fuel pressure settings

[drummondracing]

I have been reading these post over and over and you learn something new everyday. I have a non adjustable 125 plate on my luv, so do i need to.......

1. adjust my fuel pressure with the pump running and the fuel solenoid on? do i leave the fuel line attached to the carb while doing this? i have the f.p. set a 7# now just with everything hooked up and the pump on is this too much ?

2. i am running one regulator one side to the carb the other to the nitrous, it this still acceptable i have been using this setup for about 3 years trouble free

3. I generally take 6 degrees of timing out. are you saying that by setting the f.p. flowing i mignt be able to put more timing back in?

4.will adjusting the fuel pressure flowing affect the carb?

thanks for your help guys

[rustbucket]

I have a extra plate that I put my jets in, stick the thing in a 5 gallon bucket, turn it on and adjust the regulator for 5 to 5.5 pounds. You could take your plate off and do the same thing. Im not sure if you can accuratly set the right pressure being that your carb probably wants more fuel than your n2o.
Also your fuel demand would not be their unless your carb was wide open. I would suggest a 1/2 t fitting and a extra regulator. Im no expert being that I cant make my own car run right on the bottle but maybe it was some help.

[John_Heard]

Rustbucket is spot on about adding another regulator, you MUST do that to be able to tune the nitrous system without worrying how it's going to affect the carb.

If you're really at 7 psi, then you're probably running the kit nice and fat, you'd probably see a very significant performance increase by leaning it out down to around 5 or 6 psi. Warning: Don't trust those little 1" dia fuel pressure gauges like Jegs and Summit sell, I have never seen one that is accurate, and for doing this yes you do need an accurate one or you're wasting your time.

There are several ways to go about setting your flowing fuel pressure, the lowest buck way would be to take the plate off and put it in a bucket like mentioned above and set your fuel pressure, then stick it back on. However most people eventually make some sort of flow test gauge, my friend Dave Koehler sells a great one, take a look at http://www.koehlerinjection.com/Koehler ... en_kit.htm that'll give you an idea of how what tools are typically used to set the pressure. Many make their own, it's not that complicated to do should you want to go that route.

That line and guage are plugged in between the nitrous fuel solenoid and the regulator, you turn the fuel pump on and make your pressure adjustment.

6 degrees is "probably" more timing than you need to be taking out, you might be able to pull that back to as little as 2 or 3 depending on many things, 4 degrees would be pretty typical but this also depends on how much timing you have in the motor before activating your retard.. Before you do any of that you want to get good at reading your plugs - http://www.dragstuff.com/techarticles/r ... plugs.html

Don't just go out and put more timing in it and lower the fuel pressure, you want to take this one step at a time so you don't tear things up.

But you'll be pleased to know there's probably at the very least a tenth you're leaving on the table.. Maybe as much as 1/2 sec.

[drummondracing]

WOW......... man thanks a bunch i will definately be doing some further tuning. as for a gauge would an auto meter gauge between the second regulator and the nos solenoid be suffice for now? as i said i am just running a 125 plate, i may however upgrade to the kit you listed it seems like a very nice piece. thanks for all your help.

[John_Heard]

I'm sure the autometer is better than those little 1" gauges. If you feel confident that it's accurate and it does repeat then it should work ok for this. Investing in the Koehler tool or making you a good flow test kit with an accurate gauge would be a good idea first chance you get.

[drummondracing]

on the phone ordering stuff as we speak should be chrsitmas shoppin though...........oh wait i am just for me though