As others have posted, aftermarket chips in stock or near stock engines will do little to nothing for increasing horsepower. Exhaust and intake modifications will not exceed most factory-installed PROMs' ability to compensate for these changes. Forced induction, cams, and other significant modifications will likely require a change in programming but in those cases, custom-burned PROMs should be made rather than off-the-shelf chips. Most off-the-shelf chips only change timing and fuel curves at WOT (open loop) anyway. What some chips are useful for are turning on cooling fans at a lower temperature, torque converter clutch engagement points, etc. These are more drivability concerns than performance enhancements. I have a Hypertech Thermomaster chip in my Corvette that, in conjunction with a cooler thermostat and fan temp switch, allows my cooling fan to turn on at 175F rather than the factory setting of about 200F, prevents torque converter lockup until car is in OD, and accounts for cooler engine temps by keeping the car in closed loop operation at lower temps than stock. It does have different fuel and timing maps at WOT but it's nothing you would notice, let alone take your breath away. The biggest advantage is keeping underhood temps down. Al > I know this isn't directly related to a DeLorean, but I keep seeing > performance chips on sale for cars. Do they really work, or add any > performance that is noticeable? Thanks