FD alternator conversion and FD alt questions...
10-09-03, 10:41 PM
#51
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87- An overdrive pulley on the Alt will spin it less, so it will put out less power, but more power will go to the wheels. A smaller pulley on the alt will make it put out more power.
10-10-03, 01:30 AM
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Originally posted by BDoty311
87- An overdrive pulley on the Alt will spin it less, so it will put out less power, but more power will go to the wheels. A smaller pulley on the alt will make it put out more power.
87- An overdrive pulley on the Alt will spin it less, so it will put out less power, but more power will go to the wheels. A smaller pulley on the alt will make it put out more power.
10-10-03, 01:15 PM
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Pulley explanation:
One aspect affects the speed of which an accessory is driven: The ratio of the drive pulley to the driven pulley.
SO...
Let's take an example of a 3"(diameter) eccentric shaft pulley. Let's make the alternator pulley 1" in diameter.
The ratio of the pulley diameters is 3:1 from drive to driven.
Thus, at an engine speed of 8000 rpm, the alternator pulley would be seeing an rpm 3 times greater, so 24,000 rpm.
To underdrive an accessory, in this example the alternator, you would need to lower the accessory rpm. The only way to do this is to decrease the difference of the pulley ratio. To do this, you can make the drive pulley smaller, or the driven pulley larger.
Using our example... if we made the eccentric shaft drive pulley 2" in diameter, the ratio would now be 2:1, and the alternator speed would be 16,000 rpm when the engine rpm is 8000 rpm.
If we kept the 3" eccentric shaft pulley, and made the alternator pulley larger, say to 2", we would have a 3:2 ratio, so when the engine was at 8000 rpm, the alternator would be at 12,000 rpm.
Likewise, to OVERdrive an accessory, we would need to increase this ratio, either by making the drive pulley larger or by making the driven pulley smaller.
An underdrive pulley on the eccentric shaft will underdrive every accessory connected to that pulley, so both the waterpump AND the alternator, and vice versa with an overdrive main pulley. An underdrive pulley on the accessory itself will only affect that accessories speed, and not any of the others. SO, if you put an underdrive pulley on the water pump, you would not lose speed on the alternator (and thus charging capabilities).
One aspect affects the speed of which an accessory is driven: The ratio of the drive pulley to the driven pulley.
SO...
Let's take an example of a 3"(diameter) eccentric shaft pulley. Let's make the alternator pulley 1" in diameter.
The ratio of the pulley diameters is 3:1 from drive to driven.
Thus, at an engine speed of 8000 rpm, the alternator pulley would be seeing an rpm 3 times greater, so 24,000 rpm.
To underdrive an accessory, in this example the alternator, you would need to lower the accessory rpm. The only way to do this is to decrease the difference of the pulley ratio. To do this, you can make the drive pulley smaller, or the driven pulley larger.
Using our example... if we made the eccentric shaft drive pulley 2" in diameter, the ratio would now be 2:1, and the alternator speed would be 16,000 rpm when the engine rpm is 8000 rpm.
If we kept the 3" eccentric shaft pulley, and made the alternator pulley larger, say to 2", we would have a 3:2 ratio, so when the engine was at 8000 rpm, the alternator would be at 12,000 rpm.
Likewise, to OVERdrive an accessory, we would need to increase this ratio, either by making the drive pulley larger or by making the driven pulley smaller.
An underdrive pulley on the eccentric shaft will underdrive every accessory connected to that pulley, so both the waterpump AND the alternator, and vice versa with an overdrive main pulley. An underdrive pulley on the accessory itself will only affect that accessories speed, and not any of the others. SO, if you put an underdrive pulley on the water pump, you would not lose speed on the alternator (and thus charging capabilities).
10-13-03, 08:05 PM
#56
Test results on the batt/alt:
Battery: GOOD
Alt: Amps at idle-25-30 Max amps read during the test- 95.6
Volts at start up were 12.38 and held like that for 5 min.
Upon reving to the RPM that the machine wanted- the volts jumpped up to 14.6 and remained untill the next time we tested it and I had to rev it again to et it to charge to 14.6v.
