getdowngranny
Mr. Fix It
- Joined
- Jan 8, 2006
John, what is your take on the volt booster causing issues with Alky injection?
Volt booster or not?
- Thread starter baby6
- Start date
There shouldn't be any ill effects to your computer and everything else as they are seeing 14.8 volts. That's the part I like. The only concern I would have is for the battery,ignition,and fuel pump as they are the things that are seeing 15.8(we presume). I don't know if it would harm the pump and ignition. My only concern is the battery. If it's not boiling fluid out,I would be less concerned.
Heck,I've had batteries that didn't last any longer than 40K and low voltage might be as bad or worse than high on the module and coil.
You get extra volts to the computer all the time. No problem.
I get extra volts to the computer only when I need it the most. No problem.
You get extra volts to the ignition all the time.I'm thinking no problem.
I get extra volts to my ignition only when needed. No problem.
Your set-up provides the two extra benefits of the volt booster other than fuel pump. Computer and ignition. Good.
When you do a voltage test at the battery and generator,you should find something over 15.
If you do and you've been running this same voltage for 40K,I'm gonna change nothing.
Look at the battery fluid and monitor fuel pressure.
If you use alky and tune it to your liking then add the volt booster you would have to re-tune because the extra voltage would cause the alky pump to spray more. Essentially, you're running a volt booster because your alky pump is seeing more volts than it would otherwise. If you raise voltage via the volt booster,you would want it to activate before the alky was commanded.
- Joined
- Feb 18, 2006
The factory wires are fine until you start adding stuff. Aftermarket accessories that every car has stacked on the fuse panel is the problem. I've proven that. After isolating all my stuff, ecm voltage went up somewhere around 1.5 volts. My scanmaster reports upper 13 low 14 volts. Want to see? 
- Joined
- Feb 18, 2006
Allot of guys are using a volt booster with alky. Like anything just tune accordingly.
Going astray from the OP:
I'm not sure how elaborate the alchy systems out there are. I really have no idea how many systems are available to the turbo guys and have never used alchy on my cars.
I presume the most simple systems turn on the pump when needed using a switching device. If that's correct, then extra voltage from the booster will cause the pump to run at a higher speed, adding more alcohol to the mix. This would make the alchy system very difficult to precisely administer, since system voltages are all over the place.
However, if the pump speed varies with demand based on a controller, then I would think the system voltage has less of an effect on alcohol delivery. Still not highly precise, but much better than just blasting the pump with a switch.
Finally, if the pump speed is constant and there is a solenoid for the alcohol delivery, controlled by PWM (similar to our factory wastegate control), the system voltage would probably have very little effect on precise metering of the alcohol.
And, regarding the OP (Voltage 101):
Did you ever notice the car losing power, or the exhaust "popping" and backfiring at the top of the RPM, top of 3rd. gear? That is usually what happens when you run out of spark. And, you run out of spark every time when you run low on voltage.
What everyone should consider with a volt booster is the positive effect voltage has on our ignition system. The ignition system voltage level is critical to a healthy spark. It's the voltage that gets your spark in the efficient range. Average current consumption, in fact, DROPS as the RPM increases, so voltage control is necessary to achieve an acceptable spark under load. That's the main reason you would want to use a volt booster, as it does more for your ignition system than for your fuel system.
Assuming your fuel pump puts out more volume and pressure at 12 volts than you actually need under worst-case scenario, and is not "on the fence" with delivery, the fuel system should be more than adequate, so a system voltage drop of a volt or so won't have any real effect on your WOT blasts.
But your alternator will fill the battery as needed. Everyone who monitors WOT blasts will almost always record a voltage drop in the scan, as the RPM's hit the top of each gear, especially at the top of third gear (when you're near the end of the quarter mile run - and when you need a hot spark the most). With all that power being consumed, the alternator can't keep up with the 13+ volts required by the ignition system. So the voltage drops. It doesn't matter so much what size of alternator you use, nor does the current output really matter - those 240 amp beasts won't give you more voltage. What really matters is that voltage. That is exactly why you use the volt booster - to compensate for that voltage sag. There aren't too many other ways to do it the way the volt booster does it. It's taking over where the alternator/battery system falls off. You can't really call it a "band-aid" since it's not really covering up for something, but rather compensating for a design fault. Most vehicles out there can handle a slight drop at WOT, but our cars need all the help they can get, because we've been pushing the design envelope forever.
Off the soapbox for now.
I'm not sure how elaborate the alchy systems out there are. I really have no idea how many systems are available to the turbo guys and have never used alchy on my cars.
I presume the most simple systems turn on the pump when needed using a switching device. If that's correct, then extra voltage from the booster will cause the pump to run at a higher speed, adding more alcohol to the mix. This would make the alchy system very difficult to precisely administer, since system voltages are all over the place.
However, if the pump speed varies with demand based on a controller, then I would think the system voltage has less of an effect on alcohol delivery. Still not highly precise, but much better than just blasting the pump with a switch.
Finally, if the pump speed is constant and there is a solenoid for the alcohol delivery, controlled by PWM (similar to our factory wastegate control), the system voltage would probably have very little effect on precise metering of the alcohol.
And, regarding the OP (Voltage 101):
Did you ever notice the car losing power, or the exhaust "popping" and backfiring at the top of the RPM, top of 3rd. gear? That is usually what happens when you run out of spark. And, you run out of spark every time when you run low on voltage.
What everyone should consider with a volt booster is the positive effect voltage has on our ignition system. The ignition system voltage level is critical to a healthy spark. It's the voltage that gets your spark in the efficient range. Average current consumption, in fact, DROPS as the RPM increases, so voltage control is necessary to achieve an acceptable spark under load. That's the main reason you would want to use a volt booster, as it does more for your ignition system than for your fuel system.
