My clutch sort of "locks up" when pressed too quickly...aka, if I press the clutch slowly, or even slightly quickly then it is fine, but if I press very quickly, like if I was racing the car then the clutch makes an odd noise and the clutch pressure gets very heavy, like it hit a wall...I can push through it but I would say the clutch pedal is easily 3 times harder...it's almost like some sort of hydraulic lock.

 

No one has ever experienced this or knows whats causing it?

 

Have you checked the fluid level or see any leaks on the floor/ground?

What year is the Z? Do you know the maintenance history of the car? Done any mods to it?

These are the types of questions that will come up if anyone is going to be able to get an idea of how to answer you.

 

+1...sounds like an issue with your brake fluid...

Have your old fluid removed and put some new fluid in and see how it goes...

 

Fluid level was at the max mark, it looks clean. There are no leaks that i can see.
Car is a 2007 350Z with 97k on it, I put 3k on it since buying it a few months ago, it just started doing this a few days ago.
The car had a new clutch installed before I bought it.
Car mods are CAI, exhaust, wheels, lowered springs, stereo. I dont know the cars history of maintnance but it was a very clean car for having 94k on it.