nos launcher controller problems

2weeks ago I had no problems candles stayed lit,this week it has the dreaded surge problem.16volt system 16 at the start of the run 14.5-15volts at end,their should not be a volt problem.all wiring to noids etc have shields with extra care to make sure connections are solid.i am using the 7531 with all of the grounds separate and their is no ramp in the program.

the grounds for the launcher are 2.5ft from the 7531.launcher is grounded to the subframe connectors,7531 is grounded to the roll cage. how far do the grounds need to be apart?

Check WOT switch?

We mount the little ground to the chassis and the big ground to a stud welded to another chassis location with a battery cable to the battery. All major grounds go to this location. The last car we did they were about 2 ft apart. We had a surging problem this weekend with a customer that was solved by putting the backup micro switch on.

Larry, run a number 12 wire to all the way to your battery for the launcher. The battery acts as a filter for any interference from chassis grounds. I also use shielded cable from launcher to the noids. I try to stay away of chassis ground on all critical electronics.

whatbumper wrote:Check WOT switch?

We mount the little ground to the chassis and the big ground to a stud welded to another chassis location with a battery cable to the battery.  All major grounds go to this location.  The last car we did they were about 2 ft apart.  We had a surging problem this weekend with a customer that was solved by putting the backup micro switch on.

ok I can move the bigger ground to the stud that I have welded to the cage were all of the major grounds are.the cage is welded to the chassis very well so that shouldn't be a problem.the ground from the battery is at the rear bolted to the chassis and I have a ground from the motor to the chassis up front.yes I have the double micro switch,the pad from the carb catches the micro switch about 1/8th-1/4 before wfo  

chuck:as bad as I hate to do it I will run a ground up their if that will fix it.i do have very good shields on all of the noid wires.


long story short over the winter I had to take the launcher out of the car and give it back to the owner.later on I purchased it back i took my time rewiring it back but I moved it to a new location and so were the grounds.

I have a friends car in my shop, that we are trying to get ready for No Mercy U/S. He had a lot of problems with his launcher, we are taking it out and putting my eldebrock unit in.

I have a welding leed ran from the batteries to negative post to a stud in the rear of the car, then I ran a cable all the way thru to the front of the car and hooked it to a stud up front. All ground wires go to one of the ground studs... NEVER USE A CHASSIS FOR YOUR GROUND
I was told by many Chassis builders that you are not trying to start your chassis, you're trying to start your engine and run your electronics. You should have a Positive and a Negative cable ran from the back of your car to the front everything should be connected to them, it keeps from having surges and unexplained power blips....and I make sure all my wire connectors are soldered, crimping is just not good enough.

ok,I will run the ground cable to the front 3 days ago I wanted to rip this thing out and put the eldebrock unit in after doing some reading they can have the surge problem as well.

what do you guys think about the relays that comes with the unit?i have wread were they are weak and should be replaced with 30/40 relays?

http://www.leashelectronics.com/Simple-Single-Stage-Nitrous-Board-SSN2012.html

We use the single stage controller from leash electronics to wire the launchers in.


This post was concerning the relays above.


I always wire cars to set them up to run fuel injection which is why I build the modified floating style ground in the front using a 1/0 ground cable.

Larry, think you it would be best to run a #12 from the progressive to the battery post, away from any chassis ground. I know 4 people personally, that have had their ass kick by the launcher. Hope you get the thing work out!

good news,I ran a 3/8 cable from the battery ground post to a plate on the cage then made the bigger ground longer on the launcher.i also separated the 2 smaller grounds on the launcher and all is good   I am learning about the program of the launcher and give the motor what it wants with the small shot.

update:we went to Bristol Tennessee for the lazer race.i had been doing some reading of the manual trying to figure out why on the shift the programmer would reset and start over.i now under stand why if you let out of it the launcher wont come back under full power.i did some changes and netted some decent times you can see the flames pretty steady after 2.8sec in the run.

Diggin the car  

soupbean wrote:Diggin the car  

thanks man,we have the motor out at the moment im trying to expel some of the demonds from the passed and the converter is too tight -4%

Have a few problem with my controller also nitrous solenoids doesn't want to open over 900psi if its at 975psi it wont open wonder if the ground is the problem

What Coug said.

quick 52 wrote:Have a few problem with my controller also nitrous solenoids doesn't want to open over 900psi if its at 975psi it wont open wonder if the ground is the problem

please make sure your grounds are correct go through them one at a time and run a dedicated cable from your battery to a stud then connect the larger ground of the controller to it.in the manual of the launcher it says to set the Hlz at 20 some people set them higher some set them lower.some of the solinoids on the market were not ever designed to be used with a pulse controller and should be gone through for intended use.900psi is the max most people use,in my experance the higher psi will increase the likelyhood of a nos explosion.