What Nitrous Jet

nitrouspaul

nitrouspaul

Registered User
I have not run my nitrous kit for a while and after having new fel pro head gaskets put on the car I want to run my dry set up again. The nitrous injector nozzle is in the upper tube before the intake and of course the hoses for fuel enrichment pull vacuum on the fpr. I have a new fuel pump stock gpm and I forgot what the jetting should be for a 70-100 shot. Any one out there with this experience please let me know.

Ps. has anyone pulled timing out and how did they do it.
 
Timing can be retarded 4 degrees by pulling the octane spout. A 75 shot should be around .044 and a 100 shot should be around .051.

Suggest you consult Zex on what size jet to use.

David
 
Zex dry kit on a v6 for a 75hp shot it should be fuel/N2O: 32/38
for 100hp shot it should be fuel/N2O: 26/46
 
that info was off of the Zex website. I am running the combination for the 75hp shot but am still running pig rich. David didn't you use a different jet to get your fuel right then what was recomended? if so what was the combo for 100hp?
 
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I cant remember off the top of my head which jet i was using on the nitrous side but i know i was running a 21 on fuel and it was just at 12.3 on the wideband. This was for a 75hp shot.
 
21/40 is for a 75hp wet kit 32/38 is for the dry kit as per zex's website
 

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AJ,

I don't really understand why fuel jets are used on a Zex dry system. Are these jets actually used to control how much of a boost signal goes to the fuel pressure regulator using a portion the nitrous and various size jets to control the signal/fuel pressure ? Or are you actually tapping into the fuel supply ?

David

PS: BTW, The jet sizes I estimated are for an NOS wet system. For my car .028 fuel/ .051 nitrous makes about 100 rwhp.
 
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David Neibert said:
AJ,

I don't really understand why fuel jets are used on a Zex dry system. Are these jets actually used to control how much of a boost signal goes to the fuel pressure regulator using a portion the nitrous and various size jets to control the signal/fuel pressure ? Or are you actually tapping into the fuel supply ?

David

PS: BTW, The jet sizes I estimated are for an NOS wet system. For my car .028 fuel/ .051 nitrous makes about 100 rwhp.
Click to expand...

As far as the reason for the fuel jet my understanding is it's to lean on the fpr using vaccum/boost to increase fuel to the rail. There is a kit that zex sells that converts their dry system to a wet but I think I will just end up purchasing their actual wet kit. It is a little easier to tune. I heard that the different nitrous systems used different jetting but I dont know what the reasons are behind it. I really am very happy with the Zex technology because of its ease of installation and everything is pretty much self contained. No extra brackets for solenoids, tps votage sensor or micro switch. The only downside is Zex is limited to 175hp shot wet and 125 dry (which is plenty high for me and I will never run that much) but maybe for someone that has alot stronger bottom end they may want to run more.
 
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