I want to know how can I retard my timing on a b16, using adjustable cam gears, and how would know how much to retard?

 

just search for uberteg and check out his chip. It retards the timing 1 deg for every 1lb of boost.

 

I have a jun chip installed, I want to replace it, so how can I manually retard timing?

 

cam timing or ignition timing ?

 

doing that would retard your cam timing, you need to retard your ignition timing for boost. If you don't have a stand alone then your second best option is to buy a msd btm to retard your timing relevent to boost. Or you can just retard your timing by turning your distributor, stock is 16 degrees so depending on how much boost your runing set it to about 14 up tp about 7psi and 12-13 for more boost. Doing it that way is not the best for power because it throws all your timing off (cam,ignition, injector,etc)......