Can we get a guide on how to select jets for different shots. I'm searching around and it looks like there are many different factors (what kind of nozzle, fuel pressure, etc). I always thought it was universal...

btw, i'm trying to figure out the jet sizes for a 100 125 and 150 wet shot going through a nos fogger nozzle.

i believe the 100 shot is 51n 34f

 

you are correct in that there isn't a universl jet chart....it all depends on the method of delivery (nozzle, spraybar, plate) and the fuel pressure used.

Even using the same nozzle and different fuel pressure will end up with different jetting.....

for an NOS nozzle I would call NOS directly and that way they can tell you the jetting for the exact nozzle and fuel pressure used

 

I had my jets out messing around. Just to make sure I didn't mix anything up is the nitrous jets always the ones with the higher number stamped on them and the fuel jets the lower number?

 

the number stamped on the jet is the orifice size...a 62 jets has a .062" orifice.

Depending on the fuel pressure and the spray device used there is the chance the fuel jet could be larger than the nitrous jet.

We have jets that range from a .009" to .136"

 

and if the jets were ever mistakenly mixed up?

 

If you mean what would happen if the fuel & nitrous jets are inadvertently swapped and installed into your system, then because most typical systems use a larger nitrous jet and a correspondingly smaller fuel jet, the A/F ratio would then go excessively rich then the nitrous system was activated (the opposite would occur...an excessively lean A/F ratio, if your system typically used a fuel jet that was larger than the nitrous jet). It is good practice to always write down and keep a log of what the different variables are that you are using ie. jetting for N2O & fuel, fuel pressure, timing, timing retard, etc. so you have something to refer back to. Also, it is a good idea to always double check the jet sizes that you are installing when making a change, as well as ensuring the orifice is clean and free from debris.

Here is a reference chart that allows you to plug in different variables and see what the changes would net you from a H.P. standpoint, but as Dave said earlier in this post, use the manufacturers jetting chart specific to your system to be sure you make the correct jetting choices.

http://www.robietherobot.com/NitrousJetCalculator.htm