Increase of Base Fuel Pressure and K Value

Well, yes.

Adding to the K or increasing fuel pressure will do the same thing just as subtracting or reducing the fuel pressure. It's a constant setting either way for the K… just move it up or down when changing effective flow rate; BUT you may or may not have to adjust your null time at all.

AHHH so this K value that I always hear so much about is basicly just to change the raw fuel curve? Is K= full rpm+full boost? On the TEC this value is represented by TOG time on for one gamma.

Yeah, I think most high end standalones use a similar method for fuel compensation (or so I have heard).

The K is the injector constant value. In Nissan ECU's (like many others) it's a preset value used primarily for setting the injector size. You then use the void, null, latency, etc time to correct for the injector's "speed". Obviously, you can run bigger injectors rather easily by adjusting these two values… but the maps and load and RPM scales need to be changed for more accuracy in the regions you will now be tuning the car for.

If that makes any sense?

So let's say i install these 380cc injectors i'm getting.

Assuming they're benched @ ~380cc's

Stock K value = 025F Hex

025F Hex = 607 Dec

260cc * 607 K Value = 157820.

380cc * X = 157820.

X = 415.32 Dec or 019F Hex

Would it be ok to just change the hex to "019F" in the ECU and run it as is? I really don't want to screw up my engine and attempt to tune with live edit.

I think I am following your logic there but I think you have an issue with the values listed. Line 4??

I am no tuning expert but if your math is correct and the K value is a linear equation for adjustment…then yes. I think you are on the right track.

Actually, I am very interested to hear what others with tuning experience with the K value have to say on this. I will be entering the league of tuning with Nistune shortly. :shock:

Who are you replying to, Zman?

If you're replying to me: I got that entire equation from Jasons "tuning for your k value" write-up. i substituted my values and recalculated.

If you're not replying to me: Nevermind

I was replying to you…but…

now that I read through it a couple more times…I get it, my brain was working backwards there for a couple minutes. Sorry for the confusion on my part. ops:

i am so confused right now

I have a 88N/A ecu with a romulator installed inside it right now. I was going to go livedit but with nistune coming out i dont know anymore. Can i use this ecu and romulator for nistune or should i sell it, make a little money on it and go with an early ecu and nistune? Anyone running nistune yet?

The K you figured seems right based on that equation, but that's only a starting point. What I should really say is that there's no way to know for sure without a wideband O2 sensor; but again that's not to say that you can't do it without one.

Um, quite a few of us have been running pre-production versions for the better part of this year.

The current version works with the romulator to accomplish what the NVram version will without the romulator in the future (when it is released).

Even with how much i've read about tuning with live edit, i still think i'd explode if i tried to do it.