Nitrous jet question.

bigbird

Member
Sep 18, 2006
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Edmonton, Alberta, Canada
For the guys who run spray, do you find the HP rating of the jets in the Diesel kits to be accurate? I am set to run a .054 whick according to ZEX is a 125hp jet. would this be close? I always here guys running .088 or bigger.

Kelly
 

Diesel power

New member
Jun 2, 2008
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maryland
For the guys who run spray, do you find the HP rating of the jets in the Diesel kits to be accurate? I am set to run a .054 whick according to ZEX is a 125hp jet. would this be close? I always here guys running .088 or bigger.

Kelly

Nitrous jetting in a diesel and HP ratings for gassers are far from close.

It is dependent on lots of engine factors such as timing, duration, fuel presure(High) and (low)sides, turbo size, back pressure, boost levels, CR, Outside temp, engine temp, and rpm encountered.

Then you have to consider the bottle itself, like: what psi is the bottle at?, what temp is the bottle at? where is the bottle mounted, what size lines are feeding your solonoids and even the nozzels size.

Just these issues here can result in a power decrease as much as 300HP+ in a diesel.

the best thing to do if your new to nitrous is to tune it by sound of engine( no loud noise or popping), and only increase jet size as untill smoke clears up, and dont inject it untill at least 20psi or 2k rpm!!!!!!!

start with a small jet like a .20 and move up from there dependant of the areas i covered above.
 

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
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Norco CA
www.mcratracing.com
The only dyno testing I ever did with nitrous found that with a single stock CP3 pump, a stock to 66mm inducer (HTT Turbo), running a .070" jet netted 60-80rwhp.

Fueling is the big variable. The more over-fueled you are, the more power from nitrous.

The same .070" jet dropped ET at Bandimere from 11.500 to 11.008, which is about 100hp. Bandimere had thin air (10,000' DA) so the nitrous had more kick. But in Texas in thick air, it only gained perhaps 60hp at best, 10.83 before, 10.65 after with .15 lost on the line on the 10.65 pass at the 60' time, so .83 vs .50.

If you run high boost, high EGT's and are not overfueled, you stand a big chance of eroding the pistons with nitrous. Spraying at low RPM's increases torque wildly and puts stock rods at risk.

Pull about 4° timing when spraying for max power.
 

SBCNX20

Junior Member
Aug 7, 2006
354
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Central MA
The times below in my SIG were with a 45 jet. At the time I was running 13.teens @102.5 ish on fuel only so that got to be 80-90hp
 

SBCNX20

Junior Member
Aug 7, 2006
354
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16
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Central MA
Everyone should post pics of were there spraying..

PRE turbo in intake tube about a foot' before the mouthpiece. I used NOS parts to build the system #4 line, super power shot solenoid, dry nozzle,
and jetting from their diesel kit.