When I dip my clutch to pull up to lights, junction etc. The revs drop right down to nearly 0. Then the car revs back up to normal idling revs. It sits fine on normal idle/tock over. It's only when I dip the clutch when driving. Any ideas?

Have you had your car mapped?

No mate. Would that effect it

cam sensor mate, same on my skyline that or your a tooth out

Wouldn't that of put the engine light on though?

Mine does this when I dip the clutch, I just presumed it's a normal thing to happen. My car is mapped by Prodrive though?

I wouldn't of thought it's normal for the revs to drop to 0 and nearly cut out

I would almost put my life on it being the MAF or an air leak. But can be what Ash said among a few other things. But would say MAF

Unplug the maf while it's running and see if it stalls 

And if it stalls that means it's not working?

No stallings a good thing :D means it working or it worked that time :)

Isn't that what you want though? Means it is at fault rather than something else yet to be found :P

That is true does mean you have found the problem but not cheap them MAFS :(

Right I'll try that then. And see if it stalls :)

Have a look at your throttle body, it could be dirty causing it to stick

yeah or the maf, and as for engine lights on the dash, no not necessarily 

No engine light on

Yeah, no light then I would check the throttle body first. Apparently the turbo covers it with oil over time or something

You won't always get an engine light with the MAF fault. And throttle body would be next clean the carbon build up from it