[Hottarod]

Don't forget to jet up your carb. It takes at least 2 notches up on the secondaries and 1 to 2 notches up on the primaries for even the small NOS jets. Unfortunately, this will make the motor run a bit rich and therefore also a bit slower without the NOS on.

When you first go out to try it just hit it off in high gear first for 4 or 5 seconds and then stop and check your plug color. If you burned the tips of your plugs off you know its too lean, LOL.

After you shut off your NOS stay in the motor for a full second. Its still all up in the intake and if you shut it down abruptly and immediately get off the gas you can get a big BOOOOMMMMMMMM.

If you don't have a low fuel pressure shut off it would be wise to at least put a fuel pressure gauge in there where you can see what its doing.

I would just go ahead and put in the second fuel pump for the NOS.


You can see my 65 fastback at: http://hottarod.stangnet.com/
http://members.aol.com/macstang/Gifs/macstang4.jpg

 

[Hottarod]

I don't know the official, technical, engineering answer.

I helped a buddy one night with his Fox stang, 351W, Demon 750 that he had just put a plate on. After the first run we could barely get the spark plugs out of his aluminum heads. He said he thought it had run a bit lean even though it picked up around 6 tenths. When we finally got the plugs out the wire pins had burned off all the way down to the threads. I said, looks a little lean to me too, LOLLLLL. I asked him, you DID jet up your carb didn't you? He says, huh? .

My understanding is that even though the NOS and fuel are being mixed in your spray bar, the NOS has so much oxygen content in it that it is inherently a leaner mixture. That requires you to rich up the carb side of the system, especially in the secondaries when the juice is flowing. Another reason I can think of is that the NOS bar is designed to work with your carb and the carb has a lot more adjustability in it. The NOS side has a couple nozzles and thats it. Maybe the NOS is purposefully calibrated a bit lean to allow you to fine tune it on the carb side.

The more you spray, the more it flows, the more horsepower you make and the more you have to jet up the carb.



You can see my 65 fastback at: http://hottarod.stangnet.com/
http://members.aol.com/macstang/Gifs/macstang4.jpg