I'm having the same problem. My MSD Digital window switch is set to 2500 rpms but doesn't hit until 4500. Whats the problem?

 

Reset the WOT voltage .2-.4 below the max you see as it will vary.
If the max value the WOT switch sees it 4.6 set it to 4.3 seems like I have to do this once a year or so not sure why.

I had the same problem you can have a friend sit in the pas seat and watch the display is it the 3 digit?

this one?


If so watch for 1 1 0 if one of the 1's flickers to 0 then thats the problem.

Dont forget to raise the window back up b4 you test it.

 

Make sure the ws is seeing the same rpm as the tach

 

It seems to be. Are the digital window switches just slow?

 

Sometimes they are a touch slow yes. BUddy of mine's car has this problem, he has a 3500 converter and the nitrous wasn't coming on until probably 3800 or so. He had a 3000 rpm chip in the car, msd window switch.

We pulled the chip out so it would come on as soon as the wot engaged, no rpm range, figuring that if the converter flashes to 3500 it would be o.k.,a nd it worked, took .2 off his times doing it.

If you have a loose converter in the car/truck, stop somewhere and just floor it, see what the RPM shoots up to, if it's over 3000 rpm, then try turning the rpm the nitrous turns on at lower.

This is probably something that can be done safly with 100 to 125 shots, any more then that it's probably not a good idea. Nitrous creates alot of cyl pressure, and that's what kills parts, engage it too soon adnd the pressures that are created at low rpm (more time for more nitrous to get in) can be distructive.

 

i have mine come on at wot...so about 1000 rpms for 125 shot....hite nicely

 

Use a real WOT switch and no minimum on the window switch.

 

24 inches is kind of long for the fuel line, i would shorten it to minimize any lean spike, but that's likely not your issue. I think checking the WS would be the way to check things. What i do in my drive way is to hook up my air comp to my n2o supply line (block off the fuel side), then tape the WOT SW open, then as soon as you hit the rpm you have set in your WS it should release the air from your compressor. A very easy way to check that the WS is working, and at correct RPMs. Don't forget to take the tape off the WOT SW as this will cause issues if you don't, ask me how I know, lol.
A nozzle as your supply choice for diagnostics should have no change in what is happening, as they both work basically the same. Check out HSW's sight for a video of how their plate actually sprays, you will be amazed at how the 360° pattern works to put the spray into the intake. It's really the best method concerning any plate or nozzles coming in from the throat area. I think your problem lies else where, and many gave some ideas to check. You'll get it, just keep at it and good luck. Make sure you let us know what finally is the culprit.
Robert

 

Yep thats the same window switch im using.

It has a built in WOT switch so thats what ive been using for my activation, are you saying that is what is causing the delay??

I wasnt thinking it was the plates problem since it does seem to have the best distribution into the intake, just throwing out ideas.

The window switch RPM matches the rpm the truck is running at.

For the WOT setup you just open the throttle to 100% and it sets the voltage for me, I think it is the 4.6 that you said, do you suggest not going all the way to 100%?? Thats the only way I can lower the voltage.

Ill mess with it tomorrow when there isnt a tornado outside haha.
Ill turn the activation RPM to 0 and see what it will do.

 

Does yours do something like this?

 

EXACTLY like that, what gives??

 

Yes you need to set it at ~98% WOT becase the voltage varies and causes the problem, that is the same WS I am using and I had the same problem I lowerd the WOT voltage a bit and problem gone.

You are still going to put your foot to the floor every time you spray just set it at 4.4 and drive the same.

No dont lower the rpm you have already proved that does not work try the tests or change the WOT voltage a bit.

 

Sounds good, ill give that a try.

Thanks!!

 

Mine would hit, then hesitate, then hit and all good...

I did not know what was up with at first and let it sit all winter till now. My 1st project was to put in ARP head studs as I was pushing water. N/A I was fine but on the spray it would disappear.

So, last weekend I tore the motor apart and found this.



and I found I had a leaky injector as an o-ring was pinched.....

The broken rocker pedastool relates to the dart heads and stock GM's pedastools dont line up unless you notch it, witch i did not know to do so it was sitting up off the head until it broke...

So, after I fixed that and put new 0-rings in and got her all back togther (along with new plugs) I sprayed it with the 100 shot shortly later and it was all good to go. No more hesitation at all...

Im not sure what it had to do with the N20 or even at all for that matter. Alls I know is those are the problems I had and fixed that and now the N20 is fine..

If it makes any difference I have my WS set up to come on at 3500, and I have a 4K stall.

 

Yea after watching your video again you can hear it activate then cut off then hit again. Mine doesnt do that, just launch then hit. But the delay is about the same.

 

I had some problems with the nitrous not coming in as soon as I wanted it to and then it would come on and off a couple of times down the track. I bypassed the mechanical wot switch and the problem has not come back yet.

 

Well did you find the problem?

 

mine works fine... id expect a small delay but just back up the rpm that its suppose to fire at(if its causing issues) i spray at 4000 but my convrter flashes past 4000 so my hit seems almost instant to me

01ws6 you saw my log you can see the msd aint really reacting that slow (.1-.25 sec)

 

See the pic in my sig? That's what a 150 hit that's right off the transbrake when I'm up on the converter gets me