DERTY

Someone was asking about this last week. Anyway, I just got the information off my kit. Thought that I would share it for those that are interested. This is for the NX Direct Port setup only, using a stand alone low pressure fuel system set at 9PSI. DO NOT USE THIS with NX High Pressure DP setups!!! All other kits (NOS, TNT, etc.) please check with the manufacturers.

HP N20 Fuel Pressure Check Jet
100 20 18 NA
150 24 20 NA
200 26 20 57
250 28 24 NA
300 31 24 70
400 35 26 78
500 41 28 82

The flowing fuel pressure should be done through a check jet using a master flow gauge. The set PSI for this setup is 9PSI through the check jet. The gauge should be held level with the exit flow of fuel to get the most accurate read (this is really only the case if you use the master check gauge like I have). NX Recommends starting out at 10PSI and working your way down during tuning. My A/F was a little fat on this jet map, but it's a safe fat that I'm going to continue to run all next year.

I have found that the flowing fuel pressure will creep to about 10PSI on the gauge in the car with a restricted return/vent line to the tank after the pressure is set at 9PSI. Also, if the pressure does drop below 9PSI, I've found that my car spits a little bit into the exhaust. Sounds like little backfiring pops. As long as it remains above 9PSI flowing, everything is good!

I'm going to tighten up my restriction size on my return line to sustain more fuel pressure in the main line. I think I have a .024 restriction in there now. I'll look at cutting that down in half. It only needs to be there to evacuate the air in the line back to the tank anyway.

Another couple quick comments. NX Strongly urged me to use the bigger Ice-Man solenoids on the fuel and nitrous side when spraying the bigger shots that I will be dealing with. The smaller ones that come in the 80000efi kit will not sustain enough flow to run 300HP or more efficiently and safely. Also, the effective flow for the -4 nitrous line is pretty well capped at 300HP as well. Anything more than 300 and you need to consider a -6 feed line.

Read this how you want. It's a good place to start.

You know you have a race car when your feed line is 4' long and -6!

EDIT: Oh yeah, I forgot, here's some pics of my setup. Needless to say, my jet changes are very easy to do!

EVIL

AWESOME info!


thanks alot man!

Gofast

I thought a person is supposed to set fuel pressure with a laptop? LOL!!

That fuel psi creep is mainly caused from your regulator. There is a fix for this and quite frankly I'm surprised that non of the great individuals from Gofast never let ya in on it. Then again ya I can believe it.

If your interested Steve e-mail me. I just hate to give out those so very well kept nitrous secretes to everybody. LOL!!!

See Ya,

Louis

iTrader: (7)

Steve, is that a NX LS1 specific DP kit?

I like the soft lines

DERTY

Nope, it's just a upgraded EFI 8 DP kit. Ice Man solenoids, the rail upgrade and Piranah nozzles. I did all the soft lines myself, pricey little bitches too! They are all 12.5", which is really nice to keep them equal. I did plumb it all in hard lines, but I found out that the combination of the ARE K-Member and Spohn solid motor mounts actually lifts the motor 1/2" higher up into the engine bay and steals a lot of valuable space off the top of the intake. When I went to slide the intake in I just couldn't get it to clear the bumps for the windshield wiper motors. Basically there is only enough space on top of the intake for the rail to fit, but not the fittings. If you look closely you'll see that on almost all of the rail fittings that I actually tapped into it off the bottom on this setup. That was to prevent this from happening with the soft lines. Another benefit, it's really easy to work with. No torquing of the nozzles by the hardlines misalignment and crap like that.

I made the clamps and bolts to hold the rails down. I just replaced the studs that hold the fuel rail down with some longer ones that are tapped at the top. Then the little blocks of aluminum simply have a circular cut in them and when you tighten them down it locks the rails in place.

As far as the creep, that is a newly found problem. I just figured it out after watching it very closely a couple weeks ago. I think it may be regulator related because it is a little flaky. I'm also trying to figure out if 140GPH is going to be enough. I might upgrade to 300GPH just for grins. As far as the GFZ guys, I just haven't said anything yet. I'll email you though.

Vents

iTrader: (9)

where'd you end up getting the lines made?

DERTY

I did them out in the driveway. Just buy 20' of -3 TFE Aeroquip hose, a bunch of -3 straight TFE fittings (8), a bunch more -3 45deg TFE fittings (24) and put them together. It was pretty easy to do. Took about 3 hours to cut them and put the fittings on them. All of them are 12.5" long so the flow lengths are equal.

EVIL

i got to get the soft lines! looks like its much easier to change jets.

DERTY

Just be careful. It's expensive, so ask yourself is it worth it. 20' of line is about 140 bucks, 6 bucks for the straights and 10 for the 45's. Add all that up real quick and you'll find out that I'm actually a lunatic!

EVIL

after messing with it last night, the price woulda been worth it! my ****** hands are all cut up!


im a lunitic too, so dont feel rained on.

Vents

iTrader: (9)

(raises hand and jumps 'roud like a 'tard..) me too

DERTY

The funny thing is, I can sort of picture that.

"Hi, my name is Vince. My favorite color is clear. And I ride the little bus!"

Vents

iTrader: (9)

lol.. the short bus!!! huge inside joke round here Steve. i could explain it to ya, but it's one of those that "just wouldnt be the same" (shakes head and smiles.) stupid internet, cant ever get my personality across..

anyway, thanks for the heads up on the fittings, i had found them @ lunch time. $6 apiece from summit

(continues on in lunacy..)

GrannySShifting

iTrader: (10)

We got lcal place that made up thsoe lines for $200 or so. Worth it if it includes someone else $300 bucksa ot do it

EVIL

then get me some jeff!

Reckless

iTrader: (9)

Looking good Derty Looks a little different than it did at the N/S shootout Can't wait to see it run.