I'm looking to install an amp and subs into my 98 legacy. Any suggestions or open grommets to send the power wire through the fire wall

most good stereo shops or hardwares store will sell the firewall grommet.

 

run your power line on the opposit side of the car from the rca inputs to eliminate electrical noise (alternator whine). make sure you have a fuse within 12" (preferred) of the battery. when grounding, the shorter the better for the ground wire.

 

basically find a good spot to drill your firewall or! run the cable in through one of the factory harness holes. make a small cut in the boot and slide the power line through.. may save some time.

 

depending on how much power your working with heres some suggestions for cable:

8 gauge - up to 300watts

4 gauge - up to 1000watts

1/0 gauge 800watts and up

just a few recommendations

 

rllywgn

the easiest way is to cut a grommet already in your fire wall, pull the cable thorugh then make sure to silicone up the grommet just to make sure water cant get in.

 

if your going to get serious go 1ga but just for an average amp/sub install 4ga will be fine as long as you use a descent fuse close to the battery. make sure you solder all wire joints if this is going to permanant or semi permanant because even the best crimp conections will come loose ove time.