I recently intalled the nos sniper system on my Z. I put in the recommended jet sizes that nos gave me to produce a 100 shot. When I tried it out, it felt awesome. I only sprayed it for a few seconds at a time for three times. After checking my plugs I saw that they had been killed. The porcilin had been blown off and the electrode kinda ate up. I checked with a very knowing racer and he said I was getting too much nitrous and too little fuel. I checked my fuel pressure before installation and it was up to snuff. I know that my fuel pump is sufficient enough. My problem is that after doing much reading on this board, it has been said time and time again that nos recommended pill sizes are very cautious in making sure there is enough fuel. I read that most of the time it is way too rich on fuel. It was suggested that I go to a bigger pill size on the fuel and stay the same on the spray.

nos recommended(100 shot) n20/fuel - 47/53
what I am going to try 47/61

Any suggestions? Comments? Is this something worth trying?

 

Yeah, it is lean in a bad way. Did you check the fuel pressure when you did the nitrous test before opening the nitrous bottle? Make sure you have enough pressure when you are using the nitrous. The fuel pressure without the notrous fuel solenoid on doesn't tell you all that much. Do the test with the nitrous solenoid closed (no nitrous flowing).

When you break the porcelen of the spark plug it shows things were really bad.

 

WAIT!!!

Where did you get those jetting recommendations? Is this a carbed car?

A 100 shot for a carbed Sniper kit is 47 nitrous/ 53 fuel. On carbed car running 7psi fuel pressure, the nitrous jet is always smaller than the fuel jet.

Here is a link:
http://www.holley.com/data/Products/...A7001-SNOS.pdf

You were running a nitrous jet allowing enough flow for almost 180 horsepower and a fuel jet big enough for a 100 shot .

 

OOPS! really sorry on that one! i meant 47, i really screwed up on that one, dont know what i was thinking. im a real idiot

yeah i did check it with it hooked up with no nitrous flowing

 

Standard practice is to reduce the nitrous jet, not increase the fuel jet. What is your fuel setup like? Pump? Line size?

I wouldn't mess with jetting until you figure out what is causing this. What is your total timing you are running? What kind of fuel?

 

i just put on a higher output fuel pump, i have the larger line for fuel (i guess 7/16?). i dont know total timing, but i know on the dampener its at 12 with the venturi vacuum advance pulled. i dont have a smaller nitrous size. how did you test fuel pressure? maybe i need a new pressure gauge?

 

You need to get a hold of a dial back timing light and see what your total timing is. I ran a standalone fuel system with a pressure gauge built in.

What you need to do is tape your fuel pressure gauge to your windshield and make a WOT pass to see if your fuel pressure is dropping under a load.

It would be a VERY good investment for you to purchase a fuel pressure safety switch, like this one:



http://store.summitracing.com/defaul...=egnsearch.asp

Figure out what your total timing is and let me know, what are the specs on your engine as far as compression, camshaft, displacement and cylinder heads?