140A alternator vs. volt boster

[mikestertwo]

A lead acid battery does not act like any other electrical accessory in the car when the voltage is increased. I'm not going to get into a p**sing contest on this one. Volt boosters are a band-aid for other issues.

 

[GNVenom]

I suppose I should put my two cents in here. To set the record straight, the volt booster is implemented to improve IGNITION performance, not fuel pump performance. And it does a good job at it.

It's the CCCI that could use some help, particularly at WOT, top of the gear, when the engine is revving at its peak. A 15% increase in voltage equates to a considerably hotter and more efficient spark.

I can't speak for other volt boosters, but the Caspers unit uses TPS to switch the boost circuit on, somewhere around 70% TPS and above. And, it only raises the bar around 2 volts of system voltage when switching on. More voltage, albeit temporarily, will noticeably improve ignition performance every time. The battery and the alternator can sustain a temporary increase in voltage under these conditions without permanent side-effects, provided the components are in good condition and up to OEM specifications.

 

[A2000RICH]

A lead acid battery does not act like any other electrical accessory in the car when the voltage is increased. I'm not going to get into a p**sing contest on this one. Volt boosters are a band-aid for other issues.

there is no contest--------just FACTs------the only time the battery does not draw current from the alternator is when the alternator is overloaded and the alternators output voltage drops to the EXACT charge state of the battery whatever that is at a given time-------if the current demands continue to go up the battery and alternator will BOTH supply current as parallel voltage sources------ie in different amounts--------under these conditions there will be no regulation (ie poor regulation) and the voltage will continue to drop in increasing amounts relative to the current being drawn----this voltage drop will be relative to the thevenin equivalents of the two voltage sources--------as soon as the current demands decrease to the level where the alternator can again supply the demand the battery will once again become a parasitic load on the alternator while it is recharging------EVEN when the battery is fully charged it still is a load on the alternator and the higher the alternators voltage (and the bigger the battery) the higher this parasitic load is--------it always puzzles me how many folks just don't understand the simplicity of a basic automotive electrical system................RC

 

[A2000RICH]

I suppose I should put my two cents in here. To set the record straight, the volt booster is implemented to improve IGNITION performance, not fuel pump performance. And it does a good job at it.

It's the CCCI that could use some help, particularly at WOT, top of the gear, when the engine is revving at its peak. A 15% increase in voltage equates to a considerably hotter and more efficient spark.

I can't speak for other volt boosters, but the Caspers unit uses TPS to switch the boost circuit on, somewhere around 70% TPS and above. And, it only raises the bar around 2 volts of system voltage when switching on. More voltage, albeit temporarily, will noticeably improve ignition performance every time. The battery and the alternator can sustain a temporary increase in voltage under these conditions without permanent side-effects, provided the components are in good condition and up to OEM specifications.

john--------i have to say that improved fuel pump performance would have to be a big part of increased voltage advantage------for example the flow of a typical walbro 340 pump increases about 25% at 70 psi with the addition of an extra 2 volts---------i think i could build a pretty strong case that in most cars that 25% would equate to more real performance advantage ( if nothing else a comfortable safety margin) than an increase in ignition voltage even though increased ignition is also important---------my experience is that more GN's suffer from poor fuel supply than lack of adequate ingnition----------and WAY more cars suffer catastrophic engine failure from lean fuel conditions than from lack of ignition performance-------bonus is that this extra 25% is only there when you really need it ie under boost or full throttle conditions-------rest of the time the pump loafs-------bottom line is that volt boosters just make sense and the more that someone understands the facts the more they believe in their use--------my opinion is that all along they should not have been called "boosters" since that seems to conjure up the "mysterious" to the technically challenged-------perhaps "performance voltage regulator" would have described them in a more accurate and less benign way............RC

 

[GNVenom]

Richard, the extra fuel delivery is actually a bonus side-effect. The main reason for it was to improve spark.

