Peak and Hold are low impedance injectors, meaning they operate off of ~1-4 ohms and require a resistor box. Saturated injectors are high impedance, meaning that they operate off of ~10-16 ohms and do not require a resistor box. If you are going to turbo your engine, you will most likely be using low impedance injectors, because most high CC injectors are peak and hold. If you are not expecting more than 350 whp, you will probably be fine with DSM 450 cc's. But if you will be around 300-350, you will be running a very high duty cycle. You can find a resistor box on almost all older model fuel injected Hondas, and can use it with the DSM's. It is simple to wire, you can find instructions online.