the msd boxes are nice on domestic cars because their ecu setups suck but on imports i put one in my friends car and it didn't do shit what they're used for is so you can advance your timing and the car will start up easier so lets say you advance it 20degrees all the box does is retard it down so you can start it up easy and once you hit some rpm it will let the advance timing kick in if you have a turbo though u can buy a 6btm and that will retard the timing while boost kicks in but in all reality here get your ecu setup for uberdata and tune away w/that msd is nice when you make a lot of power or don't really know what to do w/ecu tuning or have dinosaur parts like carburetors that just throw gasoline into the motor so then you need that extra voltage to get in there one other nice thing is the 6al has a rev limiter you can use a 2step to launch the car at the exact rpm you want while holding your foot all the way down to the floor but the rpm willl still stay where you set it at until let go of the switch and clutch some are even rigged up to work off the clutch if your transmission is setup to were you don't need to use the clutch sorry for the long explanation