As title asks :

I have a Dry Nitrous kit with a few jets and manufacturer rates them like this :

.039 = 20hp
.046 = 35hp
.063 = 65hp
.076 = 85hp
.086 =100hp

Is this correct?

 

Some manufacturers have different methods for determining jet sizes. If the kit is from NOS those numbers look wrong. The dry kit NOS sells for Mustangs uses a .042 jet for 80 hp and a .067 jet for 150 hp. Might want to do a search "nitrous jet sizes" to see if something comes up!

 

BTW NOS rates there hp differently from what I've listed for the same jets if the car is a 4 or 6 cylinder. Hope this helps.

 

It is a Compucar kit.. I too checked the .067 jet size out and in a wet kit it is a 125-135HP or so... Would it still make sense that in a dry kit it would be only good for 65HP?

 

The differences should be minimal, when I referred to the jet sizes I was implying both wet and dry. It really doesn't matter how the fuel is administered, a .067 jet will give you the same amount of nitrous wether wet or dry in a NOS kit. I'm not entirely sure about the subtle differences between Compucar and NOS, so I would suggest going with what the manufacturer suggests. Just so you know, I use a .067 jet in conjunction with a 05151 TPI plate setup and the dyno shows a rear wheel power increase of over 120 hp--more accurate measurements were not possible due to wheel slip on the drum.

 

a 68 to 73 jet flows 6 # per min of nitrous, which is basically 150 hp, I say 68-73 because different kits request a different running pressure for the bottle although most are close.