VQ35HR specific Zex Nitrous kit just arrived
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I still cant find anyone that makes a colder plug for a HR, anyone know?
If not, I am only going to run a 75 shot, probably shoot for a 350whp 350z
They forgot 1 of the nozzles, so they are sending me another one. Since I believe so much in the stock intakes on this car, I think I am going to weld some 304 together and ditch the stock plastic pipes for the nitrous. There are adaptors (they even give you a tap) used for the OEM intakes though.
Ill be doing an install video with dynos.




Fuel Fitting that clamps the stock line and then use the small supplied line to fit back onto the other side, no cutting of fuel lines

To keep out any CELs, Zex puts a resistor on the TPS wire

just incase your still confused...
If not, I am only going to run a 75 shot, probably shoot for a 350whp 350z
They forgot 1 of the nozzles, so they are sending me another one. Since I believe so much in the stock intakes on this car, I think I am going to weld some 304 together and ditch the stock plastic pipes for the nitrous. There are adaptors (they even give you a tap) used for the OEM intakes though.
Ill be doing an install video with dynos.
Fuel Fitting that clamps the stock line and then use the small supplied line to fit back onto the other side, no cutting of fuel lines
To keep out any CELs, Zex puts a resistor on the TPS wire
just incase your still confused...
Interesting. I like the T-fittings that are supplied with the kit. I also like the lines that come with the kit and the way the ends are set up. However, the fuel fitting could be better or more conventional. And I'm not sure you need the resistor on the TPS, as previous kits have been perfectly fine thus far.
edit -
Just curious. Where does the jet shots fit on the ZEX? I vaguely remember the jet pills going somewhere around the ZEX "Brain" (nitrous management unit), but I could be wrong. At any rate, the jet sizes in the instruction manual seems off. If it requires two of the listed sizes, then the shot is too big. If it requires 1 of each listed sizes, then the shot is too small.
edit -
Just curious. Where does the jet shots fit on the ZEX? I vaguely remember the jet pills going somewhere around the ZEX "Brain" (nitrous management unit), but I could be wrong. At any rate, the jet sizes in the instruction manual seems off. If it requires two of the listed sizes, then the shot is too big. If it requires 1 of each listed sizes, then the shot is too small.
Last edited by 3hree5ive0ero; May 27, 2008 at 10:41 PM.
Originally Posted by coachk
The pills go in where the lines attach to the nozzles.....IIRC my 75 shot was 41/28
If the jet pills go where the ZEX brain is, then the jet pills sizes (which would mean one of each numbers, as it'll split off later) are too small.
I'm not sure how these sizes come out to be the claimed 75 and 100 shots. Maybe they're rated at the crank, as many people have told me ZEX does.
You bring up some good points.... I know that when JT @ PF did my 75 shot he looked through a universal manual on jet sizes and thats where he determined the size jets for my ZEX 75 shot. When I had the 35 shot, I'm certain that the whp increased almost dead on when comparing just boost (425whp) and then boost with N20 (460 whp).
I wonder if nitrous shots are still constant when combined with other methods of boost (i.e., turbo). That is, if you had a 35 shot (rated at the wheels) while you're boosting on a turbo, do you get the 35 shot that was rated or do you get a different amount (less or more)?
But anyway, those shot sizes are definitely off more or less (pun intended).
But anyway, those shot sizes are definitely off more or less (pun intended).
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Originally Posted by 3hree5ive0ero
If the jet pills go where the foggers are, then the jet pill sizes given by the instruction manual (which would mean two of each numbers, one for each fogger) is too big.
If the jet pills go where the ZEX brain is, then the jet pills sizes (which would mean one of each numbers, as it'll split off later) are too small.
I'm not sure how these sizes come out to be the claimed 75 and 100 shots. Maybe they're rated at the crank, as many people have told me ZEX does.
If the jet pills go where the ZEX brain is, then the jet pills sizes (which would mean one of each numbers, as it'll split off later) are too small.
I'm not sure how these sizes come out to be the claimed 75 and 100 shots. Maybe they're rated at the crank, as many people have told me ZEX does.
Here is the response from Matt Patrick at Zex
The long answer involves looking at a few things:
The single nozzle 2003-06, 350Z kit uses a 40 nitrous jet and a 26 fuel jet for the 75hp tune-up
The dual nozzle 2007-Current, 350Z kit uses a 30 nitrous jet and a 17 fuel jet for the 75hp tune-up
If you run the orifice area calculations on the nitrous jets, you will see that two .030 jets have a combined flow area that is only slightly larger than that of a single .040 jet. So in reality, while the numbers may seem larger than they “should” be, two 30 jets have just a little bit more flow area than a single 40 jet. The reason we had to “upsize” the jet area a little bit was due to the fact that since the 2007 dual nozzle kit has an additional two feet of nozzle delivery hose, there are additional frictional line losses that do affect nitrous flow by around 10 percent. So, in the end, when all these factors are accounted for, a dual nozzle system with two 30 jets flows the exact same amount of nitrous as a single nozzle system with a 40 jet.
On the fuel side, we actually needed less jet flow area for the dual nozzle system to get the proper amount of fuel flow for the 75hp shot. This goes to show you why it is important to engineer a nitrous kit as a complete system using flow testing and dyno work. It is easy to design something on paper, but ultimately it has to function properly in the “real” world.
Just remember, there are many areas we look at when designing a nitrous system. Flow area is just one of the more straight forward things we can look at to help explain jet size selection.
I hope this didn’t confuse you too much, let me know if I can help in any other way.
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Great answer. Thanks for asking the manufacturer for the correct and more accurate answer than guessing. And ZEX just earned my respect.
If their 03-06 kits used a 40/26 jet sizes, that would pretty much be rated at the wheels.
Logic would dictate that they rated at the wheels for the 07+ kits also.
Logic would dictate that they rated at the wheels for the 07+ kits also.
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From: Oceanside, CA
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it is not installed yet, been too busy.
the fuel fitting is custom made by them so you dont have to cut anything, that was actually the biggest hold up on getting this kit released.
the fuel fitting is custom made by them so you dont have to cut anything, that was actually the biggest hold up on getting this kit released.
Originally Posted by sekret
how much was it and would you need tuning for a smaller shot, lets say a 75?
i will be ordering this zex kit and drag radials within the next month, hopefully i can be one of the first HRs that touches 11s! anyone know of a good standalone i could run for a track nitrous / street car? would aem ems work on the hr?
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11s might be tough, im going for low 12s myself. you can run an EMS or an F Con pro, etc.
i plan to install my kit in about 2-3 weeks.
do you know any DRs that are in the 245-255 range for the 18s? nitto doesnt make a 555r
i plan to install my kit in about 2-3 weeks.
do you know any DRs that are in the 245-255 range for the 18s? nitto doesnt make a 555r