Diodes-ok
The one indteresting thing he mentioned though is that ever so often the volts and amps would drop for no reason. This while HOLDING an RPM of either 2k rpms or 3200rpms.
I never went part 4500rpms tho.
He said that in his oppinion the alt and battery are not the problem. Now that the alt iself is eliminated from the problem as if functions OK I have to find a smaller pully so that I don't have to be blipping the damn throttle all the time.
Santaigo
Battery: GOOD
Alt: Amps at idle-25-30 Max amps read during the test- 95.6
Volts at start up were 12.38 and held like that for 5 min.
Upon reving to the RPM that the machine wanted- the volts jumpped up to 14.6 and remained untill the next time we tested it and I had to rev it again to et it to charge to 14.6v.
Diodes-ok
The one indteresting thing he mentioned though is that ever so often the volts and amps would drop for no reason. This while HOLDING an RPM of either 2k rpms or 3200rpms.
I never went part 4500rpms tho.
He said that in his oppinion the alt and battery are not the problem. Now that the alt iself is eliminated from the problem as if functions OK I have to find a smaller pully so that I don't have to be blipping the damn throttle all the time.
Santaigo
10-13-03, 10:46 PM
#59
Did you all not see that it was a LOOSE CABLE?
I tightened it before and it still didn't give me any problems even till right the moment before I put the FD alternator on the car. There is no reason that my charging system is bad. Perhaps the gauge being faulty but my car doesn't loose charge or dies out EVER with the small exception of when my first FC alternator lost its regulator and that ended up with me getting my second FC alt which never let me down. It still works and chages to 13.8 volts at idle. I swapped them when I got home and it works just fine. How do you explain that?
I tightened it before and it still didn't give me any problems even till right the moment before I put the FD alternator on the car. There is no reason that my charging system is bad. Perhaps the gauge being faulty but my car doesn't loose charge or dies out EVER with the small exception of when my first FC alternator lost its regulator and that ended up with me getting my second FC alt which never let me down. It still works and chages to 13.8 volts at idle. I swapped them when I got home and it works just fine. How do you explain that?
10-14-03, 08:01 AM
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I am into hydraulics, not electronics, so bear with me.
a main difference between generators and alternators is generators use magnets and alternators use ELECTROMAGNETS to generate the magnetic fields that the wires cut through to generate the electricity.
as in, I was suprised to learn that my first alternator REQUIRED a generator light in order to work, because it got the needed bit of juice through that wire to jump start the magnetic windings.
so, it sounds like you might not be getting enough electricity into your ALT light to jumpstart the alternator.
I would look at this area.
a main difference between generators and alternators is generators use magnets and alternators use ELECTROMAGNETS to generate the magnetic fields that the wires cut through to generate the electricity.
as in, I was suprised to learn that my first alternator REQUIRED a generator light in order to work, because it got the needed bit of juice through that wire to jump start the magnetic windings.
so, it sounds like you might not be getting enough electricity into your ALT light to jumpstart the alternator.
I would look at this area.
10-14-03, 10:58 AM
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Originally posted by RoninAutoBoX
Methinks I will be going to a machine shop with my GM 200 amp alty instead.
Methinks I will be going to a machine shop with my GM 200 amp alty instead.
10-14-03, 11:09 AM
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Santiago
First off, the gauge is probably off. With my DMM on the battery terminals, at 1100 RPM cold idle, I get exactly 14.0 volts. My gauge is reading roughly 12.5.
You also need new battery cables most likely. I guarantee you are hard pressed to find any 16-18 year old car with perfect neccessary cables, such as the to the charging post, to the starter, to the firewall, etc.
First off, the gauge is probably off. With my DMM on the battery terminals, at 1100 RPM cold idle, I get exactly 14.0 volts. My gauge is reading roughly 12.5.
You also need new battery cables most likely. I guarantee you are hard pressed to find any 16-18 year old car with perfect neccessary cables, such as the to the charging post, to the starter, to the firewall, etc.
10-14-03, 11:36 AM
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Originally posted by Black13B
GM 200 amp alternators can't handle 9000 RPM. They weren't designed for it.
GM 200 amp alternators can't handle 9000 RPM. They weren't designed for it.
