Voltage regulator or DC to DC converter ?

[Cs19]

I need something that can regulate the voltage that is coming off a relay that powers one of my fuel pumps.
I see some fluctuation in my voltage during a run due to some big nitrous solenoids that draw alot of amps. The changes in voltage is screwing with my fuel pressure (pump psi. changes as voltage changes) so Im looking to keep the voltage to my pump constant at roughly 13.5 volts. Are there voltage regulators or converters that will work for my application?
Thanks.

[placecrafttim]

Sounds like you need a capacitor. But I dont know how your system is wired so I'm little help to ya.
Tim

[Cs19]

Its wired like anyone else would wire a fuel pump using a bosch 30 amp relay.
CS

[sanger rat]

Maybe this would work for you. http://www.aeromotiveinc.com/pdetail.php?prod=31

[placecrafttim]

Do you have relays controlling your solenoids? If so are they on the same circuit as the fuel pump? Meaning that you have one main wire that feeds all relays. If so maybe you can increase the size of wire or get a bigger battery or both. Have you checked the battery to make sure it's up to par. Just a couple things I could think of. Hope it helps.
Tim

[Cs19]

The wiring is up to par, not the problem here...
The problem Im having is the changes in voltage change the fuel psi. in my nitrous system.
Is there something available like a regulator that will keep my voltage steady?
CS

[Cs19]

Maybe this would work for you. http://www.aeromotiveinc.com/pdetail.php?prod=31
thats a neat deal there Sanger but Im looking for a steady rock solid voltage for my fuel pump, not something that changes as the RPMS go up, Im seeing enough of that as it is..LOL
thanks for the replys.
CS

[sanger rat]

Are you running a alternator?

[Cs19]

yes its a mini denso type, puts out 55 amps.

[deltaAce]

If the application of the nitrous solenoids taxes the battery enough to decress voltage to the fuel pump, it may also have a degrading effect on your ignition system. Perhaps a higher amp battery is in order.

[shaun]

I agree with above, sounds like you may need a capacitor. You can find 12-24v caps at most car audio places. They are simple to install, basically just goes inline on your positive batter wire (if you have multiple wires running off the batters positive term you'll need to move all these to the other end of the cap). I'm not quiet sure the size cap you need, if it where me i would just try throwing a One farad cap inline...

[Animal Magnatism]

You can get 12v regulators, but they themselves can drop a couple of volts and so you would need a good 14V at the battery. Perhaps you need a bigger alternator, and you should be running the pump on it's own line directly from the battery (if you're not doing this already).
How much does the fuel pump draw?
How much do the solenoids draw?
How much does the voltage vary by, and is that variation happening at the battery as well?
P.S. you could get a cap (or another small battery) and run it via a diode so that the solenoids don't discharge it.
Paul.

[Cs19]

You can get 12v regulators, but they themselves can drop a couple of volts and so you would need a good 14V at the battery. Perhaps you need a bigger alternator, and you should be running the pump on it's own line directly from the battery (if you're not doing this already).
How much does the fuel pump draw?
How much do the solenoids draw?
How much does the voltage vary by, and is that variation happening at the battery as well?
P.S. you could get a cap (or another small battery) and run it via a diode so that the solenoids don't discharge it.
Paul.
They wont give me a direct answer on how much the pump draws, they only tell me its a low draw pump, its a small pump, about the size of a holley blue. For comparison...A large full race pump draws up to 20 amps from I am told, Im guessing this one draws 8-10.
Solenoids draw near 50 amps total.ouch.
Vairiation is from 15.5 to 12.5, I take this reading right off the batt.
If there is something out there that could keep my voltage to the pump at 12.0 volts I could live with that.
Thanks.

[SmokinLowriderSS]

yes its a mini denso type, puts out 55 amps.
I think there's part of it.
It's my understanding that Alts are only actually designed to run 50% cycle time. As such, yours is not actually capable of maintaining 55 amps for very long at all, and is designed to only SUSTAIN arround 25 to 30 amps. If your fuel pumps draw hard, and so does the ignition (an MSD does I understand), you may well be maxing the poor thing out right there.
If the wiring isn't undersize, and is separately circuited, to a large enough feeder trunk, I'm afraid you may not get it settled without a heftier alternator output.

