Installing a turbo in your vehicle changes the risks associated with the car. When you do so, make sure to contact your car insurance company and let them know what modifications have been made so that they can update your policy to keep you fully insured.
If you install a turbo charger and do not tell the insurance company, the equipment would not be covered if the car is involved in an accident, and you will have to replace the turbo charger yourself. It is a much better idea, financially, to inform the insurance company, present them with the monetary value of the installation, and insure the car in its modified condition.
Keep in mind that the turbo charger automatically pushes the car to a new risk level. Because the after-market installation increases the likelihood of having an accident, your premiums will increase. This is not penalizing your for adding turbo to the car, but balancing the risk versus value ratio of your policy to meet the new value of the car with the turbo installed. Unless you are in a financial position to replace the turbo unit out of pocket, insuring it as part of your car is the only way to protect yourself.
Before you install the turbo unit, compare car insurance rates online and find out what you can expect the premiums to be. By using online insurance quotes, you can get an estimate of what the premiums look like before and after the addition. Some car owners will decide that the addition of turbo increases the cost of insurance premiums beyond their budget, but others will be happy that the rates only increase by a small amount.