I done some research and i notice my 08 nissan 350z comes with a 150 amp alternator. I like to know if would it be safe if i were to run a jl audio 1000/1 at 4 ohm and a alpine pdx f6 150 x 4 amp on my component speakers without upgrading the alternator in my car. Everything in the car is stock with a optima yellow top up front with 0 gauge big 3 upgrade. I am running 0 gauge wire from battery to a distribution block in the back. I will be feeding the jl audio 1000/1 with 0 gauge wire and the alpine with 4 gauge wire.

 

How about install it , try , then you will certainly know if you need an alternator or not .

 

Like jdm said...install it. Then see if any of these apply.
- Dim headlights when the music is playing
- Stereo performance is way below expectations
- Other electrical system perform poorly
- OEM alternator fails (great time for an upgraded replacement)

You can get a good idea of your electrical load by putting and ammeter in series with battery ground then switching each electrical system on and off and noting the amp change. Add all the amp changes to get your 'load'. Your alternator output should be 50% greater than the load. (if your load is 90 amps your alternator output should be 135 or greater)

If you run your stereo at 'average' levels you should be OK. If you constantly run the JL and the Alpine near their limits you might need to upgrade.

Just my 2 cents or 0.02amps

 

You will be fine with the stock alternator using the equipment in your list.