anyway there is micro compressor and air injection , micro compressor is only vacumn and air injection in 1 way walve in and never go out , so when your top head when you are open your throttle also mean that u are on acceralate ..air injection only will open when your top head valve that between inlet and top head cover , when u stop it the engine will stay on compression , and if u using micro compressor , that will non stop pumping air so when they want power u giving it so much air and they can't produce out that much of power ..~hardly explain 0166688899 call me i explain la..loLz..this is what i learn ..since so long lo~..air injection better for turbo , micro crompressor is for n/a ..if u have air-fuel ratio or safc /safc2 u will see the different anyway~ i have micro compressor , fuel regulator , safc , i will do a testing next week by greddy tuner ..that did the vas mas rx-7 which go for drag 1..mutaria motorsport ..=D ..i will see what tuner said but not forum said ..=D ciaoZ..answer is going next week better~ after my car have been tuned with micro or without it~ which is better..i will let u guy know till u all find out what it actually happening