Car Alternator or Battery Issue

[gunnerzz]

I am using BMW fan from M43B19, its supposed to be high speed fan. The voltage dropped to 12.7 when the fan is spinning very fast for few seconds, and voltage recover back to 13.3 - 13.4 v after it slow down.

Thanks,
Ken

dual speed fan?

 

[Mitevo7]

Yup, agree with bro. pomen. If voltage drop below 13v then you battery not enough charge already.....

Hi,

The drop is momentary and recover back to 13.3-13.4, this was taken only during idling. I am not 1JZ ECU is OB2 compliant or not, but can we actually tune up the idling RPM so that the idling charge is enough?

Thanks,
Ken

 

[Mitevo7]

dual speed fan?

From the sound of it when its activated, it looks like a dual speed fan. I remembered there was a year when the original cooling fan will constantly tuned into highspeed mode (real loud from the outside when its spinning very quick) and slow down to normal fan speed after engine reached warm up temperature, in the end we found out the fan switch is faulty and constantly putting the fan into highspeed mode. That burned out the motor pretty quick.

Thanks,
Ken

 

[Mitevo7]

Folks,

I have been seeing online and found there's alternator voltage booster module available for certain type of cars. Wondering is there such devices in Malaysia to help with my current issue ?

Thanks,
Ken

 

[Izso]

Folks,

I have been seeing online and found there's alternator voltage booster module available for certain type of cars. Wondering is there such devices in Malaysia to help with my current issue ?

Thanks,
Ken

Which booster you read up about?

 

[Mitevo7]

Which booster you read up about?

Here you go: https://zzperformance.com/products/alternator-voltage-booster

Although its available for most U.S car brands, some Toyota models like Prado, Land Cruiser, Hilux ... Not sure about 1JZ.

Thanks,
Ken

 

[Izso]

Here you go: https://zzperformance.com/products/alternator-voltage-booster

Although its available for most U.S car brands, some Toyota models like Prado, Land Cruiser, Hilux ... Not sure about 1JZ.

Thanks,
Ken

Ah... I would not use those things.

I like this guys videos, might help you :

 

[Mitevo7]

Ah... I would not use those things.

I like this guys videos, might help you :

Alternator returned fine, only at low rpm the charging seems inadequate. Besides increasing the RPM (which is out at this moment), i ran out of option to try to increase the voltage output, earth cables are fine and can't seems there's much resistance in the system. Hence comes to this booster module.

Thanks,
Ken

 

[gunnerzz]

Did u check or is there any way to check the alternator output at the source meaning at the alternator itself.

After reading this all over again i think there is a bad connection somewhere.

 

[vr2turbo]

Did u check or is there any way to check the alternator output at the source meaning at the alternator itself.

After reading this all over again i think there is a bad connection somewhere.

But the charge is fine with accessories off, pass 14v....

 

[^pomen_GTR^]

I am using BMW fan from M43B19, its supposed to be high speed fan. The voltage dropped to 12.7 when the fan is spinning very fast for few seconds, and voltage recover back to 13.3 - 13.4 v after it slow down.

Thanks,
Ken

i see... from the way you describe it...


my suspect would be the alternator amperage not enough for your bimmer electrical...changing into bigger amperage alternator would help in solving this issue...

 

[^pomen_GTR^]

Here you go: https://zzperformance.com/products/alternator-voltage-booster

Although its available for most U.S car brands, some Toyota models like Prado, Land Cruiser, Hilux ... Not sure about 1JZ.

Thanks,
Ken

the voltage should be sufficient... but the amperage problably fell below than what the car body electrical demands... (load too much supply too little)

 

[Izso]

the voltage should be sufficient... but the amperage problably fell below than what the car body electrical demands... (load too much supply too little)

I'm still debating whether that tiny little booster wire is going to help you. Looking at the thing itself, it looks like it'll probably have some diode to upscale the V, but this will reduce the amperage I suspect and something else is going to suffer

 

[^pomen_GTR^]

I'm still debating whether that tiny little booster wire is going to help you. Looking at the thing itself, it looks like it'll probably have some diode to upscale the V, but this will reduce the amperage I suspect and something else is going to suffer

i'm more afraid that when this device increase the voltage during load,

it will over-volt the system when the load is taken off from the system (like when fan turns off and ac turns off)

unless if the system auto compensate when the load if lower and keep true to 14v limit

 

[gunnerzz]

i see... from the way you describe it...


my suspect would be the alternator amperage not enough for your bimmer electrical...changing into bigger amperage alternator would help in solving this issue...

I just finished reading an experiment paper by Utem student on car alternator.

Lots of interesting info abt alternator such as;
-normally alternator rating is the output it produce when its (the alternator) spinning at 6k rpm. With 1:2 ratio, thats 3k rpm engine speed.
-alternator will produce >12v to overcome the battery internal resistance in order to be able to charge it.

Apart from the basic higher speed will produce more current i also learnt one interesting thing;

In the paper they mentioned about crankshaft-alternator speed ratio. Normal car is 1:2 which means 1k rpm on crank is 2k rpm on alternator. This means to make the alternator produce more output during engine idle we can play with this ratio by changing the pulley size so it spins faster right?