10-14-03, 11:41 AM
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Originally posted by RoninAutoBoX
Funny, the ZR-1 engines never had problems with 9000rpm and this very same alternator. Perhaps it was designed for it.
Funny, the ZR-1 engines never had problems with 9000rpm and this very same alternator. Perhaps it was designed for it.
I thought you were talking about their Pick-up Truck alternators.. Some of the chevy ones were around 200a. They couldn't take the revs.
I looked into that briefly before going with the FD alternator.
Never occurred to me to try a 'vette alternator.. I can't imagine it being cheap though.. is it?
10-14-03, 04:42 PM
#68
Originally posted by Black13B
Santiago
First off, the gauge is probably off. With my DMM on the battery terminals, at 1100 RPM cold idle, I get exactly 14.0 volts. My gauge is reading roughly 12.5.
You also need new battery cables most likely. I guarantee you are hard pressed to find any 16-18 year old car with perfect neccessary cables, such as the to the charging post, to the starter, to the firewall, etc.
Santiago
First off, the gauge is probably off. With my DMM on the battery terminals, at 1100 RPM cold idle, I get exactly 14.0 volts. My gauge is reading roughly 12.5.
You also need new battery cables most likely. I guarantee you are hard pressed to find any 16-18 year old car with perfect neccessary cables, such as the to the charging post, to the starter, to the firewall, etc.
Lets see I Checked it with a DMM, the stock gauge, and the alternator tester at autozone. How many more instruments would you like for me to use until you all stop blaming my ****? I have 3 month old cable to the starter 4gauge. 1-2 week old 2 gauge wire from the alt to the battery PLUS the stock wire the FC alt uses. I have added grounds and a new Ground cable. I have two new battery terminals. How much more ******* wires are there?
10-14-03, 04:55 PM
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It isn't a cheap option, but I can't get over 2 things:
1. The results of this swap seem to be mixed.
2. FD guys don't exactly have a high regard for the stock alternators.
It may be better than ours, but I' rather spend a little more money on something that WILL work for all situations, rather than one that a lot of the owners of the original car wish was more powerful and seek to upgrade.
1. The results of this swap seem to be mixed.
2. FD guys don't exactly have a high regard for the stock alternators.
It may be better than ours, but I' rather spend a little more money on something that WILL work for all situations, rather than one that a lot of the owners of the original car wish was more powerful and seek to upgrade.
10-14-03, 07:43 PM
#71
Originally posted by RoninAutoBoX
Methinks I will be going to a machine shop with my GM 200 amp alty instead.
Methinks I will be going to a machine shop with my GM 200 amp alty instead.
May I ask If anyone In existance of purchasing one of my FD Alternators experiences the same problems as Santiago? Please speak now.
I will say that you seem suggestive to say It's the Pulley. Yes It's bigger but the grooves carry the same depth as a FC Pulley, with obvious regards to the FD's serpintine Pulley being comparitively smaller. Looking at the Double Pulley that Is provided with the Kit, you would Infact say that It Is bigger. But keep In mind, that these are machined to FC specs.
How high does the FD Alternator sit mounted, as compared to that of the FC Alternator? Pretty much the same height?
10-14-03, 07:56 PM
#72
Ive already submitted my theories as to why I was seeing the same problem. Possible that the pulley is causing the difference, and only people with no AWS/Thermowax/Etc would even notice.
Also, as I recall, I was able to cure this problem (or at least improve it), by running a fresh length of wire ( I forgot the gauge, 8 I think?), from the alternator direct to the battery.
Now, I have the FD alternator that I installed in my N/A, and it hasnt yet been in my TII. I would be MORE then happy to swap them out and post my results.
My guess? Its one more of those random FC problems that we all know and love, and has really nothing to do with the FD alternator itself.
And honestly, it really isnt much of a problem, is it?
Also, as I recall, I was able to cure this problem (or at least improve it), by running a fresh length of wire ( I forgot the gauge, 8 I think?), from the alternator direct to the battery.
Now, I have the FD alternator that I installed in my N/A, and it hasnt yet been in my TII. I would be MORE then happy to swap them out and post my results.
My guess? Its one more of those random FC problems that we all know and love, and has really nothing to do with the FD alternator itself.
