SM Tire Limiting Proposal
#28569 from Marc Briley · Taken care of · Minutes (2019-05 Fastrack)
Thank you for taking the time to respond to the WDYT. Please see response to initial request letter #27041 in the May Fastrack.
BoP Lab / Drivers / Marc Briley
Marc Briley 1 letter 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) | SM | 8 | +16.392s (10.02%) | +11.415s (7.04%) |
| Barber Motorsports Park (2.38 mi) | SM | 4 | +4.452s (4.24%) | +4.269s (4.10%) |
| Virginia International Raceway (3.27 mi) | SM | 6 | +9.842s (7.27%) | +4.829s (3.54%) |
| Unknown track (3.27 mi) | SM | 7 | +7.329s (5.37%) | +6.806s (4.99%) |
| Indianapolis Motor Speedway (2.59 mi) | SM | 13 | +2.746s (2.32%) | +0.572s (0.47%) |
| Hallett Motor Racing Circuit (1.80 mi) | SM | 4 | +2.731s (3.12%) | +2.717s (3.08%) |
| Circuit of the Americas (3.41 mi) | SM | 5 | +8.261s (4.95%) | +6.371s (3.94%) |
| Unknown track | SM | 1 | +2.551s (2.12%) | +2.551s (2.12%) |
| Unknown track (2.59 mi) | SM | 9 | +3.388s (2.83%) | +2.156s (1.79%) |
| NOLA Motorsports Park (2.75 mi) | SM | 5 | +4.288s (3.61%) | +3.771s (3.17%) |
| Daytona International Speedway (3.56 mi) | SM | 5 | +7.848s (5.66%) | +5.763s (4.13%) |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2026 | SM National Championship Race | SM | 151 | Mazda Miata (1999) | 37/35 | 2:42.725Francisco Barroso | |||||
| Runoffs 2026 | SM Qualifying 3 | SM | 151 | Mazda Miata (1999) | 34/34 | 2:53.588 | 2:42.173Brett Kowalski | +11.415s (7.04%) | 108.734/34 | 118.6Ryan Maloney | -9.9 mph (-8.4%) |
| Runoffs 2026 | Tue Grp 5 SM STL Run 3 | SM | 151 | Mazda Miata (1999) | 23/23 | 2:57.480 | 2:33.841Brett Kowalski | +23.639s (15.37%) | 109.123/23 | 129.7Brett Kowalski | -20.6 mph (-15.9%) |
| Runoffs 2026 | Tue Grp 5 SM STL Run 2 | SM | 151 | Mazda Miata (1999) | 20/20 | 3:00.024 | 2:43.632Tyler Brown | +16.392s (10.02%) | 109.819/20 | 118.7Cole Lucas | -8.9 mph (-7.5%) |
| Runoffs 2026 | Mon Grp 1 SM SMX Run 4 | SM | 151 | Mazda Miata (1999) | 10/6 | 2:44.866Wyatt Couch | |||||
| Runoffs 2026 | Mon Grp 1 SM SMX Run 3 | SM | 151 | Mazda Miata (1999) | 10/7 | 2:43.951Ken Sutherland | |||||
| Runoffs 2026 | Mon Grp 1 SM SMX Run 2 | SM | 151 | Mazda Miata (1999) | 10/8 | 2:43.423Ken Sutherland | |||||
| Runoffs 2026 | Mon Grp 1 SM SMX Run 1 | SM | 151 | Mazda Miata (1999) | 7/4 | 2:46.387Jason Rawlins |
Barber Motorsports Park (2.38 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Alabama and Tennessee Valley Region SCCA Hoosier Super Tour @ Barber Motorsports Park | Grp 3 SM SMX Race 2 | SM | 151 | Mazda Miata (1999) | 34/32 | 1:44.611Stanley Brock Jr | |||||
