Many questions regarding power
05-01-2004, 04:11 AM
#1
50 Watt CAFz'r
Thread Starter
Join Date: Apr 2004
Posts: 238
Ok, im being a **** now for sure.
Specs:
1990 Celica GTS
Alpine MRD-M1000 80 watt inline fuse
Alpine MRV-F540 2 30 watt fuses
An optima yellow top battery
Might run a 3 farad cap
Ok, now for my questions:
The amps will be on the right side of the hatchback, both power and negative leads maybe 10 inches from each other, probably less. The optima yellowtop on the left corner of the trunk, leads running to the battery isolator. That leaves maybe 4 feet at most between the amps and the battery.
1. Is it better to have the cap close as hell to the amps and use it as a power distributor? Or, should I put it across the trunk by the battery? Why?
2. Would the mrv-f540 even need to be on the cap? I will be running 2 alpine spr-176a component sets (50w rms 200 max I think) might do a spx-177a 6.5comp set if so convinced for the front, as the stock speaker was an 8" sub in the door.
3. What size cap would be sufficient? Does the amperage from the amplifiers add with the cap amperage at all times? Or does it only draw the additional amperage when the cap is drained? (not sure if thats an accurate question)
4. What guage wiring for power up to and including from the isolator>yellowtop>cap>amps. Are AGU fuses better? I've heard a metal conduit for power is good in high current systems to protect against noise; true? Would I want a breaker or maybe a fuse between the battery and the cap? If yes, what amperage? (Relate to question 2)
Lots if questions i know, but yeah, i already addressed that with the 5th word in this post. Thanks [img]graemlins/headbang.gif[/img]
[ May 01, 2004, 05:14 AM: Message edited by: '90 Alpine Celica ]
Specs:
1990 Celica GTS
Alpine MRD-M1000 80 watt inline fuse
Alpine MRV-F540 2 30 watt fuses
An optima yellow top battery
Might run a 3 farad cap
Ok, now for my questions:
The amps will be on the right side of the hatchback, both power and negative leads maybe 10 inches from each other, probably less. The optima yellowtop on the left corner of the trunk, leads running to the battery isolator. That leaves maybe 4 feet at most between the amps and the battery.
1. Is it better to have the cap close as hell to the amps and use it as a power distributor? Or, should I put it across the trunk by the battery? Why?
2. Would the mrv-f540 even need to be on the cap? I will be running 2 alpine spr-176a component sets (50w rms 200 max I think) might do a spx-177a 6.5comp set if so convinced for the front, as the stock speaker was an 8" sub in the door.
3. What size cap would be sufficient? Does the amperage from the amplifiers add with the cap amperage at all times? Or does it only draw the additional amperage when the cap is drained? (not sure if thats an accurate question)
4. What guage wiring for power up to and including from the isolator>yellowtop>cap>amps. Are AGU fuses better? I've heard a metal conduit for power is good in high current systems to protect against noise; true? Would I want a breaker or maybe a fuse between the battery and the cap? If yes, what amperage? (Relate to question 2)
Lots if questions i know, but yeah, i already addressed that with the 5th word in this post. Thanks [img]graemlins/headbang.gif[/img]
[ May 01, 2004, 05:14 AM: Message edited by: '90 Alpine Celica ]
05-01-2004, 05:33 AM
#2
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
Considering that you have a battery in the trunk already here is what I'd do:
Forgo the cap, and put the money into good power wire and connections.
I'd run both the positive and negitive wires from the amps directly back to the battery. For both amps, I would run 4 awg wire on both the positive and negitive runs. (You are just on the limit of what 8 awg can handle)
The positive runs should have a fuse within 12" or so of the battery. The inline fuse's purpose is for safety, to prevent a wire melting and catching fire in the even of a short. The amps have fuses mounted in them, so they will be fine by themselves. For simplicies sake, I would run identical 80 amp fuses for both the sub amp, and front stage amp. If you can, run ANL fuses. They are designed to offer better surface contact on each side of the fuse to reduce losses.
Final comment for your entertainment:
I'm running 2 yellow tops, 1/0 wire to distro blocks, and 4 awg to my amps. My subs have about 2000 watts driving them, and my 3 way active front stage has about 900 watts driving them. I've got 2 - 1 farad caps, and I experience dimming of my interior lights.
Take your time, do your grounds well, and you will enjoy the system for a long time.
Adam
Forgo the cap, and put the money into good power wire and connections.
I'd run both the positive and negitive wires from the amps directly back to the battery. For both amps, I would run 4 awg wire on both the positive and negitive runs. (You are just on the limit of what 8 awg can handle)
The positive runs should have a fuse within 12" or so of the battery. The inline fuse's purpose is for safety, to prevent a wire melting and catching fire in the even of a short. The amps have fuses mounted in them, so they will be fine by themselves. For simplicies sake, I would run identical 80 amp fuses for both the sub amp, and front stage amp. If you can, run ANL fuses. They are designed to offer better surface contact on each side of the fuse to reduce losses.
