The NASCAR Whelen Tour Modified and SK Modified are two of iRacing’s most distinctly American racing experiences. Open-wheel and fender-finned, these tube-frame machines are the foundation of short track oval racing in New England and the Northeast. They have been in iRacing for years. However, the underlying physics model that governed how they drove had not received a comprehensive update in a long time. That changes today. iRacing Season 3 2026 ships a full, ground-up physics refresh for both the Tour Modified and the SK Modified. Brand-new tires and rebuilt suspension geometry are also included.
➡️ iRacing Season 3 2026: Full Build Breakdown
What Got Rebuilt
iRacing’s dev blog called this update “long overdue,” which is a direct acknowledgment that both cars were running on physics that no longer reflected iRacing’s current simulation standards. The refresh covers every major system in both cars.
Both the Tour Modified and SK Modified received rebuilt front and rear suspension geometry based on real-world build specifications. Front suspension now produces more compliant behavior with more consistent alignment curves. The rear Track Bar has been repositioned to reduce severe rear-steer effects present in the old model. It now uses iRacing’s live height system, meaning the garage display reflects actual height above ground rather than a nominal value.
Spring rates are now track-type dependent, with larger tracks allowing stiffer springs. Shocks have been rebuilt on both compression and rebound sides, with digressive behavior and a blowoff valve to handle sudden inputs over bumps. Shock adjustment range is reduced from 40 to 20 clicks. The overall range is unchanged, so each click is coarser while the endpoints stay the same. Aerodynamics received reduced downforce on both cars following real-world feedback.
New Tires and the SK’s New Engine
Both cars get entirely new bias-ply tires with redesigned construction for left and right sides. The tire compounds are now unique per side. The new oval compound formula changes how tires build grip: significantly less grippy at low temperatures, requiring a proper warm-up lap before they come on. Once up to temperature, grip builds before falling off on a longer run. This should change how you approach qualifying and race starts on both cars.
The SK Modified also receives a new engine. The new 604 Crate motor brings more power and a revised torque curve compared to the previous power unit. Brake systems on both cars have been updated to iRacing’s most recent brake model. Different front and rear pad compounds reduce brake bias shift at high rotor temperatures.
Separate Tech Limits and Setup Implications
Because the two cars now have different real-world tech rules and different suspension geometry, iRacing has separated their garage configurations entirely. Setups will no longer transfer between the Tour Modified and the SK Modified. Both garages have been reorganized with car-specific parameters. If you have existing setups saved for either car, they will not carry over to the updated versions.
Short Track Side-Draft Improvements
The Modified refresh pairs with a broader short track physics improvement also in Season 3. Multi-car aero modeling for asphalt oval race cars has been updated, with more pronounced side-draft effects at smaller circuits. iRacing’s ongoing oval refresh work has also produced improvements. These cover how marbles and rubber accumulation interact with aerodynamic sweep from passing cars. Wider driving lanes should become available more naturally as the race surface develops. This is a meaningful change for the longer sprint and feature races these cars typically run.
The Modifieds have always offered some of the most competitive and entertaining short track racing in the sim. For anyone who has not run them recently, Season 3 is a good time to revisit. The cars are rebuilt on modern physics foundations. The tires require actual management, and the side-draft improvements make close racing more realistic. iRacing also mentioned in the dev blog that another oval car update is coming in Season 4. It is described as something that will “surprise and delight” hardcore short track fans.