| Alabama and Tennessee Valley Region SCCA Hoosier Super Tour @ Barber Motorsports Park | Grp 3 SM SMX Qualifying 2 | SM | 151 | Mazda Miata (1999) | 25/31 | 1:48.431 | 1:44.162Stanley Brock Jr | +4.269s (4.10%) | 97.728/31 | 104.3Logan Stretch | -6.5 mph (-6.3%) |
| Alabama and Tennessee Valley Region SCCA Hoosier Super Tour @ Barber Motorsports Park | Grp 3 SM SMX Race 1 | SM | 151 | Mazda Miata (1999) | 27/34 | 1:49.443 | 1:44.991Chris Rawlings | +4.452s (4.24%) | 94.532/34 | 103.9Preston Pardus | -9.4 mph (-9.0%) |
| Alabama and Tennessee Valley Region SCCA Hoosier Super Tour @ Barber Motorsports Park | Grp 3 SM SMX Qualifying 1 | SM | 151 | Mazda Miata (1999) | 30/33 | 1:49.278 | 1:43.599Stanley Brock Jr | +5.679s (5.48%) | 94.830/32 | 104.3Preston Pardus | -9.5 mph (-9.1%) |
Virginia International Raceway (3.27 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2023 | SM Race | SM | 5 | Mazda Miata | 52/46 | 2:16.229Julian DaCosta | |||||
| North Carolina Region Dual Conference Hoosier SCCA Super Tour @ Virginia International Raceway | Grp 2 SM Race 2 | SM | 5 | Mazda Miata | 44/51 | 2:27.112 | 2:17.065Peter Ensor | +10.047s (7.33%) | 113.839/51 | 118.4Charles Mactutus | -4.6 mph (-3.9%) |
| North Carolina Region Dual Conference Hoosier SCCA Super Tour @ Virginia International Raceway | Grp 2 SM Race 1 | SM | 5 | Mazda Miata | 42/57 | 2:21.269 | 2:16.440Jonathan Davis | +4.829s (3.54%) | 111.652/57 | 118.2Todd Buras | -6.6 mph (-5.6%) |
| North Carolina Region Dual Conference Hoosier SCCA Super Tour @ Virginia International Raceway | Grp 2 SM Qual 2 | SM | 5 | Mazda Miata | 54/58 | 2:25.307 | 2:15.465Connor Zilisch | +9.842s (7.27%) | 108.253/58 | 120.9Tyler Quance | -12.6 mph (-10.5%) |
| North Carolina Region Dual Conference Hoosier SCCA Super Tour @ Virginia International Raceway | Grp 2 SM Qual 1 | SM | 5 | Mazda Miata | 57/59 | 2:23.459 | 2:15.150Jim Drago | +8.309s (6.15%) | 106.759/59 | 117.6Jim Drago | -10.9 mph (-9.3%) |
| North Carolina Region Dual Conference Hoosier SCCA Super Tour @ Virginia International Raceway | Grp 2 SM Practice | SM | 5 | Mazda Miata | 56/57 | 2:33.455 | 2:14.922Elivan Goulart | +18.533s (13.74%) | 107.854/57 | 117.2Danny Steyn | -9.4 mph (-8.0%) |
Unknown track (3.27 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2023 | SM Qual 3 | SM | 5 | Mazda Miata | 52/51 | 2:15.037Preston Pardus | |||||
| Runoffs 2023 | SM Qual 2 | SM | 5 | Mazda Miata | 50/52 | 2:21.998 | 2:14.986Danny Steyn | +7.012s (5.19%) | 114.042/52 | 118.6Jim Drago | -4.6 mph (-3.9%) |