Assuming you have a fuel pump that is more than adequate for your application, extra voltage won't really deliver more HP - that's ASSUMING the pump delivers considerably more than you actually need for your desired HP. Extra voltage at the pump is a good thing regardless - hence the hotwire application.

Does that make sense? I am thinking ahead of typing...

There are contributors to the forums that insist the hotwire kits, plenum spacers, hotter ignition coils, underdrive pulleys and boosters are nothing other than band-aids. I guess to each his own. Plenty of opinions out there.

 

[Turbo6Smackdown]

can't agree with you more------problem is few folks really understand ohms law-------a thousand amp alternator will not work on these cars one bit better--------several years ago i did a test of a GN just to see how much current was actually needed to prevent voltage drop due to current demands--------put a car on the dyno and proceeded to turn on accesories-------car had XP super pump-----ATR liquid intercooler with electric pump-------i turned on the AC with cabin fan on high (means the radiator cooling fan starts)-----turned on the high beams------turned on the rear defog------turned on the emergency flashers-------lightly pressed on the brakes to light the brake lights--------turned the radio on-------pressed the cigarette lighter on----------turned on the windshield wipers-------blew the horn steady-------turned on the map reading lights and left the door open so the interior lights would stay on-------not exactly the conditions that i would consider would relate to race conditions-------certainly worst case for sure--------if memory serves me right current demand was 107 amps and the factory alt kept the voltage no lower than low 13's when hot------measured with over $30K of lab grade equipment not counting the price of the dyno-------a volt booster is nothing mysterious-------it simply changes the reference voltage to the regulator so the alternator outputs a voltage slightly higher--------it is a very elementary engineering exercise to prove that the type of fuel pumps that we use can supply more volume of fuel at higher pressures with a stock 120A alternator and a volt booster than they will with a 200A unit with standard output voltage set points--------as an electronics engineer listening to folks discuss alternators, batteries and volt boosters reminds me of how i feel when i hear old timer carburetor lovers talking down the use of turbos and electronic fuel injection because they don't really understand it--------anyone wants to see a demonstration just come to the turbobuick.com nationals (with your magic physics defying alternator) and i will be glad to give you a lesson in electrical theory and show how it applies to our cars.............RC

I know you're the man when it comes to this stuff but... Why did gm put higher amp alternators in cop cars then?

 

[DR BOOST]

I know you're the man when it comes to this stuff but... Why did gm put higher amp alternators in cop cars then?

lights, radio, computers etc

 

[88 CuttyClassic]

Rich- I wont be able to make it down with the pittsburgh crew this time but i glad to know this information. I'm in my 2nd semester of electronics engineering. We haven;t gone over parrallel yet but we just got done with the basic series circuit. Most of what you are sying is making sense to me, about the current and voltage being directly proportional, etc.. Would a battery ever be considered an opposing source or is it strictly a load in relation to the alt?

 

[Turbo6Smackdown]

Originally Posted by Turbo6Smackdown
I know you're the man when it comes to this stuff but... Why did gm put higher amp alternators in cop cars then?

lights, radio, computers etc

I thought he said a higher amp alternator doesn't make a difference? Why didn't they just a booster in there then?

 

[Adam Connell]

^amperage and voltage are related, but not the same in any way.

found a good explanation online:

"The* three most basic units in electricity are voltage (V), current (I, uppercase "i") and resistance (r). Voltage is measured in volts, current is measured in amps and resistance is measured in ohms.

A neat analogy to help understand these terms is a system of plumbing pipes. The voltage is equivalent to the water pressure, the current is equivalent to the flow rate, and the resistance is like the pipe size.

There is a basic equation in electrical engineering that states how the three terms relate. It says that the current is equal to the voltage divided by the resistance.
I = V/r" HowStuffWorks "What are amps, watts, volts and ohms?"