 

[^pomen_GTR^]

Apart from the basic higher speed will produce more current i also learnt one interesting thing;

In the paper they mentioned about crankshaft-alternator speed ratio. Normal car is 1:2 which means 1k rpm on crank is 2k rpm on alternator. This means to make the alternator produce more output during engine idle we can play with this ratio by changing the pulley size so it spins faster right?

they got it wrong.. (although i'm from utem myself )

car alternator doesnt operate on 2:1 pulley ratio...its more than that.. probably atleast 3:1 or 4:1 (see the alternator pulley size vs crank pulley size to get the idea)

2:1 is crankshaft to camshaft ratio....



yes u can change the alternator pulley into smaller one (or bigger crankpulley) to increase the rpm ratio between those 2...

problem is on the market, most is people selling under-drive pulley (which lower the ratio and effective rpm of alternator) for race purpose and use it on the street (wrong concept)....

the reason of under-drive pulley invented for racing purpose, race engine never saw rpm lower than 4.5k rpm...it will spend most of the time at high rpm range..so to reduce alternator speed damage (as well as power steering pump)...race car build install the under-drive pulley....

installing under-drive pulley will make alternator (and power steering pump and ac compressor) working under its designated speed make it worst in slow moving traffic or on idle during traffic jam...

what people on the street is over-drive pulley...

in this jz bimmer case, is ideal solution (if not changing bigger amperage alternator)....but since sourcing the over-drive pulley which definately need to be custom made is freakin expensive, then bigger alternator is the simplest route to follow... because bigger alternator is more common mod especially in car audio shop...

 

[parakey]

i see... from the way you describe it...


my suspect would be the alternator amperage not enough for your bimmer electrical...changing into bigger amperage alternator would help in solving this issue...

+1

 

[gunnerzz]

they got it wrong.. (although i'm from utem myself )

car alternator doesnt operate on 2:1 pulley ratio...its more than that.. probably atleast 3:1 or 4:1 (see the alternator pulley size vs crank pulley size to get the idea)

2:1 is crankshaft to camshaft ratio....



yes u can change the alternator pulley into smaller one (or bigger crankpulley) to increase the rpm ratio between those 2...

problem is on the market, most is people selling under-drive pulley (which lower the ratio and effective rpm of alternator) for race purpose and use it on the street (wrong concept)....

the reason of under-drive pulley invented for racing purpose, race engine never saw rpm lower than 4.5k rpm...it will spend most of the time at high rpm range..so to reduce alternator speed damage (as well as power steering pump)...race car build install the under-drive pulley....

installing under-drive pulley will make alternator (and power steering pump and ac compressor) working under its designated speed make it worst in slow moving traffic or on idle during traffic jam...

what people on the street is over-drive pulley...

in this jz bimmer case, is ideal solution (if not changing bigger amperage alternator)....but since sourcing the over-drive pulley which definately need to be custom made is freakin expensive, then bigger alternator is the simplest route to follow... because bigger alternator is more common mod especially in car audio shop...

Good additional info...

 

[parakey]

in this jz bimmer case, is ideal solution (if not changing bigger amperage alternator)....but since sourcing the over-drive pulley which definately need to be custom made is freakin expensive, then bigger alternator is the simplest route to follow... because bigger alternator is more common mod especially in car audio shop...

You may change to a smaller alternator pulley to increase the rpm but wont that place a larger idle load on the engine? He's already complaining it's not idling well

 

[Mitevo7]

they got it wrong.. (although i'm from utem myself )

car alternator doesnt operate on 2:1 pulley ratio...its more than that.. probably atleast 3:1 or 4:1 (see the alternator pulley size vs crank pulley size to get the idea)

2:1 is crankshaft to camshaft ratio....



yes u can change the alternator pulley into smaller one (or bigger crankpulley) to increase the rpm ratio between those 2...

problem is on the market, most is people selling under-drive pulley (which lower the ratio and effective rpm of alternator) for race purpose and use it on the street (wrong concept)....

the reason of under-drive pulley invented for racing purpose, race engine never saw rpm lower than 4.5k rpm...it will spend most of the time at high rpm range..so to reduce alternator speed damage (as well as power steering pump)...race car build install the under-drive pulley....

installing under-drive pulley will make alternator (and power steering pump and ac compressor) working under its designated speed make it worst in slow moving traffic or on idle during traffic jam...

what people on the street is over-drive pulley...

in this jz bimmer case, is ideal solution (if not changing bigger amperage alternator)....but since sourcing the over-drive pulley which definately need to be custom made is freakin expensive, then bigger alternator is the simplest route to follow... because bigger alternator is more common mod especially in car audio shop...

I would agree to changing higher amp alternator, the stock 1jz alternator possibly isn't big enough to supply to all those gizmos in the beemer.

I am thinking of 2JZ alternator instead as it is still affordable. What's your opinion?

Thanks,
Ken