| Runoffs 2023 | SM Qual 1 | SM | 5 | Mazda Miata | 41/49 | 2:23.946 | 2:15.763Raiden Nicol | +8.183s (6.03%) | 108.843/49 | 118.4Jim Drago | -9.6 mph (-8.1%) |
| Runoffs 2023 | Run 2 SM Mon | SM | 5 | Mazda Miata | 40/42 | 2:23.762 | 2:16.433Danny Steyn | +7.329s (5.37%) | 110.340/42 | 118.1Charles Mactutus | -7.8 mph (-6.6%) |
| Runoffs 2023 | Run 1 SM Mon | SM | 5 | Mazda Miata | 36/40 | 2:23.218 | 2:16.412Preston Pardus | +6.806s (4.99%) | 109.740/40 | 119.1Rob Hines | -9.4 mph (-7.9%) |
| Runoffs 2023 | Run 3 SM. T3, T4 Sun | SM | 5 | Mazda Miata | 30/31 | 2:25.757 | 2:16.980Charles Mactutus | +8.777s (6.41%) | 109.131/31 | 118.1Elivan Goulart | -9.0 mph (-7.6%) |
| Runoffs 2023 | Run 2 SM. T3, T4 Sun | SM | 5 | Mazda Miata | 28/30 | 2:26.562 | 2:16.475Jonathan Neudorf | +10.087s (7.39%) | 110.029/30 | 117.5Ethan Goulart | -7.6 mph (-6.4%) |
Indianapolis Motor Speedway (2.59 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2021 | SM Race | SM | 5 | Mazda Miata | 66/71 | 2:02.813 | 1:58.837Brian Henderson | +3.976s (3.35%) | 116.454/71 | 119.8Kyle Greenhill | -3.3 mph (-2.8%) |
| Runoffs 2021 | SM Last Chance Race | SM | 5 | Mazda Miata | 9/29 | 2:02.354 | 2:01.548Andrew Charbonneau | +0.806s (0.66%) | 111.021/29 | 114.9Nick Stagl | -3.9 mph (-3.4%) |
| Runoffs 2021 | SM LCR | SM | 5 | Mazda Miata | 10/29 | 2:02.354 | 2:01.782Andrew Charbonneau | +0.572s (0.47%) | 109.722/28 | 114.9Nick Stagl | -5.1 mph (-4.5%) |
| Runoffs 2021 | SM (B) Qual 2 | SM | 5 | Mazda Miata | 29/45 | 2:02.743 | 2:00.689Samantha Silver | +2.054s (1.70%) | 109.142/45 | 116.0Andrew Charbonneau | -6.9 mph (-5.9%) |
| Runoffs 2021 | SM (B) Qual 1 | SM | 5 | Mazda Miata | 31/44 | 2:03.155 | 1:59.328Kyle Greenhill | +3.827s (3.21%) | 109.737/44 | 115.1Clayton Cavell | -5.4 mph (-4.7%) |
| Runoffs 2021 | Grp 6 Run 3 SM Sun | SM | 5 | Mazda Miata | 41/48 | 2:02.928 | 1:59.293Grayson Farischon | +3.635s (3.05%) | 109.946/48 | 117.4Elivan Goulart | -7.4 mph (-6.3%) |
| Runoffs 2021 | Grp 6 Run 2 SM Sun | SM | 5 | Mazda Miata | 40/46 | 2:03.912 | 1:59.380Elivan Goulart | +4.532s (3.80%) | 111.044/46 | 118.8Travis Wiley | -7.8 mph (-6.6%) |
| Runoffs 2021 | Grp 6 Run 1 SM | SM | 5 | Mazda Miata | 41/47 | 2:04.193 | 1:58.953Danny Steyn | +5.240s (4.41%) | 114.415/47 | 118.6Chris Haldeman | -4.1 mph (-3.5%) |
| Runoffs 2017 | SM Race | SM | 5 | Mazda Miata (1999) | 51/71 | 2:01.882 | 1:59.100Michael Gagliardo | +2.782s (2.34%) | |||
| Runoffs 2017 | SM (Top 60) Qual 4 | SM | 5 | Mazda Miata (1999) | 48/60 | 2:01.052 | 1:58.306Chris Haldeman | +2.746s (2.32%) | |||
