dennis blackstone

my alternator was rebuilt before i put it on from a alternater rebuild shop who i know all the rx7 i know in our band do not have any problems with the fd alternator .. i got mine from ebay so i rebuilt it for safe measure and it is perfectly sound day in day out ..also the rest of rx7 owners in our crew do not have any problems ...aron you do make sense in your theory but we dont have any problems with the fd alternators ..its bolt on and go

JustJeff

iTrader: (13)

I've got a 1 farad cap on the main power line before I split it off to the amps. I've got a 2 channel JL amp, a 4 channel Alpine, and the sub will use a bridged Zapco. I've got the headrest speakers using the headunit's amp and simply use the fader to turn them on and off. I rarely use the headrest speakers, usually just on the highway when the top is down.

Things seem pretty stable, I'm just asking too much of the FC alternator.

The Wankler

iTrader: (14)

I would use a cap on each. Mine are both 1 farad. I went home at lunch and tested it, cause I recently installed them. When my e-fan kicked on, it did not bog at all like it did prior. I will log the volts and see what happens.

JustJeff

iTrader: (13)

Once I get my fuel system worked out (FD fuel pump, upgrading secondaries, etc) I'm going to start concentrating on electrical. Going to reground everything while the intake is off. Rewire my amps, cause I've moved them around. Install an aftermarket alarm I've been meaning to install since last summer. I'll look into whether another cap will suit me.

Being devil's advocate now, I've read on a car audio forum that capacitors aren't useful if you've got everything gounded. The Big Three they call it, battery grounded, engine grounded to the chassis, and one other...can't remember the last one. It's been a while since I read about it so I'm not sure of the validity of it, but now that it's fresh in my mind I'll do some more reading.

The Wankler

iTrader: (14)

Not useful as in what though? They store power and provide it to the amp at a steady rate. That way when a extra load is put on you power system, it still is able to provide constant power. That is how I understand they work.

deuce_fc

what would i need to do to change a fd alt? into a fc

JustJeff

iTrader: (13)

This is what I found on the12volt.com

http://www.the12volt.com/installbay/forum_posts.asp?TID=4379&KW=capacitor

People don't really "badmouth" capacitors. They just aren't the miracle that people make then out to be. A capacitor is just a temporary reservoir of energy. When current is drawn from it, it draws current from the battery. Then the battery draws it from the alternator. People think that they can use capacitors to make up for their lack of energy production but the fact of the matter is, a capacitor is only useful until the alternator cannot keep the capacitor with the charge it needs. Then the capacitor is EXTRA load on the electrical system and becomes more of a hinderance than an asset.

Basically that thread talks about the importance of matching up a big enough capacitor for how many watts you are pulling. I've read in the past that simply having large enough gauge grounding on The Big Three makes a capacitor irrelevant. I don't know enough to say what's right or wrong, that's just what's out there being said.

JustJeff

iTrader: (13)

I haven't done it yet, but this is what I understand the process to be. You need to bore out your FC pulley so that it will fit on the wider alternator. You'll also have to get a spacer so the pulley lines up correctly. If you have a S5 you're putting the FD alternator on it's a direct swap for the harness. If you have a S4 then you need to fab a harness to wire it in.

The Wankler

iTrader: (14)

I noticed the difference in my car. I will go home again and see. Prior to installing the caps, you could here my engine drop a bit when the e-fan kicks on. Yesterday, I did not hear the load when it kicked on. I will try again today to make sure that is the case.