In short, they gave me incorrect info about the fuel system in my car. Their directions don't add up, and because of this, the jetting may be off as well. Here's a link to the whole story.

http://web.camaross.com/forums/showthread.php?t=338680

 

There is only 1 reason I can come up with, as to why the injectors will see more pressure.

the actualy FP the injectors see, is a combination of line pressure, and the air pressure at the injector tip. At WOT, if the the sucking of the TB is somehow creating a pressure zone less that atmosphiric. That would make the effective fuel pressure on the injector higher than the line pressure.

Only possibility I can come up with.

 

Dewey, you've got it backwards. NOS claims that the supply line pressure will be 15-20, while the injector pressure will be 9-13.

 

From the other thead. NOS is saying 15-20psi, you saying 9-13psi, that means NOS is saying they are jetting for 6-7psi MORE than you are setting your line pressure, correct?

 

Correct, but the kit is supposed to be designed to work on a stock motor, which means stock fp which is 9-13 psi. It is also designed to be used with the stock pump, which I doubt can even push 20 psi. Doesn't make much sense now does it. BTW, I was also told not to run a high flow fuel pump because it will raise line pressure and cause the nitrous to run extremely rich. Sounds like they don't know wtf they are talking about to me.

 

well, to large of a fuel pump, and you out run the return line, which will cause it to build pressure.

I really don't know what they are getting at, I told you, that was the only way I could see a pressure of greating the line pressure, is if the injector is actulay sitting in less pressure than 14.7.

 

That is not a problem, especially with the fuel solenoid open. I don't think they even knew what they were getting at.

 

Well, I can give you the jetting I'm using, if that will help. LOL

 

We can atleast compare jetting just to see if they gave us consistant info.

36 nitrous/26 fuel for 50 shot
47 nitrous/36 fuel for 100 shot
52 nitrous/39 fuel for 120 shot
65 nitrous/42 fuel for 135 shot

EDIT: IIRC I was also told a 72 nitrous/55-56 fuel jet for 150 shot

 

Hmm, that is the same jetting I have. After arguing with the NOS techs about fuel pressure, and why my i was running more than 6.5psi on a carb intake....

Guess I'll have to get wideband readouts on the dyno.