| Runoffs 2017 | SM (A) Qual 3 | SM | 5 | Mazda Miata (1999) | 40/43 | 2:01.527 | 1:59.248Chris Haldeman | +2.279s (1.91%) | |||
| Runoffs 2017 | SM (B) Qual 2 | SM | 5 | Mazda Miata (1999) | 6/45 | 2:01.583 | 2:00.245Michael Carter | +1.338s (1.11%) | |||
| Runoffs 2017 | SM (B) Qual 1 | SM | 5 | Mazda Miata (1999) | 18/43 | 2:02.389 | 1:59.995B.Clark Cambern | +2.394s (2.00%) |
Hallett Motor Racing Circuit (1.80 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| AVRG Green Country Grand Prix 2021 | Grp 3 SM, B-Spec Race 2 | SM | 5 | Mazda Miata | 11/24 | 1:30.981 | 1:28.264Travis Wiley | +2.717s (3.08%) | 90.417/24 | 93.6Quyen Tong | -3.3 mph (-3.5%) |
| AVRG Green Country Grand Prix 2021 | Grp 3 SM, B-Spec Qual 2 | SM | 5 | Mazda Miata | 14/24 | 1:30.206 | 1:27.475Travis Wiley | +2.731s (3.12%) | 91.814/24 | 94.0Grayson Farischon | -2.1 mph (-2.2%) |
| AVRG Green Country Grand Prix 2021 | Grp 3 SM, B-Spec Race 1 | SM | 5 | Mazda Miata | 19/25 | 1:30.997 | 1:27.979Jim Drago | +3.018s (3.43%) | 90.719/25 | 93.5Christopher Shaffer | -2.8 mph (-3.0%) |
| AVRG Green Country Grand Prix 2021 | Grp 3 SM, B-Spec Qual 1 | SM | 5 | Mazda Miata | 21/26 | 1:34.556 | 1:28.402Jim Drago | +6.154s (6.96%) | 0.621/26 | 0.7Jim Drago | -0.0 mph (-6.8%) |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Circuit Americas 2018 | GRP 4 SM Race 2 | SM | 5 | Mazda Miata (1999) | 33/48 | 2:48.210 | 2:41.839Chris Haldeman | +6.371s (3.94%) | 112.239/48 | 117.5Tyler Quance | -5.3 mph (-4.5%) |
| Circuit Americas 2018 | GRP 4 SM Race 1 | SM | 5 | Mazda Miata (1999) | 37/54 | 2:55.053 | 2:46.792Thomas Martin | +8.261s (4.95%) | 105.737/54 | 114.7Tyler Quance | -9.0 mph (-7.9%) |
| Circuit Americas 2018 | GRP 4 SM Qual 2 | SM | 5 | Mazda Miata (1999) | 34/29 | 3:03.098Nick Leverone | |||||
| Circuit Americas 2018 | GRP 4 SM Qual 1 | SM | 5 | Mazda Miata (1999) | 46/55 | 2:48.337 | 2:40.183Michael Ross | +8.154s (5.09%) | 113.237/55 | 118.6Michael Ross | -5.4 mph (-4.6%) |
| Circuit Americas 2018 | Grp 4 SM Practice | SM | 5 | Mazda Miata (1999) | 44/53 | 2:50.201 | 2:40.440Chris Haldeman | +9.761s (6.08%) | 113.032/53 | 117.5Lee Thomas | -4.5 mph (-3.9%) |
Unknown track
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2017 | Sun Grp 8 Run 2 | SM | 5 | Mazda Miata (1999) | 28/46 | 2:02.678 | 2:00.127Preston Pardus | +2.551s (2.12%) |
Unknown track (2.59 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2017 | Sun Grp 8 Run 2 | SM | 5 | Mazda Miata (1999) | 28/46 | 2:02.678 | 2:00.127Preston Pardus | +2.551s (2.12%) | |||
