One of the extreme automotive sports branch is Speed Off-road. Speed Offroad is a type of Off-road race which is a competition of speed according to the time specified by a sandy and muddy road terrain. Due to the extreme and dangerous types of races it is necessary to have a very strong component to support the car while driving on the Speed Off-road track. One of its components is a strong suspension system. So the strengthening of suspension on Suzuki Katana car is something that must be considered, because the strong suspension component will affect the performance of Speed Off-road car. In the strengthening of suspension for the Speed Off-road specification there are several stages, including alignment per leaf, and increased shock absorber by repairing the shock absorber. The final results achieved in the development of Suzuki Katana Speed Off-road specification is that in the data test there is an increase in the final data. From the research that has been done there is the end result of the Suzuki Katana car suspension system data on each test performed significant progress, such as on the test results of vehicle weight reduction is from 1190 kg to 815 kg, the results of handling testing is from 6.7 meters to 7 meters, on the results of testing the braking distance, it is increased from 12 meters to 7 meters, for stability testing increased from 5 degrees to 3 degrees of slope and for testing drag on each distance tested in Speed Off-road car get travel time from 11.87 seconds to 10.15 seconds at 100 meters and from 19 seconds to 17.54 seconds for 200 meters. Thus the specification of speed off-road car is fulfilled.