I was wanting to know exactly what do they do and how does it work? Thanks I tried a search but was still confused.

 

umm im thinking they adjust the opening and closing of valves and valve overlap whaich is i think when both the exhaust and intake valves are open at the same time hope i helped a little

 

Allows you to adjust the cams for the intake and the exhaust indepentantly of one another. If you have built up other areas of your engine (like different cams) you will find them usefull. In no way will they add 10 whp like AEM says they will on a stock GSR. Lol thats just laughable.

 

Your cams spin. When they spin, they open and close your valves. They are driven by the timing belt, which comes off of the crankshaft pulley. Adjustable cam gears let you adjust--either advance or retard--the timing of each cam in the case of a DOHC motor. What this allows you to do is both play with the overlap (the amount of time both the intake and exhaust valves are open) and the overall relationship between the opening of the valves compared to when the pistons are at TDC.

In simpler terms, you don't really need them unless you have aftermarket cams which need to be tuned with your stock motor. They're a tuning tool, that's about it.