bmbutler

I have the NOS-5176 kit and want to go from a 150 shot to a 175 shot.

Changing the nitrous jet is easy, but how to increase the fuel?
I believe there is a jet in the nitrous pressure regulator that T's off of the vacuum fuel return line. Can you change the jet in the nitrous vacuum regulator to compensate for a bigger nitrous jet?

I just need 25 more horses....I tried calling NOS, but after 45 minutes of long distance "on hold" for the tech support (ABSOLUTELY FREAKIN REDICULOUS), I gave up. I have called them twice today, with the same outcome.


Anybody that is familiar with this kit, please chime in!

Hit Man X

Smaller fuel jet = higher pressure; hence more fuel. It's the opposite of a wet kit.

.030-.040 is about the 175hp from my memory...I haven't used nitrous in a looooong time but that should be a ballpark idea.

Also, you should shim the regulator w/ a .020" shim for more pressure.

I'm pulling these sizes from 4 years ago, so they may be off a bit. Hopefully someone else with dry nitrous experience will chime in too.

bmbutler

Thank goodness someone is at least familiar with this kit! LOL

Does NOS make the shims, or will I need to make do with something in the shop? I wonder what jet it comes with in the kit (to be honest, I've never even opened the blue regulator--looks )

Hit Man X

Well the 5117-2 Ford kit actually... it's a Ford setup. Same basic premise for a dry setup.

Hrm, I dunno if NOS Systems makes that shim or not. I think I paid a whole $6 for it back in the day. You have to open the big blue thing between the solenoids (if they are attached at a bracket) with a pair of wrenches. You simply toss that washer in there and close it up.

I recall 125hp or 150hp jets being .063 nitrous and .042 fuel for some reason...and if they are flipped it's like a 75hp shot. Also those Power Shot solenoids only flow to like 175hp and I think a .073 or .083 maxed the flow on them.

I'd make sure you have a large enough pump as it seems you have the injector aspect covered. I'd start rich and come down from there. A jet in the .025-.038 area is where I'd start (prolly a .030). PLEASE monitor your A/F levels with some logging decive to be certain on the proper jet...going lean is bad news.

As you know nitorus is pressure dependant so if you don't already have a pressure gauge in the dash area I'd get one as well as a warmer for the bottle too. I didn't like nitrous due to that inconsistancy it created as it could be either too warm or too cool.

bmbutler

Thanks Hitman, you were right on the money with those jet sizes....I finally got a hold of NOS Tech! ...and yes, 175 is the max I can get out of this kit, per NOS techline

They gave me three part numbers to make the kit a 175 shot from 150:
NOS-17933-00 Spring Shim (put in the blue regulator)
NOS-13750-73 .073 N2O Jet
NOS-17538-42 .042 T-Piece (The T that goes between the 2 solenoids with the regulator in the center) The tech said instead of selling the pills, I have to buy the whole T because the pills are not interchangeable

With my setup, I have an NOS inline fuel pump (came w/kit)
I have a NOS bottle heater with dynotune pressure switch (set to keep pressure from 1000-1050)
N/X Remote Bottle Opener
Inside cab, I have Fuel Pressure & Nitrous Pressure guages

He said to definitely go with the colder plug (I already have NGK-TR6-IX)
Retard the timing more (I have LS1 Timing Tuner)
and hope that the stock motor can take the extra HP without blowing (I guess we'll find out)

Hit Man X

Excellent, glad I could help.