This paper presents a Tire-Suspension-Steering Hardware-In-the-Loop Simulator (HILS) system for using in a development of a student formula car suspension. The HILS system was modified from an existing Tire-Suspension-Steering Hardware-In-the-Loop Simulator developed in Chulalongkorn University. The system can be used to reduce the development time and cost when comparing to testing a real prototype car on a test track. Firstly, we designed and built the adjustable support for the student formula car suspension on the HILS such hat wheel parameters such as camber and toe can be adjusted. CATIA V5 was used to design and test the structural strength. On the other hand, the HILS system is used to simulate and test vehicle dynamics by replacing the front wheel of a bicycle model with a real student formula wheel and suspension. The wheel is running on a rotating drum whose speed and orientation can be controlled to simulate the car speed and the tire side slip angle. Tire force due to slip angle between the wheel and the drum can be measured. Undesteer gradient can be measured and compared with the real prototype car testing results to validate that HILS can predict the handling of the student formula car.