I am installing the Zex WET NOS kit but my buddy insists on putting the Dry kit in his 12v
04-17-2003, 05:40 AM
#1
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I am installing the Zex WET NOS kit but my buddy insists on putting the Dry kit in his 12v
Is there anything to worry about? His connects a vacuum line to the fuel regulator and he plans to run the 65-75 shot.. is our fuel system powerful enough to run this and what are the benefits from the wet kit that i am installing besides the added fuel..
04-17-2003, 06:50 AM
#2
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If the stock pump can handle it,the dry system will give a better fuel mixture vs a single point wet
system. Single point wet systems may lead to uneven fuel distribution which will cause some cylinders to run rich and others lean.If the fuel system on a car is not up to snuff(pressure wise) a stronger pump(some companies offer in-line booster pumps) will need to be used.This is from what I've read and the pros and cons of single point wet and dry systems are debated but it seems to be the consensus that for each set-up it's best to keep it at a 75 shot or less.
04-17-2003, 10:30 AM
#4
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Have you seen the new kits? They inject NOS and fuel right at the fuel injector...
they have nozzles that go between the bottom of the injector and the manifold.
That would be the ideal setup, as you'd be sure of even distribution. I'd be curious whether it affects the injectors ability to atomize the fuel though.<ul><li><a href="http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/NOSzle.html">http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/NOSzle.html</a></li></ul>
That would be the ideal setup, as you'd be sure of even distribution. I'd be curious whether it affects the injectors ability to atomize the fuel though.<ul><li><a href="http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/NOSzle.html">http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/NOSzle.html</a></li></ul>
04-17-2003, 11:35 AM
#5
Too high. We have 15.4 lb per hour injectors - even a Hyundai V6 has larger injectors....
At 100% duty cycle - which is unlikely, and the maximum 5psi increase of a stock regulator, he can safely boost 54hp at stoich, maybe add another 20 at lean - again this is at 100% duty cycle.
At low to mid rpms, the injector duty cycle varies from 20 to 60%, meaning 40 to 80% less fuel.
Depending on how he triggers a 75 shot, he is adding the same amount of 02 at low or high rpms. Whereas at low rpms, there is not enough fuel to combine with that 02 if you get my drift.
Make sure he adds a WOT switch that will only toggle the nitrous at high rpms. Otherwise, you will ping your engine everytime and eventually weaken it and damage it.
BTW, I measured 13:1 A/F with a sniffer with 50 shot nozzle after installing 21 lb injectors running effectively 60% duty. Be careful
Stay at 50 shot dry - get an A/F gauge to monitor it. Or find 17lb injectors - no ECU work is needed. It can compensate for it at close loop.
Don't worry about the fuel pump. It can handle 350hp
At low to mid rpms, the injector duty cycle varies from 20 to 60%, meaning 40 to 80% less fuel.
Depending on how he triggers a 75 shot, he is adding the same amount of 02 at low or high rpms. Whereas at low rpms, there is not enough fuel to combine with that 02 if you get my drift.
Make sure he adds a WOT switch that will only toggle the nitrous at high rpms. Otherwise, you will ping your engine everytime and eventually weaken it and damage it.
BTW, I measured 13:1 A/F with a sniffer with 50 shot nozzle after installing 21 lb injectors running effectively 60% duty. Be careful
Stay at 50 shot dry - get an A/F gauge to monitor it. Or find 17lb injectors - no ECU work is needed. It can compensate for it at close loop.
Don't worry about the fuel pump. It can handle 350hp
04-17-2003, 12:02 PM
#7
Yes because during mad acceleration, it will slighlty richen your system compared to stock...
the net effect is more low end torque or better acceleration after cruising.
17lbs are tough to find as they are installed on very few cars - like a 95 M3, and a few more I can't remember. I think RC makes them - as long as they are high impedance which typically they are.
If you want, you can change your stock fuel regulator to a 3.0bar from a TT or VW bug (cheaper for the same part) and get 19lb injectors for a '95+ Ford Mustang (the early ones are shorter) and be done with it. Then, you can add a fuel pressure riser after the 3 bar and inject 100 shot dry NOS
Ok, don't do that unless you know how to tune the system for that high 
17lbs are tough to find as they are installed on very few cars - like a 95 M3, and a few more I can't remember. I think RC makes them - as long as they are high impedance which typically they are.
If you want, you can change your stock fuel regulator to a 3.0bar from a TT or VW bug (cheaper for the same part) and get 19lb injectors for a '95+ Ford Mustang (the early ones are shorter) and be done with it. Then, you can add a fuel pressure riser after the 3 bar and inject 100 shot dry NOS
Ok, don't do that unless you know how to tune the system for that high
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04-17-2003, 12:21 PM
#9
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Re: Yes because during mad acceleration, it will slighlty richen your system compared to stock...
interesting.. but what would i need for 75 i dont plan on going crazy.. would the zex computer vacuum attachment let his stock regulator open enough with getting the larger injectors? and do the 19lb ones fit directly? i am not to familiar with fuel injectors...