I use a MoTec system and it works great. have a light that tells he when i get to a preset % slip. will be activating the traction control piece this year. because the car is all wheel drive, have had to adapt a GPS system to input the car velocity. Commercial GPS generally is not sensitive or responsive enough to provide input. i use a system made in the UK that was developed for just that purpose. as stated above, it is somewhat expensive, but the MoTec offers a ton of options for data logging and tuning. i originally bought the MoTec because of the complexity associated with running compressed natural gas as the fuel. found that it had a lot of additional features, some useful, some just cool. pm me if you would like more info.