BoP Lab / Buttonwillow Raceway Park
FV vs GT3U pace at Buttonwillow Raceway Park
Quickest here: FV 1:58.898 Mace Gjerman, Cal Club 2026 race · GT3U 1:55.650 Michael Lewis, Cal Club 2025 race
| Event | FV | GT3U | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Qual best | Race best | Trap | Qual best | Race best | Trap | vs FV | % of FV | |||
| Cal Club 2026 CALCL262026-02-21 | 2:02.562Gavin Sweeney · fastest of 7 · top 5 within 3.3s+0.208s (+0.17%) | 1:58.898Mace Gjerman · fastest of 7 · top 5 within 6.0s-2.299s (-1.90%) | 124.6Gavin Sweeney+21.2 mph (+20.5%) | |||||||
3 rule changes (GT3U: 3)3 weight · STU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments. · STU-GT3U non-TCR cars may reduce weight by 4% after all other modifiers. · STU GT3U minimum weight increases 150 to 250 pounds.show
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| Cal Club 2025 CALCL252025-02-22 | 2:02.354Gavin Sweeney · fastest of 5 · top 5 within 10.3s | 2:01.197Gavin Sweeney · fastest of 5 · top 5 within 9.6s | 103.5Gavin Sweeney | 2:00.536Michael Lewis · fastest of 2 | 1:55.650Michael Lewis · fastest of 2 | 108.8Michael Lewis | -5.547squal -1.818s | 95.4%qual 98.5% | ||
18 earlier rule changes on record, in force before Cal Club 2025 (from 2019)5 tyres & wheels · 1 aero · 1 suspension & brakes · 1 weight · 10 wording · FV ferrous rotor no longer required to be smooth; may have up to three pad cleaning grooves per side. · FV front wheel bearings wording clarified in GCR 9.1.1.C.10.G. · FV connecting rod rules add Brian Crower part #BC6417 and Newland Group #4M113077 as allowed replacements. · FV connecting rods minimum weight 425.0 grams, center-to-center length 130 ± 0.10/-0.25 mm specified. · FV connecting rod suppliers clarified: Crower SP93280B and BrianCrower BC6417 allowed as direct replacements. · FV allows Crower SP93280B and Brian Crower Racing Rods as direct replacement connecting rods, must meet OEM minimum weight. · FV now allows 4 bolt wheels, previously restricted to 5 bolt wheels. · FV now supports 4-bolt pattern wheels in addition to existing wheel specifications. · FV rain tire requirement changed to Hoosier #44266 22.5 x 5.0 x 15 WET or W3. · FV allows non-spec Hoosier tires in Regional races until 2020-01-01, when spec tires become required. · FV allows rear tires on front of car; mandates Hoosier #43337 fronts and #43353 rears, plus #44266 rain tire from 2020-01-01. · FV wheels clarified: 15" x 4J standard or 15" x 4.5J steel VW, 5-bolt pattern, same track dimensions. · FV exhaust outlet location tightened to 1–4 inches behind rearmost body part. · FV wheels now permit 15-inch 4.5J steel wheels within C.2 track dimensions, adding to standard 4J options. · FV exhaust opening can now extend to 4 inches behind body rear, previously 3 inches maximum. · FV front track maximum 52.500" and rear track 49.125"-50.750" no longer prohibits spacers. · FV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement removed. · FV intake manifold horizontal tube measurement locations clarified between 1.500" and 8.000" on short side.show
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Best is the class's fastest lap in that event's qualifying or race sessions, with the driver who set it, how many cars set a time that session and how close the top five were; a best from fewer than three cars is greyed. With two or more classes, "vs" is the gap of each class's best to the first class's at the same event. "% of FV" is the class's best as a share of FV's best at the same event (100% is level, less is quicker): weather and track condition move every class together, so this compares across years where the raw times do not. It still breaks when FV's own field changes or one session was wet and another dry. Newest event first. The coloured figure under each value is the change from the previous event that has one (green is quicker, red slower). Whole laps only, so events with different sector layouts still compare. Weather and track condition are not accounted for.