Batteries effect on ignition and fuel pump.

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milkandoj

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I was going to buy a yellow top optima battery for my car as i have the battery in the boot, and wanted a strong current to the ignition system and walbro when giving it the boot. Going to get a d34, rated at 750 CCA. They are a deep cycle/starting battery.


Will having a stronger battery make a difference with the ignition system and fuel pump.

What about an uprated alternator?

I ask as i see many 4g63 drag racers getting massive alternators, although they have modified ignition systems aswell.
 
milkandoj said:
I was going to buy a yellow top optima battery for my car as i have the battery in the boot, and wanted a strong current to the ignition system and walbro when giving it the boot. Going to get a d34, rated at 750 CCA. They are a deep cycle/starting battery.


Will having a stronger battery make a difference with the ignition system and fuel pump.

What about an uprated alternator?

I ask as i see many 4g63 drag racers getting massive alternators, although they have modified ignition systems aswell.
Click to expand...
I know quite a few drag racers that don't have an alternator. You won't see any difference in your fuel pump unless you rewire it. As far as your ignition, I would say no or hardly noticable. But you may experience brighter interior/exterior lights.
 
That was my other reason for asking, like you have a battery in the car that rated say 500 cranking amps, recharge time of near 100amp hours, so it delivers 50amps for two hours, or 20 amps for 5 ect, till it drops below the voltage standard they use for the test, like 10v.


Yet when you notice lights dim when at idle and fans kick in ect.

So would the alternator have more to do with it? I'm thinking putting an 90amp alternator in it from another mitsi.

i don't have problems, just wondering if its worth spending the extra coin on an optima when a normal lead acid battery is under warranty also if it dies. Either battery will be bought through work.

I have read a few so called horror stories of batteries slowly dying and car still run but fuel pumps arn't flowing like they should, or boost controllers have over boosted. And destroyed a motor. but i could be all forum bullsh!te

i will rewire my fuel pump soon. Its a walbro also. Stock ignition system.
 
Both the optima or the DIN series century battery ill use have a 2 yr warranty period. So I'm not concerned about that really.

Its more the other aspects i looking at.
 
milkandoj said:
That was my other reason for asking, like you have a battery in the car that rated say 500 cranking amps, recharge time of near 100amp hours, so it delivers 50amps for two hours, or 20 amps for 5 ect, till it drops below the voltage standard they use for the test, like 10v.


Yet when you notice lights dim when at idle and fans kick in ect.

So would the alternator have more to do with it? I'm thinking putting an 90amp alternator in it from another mitsi.

i don't have problems, just wondering if its worth spending the extra coin on an optima when a normal lead acid battery is under warranty also if it dies. Either battery will be bought through work.

I have read a few so called horror stories of batteries slowly dying and car still run but fuel pumps arn't flowing like they should, or boost controllers have over boosted. And destroyed a motor. but i could be all forum bullsh!te

i will rewire my fuel pump soon. Its a walbro also. Stock ignition system.
Click to expand...


remember bigger Alternator still works the same as a normal one just with more juice. remember alternators dont run on full Amps untill they reach a set engine speed, so upgrading issnt always a big thing. more of a battery that is rated to power all the accessories attached to your car..
 
So when on boost, in relation the the strength of the ignition system and walbro; Is the stronger battery going to make a difernce or having a 90 amp rather than 75 amp alternator.
 
There are a few things to look at when you start looking into electrical voltage systems in a car. They have a large influence on the overall running of an engine.


-FUEL SYSTEM

The voltage system will play a crucial part to your cars running tune simply because the voltage of the vehicle will affect the fuel pump flow rate and injection performance.

Some/Most aftermarket ECU's have some form of voltage compensation so when a fan kicks in/ headlights go on etc, it will inject more fuel for that split second etc etc.


-ALTERNATOR

The higher the rating, the more HP it takes out of the engine (increased engine load). Most guys upgrade the ALT with big Audio systems.

I believe the stock ALT on the VR4 is 75 amps which is plenty. As for racers, there are a few options. Some run without an alternator which means all power is provided by the BATT.The downside, you need to have a battery big enough to keep the engine running for the race (more weight). The good thing is that they make a bit more power due to the load taken off the crank.

-IGNITION

From what I am aware of, most standard coils require a min of 10Volts to work. Ideally you'd want over 12v to 14v (charging). If you have a working ALTERNATOR, the battery shouldn't affect the performance. The battery only really stores the power and allows you to crank the engine over. You could pretty much disconnect your battery after you start it and it will keep on running.

So all in all, I say just get a battery that will allow you to start your engine and if you have a big sound system, a battery big enough so you can listen to your music without starting the car for whatever time you desire (I used to have 2x 1000cca batteries and was able to pump out the tunes for over an hour!! with 2 subs / 3 amps etc etc).

The only reason you'd go for a bigger battery / alt is if your using MORE power than your batt / alt can supply with the engine running..

Hope that helps!
My understanding of it anyway.
 
I used to have a 230cca battery in my old vr4. Started the car and the car ran fine (not big stereo in it though). As BAz said, the alternator does the work once the engine is running, the battery is merely a filter (like a capacitor) and provides some reserve power if you exceed what the alternator can supply.
 
if you put an clamp ammeter on some of the things that drain power you will find that the ignition isn't that much,from memory my walbro pump is 10amps and the electric fans when they run are 8amps.i think the ignition is about 5amps,ecu wouldnt be much.so overall with fans on you wouldnt be much over 20 amps peak.as everybody else says that the alternator takes care of that and the battery is just being used as a big capacitator when running.
big stereos are the killer with 1000w amps pulling nearly 100amps of power out of the system.
point as far as batteries lasting a long time,how long are people expecting,ive been lucky getting about 5years out of a standard batteries.
 
battery life is a hit and miss thing... if they NEVER go flat they can last years, the moment they get drained completly it affects the life alot, espicially an older battery
 
turbovr4 said:
if you put an clamp ammeter on some of the things that drain power you will find that the ignition isn't that much,from memory my walbro pump is 10amps and the electric fans when they run are 8amps.i think the ignition is about 5amps,ecu wouldn't be much.so overall with fans on you wouldn't be much over 20 amps peak.as everybody else says that the alternator takes care of that and the battery is just being used as a big capacitor when running.
big stereos are the killer with 1000w amps pulling nearly 100amps of power out of the system.
point as far as batteries lasting a long time,how long are people expecting,ive been lucky getting about 5years out of a standard batteries.
Click to expand...

Is that with a big stereo?
I don't have plans for one yet, but some decent sound might be on the cards later.
I keep turning the crappy stereo i have down all the time to hear the motor and tires around corners anyway

Thanks everyone for the replies.
 
Well i’m up for a new alternator anyway now...

Is there any reason not to go a 90amp alternator rather than 75amp stock replacement?
Is the increased drag on the motor from a stronger alternator noticeable at all, i wouldn’t imagine so?

Battery is 580cca and 105 rc so it can handle the increased charge. I don’t have plans for a big stereo but it 'may' have something with an amp one day, so I’m thinking to just get a 90amp.
 
The RC time would have more to do with it surely, it gives an idea of the capacity of the battery.
I was more just saying i dont have a tiny battery so the increased charge from the alternator shouldnt boil it?
 
auto vr4's had 90 amp alternators. AFAIK all manuals came with 75amp. my aus spec had a 90amp in it however i'm fairly sure that it wasn't the standard one
 

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