[SmokinLowriderSS]

Im guessing this one draws 8-10.
Solenoids draw near 50 amps total.ouch.
Thanks.
There it is, estimated 60 amps pull, then add the ignition, instrumentation, is anything else in there?
You may well be running on 80 amps requirement flat out, only a MAX of 55 amps supply.
Heavy battey cables (I'm thinking 2-gauge, fine strand, anything less and you are shorting yourself in capacity), 8-gauge feed to the solenoids (6 would be better), 10 gauge to the pump circuit.
http://www.powerstream.com/Wire_Size.htm
single conductor amperage capacity (ampacity), in air (drops in bundle due to heating, stranded's somewhat higher, but I have not found how much.
Size ....... Max for chassis wire / max for power transmission
10 gauge ampacity, 55 amps / 15 amps
8 gauge ampacity, 73 amps / 24amps
6 gauge ampacity, 101 amps / 37 amps
4-gauge ampacity, 135 amps / 60 amps
2 gauge ampacity, 181 amps / 94 amps
There is also a voltage drop calculator on that page, at the bottom, accepts 12VDC.

[Cs19]

Thanks Smokin, Im gonna think about this for a bit. :)
We realize there is more draw than the mini alt. puts out but we only run the nitrous for about 3 seconds on average so we were trying to avoid having to go that route and add more weight than we already have.

[SmokinLowriderSS]

Yea, I realize you're fighting weight issues as well. (kinda thought of it after the first post .... just getting awake LOL)
Even heavy wiring is just that, heavy. If the battery is sufficiently oversized (in supply amperage) and wiring is plenty, you might get away with it, but then, weight, which weighs more, a larger battery and wiring, or a 100 A alternator? The Alt prob be lighter.
Hell, I'm trying to envision nitrous solenoids drawing 30 amps EACH! How big are they, 5 pound coffe cans? :p
Good luck cs19.

[victorfb]

chris. i believe "Smokin" is right on with his diagnosis and recommendations. it sounds like you need a higher output alternater. i understand you are concerned about added wieght, but a higher output alt. wont add much more wieght. the cases can be the same size with just increased windings inside. plus the added output will most likely give you better performance on the top end as your ignition will be more efficient. also the mention of multi strand wires/cables are a big plus. i use the extremely fine multi stranded cables you would see in high end stereo shops. much better than your average stranded battery cables found on production vehicles and in automotive parts stores. overkill on the wire size is never bad in my opinion. finally: check your battery for its amperage rate. it may show 13.5 volts but the amps can be way low. meaning your battery lost its storage capacity. under load it can be draining itself and causing the same problems you are having.
P.S. Good grounds and ground straps everywere!

[roostwear]

Don't know what solenoids you're using, but you may be able to lower your draw by changing solenoids. Foe example, NOS nitrous solenoids draw 8.6 to 10.0 amps each. Zex.... from 8.6 to 16.0 amps each! Typically, fuel solenoids draw very little... 1.5-1.8 amps.
The holley black pump uses a 7.5amp fuse, so start adding it up, and depending on if you're using a purge solenoid, your fuel system alone could draw less than 30 amps depending upon your nitrous pressure/flow requirements. That should not present a problem for your ignition circuit.
Find out what you have now, and consider new solenoids. Remember, the more output from your alt (even at only 55 amps), the more parasitic loss. If you're chasing every horse, take a quick look at your system.

[rrrr]

It's the alternator.....
Answers pointed at the battery miss the mark. The battery can't provide more than 12 volts to a load. It's only sposed to start the boat and then be recharged.
I would use a small bus bar (like the top one) for power takeoff to the solenoids and pump. You'll need one for positive and negative. Run a #4 wire to the bus bar from the alternator output and to the battery, #10 to the solenoids, and #8 to the pump. Use Ancor tin plated marine grade wire and Ancor marine type solderless connectors. install inline fuse holders as required-for a race boat I wouldn't be too worried about it.
Make the circuits as short as possible to avoid voltage drop. Most people ignore it, but like the other kind of VD it can cause real problems.... :crossx:
http://images.westmarine.com/full/bluesea23032304.jpg

[Cs19]

Thanks guys.
Roost, replacing the solenoids isnt an option, these are high quality solenoids, those of us that use them just have to deal with the draw they have.
Thanks again.
CS

[DEL51]

I use welding cable for the battery. The capacitor will drain too fast, even the big ones. That said, a capacitor will help dampen the voltage spikes from the on/off action of the solenoid coils. I agree about the alternator size and estimated current draw.Have you seen the 16 volt turbo start batteries and their accessories? this may be the way to go.I trust you know enough about the wiring end of it. Are you going to have any posters at the world finals?

[Cs19]

Del, I heard your boat ran some big time numbers, congrats!!!!
Are you coming to world finals?

