New Alternator Recommendations?
Thread Starter
Instructor
Joined: Apr 2001
Posts: 140
Likes: 0
From: Las Vegas NV
New Alternator Recommendations?
I've decided that some of my probelms may be related to my alternator not being big enough. I have dual SPALs, a RCA MP3/digital reciever, a 100W Amp for the rear speakers, and an electric fuel pump. The alternator I have is a replacement, but meets stock specs (63A, (??)).
Question is two, or three fold (depending on what i think of in the next few moments ;-)...
1) How do I adequatley estimate the amperage required;
2) My ammeter is at 0 most of the time, unless at highway speed,
less (on the left, negative numbers) at stoplights/idle (what should
I expect, what is normal for a 454?)
3) what should I get? I looked at Jegs 80Amp but it seems like a lot
at over $200, and the 90Amp at over $300.
Thanks,
David
Question is two, or three fold (depending on what i think of in the next few moments ;-)...
1) How do I adequatley estimate the amperage required;
2) My ammeter is at 0 most of the time, unless at highway speed,
less (on the left, negative numbers) at stoplights/idle (what should
I expect, what is normal for a 454?)
3) what should I get? I looked at Jegs 80Amp but it seems like a lot
at over $200, and the 90Amp at over $300.
Thanks,
David
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
David,
www.alternatorparts.com
I rebuilt by 42Amp into an 80 Amp for less than $30. I also have dual Spals.
The problem is that alternators really need about 1500 rpm to put out a good charge. At idle, mine will stay barely positive unless my lights are on then it goes from zero to barely negative. As soon as I start driving again, I am usually at about 10 Amps while it recharges the battery or it will hit if the fans are running.
www.alternatorparts.com
I rebuilt by 42Amp into an 80 Amp for less than $30. I also have dual Spals.
The problem is that alternators really need about 1500 rpm to put out a good charge. At idle, mine will stay barely positive unless my lights are on then it goes from zero to barely negative. As soon as I start driving again, I am usually at about 10 Amps while it recharges the battery or it will hit if the fans are running.
Team Owner
Joined: May 2001
Posts: 29,745
Likes: 3
From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
CI 6-7-8 Veteran
CI-VIII Burnout Champ
St. Jude Donor '06-'10, '13
I got a 105 amp unit from Autozone. It was from a 1986 Corvette I think. Just need to change the pulley from the serpentine belt to the v-belt, use the pulley off the old alternator.
Team Owner
Joined: May 2001
Posts: 29,745
Likes: 3
From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
CI 6-7-8 Veteran
CI-VIII Burnout Champ
St. Jude Donor '06-'10, '13
also, when running a higher amp alternator, run a larger wire from the alternator post to the starter post and / or a large wire directly back to the battery.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Originally Posted by SteveG75
David,
www.alternatorparts.com
I rebuilt by 42Amp into an 80 Amp for less than $30. I also have dual Spals.
www.alternatorparts.com
I rebuilt by 42Amp into an 80 Amp for less than $30. I also have dual Spals.
That is what I did.
Thread Starter
Instructor
Joined: Apr 2001
Posts: 140
Likes: 0
From: Las Vegas NV
Originally Posted by SteveG75
www.alternatorparts.com
I rebuilt by 42Amp into an 80 Amp for less than $30. I also have dual Spals.
The problem is that alternators really need about 1500 rpm to put out a good charge. At idle, mine will stay barely positive unless my lights are on then it goes from zero to barely negative. As soon as I start driving again, I am usually at about 10 Amps while it recharges the battery or it will hit if the fans are running.
I rebuilt by 42Amp into an 80 Amp for less than $30. I also have dual Spals.
The problem is that alternators really need about 1500 rpm to put out a good charge. At idle, mine will stay barely positive unless my lights are on then it goes from zero to barely negative. As soon as I start driving again, I am usually at about 10 Amps while it recharges the battery or it will hit if the fans are running.
David
Drifting
Joined: Jan 2000
Posts: 1,612
Likes: 0
From: Phoenix Arizona
djlangford,
I went with: www.4alterstart.com and bought a 135 amp alternator shipped with a new pulley for $98. I had to reclock it but that was easy. If you have to reclock yours, make sure to do a forum search on how to do it (if you don't already know).
I ended up buying a hi-amp wiring kit from Summit for $20 and wired it from the alt to the battery...
I thought this was a good deal.....
Bob
I went with: www.4alterstart.com and bought a 135 amp alternator shipped with a new pulley for $98. I had to reclock it but that was easy. If you have to reclock yours, make sure to do a forum search on how to do it (if you don't already know).
I ended up buying a hi-amp wiring kit from Summit for $20 and wired it from the alt to the battery...
I thought this was a good deal.....
Bob
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Originally Posted by BSeery
also, when running a higher amp alternator, run a larger wire from the alternator post to the starter post and / or a large wire directly back to the battery.
...Well sort of
You want to run the larger wire yes, but run it to the same place the current wire goes. The altenator need to sense how much power is being used. if you bypass that mechanism you will still have problems.
So if the current alt wire does run to the starter then go there ( I know the new models are different than my old '69 )
But on my '69 it goes to the horn relay.
That is also where you need to the all power from, NOT from the battery! ( cause of that altenator sens thing again.
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