355 alt question/sound system question.

If you have had large audio before you will know that an alternator is still an alternator, regardless of what sort of car it’s attached to. I am not sure of the current rating of the 355 alternators but if I was you I would add a 1 farad cap to the amp supply circuit and you should be fine. I would assume the amp won't be running near peak for extended periods anyway.

 

+1. I think the F355 Nippondenso alternator is rated at 140 amps. You also might want to change your battery to a Sears Platinum P1. It was rated the highest of all batteries (CCA,reserve, etc.) in a recent test.

 

My pleasure, John. You also might want to check-out this thread on alternator rebuilding. Not only will it make your alternator MUCH more reliable, but I think it also increases the output to approximately 160 Amps when tested on the bench. Good luck! Here is the link: http://ferrarichat.com/forum/showthread.php?t=124504&highlight=transpo

 

What ever you do, I would keep the total amperage draw as low as possible. In other words, keep it pretty conservative. No Ferrari is known for having a lot of excess electrical capacity. The 355 is essentially a massaged 348, and from that standpoint, they made several successive changes to alternators, and corrected grounding before they got it to work...and even then, not terribly reliably. Adding more electrical load is not going to help matters. Upgrading the alternator and battery as suggested would be advisable regardless, even without the additional stereo gear.

 

+1 ............ I 'upgraded' my alt along with a high capacity 'modern' battery and it made a noticeable difference for the better ......

 

+2 on Hugh's and Oz's suggestions. I certainly would not use anything in the factory wiring harness (grounds or current-carrying). IMHO, the Ferrari engine is so loud (but so BEAUTIFUL sounding) that you really can't appreciate the subtle nuances of a really high calibre sound system. Also, any substantial modifications of the car's front storage area or, especially, the interior can really effect the car's potential re-sale value. However, it's YOUR car - do what ever makes you happy!!!

 

I used to fit a lot of systems to 355's in the late 90's for the local dealership, the stock alternator is pretty good and the JL amps are pretty efficient.

My advice would be to check the output of the alternator, ensuring that it is charging at a healthy 14.4/14.8 volts and check the condition of the battery and its connections. We used to upgrade the battery for a higher capacity unit, a pain to fit but worth it and very little weight difference, batteries lose their ability to hold a charge over time, it may not be noticeable now but it will be when you add the audio system.

On the subject of Capacitors i think you will find it a false economy, the capacitor is simply a storage device which will smooth the power supply and allow larger amounts of current to be accessed by the amp during fast transients in the music, that power comes from the battery, no extra power gained just quicker response which at this level of system would not be noticed. Save the money for the new battery and fitting.

 

This is the battery I am using. http://www.sears.com/shc/s/p_10153_12605_02850034000P?vName=Automotive

880 CCA, top rated by Consumer Reports (factory battery is around 650 to 700 CCA). Terminals are on the opposites side, but the factory cables are long enough (at least on my 97 355 spider) to reach no problem. Absorbed Glass Mat construction, so no worries of spilled acid, and claimed very long life (which CR confirmed). 4 year free replacement warranty.

Only negative is it weighs about 6lbs more than the factory battery.

 

If by some chance acid does seep, these battery mats should help and may even lessen road vibrations which could extend battery life .

http://www.dccarcare.com/battery.html