kevin007

Anybody out there using the Zex Wet Kit that has dynoed there car and did'nt get or come close to what it is suppose to make. I dynoed 3weeks ago and with my 75shot I only made 58 to the wheels.

t6378tp

iTrader: (69)

I dyno'd with a 100 shot and got 90whp

maybe your bottle psi was low

AceofSpds

iTrader: (4)

zex rates their shots at hp @ flywheel

t6378tp

iTrader: (69)

^ +1

I took it for granted you knew that, they do this cause it's no way for them to tell what your setup is and what kind of drivetrain loss your car will have

Aaron92SE

iTrader: (128)

Also, it depends on what size jet you have installed. Just b/c it's a 75 shot jet, doesn't mean it's the same size jet for every kit. Some kits are based on different bottle pressures and that will change the required jet size in order to get a 75 HP shot. Also, some are at the flywheel and some are at the wheels. But most claim whp since that's what the customers want. It really shouldn't matter. All that matters is the size of the jet you put in their along with the bottle pressure.

The Dynotune kit uses a size 42 nitrous jet for the 75 shot with 950 psi bottle pressure.

kevin007

I did'nt know that Thanks for the info!

kevin007

The Zex kit uses 40 Nitrous and 21 Fuel jets. What fuel jet does dynotune use for their 75 shot?

pmohr

iTrader: (26)

http://www.dynotunenitrous.com/store...ousjetcalc.asp

Aaron92SE

iTrader: (128)

42N/24F for the 75 shot on 950 psi for the Dynotune Kit.

But, the bottom line is, nitrous is nitrous. As long as your bottle pressure is correct and your feed lines and solenoids can handle the particular shot you are using, you can use any calculator out there to get the desired HP level you want.

So Dynotune says to use a 42 sized jet for the 75 shot, which will spray more nitrous than the 40 jet under the same pressure.

kevin007

Thanks! The nitrous chart was exactly what I need. I also need to have my fuel pressure check because if I'm not running at 43PSI then the jet wont be putting down th e proper WHP.

kevin007

Thanks The NX Jets are 41 and 24, So based on the dyntune and NX jets it's no way I could be making 75WHP with zexs 40 and 21 jets.

Aaron92SE

iTrader: (128)

The fuel pressure and fuel jets only change the amount of fuel that go into your motor. It has nothing to do with how much HP you'll make (besides tuning for AFR).

If you want to spray a 75 shot, then you put the correct sized jet in for your given bottle pressure. Fuel pressure does not matter when you are choosing a nitrous jet for 75 HP.

Now the fuel side of things are a completely different story. You always want to make sure your stock fuel system is operating properly with 36psi at idle and 43psi at WOT. The fuel jets shown in the calculator are BALLPARK estimates for your car. The ONLY way to be sure is to have a wideband. For my car, depending on which intake setup and ECU program I'm using that day, my fuel jet sizing can vary between 22 to 32 for a 75 shot.

If you don't have a wideband and fuel pressure gauge already, I would not spray above a 50 shot without having those things. The wideband is the most important though.

kevin007

Aaron I have to disagree with your statement that "The fuel pressure and fuel jets only change the amount of fuel that go into your motor. It has nothing to do with how much HP you'll make" (besides tuning for AFR) Quoted in post #12.

With Nitrous you need fuel to make to Horsepower if there is not enough fuel to nitrous you will make less horsepower.

Aaron92SE

iTrader: (128)

You're right. If you don't have enough fuel for the nitrous jet you are using, you'll go lean and you won't make any HP. You definitely need fuel to make any horsepower. It's about AFRs. If you are overly lean, you won't make any HP b/c your car will detonate and stumble. If you are overly rich, you'll make less HP.

What I do is first determine what size nitrous jet I'd like to use (75, 100, 125 shot etc). Then I use a fuel jet according to what the nitrous calculator recommends. Then I may have to change the fuel jet and/or my fuel pressure once I get some AFR readings on my wideband.

kevin007

I'm dynoing on sat. I'm planning on running my 75 and 100shot on the dyno.
I'm changing the Nitrous jet one size larger on each see if brings me closer to the WHP I should be making with safe AFR's. Any sugestions I,m all ears? Thanks for your input Guys!

t6378tp

iTrader: (69)

I dyno'd using the suggested 100shot jets from zex at 1000 bottle psi and made 90whp with my a/f at 12.4-12.8. in my opinion the suggested 900-950 bottle psi from zex is too low. I know it's only 50-100psi but it makes a differance. I am going to retune for a 125shot soon but will run 1 nitrous jet size higher than suggested and bring 3 fuel jets, the suggested jet and the next two higher cause for this size shot I want my a/f alittle lower around 12.0

btw this is not on 93octance so if you are planning to tune for pump gas I would go for a richer jetting

Aaron92SE

iTrader: (128)

I would just go with the jet most calculators say. It will more than likely be larger than the jet Zex says to use. And I also think 950psi is a tad too low in order to get the right amount of HP out of a particular jet size. But once you start getting above 1100psi, you run the chance of the nitrous solenoid not opening at all! I've had my nitrous solenoid fail to open when I tried spraying at 1150psi before. I shoot for 1050psi and it always works.

I'm using the Dynotune kit with the normal 150hp solenoids.

I was about to ask if you were spraying a 100 shot with 93 octane with those AFRs. What fuel do you use?

t6378tp

iTrader: (69)

I use a 50/50 mix of 93 and 104octane. since I hardly spray on the street I tuned for this mixture.

kevin007

That once happened to me in the summer when I was coming off the line I hit the nitrous button and I didn't feel the hit so I coasted down the track on purpose running a very fast 16 second 1/4 mile I wanted to make sure I didn,t break anything so while I was coming up the return lane I hit the nitrous again and nothing. I checked my solenoid and the light was on red with the switch on so I knew something was wrong then I checked my bottle pressure and it was at 1200PSI I called Zex and they said that was a safety feature that nitrous solenoid will not open if the bottle pressure is high or if reads lean conditions. So I put a bag of ice on it let cool down to a 1000 PSI and made a 13.4 pass. At the time I was still kind of new to the Nitrous experience. I never will make a pass without checking my bottle pressure anymore it could of been a boom!

kevin007

Are you running leaded or unleaded 104 ?

kevin007

Are you running leaded or unleaded 104 ?

t6378tp

iTrader: (69)

unleaded

Jarods7920

When i talked to the people at comp cams or zex the told me the appropriate jets for a 55 shot and i went from 171ho ti 224hp so i would say thats pretty close but i jumped about 90ftlbs of wtq too.

TAPOUT

iTrader: (5)

RIP Kevin007.