H.O. Alternator question

[goku87]

Originally Posted by firebob

It looks like ran for the next few days. If I have not gotten a pic up by Monday morning send me a PM so I get it first thing in the morning. I’ll do my best to get a pic.

Awesome. It will do me good to know kinda where I should be looking.

[firebob]

This is the ground on the 09 lift back automatic that is on the transmission. It is on the front of the trans under the air box. I did 3 pics. The first one is a zoom of the bolt, then I zoomed out for a little location type shot, and the last one I moved out a bit more for a marker shot with a blue dot of where the camera was.

I suck with sizing pics so if you want them sent to you just let me know. I opened them up and used the snip tool to copy them down to a decent size. The originals are 3.5 meg or so and 3648 x 2736 in size.

[pennyracer]

i have to ask whats the gain on this mod ? i have a ton of amp draw on my battery and alt

[sqcomp]

The Big 3 is a charging wire upgrade that allows your alternator to get the best connection to the battery and charging system. It also makes certain your chassis is the best ground it can be. This is done by supplementing the stock wires from the alternator positive to the battery positive, engine block/alternator case to battery negative and battery negative to chassis ground.

You use a larger wire, preferably the same size as that wire which feeds the amplifier(s) but not less than 4ga for any practical gain. You also place a fuse in the wire between the alt positive and battery positive to prevent a short causing a fire.

By making these connections better, many people see as much as a full volt of increase in charging voltage. Also, many times you'll recover from a hard discharge more quickly than before because current can flow more freely into the electrical system. You also remove strain from the stock wiring when powering a high wattage system.


Here are pics of my big 3 install on a 2007 Yaris S Sedan:

Frame ground point from alternator:



Frame ground termination from alternator:



Alternator ground source ground:



Transmission to frame 1/0 gauge ground cable with compression fittings:



Transmission to frame ground (this is shot looking up from under the car):



Battery negative to frame ground:



Hope this helps...

[pennyracer]

okay thanks for the info i will try to check the voltage before and after this mod . thanks again

[firebob]

This all comes down to the theory of voltage drop.

I don’t think you are going to notice a difference in voltage unless you have a huge amperage draw. You might be able to see something on a volt meter by doing this or you might not depending on the variables.

IMO. If you are running an amp then you need to look at the grounding systems (if more than one the charging system). I’m not saying to put in a different alternator but look at its wiring (I have not looked over the wiring harness at this point so I’m not the one for this). This will take care of the grounding system on the front of a car. I always suggest running the same size neutral wire as the power wire and to ground the wire at the disruption box.

[pennyracer]

well i am running two arc audio amps here are the specs on my amps both are running at a 2 ohm load i have the 300x4 and the 1000x1 amp
they draw a bit of power so i am looking for more usable voltage .

OUTPUT POWER (RMS) @l% THD 100HZ 14.4VDC



POWER OUTPUT (2 2 OHMS

1000 WATTS (S 113 A Eff. 68%



POWER OUTPUT @ I OHM

1000 WATTS (Of 132 A Eff. 53«/

TOTAL HARMONIC DISTORTION

FREQUENCY RANGE -MB

I5dB-230dB



CROSSOVER RANGE

30Hz-230Hz



SUBSONIC FILTER RANGE

10Hz-80Hz



BASS BOOST

0-15dB(Si30Hz-125Hz



S/N RATIO (A wig) ref I Walt 4 ohms

>70dB



SEPARATION

NA



DAMPING FACTOR 25W out 4 ohm lOOHz

>IOOO



INPUT SENSITIVITY (RCA)

.30V-6.5V iff 4O

.25V-5.3V@2n
,15V-3.7V(2j in

INPUT IMPEDANCE

13KOHMS

OUTPUT POWER (RMS) @1% THD 100HZ 14.4VDC
KS 300.4



POWER OUTPUT @ 2 O

175 X 4 WATTS @ 113A Eff. 68%



POWER OUTPUT @ 1 Q

NOT RECONMMENDED



POWER OUTPUT @ 4n BRIDGED

350 X 2 WATTS @ 132A Eff. 53%



POWER OUTPUT @ 2 fl BRIDGED

NOT RECOMMENDED

TOTAL HARMONIC DISTORTION

FREQUENCY RANGE -3dB

7Hz-68KHz



CROSSOVER RANGE

55Hz-5.5KHz



BASS BOOST

0-15dB@45Hz



S/N RATIO (A wtg) ref 1 Watt 4 ohms

>98dB



SEPARATION

76dB



DAMPING FACTOR 25W out 4 ohm lOOHz

>800



INPUT SENSITIVITY (RCA)

..25V-4.0V



INPUT IMPEDANCE

[firebob]

This should help you with a system that size.