Sorry to dig this one up, but Im currently experiencing some voltage issues, and this was an excellent read! Im highly considering buying casper's "power pack" and calling it a day now. My suspicion is the alternator, but I think I may have a bad ground. I'll dig in this weekend and find out.

 

[A2000RICH]

^amperage and voltage are related, but not the same in any way.

found a good explanation online:

"The* three most basic units in electricity are voltage (V), current (I, uppercase "i") and resistance (r). Voltage is measured in volts, current is measured in amps and resistance is measured in ohms.

A neat analogy to help understand these terms is a system of plumbing pipes. The voltage is equivalent to the water pressure, the current is equivalent to the flow rate, and the resistance is like the pipe size.

There is a basic equation in electrical engineering that states how the three terms relate. It says that the current is equal to the voltage divided by the resistance.
I = V/r" HowStuffWorks "What are amps, watts, volts and ohms?"


Sorry to dig this one up, but Im currently experiencing some voltage issues, and this was an excellent read! Im highly considering buying casper's "power pack" and calling it a day now. My suspicion is the alternator, but I think I may have a bad ground. I'll dig in this weekend and find out.

if you suspect a bad alternator why would you put a volt booster on it????-------thats exactly like putting a bigger turbo on your engine if you suspect a blown head gasket................RC

 

[VIN7]

can't agree with you more------problem is few folks really understand ohms law-------a thousand amp alternator will not work on these cars one bit better--------several years ago i did a test of a GN just to see how much current was actually needed to prevent voltage drop due to current demands--------put a car on the dyno and proceeded to turn on accesories-------car had XP super pump-----ATR liquid intercooler with electric pump-------i turned on the AC with cabin fan on high (means the radiator cooling fan starts)-----turned on the high beams------turned on the rear defog------turned on the emergency flashers-------lightly pressed on the brakes to light the brake lights--------turned the radio on-------pressed the cigarette lighter on----------turned on the windshield wipers-------blew the horn steady-------turned on the map reading lights and left the door open so the interior lights would stay on-------not exactly the conditions that i would consider would relate to race conditions-------certainly worst case for sure--------if memory serves me right current demand was 107 amps and the factory alt kept the voltage no lower than low 13's when hot------measured with over $30K of lab grade equipment not counting the price of the dyno-------a volt booster is nothing mysterious-------it simply changes the reference voltage to the regulator so the alternator outputs a voltage slightly higher--------it is a very elementary engineering exercise to prove that the type of fuel pumps that we use can supply more volume of fuel at higher pressures with a stock 120A alternator and a volt booster than they will with a 200A unit with standard output voltage set points--------as an electronics engineer listening to folks discuss alternators, batteries and volt boosters reminds me of how i feel when i hear old timer carburetor lovers talking down the use of turbos and electronic fuel injection because they don't really understand it--------anyone wants to see a demonstration just come to the turbobuick.com nationals (with your magic physics defying alternator) and i will be glad to give you a lesson in electrical theory and show how it applies to our cars.............RC

Richard,

I know you stated "on the dyno" but did you vary the vehicle speed/rpm? My concern would be amp draw at low speed/idle conditions. Are alternators output rated at a minimum rpm and at what point (engine rpm) do they reach that minimum?

Thanks,
Mike

 

[A2000RICH]

Richard,

I know you stated "on the dyno" but did you vary the vehicle speed/rpm? My concern would be amp draw at low speed/idle conditions. Are alternators output rated at a minimum rpm and at what point (engine rpm) do they reach that minimum?

Thanks,
Mike

we did do both idle and high speed tests------------the output did drop slightly at idle but still was able to maintain a charge state on the battery ie > 12.8v--------but remember you could never duplicate the conditions of that test in actual use of a car----------unless you had considerable aftermarket accesories ie lots of lights/giant stereo etc---------most alternators can output a large percentage of their output as long as they are turning upwards of 2000RPM--------remember the pulleys have a 3:1 overdrive ratio so this is achieved at idle of 700RPM................RC

 

[Roger]

Richard, the extra fuel delivery is actually a bonus side-effect. The main reason for it was to improve spark.

