matching car amp fuses and power wire fuse?

[topeteontop]

I'm upgrading my amp from a 260 watt rms amp to a 750 watt rms amp, I'm currently using 8 gauge wire temporarily . i just wanted to know if i needed to change the inline fuse because my old amp used two 20 amp fuses while my new one uses two 40a fuses 'im not sure what kind of fuse i have inline because it was installed by a local shop but do i need to change it? and if so what fuses should i get instead?

Click to read more...

 

[LosIsATool 5,000+ posts]

You fuse for the wire. 8awg=50amp fuse if it's good cable.

 

[topeteontop]

and what fuse would i get for 4 gauge?