black shadow

Hi

I have just bought a 1994 import rx type r which has an apexi boost controller, it has three different settings....

setting A and setting B, and off!

i dont have a manual for it, can anyone tell me what the difference between A and B is? they both let the boost run throught to 0.7 bar. when off it boosts at 0.5 bar.

any help would be appreciated.

thanks