With a number of new drivers joining us this year, there seems to be a bit of confusion regarding what the class structure means. It’s not a power to weight ration as used by some series and championships – it’s much easier than that!

The class number refers to power, e.g. GT150 is up to 150 BHP, GT200 up to 200 BHP, GT250 up to 250 BHP and so on. If you refer to our regulations you will note this power figure relates to power at the flywheel as this is the same method used by manufacturers when they state a BHP figure for the car they want to sell you. So if the production vehicle on which your race car is based the manufacturer says it produces 195 BHP and you have played with the engine e.g. changed the cams, it’s unlikely it will be less than 200 BHP so you should be in the GT250 class.

As another guide, if you have had your car on a rolling road you may be basing the class you have registered in on the BHP figure provided. Please ensure you’re not working on the figure at the wheels which will always be lower than the flywheel figure which should also appear on your rolling road print out.

So if after thinking about it you’re in the wrong class, please get in touch and let us know what class you need to change to.

Thanks for your assistance.