TL-HAS is Thunder Lane US's height-adjustable spring system for drivers who want a lower, corner-balanced stance and sharper response — while keeping their factory dampers. If you like how your OEM adaptive suspension drives but want real control over ride height, TL-HAS is the clean solution that doesn't commit you to a full coilover package.
Each TL-HAS kit replaces the fixed OEM springs with height-adjustable perches and matched springs, letting you dial in front and rear ride height independently to suit your wheel/tire package, alignment targets, and intended use. Factory electronic damping — BMW Adaptive M / EDC or Porsche PASM — stays fully operational, along with every comfort and driver-assistance feature.
Current applications include the BMW G8X M2/M3/M4 (front lowering 20–50mm, rear 0–45mm) and the Porsche 911 991/992, 2WD and 4WD (front 15–35mm, rear 20–40mm). Every kit is built to order, with spring rates finalized with you before production begins. Not sure whether you want springs or a full coilover? Read our guide: Coilovers vs Height-Adjustable Springs.