[talnlnky]

Originally Posted by pennyracer

okay thanks for the info i will try to check the voltage before and after this mod . thanks again

i respect pretty much everything i've seen sqcomp write.... though I have to play devils advocate here....

Checking just your voltage before and after won't tell you the whole story. Your voltage MAY OR MAY NOT change with this mod.... be upgrading the wire you aren't allowing for more voltage, but actually more current (amperage)... you can send 500v over a 4awg wire, but... you can only safely send 125amps of current over a 15ft long run of 4awg.

point being... It would not surprise me much if you don't notice much... if any of a voltage increase. But even if you don't see that difference... there actually will be more amperage... which means your battery will recover/recharge quicker, thus your voltage will drop back down to normal idle range (13v) much quicker than with just the stock 6awg wires.

many variables that factor into the game. By changing just one thing... you can actually change a handful of other things.

[goku87]

Originally Posted by talnlnky

...you can send 500v over a 4awg wire, but... you can only safely send 125amps of current over a 15ft long run of 4awg.

what calculations do you use? my reference seems to be off:

http://www.powerstream.com/Wire_Size.htm

[firebob]

The only way he will see anything is if he is stressing the system to the point discharge and the alternator can not keep up (I think this goes back to the flux currents or something) or he has bad corrosion in the factory wires.

If I had my NEC with me I would give you what it says on this. But the higher the voltage the higher the amount of wattage you can transmit. The killer to most systems would be the voltage drop that happens with long runs of wirers. I don’t know what the expectable voltage drop for a 12 volt system but I do not think it would be much.

[talnlnky]

Originally Posted by goku87

what calculations do you use? my reference seems to be off:

http://www.powerstream.com/Wire_Size.htm

http://www.bcae1.com/


go to the page about wires...

[sqcomp]

To add to what Taln is saying, I didn't do the upgrade for any other reason besides simply achieving a faster recovery time from the alternator. I know already that the 80 Ampere alternator will NOT put out 125 Amperes under ANY conditions.

...he he...

I'd be an ass to start the Watt is a Watt issue (random thought)

[firebob]

If you can find a trashed alternator and get it rebuilt using smaller wires you should be able to get about 100 amps. I’m sure if you do some digging around you will find a bunch of cars using the same alternator. As far as shops find some rat roders classic car guys and see if they know of a good one. I’m sure of the cost for a rebuild.

It might be worth it to find someone that works at an auto parts store and have them buy it for you. They get a 20% discount most of the time (even with most special orders) and if you work it right by having someone order it and cancel (you have 24 hours to cancel a major order by law) they might be able to get it 30 to 50% off to get it out of there inventory.

[talnlnky]

Originally Posted by sqcomp

To add to what Taln is saying, I didn't do the upgrade for any other reason besides simply achieving a faster recovery time from the alternator. I know already that the 80 Ampere alternator will NOT put out 125 Amperes under ANY conditions.

...he he...

I'd be an ass to start the Watt is a Watt issue (random thought)

i didn't mean you had to run 4 awg... I only said 4awg cause I remember that for 15ft of 4 awg you can safetly transport 125amps +/- a few. 1/0awg is something more like 250-300 I think... don't remember off the top of my head... the upgraded "big 3" of course aren't going to be 15ft long... so a 4awg run (thats 5ft) will take much more current than 125amps.

Point being... voltage is only half of the story.

[pariahdecss]

My other question about an HO alternator, don't you get a larger belt drive load on the engine, unless it is some radical high efficiency design. I wouldn't want a HO alternator if it would kill my fuel economy - or is the added load negligible?

Mike

[sqcomp]

Oh yeah, I wasn't defending or attacking at all. I'm in agreement. My big three is just right for the car IMHO. That little alternator isn't capable of too much.

I am anxious to see where I'm going to ground three amplifiers in the trunk of the sedan...

you'd prolly lose 5 Hp. I don't know your driving style so I can't comment on fuel efficiency.

[firebob]

Pariahdecss I’m going to take a stab at this but I’m not 100%.

If it was done with the same case and bearings then you would just have the issue of starting the spin. If you just switched out the magnets I’m sure you could get 10 to 15 amps but if you went too far with the magnets you would need to change the spacing between the wirers and the magnets. If it was rewound using a finer wire you could get 20 amps. With doing both you could get 120+ with only use a miniscule more power off the motor.

I would think it would be less then 5 hp if it was done right.