[DEL51]

I am working on getting the days off. I would like to get a poster, or large pic and a shirt from you and your group. If I can't make it there,my friends already have their plans to go, so I could have them pick some up. I want to duplicate the numbers before I say more on the boat, hopefully on saturday. Can you get errors on gps receivers? I think cold air and water temps, plus fully opening up the doms may be all it needed.

[Cs19]

I sometimes carry a GPS when i race to compare it to my speed trace on my data and my time slips, from what Ive seen they are fairly accurate.
No problem on the t-shirt, just have them come by our pits.
Chris.

[deltaAce]

It's the alternator.....
Answers pointed at the battery miss the mark. The battery can't provide more than 12 volts to a load. It's only sposed to start the boat and then be recharged.
The battery provides those volts (pressure) through the volume of amps. A device (load)
is usally rated by the amps required to operate it properly. A weak battery may not provide the necessary amperage to power it, but may still measure 12V. From behind our keyboards we can only guess that its one thing or the other. A 50 amp alternator may suffice if he has a stout battery & the wiring is proper.
:)

[DEL51]

I agree with the last post regarding amps and the issue is voltage drop. I wonder if Chris could duplicate the situation on the trailer. Use the data recorder and activate the solenoids with fuel and nitrous lines disconectted.Run the jetaway in neutral run the r's up to 5 k hit the button and see what happens. Granted the fuel pressure and amp draw will be less but this might be an idea worth checking out.

[cyclone]

I see two possible solutions here. either wire a capacitor inline to the fuel pump with enough reserve capacity AND a fast enough recycle time to provide the necessary voltage to the fuel pump during a nitrous run.....
http://www.stingerelectronics.com/web/prods/capacitors.asp
or you need a box to step up and regulate the voltage coming from the battery to the pump. Stinger used to make a box that stepped up voltage from 12 to 14.4 volts for car audio amps. Dont see it on the website anymore but its likely another company is selling something similar and calling it a dc to dc voltage converter.
http://www.powerstream.com/dc2.htm
hope this helps.

[superdave013]

They wont give me a direct answer on how much the pump draws, they only tell me its a low draw pump, its a small pump, about the size of a holley blue. For comparison...A large full race pump draws up to 20 amps from I am told, Im guessing this one draws 8-10.
Solenoids draw near 50 amps total.ouch.
Vairiation is from 15.5 to 12.5, I take this reading right off the batt.
If there is something out there that could keep my voltage to the pump at 12.0 volts I could live with that.
Thanks.
If you are only looking for 12VDC then you could go down to Orvac's and buy a regulator / heatsink. You will need to know how many amps your fuel pump uses to get the correct size. Just hook an amp meter in series with the pump and measure it.

[superdave013]

I'm tellin ya, I love google sometimes.
take a look
http://www.powerstream.com/dc2.htm

[steelcomp]

CS...on that "other" website, did you see the link to the pneumatic NOS solanoids?? They looked pretty cool. I think they also had a power regulating box, like mentioned above, for steady voltage. I'll go back and check it out.
Got it..
... I also suggest you give Dave Koehler a call and discuss using this combo for your application. http://www.koehlerinjection.com/Koehler/Comboflo/comboflo.htm
...also on their site, go down the menue on the left, click on "electrical", and check out the "AccuVolt". Might be just what you need.

[JAY4SPEED]

Steel beat me to it, I've read about these a while back but never used one.
Accuvolt is made my Jacobs Electronics this is what you need:
Jacobs Accuvolt (http://www.jacobselectronics.com/ProductDetails.aspx?brandId=13&productID=6610710&majID=775&minID=7751&selection=6&minselection=0)
http://www.jacobselectronics.com/e-images04-350//510064.jpg
If your only going to be making passes at the track, this is what you need. However, with sustained cruising, I think that your eventually going to run out of reserve in the battery with such a low alt output.
What if you changed pulley ratios and spun the alt faster? That would put the alt towards the higher end of output while cruising, then slow the alt down for the track?
Jay

[Cs19]

CS...on that "other" website, did you see the link to the pneumatic NOS solanoids?? They looked pretty cool. I think they also had a power regulating box, like mentioned above, for steady voltage. I'll go back and check it out.
Got it..
...also on their site, go down the menue on the left, click on "electrical", and check out the "AccuVolt". Might be just what you need.
yep saw all that stuff. the pneumatic solenoids are trick.
got this issue sorted out and went testing last weekend and its working well.
thanks everyone!! :)
Chris.

[Animal Magnatism]

So what did you end up doing?
Paul.