T1 Tire Changes in the Rules for GT4
#37497 from Joe Rainey · Rule change · TB 25-02 (2025-02 Fastrack)
In T1-GT4 Spec Lines, Audi R8 GT4 Spec Line #4020, change Max Tire Size as follows:
"315 DOT, 305/645, or 30/65-18 (f), 33/68-18 (r) Non-DOT"
BoP Lab / Drivers / Joe Rainey
Joe Rainey 3 letters to Fastrack
Against the front of the class, by track and class
| Track | Class | Sessions | Typical gap to class best | Closest |
|---|---|---|---|---|
| Road America (4.05 mi) | EP | 4 | +11.071s (7.34%) | +9.938s (6.62%) |
| Road America (4.05 mi) | SMX | 4 | +13.023s (7.76%) | +4.534s (2.79%) |
| Road America (4.05 mi) | T3 | 4 | +5.111s (3.29%) | +4.633s (3.01%) |
| Road America | EP | 1 | +9.938s (6.62%) | +9.938s (6.62%) |
| Circuit of the Americas (3.41 mi) | EP | 5 | +0.537s (0.35%) | +0.000s (0.00%) |
| Circuit of the Americas (3.41 mi) | T3 | 4 | +2.675s (1.75%) | +2.675s (1.75%) |
| Sebring International Raceway (3.74 mi) | EP | 3 | +1.980s (1.31%) | +1.980s (1.31%) |
| Sebring International Raceway (3.74 mi) | T3 | 4 | +2.795s (1.87%) | +2.654s (1.77%) |
Gap is the driver's best lap in a session against the fastest lap in their class in that same session (zero is fastest in class), shown as time lost and as a share of the lap, so conditions cancel out and tracks can be compared. Typical is the median session.
Road America (4.05 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| June Sprints 2024 | Grp 7 STL STU SMX Race 2 | SMX | 110 | Mazda MX-5 (2007) | 37/32 | 2:38.264Noah Harmon | |||||
| June Sprints 2024 | Grp 7 STL STU SMX Race 1 | SMX | 110 | Mazda MX-5 (2007) | 29/37 | 2:47.224 | 2:42.690Matthew Novak | +4.534s (2.79%) | 122.632/37 | 126.6Justin Mason | -4.0 mph (-3.1%) |
| June Sprints 2024 | Grp 7 STL STU SMX Qual | SMX | 110 | Mazda MX-5 (2007) | 32/37 | 3:39.013 | 3:04.633Cam Ebben | +34.380s (18.62%) | 97.631/37 | 118.7Marcello Paniccia | -21.1 mph (-17.8%) |
| June Sprints 2024 | Grp 7 STL STU SMX Prac | SMX | 110 | Mazda MX-5 (2007) | 30/37 | 3:00.881 | 2:47.858Kamden Hibbitt | +13.023s (7.76%) | 118.833/37 | 125.2Will Robinson | -6.4 mph (-5.1%) |
| June Sprints 2023 | Grp 4 EP,FP,HP,GTL,B-Spec Race 2 | EP | 171 | Mazda MX-5 Cup | 8/7 | 2:29.906Jon Brakke | |||||
| June Sprints 2023 | Grp 1 T2,T3,T4 Race 2 | T3 | 17 | Mazda MX-5 Cup | 13/11 | 2:27.958Steve Smyczek | |||||
| June Sprints 2023 | Grp 4 EP,FP,HP,GTL,B-Spec Race 1 | EP | 171 | Mazda MX-5 Cup | 5/9 | 2:40.087 | 2:30.149Jon Brakke | +9.938s (6.62%) | 124.17/9 | 139.8Jon Brakke | -15.7 mph (-11.2%) |
| June Sprints 2023 | Grp 1 T2,T3,T4 Race 1 | T3 | 17 | Mazda MX-5 Cup | 9/14 | 2:38.741 | 2:34.108Steve Smyczek | +4.633s (3.01%) | 124.312/14 | 136.5Steve Smyczek | -12.2 mph (-9.0%) |
| June Sprints 2023 | Grp 4 EP,FP,HP,GTL,B-Spec Qual 2 | EP | 171 | Mazda MX-5 Cup | 5/10 | 2:41.974 | 2:30.903Tim Schreyer | +11.071s (7.34%) | 122.67/10 | 138.1Jon Brakke | -15.5 mph (-11.2%) |
| June Sprints 2023 | Grp 1 T2,T3,T4 Qual 2 | T3 | 17 | Mazda MX-5 Cup | 8/16 | 2:40.652 | 2:35.541Derek Wagner | +5.111s (3.29%) | 122.811/16 | 134.3Derek Chan | -11.5 mph (-8.6%) |
| June Sprints 2023 | Grp 4 EP,FP,HP,GTL,B-Spec Qual 1 | EP | 171 | Mazda MX-5 Cup | 5/10 | 2:43.074 | 2:30.324Jon Brakke | +12.750s (8.48%) | 120.68/10 | 138.1Jon Brakke | -17.5 mph (-12.7%) |
| June Sprints 2023 | Grp 1 T2,T3,T4 Qual 1 | T3 | 17 | Mazda MX-5 Cup | 8/13 | 2:42.569 | 2:35.583Gamaliel Aguilar-Gamez | +6.986s (4.49%) | 114.812/13 | 134.3Derek Chan | -19.4 mph (-14.5%) |
Road America
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| June Sprints 2023 | Grp 4 EP,FP,HP,GTL,B-Spec Race 1 | EP | 171 | Mazda MX-5 Cup | 4/9 | 2:40.087 | 2:30.149Jon Brakke | +9.938s (6.62%) |
