICAL MANAGER in writing of any modification(s) to their vehicle that alters the weight of the vehicle by more than 10 lbs.
● FORMULA DRIFT will be impounding all podium finishers immediately after end of competition and they will be checked for weight and tire size compliance.
I asked Kevin Wells if a team could request a lower weight class, per the example I gave in the last post. If a car weighs 3,020 pounds and technically qualifies for the 3,000 to 3,099 lb 290mm class, could they request to be placed in the 2,900 to 2,999lb 280mm weight class? The theory is that if the driver only plans to run a 265mm tire due to what is available from their tire supplier or due to what works best with their setup, they would still be well above the minimum weight in case of body damage, low fuel load, or other variables that might change during the course of the event instead of having to be in limbo of underweight penalties at nearly all times. He informed me that it would be possible, but must be requested.
I also asked about how often the cars are re-classed. He informed me that he always has the scales available prior to the Thursday practice for teams interested in changing classes or even just confirming their weight in the current setup. Typically, only two or three teams per round tend to take advantage of this.
From what we have heard, Daigo Saito was under the weight of his class based on his windshield sticker by less than 10 pounds. His weight was over the weight required by the size of the tire he was running at the time of the violation. Again, the weight class on the windshield determines the minimum weight allowed, and classification changes can only be made BEFORE the start of an event.
Currently, the weight according to the sticker on the windshield is the determining factor in what tire the car is allowed to run and what the minimum weight is, not the other way around. Should this be reversed? Should the tire size that the driver chooses to run determine the minimum weight they need to weigh? This would allow drivers to make adjustments to their tire during the course of the event in case they lose major body panels or other weight adjustments outside of their control in order to stay within compliance.