New battery, more power?
Discussion
This will sound like a really stupid question but...
I've replaced the battery with a much more powerful 092 one with 780cca.
I also added a new direct ground from the battery to the engine block.
I'm now reading well over 14v compared to over 13v and obviously cured some ground issues.
I'm running powers MBE so coil packs.
My arse dyno is saying much more power plus more pops and bangs.
Is it totally my imagination? Or does the thought hold water?
I've replaced the battery with a much more powerful 092 one with 780cca.
I also added a new direct ground from the battery to the engine block.
I'm now reading well over 14v compared to over 13v and obviously cured some ground issues.
I'm running powers MBE so coil packs.
My arse dyno is saying much more power plus more pops and bangs.
Is it totally my imagination? Or does the thought hold water?
The more current that flows through the coils primary circuit the better.
Increasing the current increases the magnetic field.........increase in HT voltage
Example....
1)
1 Ohm primary resistance coil/coils
10 Volts ignition supply @ coil during cranking
10 Amps current draw measured when earthing the coil negative terminal with all vehicle cables disconnected from it
2)
1 Ohm primary resistance coil/coils
13 Volts ignition supply @ coil @ run
13 Amps current draw measured when earthing the coil negative terminal with all vehicle cables disconnected from it
3)
1 Ohm primary resistance coil/coils
14.5 Volts ignition supply @ coil @ run
14.5 Amps current draw measured when earthing the coil negative terminal with all vehicle cables disconnected from it
There's something innit
Increasing the current increases the magnetic field.........increase in HT voltage
Example....
1)
1 Ohm primary resistance coil/coils
10 Volts ignition supply @ coil during cranking
10 Amps current draw measured when earthing the coil negative terminal with all vehicle cables disconnected from it
2)
1 Ohm primary resistance coil/coils
13 Volts ignition supply @ coil @ run
13 Amps current draw measured when earthing the coil negative terminal with all vehicle cables disconnected from it
3)
1 Ohm primary resistance coil/coils
14.5 Volts ignition supply @ coil @ run
14.5 Amps current draw measured when earthing the coil negative terminal with all vehicle cables disconnected from it
There's something innit
Listen its science, everyone knows if you polish your car it's faster.
So on that basis more voltage = more faster!
Lol
Jokes aside all I had been thinking was a higher and more stable voltage may effect coil efficiency or certainly something along those lines and presumed somebody would have a theory.
Either way the varta 092 silver battery is a good option for people, it just fits, has way more cca with a noticeable increase in starter speed. The only drawback is the terminals are reversed but the cables are more than long enough.
So on that basis more voltage = more faster!
Lol
Jokes aside all I had been thinking was a higher and more stable voltage may effect coil efficiency or certainly something along those lines and presumed somebody would have a theory.
Either way the varta 092 silver battery is a good option for people, it just fits, has way more cca with a noticeable increase in starter speed. The only drawback is the terminals are reversed but the cables are more than long enough.
V8Bart said:
...
Jokes aside all I had been thinking was a higher and more stable voltage may effect coil efficiency or certainly something along those lines and presumed somebody would have a theory.
I believe the MBE ECU performs battery voltage monitoring as part of its fuel compensation function. As the battery voltage varies the fuel injector firing pulse width varies accordingly, where low levels of voltage require a longer pulse width and high levels shorter.Jokes aside all I had been thinking was a higher and more stable voltage may effect coil efficiency or certainly something along those lines and presumed somebody would have a theory.
My theory is: a high level of battery voltage results in a shorter more dense fuel charge to be fired into the air fuel mixture, so creating better injector efficiency if you like. Plus the electromotive energising action within the injector's coil is more precise or sharper, by virtue of a higher supply voltage.
V8Bart it's just a theory, but I have also experienced similar changes in engine response after changing a battery and puzzled over the possible causes.
Edited by davep on Sunday 9th April 12:24
It may just be that your earth previously was so poor that the engine was down on power.
Certainly my car, for the first month I had it, was like this.
Then I visited a friend of this forum called Alex, and he checked my car over and pushed the number 8 spark plug cap back on.....
Your poor earth may have had a similar effect.
As a TVR owner who has had the 100 amp fuse fail, I can assure you that the car starts on battery but runs on the alternator.