Circuit of the Americas (3.41 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Lone Star Grand Prix 2023 | Grp 3 EP,FP,HP,GTL,B-Spec Race 2 | EP | 24 | Mazda MX-5 Cup | 4/2 | 2:40.745Larry Svaton | |||||
| Lone Star Grand Prix 2023 | Grp 1 STL,T2,T3,T4,STU,GT3 Race 2 | T3 | 24 | Mazda MX-5 Cup | 15/12 | 2:33.525Ross Murray | |||||
| Lone Star Grand Prix 2023 | Grp 3 EP,FP,HP,GTL,B-Spec Qual 2 | EP | 24 | Mazda MX-5 Cup | 4/2 | 2:43.218Larry Svaton | |||||
| Lone Star Grand Prix 2023 | Grp 1 STL,T2,T3,T4,STU,GT3 Qual 2 | T3 | 24 | Mazda MX-5 Cup | 14/10 | 2:32.890Simon Asselin | |||||
| Lone Star Grand Prix 2023 | Grp 3 EP,FP,HP,GTL,B-Spec Race 1 | EP | 24 | Mazda MX-5 Cup | 2/4 | 2:35.215 | 2:34.424Joey Rainey | +0.791s (0.51%) | 125.21/4 | 125.2you | +0.0 mph (0.0%) |
| Lone Star Grand Prix 2023 | Grp 1 STL,T2,T3,T4,STU,GT3 Race 1 | T3 | 24 | Mazda MX-5 Cup | 6/15 | 2:35.313 | 2:32.638Ross Murray | +2.675s (1.75%) | 123.811/15 | 135.6Ross Murray | -11.8 mph (-8.7%) |
| Lone Star Grand Prix 2023 | Grp 3 EP,FP,HP,GTL,B-Spec Qual 1 | EP | 24 | Mazda MX-5 Cup | 2/5 | 2:34.341 | 2:33.804Joey Rainey | +0.537s (0.35%) | 122.91/5 | 122.9you | +0.0 mph (0.0%) |
| Lone Star Grand Prix 2023 | Grp 1 STL,T2,T3,T4,STU,GT3 Qual 1 | T3 | 24 | Mazda MX-5 Cup | 7/15 | 2:38.549 | 2:32.272Todd Clarke | +6.277s (4.12%) | 124.77/15 | 134.5Ross Murray | -9.7 mph (-7.2%) |
| Lone Star Grand Prix 2023 | Friday Test 6 | EP | 24 | Mazda MX-5 Cup | 1/1 | 2:38.211 | 2:38.211you | +0.000s (0.00%) | 124.01/1 | 124.0you | +0.0 mph (0.0%) |
Sebring International Raceway (3.74 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 8 T2,T3,T4 Race 2 | T3 | 24 | Mazda MX-5 Cup (2018) | 8/7 | 2:29.167Todd Clarke | |||||
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 4 EP,FP,HP,GTL,B-Spec Race 2 | EP | 24 | Mazda MX-5 Cup (2018) | 6/5 | 2:29.247Don Tucker | |||||
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 8 T2,T3,T4 Race 1 | T3 | 24 | Mazda MX-5 Cup (2018) | 4/8 | 2:32.703 | 2:30.049Todd Clarke | +2.654s (1.77%) | 111.18/8 | 116.4Shaoyi Che | -5.3 mph (-4.6%) |
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 4 EP,FP,HP,GTL,B-Spec Race 1 | EP | 24 | Mazda MX-5 Cup (2018) | 5/7 | 2:33.270 | 2:31.290Doug Piner | +1.980s (1.31%) | 111.96/7 | 117.8Doug Piner | -5.9 mph (-5.0%) |
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 8 T2,T3,T4 Qual 2 | T3 | 24 | Mazda MX-5 Cup (2018) | 5/8 | 2:32.012 | 2:29.217Todd Clarke | +2.795s (1.87%) | 111.77/8 | 118.3Shaoyi Che | -6.5 mph (-5.5%) |
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 4 EP,FP,HP,GTL,B-Spec Qual 2 | EP | 24 | Mazda MX-5 Cup (2018) | 5/7 | 2:35.043 | 2:32.908Doug Piner | +2.135s (1.40%) | 108.17/7 | 115.8Doug Piner | -7.7 mph (-6.7%) |
| Central Florida Region Hoosier SCCA Super Tour @ Sebring International Raceway | Grp 8 T2,T3,T4 Qual 1 | T3 | 24 | Mazda MX-5 Cup (2018) | 4/4 | 2:46.972 | 2:41.226Todd Clarke | +5.746s (3.56%) | 105.64/4 | 110.5Paul McNamara | -4.9 mph (-4.5%) |
Letters to Fastrack
SMX5 SMX Wiring Harness Change in GCR
#36682 from Joe Rainey · Not recommended · Minutes (2024-10 Fastrack)
Thank you for your letter. Per section 9.1.7.1.3.j removal of excess wiring is allowed. Mazda is also working on a race harness
for the SMX class but is not currently available. Opening up the class to create custom wiring harnesses is not within class
philosophy and would create difficulties for the tech staff and opportunities for noncompliance. There are currently used
harnesses available on the open market that would solve this problem while the race harness continues through the
development process.
T1 BOP Changes Need Updates
#36667 from Joe Rainey · Rule change · TB 24-12 (2024-12 Fastrack)
In T1 GT4 Spec Lines, Spec Line 4020, change as follows:
Performance Control: Power level 2020, 44mm 45mm SRO compliant restrictor"
Min. Weight with driver (LBS): "3550 3400"