And honestly, it really isnt much of a problem, is it?
10-14-03, 08:05 PM
#73
Well I have never seen an FD pully up close so I can't tell if or if it is not a diff size but I will take your word for it.
I have not really payed attention to the height of the two alts yet. I will try that on friday or saturday if it stops raining. :-/ They look relatively close though
The point I am making is that there is nor was there ever a problem with my charging system as you all say. I have done over the whole thing. Wires, connector, belt tension, terminal cleaning, double check with DMM, grounding, etc.
I just want to resolve this ASAP. I don't care who is at fault but I am 99% sure that the electrical system is ok. If I have to send it back(hope not) then fine but I just want a NORMALY functional system that doesn't have to be reved. Reason being that I don't want my car do have to see revs when it is cold int he morning. I specifically save 5 minutes of my schedule for warm-up time for the car. I don't appreciate having to rev it every time the engine has cooled down. If I don't rev it then my battery is getting strained and that I also DO NOT appreciate.
Like I said TONY is the best guy in the world and he is good on his word.
BUT I still want my issue to go away and I don't have any other ideas. That is why black13b is pissing me off when he blames crap on my stuff. I just want to know how to fix it and how fast I can fix it.
I have not really payed attention to the height of the two alts yet. I will try that on friday or saturday if it stops raining. :-/ They look relatively close though
The point I am making is that there is nor was there ever a problem with my charging system as you all say. I have done over the whole thing. Wires, connector, belt tension, terminal cleaning, double check with DMM, grounding, etc.
I just want to resolve this ASAP. I don't care who is at fault but I am 99% sure that the electrical system is ok. If I have to send it back(hope not) then fine but I just want a NORMALY functional system that doesn't have to be reved. Reason being that I don't want my car do have to see revs when it is cold int he morning. I specifically save 5 minutes of my schedule for warm-up time for the car. I don't appreciate having to rev it every time the engine has cooled down. If I don't rev it then my battery is getting strained and that I also DO NOT appreciate.
Like I said TONY is the best guy in the world and he is good on his word.
BUT I still want my issue to go away and I don't have any other ideas. That is why black13b is pissing me off when he blames crap on my stuff. I just want to know how to fix it and how fast I can fix it.
10-14-03, 08:07 PM
#74
Also, as I recall, I was able to cure this problem (or at least improve it), by running a fresh length of wire ( I forgot the gauge, 8 I think?), from the alternator direct to the battery.
And honestly, it really isnt much of a problem, is it? [/B][/QUOTE]
I have a 2 gauge wire from the alternator to the POS post and the stock wire too. From day one those have been on there.
No help at all.
And honestly, it really isnt much of a problem, is it? [/B][/QUOTE]
I have a 2 gauge wire from the alternator to the POS post and the stock wire too. From day one those have been on there.
No help at all.
10-14-03, 08:14 PM
#75
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I don't remember saying that i have an FD alternator. In fact, I'm pretty sure that my comment stating that I think I will choose to use a GM alternator INSTEAD demonstrates this fact very clearly.
I chimed in my opinion on this here public forum based on what i have seen of the FD alternators; that being that they are not really anything special, and a lot of FD owners would prefer something more powerful.
I'm not kicking over your lemonade stand man, I'm just saying I'd prefer to go all the way, then simply get an upgrade that's just a little better. A 200 amp alternator could power a welder, just like those truck guys do. You can't even try and trip one of those up. Press on your brakes, sit at idle, turn on your lights, whatever, you just won't trip one of those. But it's good that you offer something better than the stock 80 amper, and it can bolt right in.
I chimed in my opinion on this here public forum based on what i have seen of the FD alternators; that being that they are not really anything special, and a lot of FD owners would prefer something more powerful.
I'm not kicking over your lemonade stand man, I'm just saying I'd prefer to go all the way, then simply get an upgrade that's just a little better. A 200 amp alternator could power a welder, just like those truck guys do. You can't even try and trip one of those up. Press on your brakes, sit at idle, turn on your lights, whatever, you just won't trip one of those. But it's good that you offer something better than the stock 80 amper, and it can bolt right in.