| Runoffs 2017 | Sun Grp 8 Run 1 | SM | 5 | Mazda Miata (1999) | 31/43 | 2:02.939 | 1:59.551Danny Steyn | +3.388s (2.83%) | |||
| Runoffs 2017 | Sat Grp 6 Run 3 | SM | 5 | Mazda Miata (1999) | 34/48 | 2:03.756 | 2:00.516Chris Haldeman | +3.240s (2.69%) | |||
| Runoffs 2017 | Sat Grp 6 Run 2 | SM | 5 | Mazda Miata (1999) | 23/49 | 2:02.714 | 2:00.558Michael Carter | +2.156s (1.79%) | |||
| Runoffs 2017 | Sat Grp 6 Run 1 | SM | 5 | Mazda Miata (1999) | 32/47 | 2:04.391 | 2:00.479Michael Carter | +3.912s (3.25%) | |||
| Runoffs 2017 | Fri Grp 5 Run 4 | SM | 5 | Mazda Miata (1999) | 17/21 | 2:05.200 | 2:00.225Tyler Kicera | +4.975s (4.14%) | |||
| Runoffs 2017 | Fri Grp 5 Run 3 | SM | 5 | Mazda Miata (1999) | 17/19 | 2:04.547 | 2:00.779Tyler Kicera | +3.768s (3.12%) | |||
| Runoffs 2017 | Fri Grp 5 Run 2 | SM | 5 | Mazda Miata (1999) | 9/18 | 2:03.573 | 2:01.171Chris Haldeman | +2.402s (1.98%) | |||
| Runoffs 2017 | Fri Grp 5 Run 1 | SM | 5 | Mazda Miata (1999) | 11/18 | 2:05.570 | 2:01.730Chris Ciufo | +3.840s (3.15%) |
NOLA Motorsports Park (2.75 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Voodoo Quartre NOLA Motorsports Park 2017 | Grp 4 Race 2 | SM | 5 | LnSt | 24/33 | 2:03.321 | 1:58.956Michael Carter | +4.365s (3.67%) | |||
| Voodoo Quartre NOLA Motorsports Park 2017 | Grp 4 Qualifying 2 | SM | 5 | LnSt | 27/40 | 2:02.676 | 1:58.229Michael Carter | +4.447s (3.76%) | |||
| Voodoo Quartre NOLA Motorsports Park 2017 | Grp 4 Race 1 | SM | 5 | LnSt | 22/43 | 2:02.645 | 1:58.874Justin Hille | +3.771s (3.17%) | |||
| Voodoo Quartre NOLA Motorsports Park 2017 | Grp 4 Qualifying 1 | SM | 5 | LnSt | 28/44 | 2:02.971 | 1:58.683Chris Haldeman | +4.288s (3.61%) | |||
| Voodoo Quartre NOLA Motorsports Park 2017 | Grp 4 Practice | SM | 5 | LnSt | 28/43 | 2:02.567 | 1:58.689Blake Clements | +3.878s (3.27%) |
Daytona International Speedway (3.56 mi)
| Event | Session | Class | # | Car | Pos | Best lap | Class best | To class best | Trap | Class trap | To class trap |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Runoffs 2015 | SM Race | SM | 5 | LNST | 61/59 | 2:24.067Todd Lamb | |||||
| Runoffs 2015 | SM Qualifying 4 | SM | 5 | LNST | 56/59 | 2:26.027 | 1:40.989Matt Reynolds | +45.038s (44.60%) | |||
| Runoffs 2015 | SM Qualifying 3 | SM | 5 | LNST | 44/43 | 2:19.936Jim Drago | |||||
| Runoffs 2015 | SM Qualifying 2 | SM | 5 | LNST | 52/59 | 2:26.509 | 2:18.661Andrew Carbonell | +7.848s (5.66%) | |||
| Runoffs 2015 | SM Qualifying 1 | SM | 5 | LNST | 48/56 | 2:25.422 | 2:19.659Todd Lamb | +5.763s (4.13%) |