Assuming you have a fuel pump that is more than adequate for your application, extra voltage won't really deliver more HP - that's ASSUMING the pump delivers considerably more than you actually need for your desired HP. Extra voltage at the pump is a good thing regardless - hence the hotwire application.

Does that make sense? I am thinking ahead of typing...

There are contributors to the forums that insist the hotwire kits, plenum spacers, hotter ignition coils, underdrive pulleys and boosters are nothing other than band-aids. I guess to each his own. Plenty of opinions out there.

Thanks for the information John, I have seen most TR owners refer to fuel pumps rathar than ignition needs. I see a more expensive "boost a pump & ignition" to be a beter way to achieve better performance than the less expensive volt booster bandaid & probably easier to tune.

 

[A2000RICH]

Thanks for the information John, I have seen most TR owners refer to fuel pumps rathar than ignition needs. I see a more expensive "boost a pump & ignition" to be a beter way to achieve better performance than the less expensive volt booster bandaid & probably easier to tune.

considering that all the extra power provided by a boostapump still has to come from the alternator it seems a poor choice to me--------knowledge of what a boostapump does makes this understandable---------a device like this cannot actually "boost power" in spite of its name--------it only trades increased input current for more output voltage and since it has inherent losses it only increases the demand from the alternator even more since thats where all the electrical power comes from anyhow---------here's how the simple math works out----------as an example lets take a 340 pump drawing about 100 watts---------i introduce the term watts here because it is a term that indicates the amount of work actually done by the pump and assume that the engine requires a certain amount of fuel regardless of how it is provided--------at 13 volts directly from the alternator that would equate to 7.7 amps supplied by the alternator--------with a volt booster raising the ouput to 15 volts on the alternator that same 100 watts would require 6.7 amps from the alternator------------if we use a boostapump to provide that same 15 volts there is always an inherent efficiency loss ---------if we say its a really good design (using low loss fets and high efficiency switching cores) and it is 85% efficient that same 15 volts at the pump would require that the alternator supply 7.9 amps to the boostapump to provide that same 6.7 amps at the pump---------there are other factors that actually complicate this calculation on a much higher level and for simplicity sake i have left those factors out but they only serve to strenghten the case against a boostapump----------if you have a car that can benefit from higher voltages there are alot of boostapumps that will do just fine but you have to remember that they still have to get all their power from the alternator and they do not boost power-----------they boost voltage--------and they boost voltage by drawing more current from the alternator--------- and they cannot do it as efficiently as doing it with the regulator circuitry of the alternator----------bottom line is that the alternator still has to supply all the power...............RC

 

[turboc87gn]

What is the" power pack"?
I know caspers makes good stuff but this is the first ive heard of it....

 

[A2000RICH]

What is the" power pack"?
I know caspers makes good stuff but this is the first ive heard of it....

i think thats the name he gives to his volt booster---------you are right John makes some good stuff---------his volt booster is triggered off the TPS and i have used several of them---------only thing i have found to be a problem with volt boosters is that SOME aftermarket alternator regulators do not work properly with them---------that is a possible reason for some folks to think volt boosters are not a good product..............RC

 

[GNRick]

So...volt booster=good, boost a pump= bad.

 

[Adam Connell]

Nope, the power back is a combo pack of all of casper's products for the TRs.

 

[Adam Connell]

if you suspect a bad alternator why would you put a volt booster on it????-------thats exactly like putting a bigger turbo on your engine if you suspect a blown head gasket................RC

Oh no, I am doing that anyways. Like I said I am going to dig around tomorrow and find my issue. I have yet to even chase the issue, but I suspect the alternator may be going, as well as a bad ground.

Gunna find and fix my issues before I chase any more power... First thing's first!