It only runs on battery for the last half an hour after the 100 amp fuse fails, and then not that well.
So you will get better starting, but the battery itself shouldn't improve power output.
A better ECU will, as will an ECU that monitors the electric power available to ignition and injectors I guess.
Certainly my car, for the first month I had it, was like this.
Then I visited a friend of this forum called Alex, and he checked my car over and pushed the number 8 spark plug cap back on.....
Your poor earth may have had a similar effect.
As a TVR owner who has had the 100 amp fuse fail, I can assure you that the car starts on battery but runs on the alternator.
It only runs on battery for the last half an hour after the 100 amp fuse fails, and then not that well.
So you will get better starting, but the battery itself shouldn't improve power output.
A better ECU will, as will an ECU that monitors the electric power available to ignition and injectors I guess.
Hi,
I will reluctantly add that this thread seems technically amiss. The voltage in the circuit, once running, is controlled by the ECU, using variable field current in the alternator. It is this which controls the voltage, not the battery. For modern cars. Older cars still had voltage regulation.
A dodgy battery, if it started the car, would be effectively running at the same voltage as the good battery, due to the control exerted by the ECU or other regulation device.
Many motorbikes I have owned had no battery at all and still ran perfectly well!
Nic
I will reluctantly add that this thread seems technically amiss. The voltage in the circuit, once running, is controlled by the ECU, using variable field current in the alternator. It is this which controls the voltage, not the battery. For modern cars. Older cars still had voltage regulation.
A dodgy battery, if it started the car, would be effectively running at the same voltage as the good battery, due to the control exerted by the ECU or other regulation device.
Many motorbikes I have owned had no battery at all and still ran perfectly well!
Nic
Edited by NicBowman on Monday 17th April 20:14
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There's no way the 14CUX ECU can control what amps the alternator generates, and I doubt an MBE ECU has such control either.
As stated the ECU in our cars monitors the battery voltage level and adjusts injector firing pulse width accordingly, this as part of its final phase fuel compensation routines.
RoverGauge log files clearly show the correlation between Main Voltage and pulse width, and they clearly show that higher battery voltage results in narrower pulse width.
There's no way the 14CUX ECU can control what amps the alternator generates, and I doubt an MBE ECU has such control either.
As stated the ECU in our cars monitors the battery voltage level and adjusts injector firing pulse width accordingly, this as part of its final phase fuel compensation routines.
RoverGauge log files clearly show the correlation between Main Voltage and pulse width, and they clearly show that higher battery voltage results in narrower pulse width.
Hi
DaveP, fully agree with you. The ECU is trying to keep the fueling constant, so it runs the same, when the system voltage changes. The system voltage will vary, but it is actively controlled by a voltage regulator, not the battery. There will be some variation in voltage, with rpm, load changes and component tolerances. The system is complex with many variables but that is the essence.
The point of discussion for the thread is ‘does changing my battery make my car faster?’ The answer is of course no. Otherwise Halford’s would advertise new batteries to make your car faster.
Best
Nic
DaveP, fully agree with you. The ECU is trying to keep the fueling constant, so it runs the same, when the system voltage changes. The system voltage will vary, but it is actively controlled by a voltage regulator, not the battery. There will be some variation in voltage, with rpm, load changes and component tolerances. The system is complex with many variables but that is the essence.
The point of discussion for the thread is ‘does changing my battery make my car faster?’ The answer is of course no. Otherwise Halford’s would advertise new batteries to make your car faster.
Best
Nic
I do not know how V8Bart measured the increase, but the same battery voltage increase of approximately 1 volt that he reported will be seen and acted upon by the ECU. Whether this voltage increase is a result of a new battery or a more efficiently regulated and earthed charging circuit is immaterial to the ECU.
Since an increase in what the ECU calls battery voltage causes an increase on the injector supply line, this results in a higher flow rate due to a shorter injector delay time.
Here's a link to a video showing what happens to the FI fueling curve when battery voltage increases: https://youtu.be/c1VqU6YsJcQ
Since an increase in what the ECU calls battery voltage causes an increase on the injector supply line, this results in a higher flow rate due to a shorter injector delay time.
Here's a link to a video showing what happens to the FI fueling curve when battery voltage increases: https://youtu.be/c1VqU6YsJcQ
Edited by davep on Tuesday 18th April 09:34
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