Final comment for your entertainment:
I'm running 2 yellow tops, 1/0 wire to distro blocks, and 4 awg to my amps. My subs have about 2000 watts driving them, and my 3 way active front stage has about 900 watts driving them. I've got 2 - 1 farad caps, and I experience dimming of my interior lights.
Take your time, do your grounds well, and you will enjoy the system for a long time.
Adam
05-01-2004, 11:39 AM
#3
Dont' need the cap, it does not make power, it uses and stores it. If your lights continue to dim with the MBA and a second battery, then you need a HO alternator. I would have a resetable ciscuit breaker at both ends of the main power line between the MBA and the second battery.
05-01-2004, 12:26 PM
#4
50 Watt CAFz'r
Thread Starter
Join Date: Apr 2004
Posts: 238
Thanks guys, I had another question, but im a pothead and forgot [img]graemlins/dunno.gif[/img]
Anyone else?
Oh and my alternator is 80amps, I absolutely do not have room for a bigger one, so what do you think rewiring the existing one with flat wire would run me $wise?
Still can't remember that other question. damnit, lol
And just to note, I dont care what my spl is, I'm setting up for complete SQ. I've been told so many times that yes a cap *can* reduce dimming, but it also makes the bass deeper on low bass notes. Are you saying it won't matter because its all running off a yellowtop?
From what you guys are saying, caps are useless because you just drain em off right away... right?
Not trying to contradict what you're saying, just trying to get a thorough explanation of a cap's purpose. Some people swear by em, some people say they are not worth buying.
thanks guys - That other question is still in limbo in my head somewheres.
[ May 01, 2004, 01:35 PM: Message edited by: '90 Alpine Celica ]
Anyone else?
Oh and my alternator is 80amps, I absolutely do not have room for a bigger one, so what do you think rewiring the existing one with flat wire would run me $wise?
Still can't remember that other question. damnit, lol
And just to note, I dont care what my spl is, I'm setting up for complete SQ. I've been told so many times that yes a cap *can* reduce dimming, but it also makes the bass deeper on low bass notes. Are you saying it won't matter because its all running off a yellowtop?
From what you guys are saying, caps are useless because you just drain em off right away... right?
Not trying to contradict what you're saying, just trying to get a thorough explanation of a cap's purpose. Some people swear by em, some people say they are not worth buying.
thanks guys - That other question is still in limbo in my head somewheres.
[ May 01, 2004, 01:35 PM: Message edited by: '90 Alpine Celica ]
05-01-2004, 12:51 PM
#5
50 Watt CAFz'r
Thread Starter
Join Date: Apr 2004
Posts: 238
Hehe, stoners prevail. [img]graemlins/headbang.gif[/img]
I remembered the question...
I plan to run all the amp grounds directly back to the negative battery terminal, but is it necessary to run both positive and negative leads from the isolator to the battery? or should I just ground the yellowtop to the chassis? Does running both have any benefit?
PEI330Ci: You said run 80 amp anl's to both amps, but the front stage amp has 2x30amp fuses... Why 80?
Thanks
[ May 01, 2004, 01:53 PM: Message edited by: '90 Alpine Celica ]
I remembered the question...
I plan to run all the amp grounds directly back to the negative battery terminal, but is it necessary to run both positive and negative leads from the isolator to the battery? or should I just ground the yellowtop to the chassis? Does running both have any benefit?
PEI330Ci: You said run 80 amp anl's to both amps, but the front stage amp has 2x30amp fuses... Why 80?
Thanks
[ May 01, 2004, 01:53 PM: Message edited by: '90 Alpine Celica ]
05-01-2004, 01:20 PM
#6
I'm pretty sure that you can fit a larger alt in there.it just takes some effort and patience.
I fit a 200amp GM alt into my colt.
there is a few high amp possibilities,200 amp cs144 large case,or 180 amp cs130 small case.
I fit a 200amp GM alt into my colt.
there is a few high amp possibilities,200 amp cs144 large case,or 180 amp cs130 small case.
05-01-2004, 01:30 PM
#7
The ground is your most important wire in a electircal system. There is an assumed way to ground things and a proper way to ground things. The proper way is to verify that the ground return has as low a resistance as possible. Do you have a meter? If the ground return from the back battery is very low, then yes you can ground the battery in the back of the car. If it is high and will not co-operate then it is in your best interest to ground directly to the front. Upgrade all power and ground wires that you have right now, battery to chassis - engine and alternator.
