[topfueldragster]

Just wondering if anyone else is having their voltage drop near the end of the run ?

It's 16.2 before the run - then drops to 15.6 when the nitrous comes on. Briefly drops to 13.6 when the electric shifter hits then goes back to 15.6 . then is fine until about 5.8 into the run it drops back to 13.6 until I lift?

Car runs 6.70 on one system. Anyone have any clue why this is happening ??

 

[NOS-Nelson]

1 battery?

 

[topfueldragster]

it's the 16 volt v-battery - and yes one battery - 54 lb battery figured it has enough umph. These things are supposed to be able to handle anything.
If I turn the nitrous off at 5 seconds it stays at 15.6.
I was thinking of putting a little alt on it ???

 

[NOS-Nelson]

1 battery isn't enough. You either need 2 or the alternator.

 

[Procrew]

Maybe the solenoid for the shifter gets powered up again?

 

[topfueldragster]

I was wondering the same thing about the shifter - but how in the world would that be ??
The only thing that says no to that is when the nitrous is shut off at 5 seconds the voltage never drops ?
I was thinking about putting an alt on - but wouldn't it be a gradual decrease in voltage - mine just spikes down on the racepak graph and when I lift spikes right back up.
Weird.

 

[NOS-Nelson]

I was wondering the same thing about the shifter - but how in the world would that be ??
The only thing that says no to that is when the nitrous is shut off at 5 seconds the voltage never drops ?
I was thinking about putting an alt on - but wouldn't it be a gradual decrease in voltage - mine just spikes down on the racepak graph and when I lift spikes right back up.
Weird.

It's probably taking all the surface charge from the battery.

 

[z289sec]

I was wondering the same thing about the shifter - but how in the world would that be ??
The only thing that says no to that is when the nitrous is shut off at 5 seconds the voltage never drops ?
I was thinking about putting an alt on - but wouldn't it be a gradual decrease in voltage - mine just spikes down on the racepak graph and when I lift spikes right back up.
Weird.

Mine used to do the same before I put on an alternator. The alternator also dramatically cut back on charging times between rounds.

If your shifter is hooked up like mine, you shouldn't have that problem. On mine it has no ground to complete the circuit until the rpm activated switch on the 7531 lets it get the ground.

 

[www.batteriesareus.com]

What charger are us using?
Shoulds like a charger issue?
What is the fully charged battery voltage?

We have alternators for these also;

www.batteriesareus.com
4024085873
TheV battery

 

[topfueldragster]

using your charger - I bought them at the same time from Jegs. The voltage is fine except where I noted.

 

[www.batteriesareus.com]

Your voltage should be 17.8+ when battery is fully charged.

Please contact us - I beleive the charger is causing part of the problem.

How many amps SHOULD the shift solenoid draw?

This battery should easily maintain 15.0v thru the run -
our 11 # batteries do.

Please also email list of what items are running,
along with a data report of the voltage of a couple of runs.

TheV Battery
www.batteriesareus.com
4024085873

 

[topfueldragster]

I will e-mail a list of everything later on tonite. Without the nitrous the voltage is ok (besides the shift).

 

[topfueldragster]

In looking at the racepak data - when it shift it drops 2 down to 13.4. The rest of the run it is 15.4 with the nitrous on. Until about 6 seconds into the run it drops back down to 13.4 and stays until I lift. If I shut the nitrous off at half track the volts do not drop. They al look the same when the nitrous is on for the entire run.

As far as other things running - your basics. Fuel pump, water pump, gauges, delay box, and then the nitrous. Is it going to get worse when I turn the second system on?

The whole reason I bought this tank (54lbs) of a battery is so I would never have this problem. Everyone I know who run the 30 lbs powermaster does not have this problem ??

Just a little annoying. Would your 33 lb battery not be enough ? Maybe this battery is taking a crap ? Or just cannot hold a "full" charge ?

 

[Uncle Paul]

From the sounds of things your battery should have more voltage from the start. I am a huge fan of 1 wire alternator. They reduce charging time and to me are simple insurance against low voltage and making your electronics go crazy.

 

[topfueldragster]

i guess i will try an alternator. Kind of annoying though when this thing is advertised with people saying they make 12 runs without losing anything, etc, etc.
So I buy a 54lb battery and I cannot make a 6.7 second run without a volt droppage??? Now I gotta add 10 more lbs with an alternator.
I guess I ave no choice - little annoying though.

 

[Scott Wasko]

I like Joe's idea about the shifter getting activated again. Is it possible when you shut the nitrous off early, the motor rpm is not getting high enough to hit the shift rpm again?

 

[Uncle Paul]

i guess i will try an alternator. Kind of annoying though when this thing is advertised with people saying they make 12 runs without losing anything, etc, etc.
So I buy a 54lb battery and I cannot make a 6.7 second run without a volt droppage??? Now I gotta add 10 more lbs with an alternator.
I guess I ave no choice - little annoying though.

I agree it can be very annoying when you think you crossed your T's and dotted your I's and spent your hard earned cash on "good stuff". As you stated you have a Racepak hooked up so now you see EVERYTHING that goes on and want it perfect.
If you have the time and a good multi-meter do a current draw on each item you have hooked up to the battery, that will give you a better understanding as to what is going on and might even shed some light on something.
Oh 1 other thing, make sure all the grounds and connections are good, poor grounding/connections can send current draw crazy.