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
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, 10:04 AM
04-17-2003, 10:30 AM
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>
04-17-2003, 11:35 AM
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
04-17-2003, 11:52 AM
will they benefit me when i run without NOS as well as him with the dry system
04-17-2003, 12:02 PM
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 ;)
04-17-2003, 12:04 PM
04-17-2003, 12:21 PM
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...
04-17-2003, 12:32 PM
they kept blowing the lines off.
04-17-2003, 12:35 PM
That's puny if you want to convert to flow rate:
new flow rate = old flow rate * sqrt (new pressure / old pressure )
Our stock regulator is 4 bar or 58 psi at '0' vacuum (wide open throttle). They drop to 3.5 bar or ~51psi at vacuum (cruising, idle). There is very little fuel improvement done by adding pressure to the stock regulator.
Our injectors are the most popular type of housing, I can't remember the exact code. It is the same injector housing used in nDBW Audis, Fords, BMW's, some GM, some Japanese and most Euro cars. If you are not sure, just tell them you want it to fit a '00 Ford Mustang 4.7L or something since all the parts stores can related to that.
I got all my injectors at EBAY, but it's a hit or miss over there. My latest ones are very good as they only have a few miles on them. I know how to flow test which is why I can buy used.
04-17-2003, 12:59 PM
Wet kit is the improvement from the dry kit since the dry kit nitrous tends to burn engine internals (pistons, etc).
"...A dry system introduces raw nitrous into the incoming airstream and is dependent on the engine to compensate for the fuel enrichment. The problem with this method is no intake manifold has perfect distribution and this allows each cylinder to receive differing amounts of raw nitrous but only provides a preset amount of fuel from each injector. This results in rich-lean conditions throughout the engine, often causing engine damage"
"...at this pressure and temperature, the molecular structure of nitrous oxide breaks down. This introduces raw oxygen into the combustion chamber. Oxygen burns hot and requires a lot of fuel to keep the temperatures low enough to keep from burning holes in the pistons."
All the information above is from this article shown below (as a link)<ul><li><a href="http://www.nissanperformancemag.com/august01/nitrous.shtml">dry vs wet</a></li></ul>
04-17-2003, 01:30 PM
I've got a article in SCC that contradicts the first statement you quoted.
They contend that " The other type of single-nozzle setup uses a fogging or mixing nozzle to mix nitrous and fuel together before spraying it into the intake tract. This is important in a single point injection system,as mixture distribution can be a problem. The intake manifolds on modern engines were designed to flow dry air,not a mixture of air and fuel.If the fuel and nitrous are sucked into the engine as a more homogenous cloud rather than as two distinct streams,you get better distribution.........However, to be safe, a single-fogging nozzle system shouldn't be run at more than 75 hp or unequal distribution of feul may lead to problems. Typically,the cylinders closest to the throttle body will be lean and burn plugs,while the end cylinders will receive a progressively ricjer mixture.......There is a debate about whether wet or dry systems are better,with industry experts equally divided. In out opinion,for systems of up to 50 to 60 hp,the dry systems are usually more reliable,due to the even distribution of fuel."
SCC May 2003 Vol 15 #05
04-17-2003, 02:40 PM
But I can't say NOS/dry kit is the one to blame. There are many factors contribute to fried engines, foolishness is the biggest of all.
I have been using my wet kit for a while now. It seems that 75hp wet kit works okay for 12v engine =)
04-17-2003, 07:21 PM
wide band 02 to help tune it. May go the way of different injectors and FPR,we'll see.