Now for the cap, there are some times when it is advantageous to use a cap, however you so not know this yet. A cap is not a magic add power device, it stores what is given yet uses some of the same power to operate. It is best described as a pool of current that is used for a brief instant in time. However all it does is place another draw on the battery as it is another device to be charged, thus can be viewed as detrimental to a system. Yes it operated faster than a battery but will still be slower than a alternator. I have a 93 MR2 with more than likely the same small alternator. It hasn't missed a beat with my system and no cap.
As far as a cap making bass deeper, well that is just [img]graemlins/bs.gif[/img] In some cases, only once in the last year have I found a need for a cap in a system. An amp cannot make power unless it is given it. If the amp needs current to cycle for a deep bass note, it must be given the power. A cap can provide this for a breif instant in time. A HO alternator can do this all of the time. I would think that the extra capacity of the battery will surely help you along as well. Run a good large guage wire from the alternator to the MBA to the new battery. I would probably go with a little larger than 4 guage myself, but it would probably be just on the line. The amps you have do not pull that amount of current all the time, they do it for brief snapshots in time. Sounds like a great project you have going on, I'd like to see it when I come through one day.
Now for the cap, there are some times when it is advantageous to use a cap, however you so not know this yet. A cap is not a magic add power device, it stores what is given yet uses some of the same power to operate. It is best described as a pool of current that is used for a brief instant in time. However all it does is place another draw on the battery as it is another device to be charged, thus can be viewed as detrimental to a system. Yes it operated faster than a battery but will still be slower than a alternator. I have a 93 MR2 with more than likely the same small alternator. It hasn't missed a beat with my system and no cap.
As far as a cap making bass deeper, well that is just [img]graemlins/bs.gif[/img] In some cases, only once in the last year have I found a need for a cap in a system. An amp cannot make power unless it is given it. If the amp needs current to cycle for a deep bass note, it must be given the power. A cap can provide this for a breif instant in time. A HO alternator can do this all of the time. I would think that the extra capacity of the battery will surely help you along as well. Run a good large guage wire from the alternator to the MBA to the new battery. I would probably go with a little larger than 4 guage myself, but it would probably be just on the line. The amps you have do not pull that amount of current all the time, they do it for brief snapshots in time. Sounds like a great project you have going on, I'd like to see it when I come through one day.
05-01-2004, 07:14 PM
#8
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
The fuse off of the battery is to protect the wire going to the amp, not the amp.
The fuse on the amp, is the protect the amp.
So based on this, you could run 100 amp ANL fuses on that 4 awg wire and still have no problems.
I would read MR2NR's ground recomendations carefully. I don't think I can improve on his words or recomendations.
Talk with LBKC, he MAKES custom alts. At the very least you'll gain some insight into how an alt works.
Once again, an illustration from my system:
I have a yellow top mounted in my engine compartment. That battery has 2 fused (300A)1/0 awg wires coming off of it; one to my alternator, and one leading to my rear mounted yellow top. There are 2 fuses on the run between the front and rear battery, each about 12" from the respective battery. If, for example, I were to ground out the center of this wire, both fuses would blow to protect my car. For grounds, I have simply used 1/0 awg from the negitive battery terminal to the chassis. I have also run a 1/0 ground from the engine block (near the alternator) to the chassis.
MR2NR is right, your amps don't draw full current all the time. But, it's nice to have an electrical system with the headroom to handle it.
Adam
The fuse on the amp, is the protect the amp.
So based on this, you could run 100 amp ANL fuses on that 4 awg wire and still have no problems.
I would read MR2NR's ground recomendations carefully. I don't think I can improve on his words or recomendations.
Talk with LBKC, he MAKES custom alts. At the very least you'll gain some insight into how an alt works.
Once again, an illustration from my system:
I have a yellow top mounted in my engine compartment. That battery has 2 fused (300A)1/0 awg wires coming off of it; one to my alternator, and one leading to my rear mounted yellow top. There are 2 fuses on the run between the front and rear battery, each about 12" from the respective battery. If, for example, I were to ground out the center of this wire, both fuses would blow to protect my car. For grounds, I have simply used 1/0 awg from the negitive battery terminal to the chassis. I have also run a 1/0 ground from the engine block (near the alternator) to the chassis.
MR2NR is right, your amps don't draw full current all the time. But, it's nice to have an electrical system with the headroom to handle it.
Adam
05-02-2004, 01:09 PM
#10
50 Watt CAFz'r
Thread Starter
Join Date: Apr 2004
Posts: 238
This is awesome info guys, thanks [img]graemlins/thumb.gif[/img]
Okay, so skipping the cap idea, since it'll prolly cost me just as much for a large cap as a high output alt.
and you say to upgrade all my car's ground... you mean buy one of those performance ground kits you see on ebay?
Okay, so skipping the cap idea, since it'll prolly cost me just as much for a large cap as a high output alt.
and you say to upgrade all my car's ground... you mean buy one of those performance ground kits you see on ebay?