Assuming your fuel pump puts out more volume and pressure at 12 volts than you actually need under worst-case scenario, and is not "on the fence" with delivery, the fuel system should be more than adequate, so a system voltage drop of a volt or so won't have any real effect on your WOT blasts.
But your alternator will fill the battery as needed. Everyone who monitors WOT blasts will almost always record a voltage drop in the scan, as the RPM's hit the top of each gear, especially at the top of third gear (when you're near the end of the quarter mile run - and when you need a hot spark the most). With all that power being consumed, the alternator can't keep up with the 13+ volts required by the ignition system. So the voltage drops. It doesn't matter so much what size of alternator you use, nor does the current output really matter - those 240 amp beasts won't give you more voltage. What really matters is that voltage. That is exactly why you use the volt booster - to compensate for that voltage sag. There aren't too many other ways to do it the way the volt booster does it. It's taking over where the alternator/battery system falls off. You can't really call it a "band-aid" since it's not really covering up for something, but rather compensating for a design fault. Most vehicles out there can handle a slight drop at WOT, but our cars need all the help they can get, because we've been pushing the design envelope forever.
Off the soapbox for now.
RmvBfrFlght
Well-Known Member
- Joined
- Sep 28, 2007
One reason that the vehicle system voltage fluctuates is that the alternator senses the voltage at the alternator. So as demand increases the voltage drop through the various wires increases, while the voltage at the alternator stays the same. The result is lower voltage throughout the vehicle.
There is an S (sense) terminal in the alternator connector that can be used to alleviate some of this voltage drop. In some vehicles GM ran a heavy wire from the S terminal to the starter solenoid. Which is where the main vehicle power originates from.
Back to volt boosters, back in the day of carbs I ran a double pump set up. Mechanical pump ran all of the time (obviously), with an electric pump coming on at WOT via a micro-switch on the throttle linkage. One day decided to use the same switch to up the voltage at WOT via the external regulator (for alternator).
Worked great, only issue was that the lights blinked brighter at WOT, then blinked dimmer on a lift. That was the one thing I didn't like about it. Could have put a low-pass filter in the works so that the voltage didn't change so rapidly. But went to an internally regulated 12SI alternator and did away with the volt boost.
RemoveBeforeFlight
There is an S (sense) terminal in the alternator connector that can be used to alleviate some of this voltage drop. In some vehicles GM ran a heavy wire from the S terminal to the starter solenoid. Which is where the main vehicle power originates from.
Back to volt boosters, back in the day of carbs I ran a double pump set up. Mechanical pump ran all of the time (obviously), with an electric pump coming on at WOT via a micro-switch on the throttle linkage. One day decided to use the same switch to up the voltage at WOT via the external regulator (for alternator).
Worked great, only issue was that the lights blinked brighter at WOT, then blinked dimmer on a lift. That was the one thing I didn't like about it. Could have put a low-pass filter in the works so that the voltage didn't change so rapidly. But went to an internally regulated 12SI alternator and did away with the volt boost.
RemoveBeforeFlight
mikestertwo
Well-Known Member
- Joined
- Sep 13, 2006
That's how I have my alternator wired. My voltage never drops below 13.6 on a WOT blast. The nice + side is the alternator will still charge if you loose the lamp in the dash.
The ideal point to attach the S wire would be the furthest point away from the battery, as long as there is sufficient current. Basically, what the volt booster does is simply tell the S input that its not doing a very good job of regulating, essentially forcing the alternator into overdrive.
So if you have the battery at the rear of the car, that'd be a good reference point. The volt booster makes it simple, though.
So if you have the battery at the rear of the car, that'd be a good reference point. The volt booster makes it simple, though.
jpwalt1987
Well-Known Member
- Joined
- Nov 9, 2003
Just placed an order for a volt booster from you John. I look forward to testing the difference it makes.
GNVenom said:
Thanks. I've never experienced any ignition problems yet with this alt. Ran a .032 gap at 25psi plus on ngk ur5s using stock ignition without issue and now run tr6 with silverado coil on .040 gap at nearly 30psi. I do shift at 5k rpms is all too. Do you think I could still benefit from a vb?
Is your ignition still hotwired? Awaiting generator output voltage. I've never hotwired my ignition,so it never sees the kind of voltage that yours does.If yours is seeing over 15 as I susspect,I think I will hotwire mine. I have yet to install my TR6. Do you use the square truck coils?
Ttype6 said:
I do still have it hotwired and I do use the square Silverado three towers in one coil pack. I never changed my ccci fuse to the 25amp that Bob Bailey recommends but he stated that wouldn't be needed with the hotwire still in place. He also stated though that he thought there would be no performance gained on a tr6 module with a hotwire vs a 25 amp fuse on the stock circuit. I like knowing it has full power though.
I thought you were using individual CNP set-up. I have the individual square truck coils. More voltage in means more voltage out. No matter what ignition you have,it seem to me that more would be better up to some limit of course. Did you get a chance to check your voltage yet? Did you take a look inside the battery?
Ttype6 said:
I haven't checked voltage at the battery yet and I have a sealed delco battery so I won't be able to look into it. I need to drive my car to work and Saturday will be the first chance I get. I don't commute it much this time of year due to deer and darkness at 8pm.
Checked it today. My voltage at the battery and back of alternator is never more than .45 volts higher then what the SM is reading so I'm leaving it alone. The SM has been setup to show between 14.5 to 14.8 volts. That may be higher than recommended for a battery at times getting 15.3 volts but it's been good for 40k mile so far so I'm leaving well enough alone.
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