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a.k.a. turbodan
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Discussion Starter #1
ok, before the track opens in the spring, i am planning on having a nitrous system. i am getting a Nitrous Express Wet system and running a 100 shot. i want to know how long to hold the button and when to first push it. i dont want to blow up my engine but want the best time.
*edit* if anybody want to get rid of their NX kit. let me know
 

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GMFS Senior Member
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well if you have traction, spray away!! i've got a a/f guage so i can watch to make sure the engine doesn't go lean. so far so good.
 

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a.k.a. turbodan
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Discussion Starter #4
i just found this on the internet. it helped me.

Combustion
Nitrous oxide does not burn, it is an oxidizer. It provides more oxygen, so more fuel can be burned, and the result is more power. The atoms in a nitrous oxide molecule are bonded together. The oxygen is not free, but fortunately the bond breaks down as temperature rises. At 565° F, the bond is broken and the oxygen is then free. Combustion temperatures are much more than 565°, so it's not a problem. By adding nitrous oxide to an engine, the total amount of oxygen is increased and other gasses that do not support combustion (mostly nitrogen) are decreased. This speeds the burn rate and requires less timing advance for peak output. It is hard from many people to grasp gaining power with less timing, but it's a fact. Peak cylinder pressure must occur at approximately 20°ATDC to make peak power. If you speed the burn rate, peak cylinder pressure will occur too soon. It is easy to run too much ignition advance with nitrous, but too much will not only hurt power, it can quickly bring a nitrous engine into detonation and destroy it.

Detonation
Nitrous will increase the chance of detonation. To keep the engine out of detonation, you must control the extra heat that nitrous makes. The easiest way to do this is to add more fuel. All nitrous systems come with rich jetting to give you a safe starting point. The extra fuel takes away heat and raises the detonation limit. Another way of controlling heat is with water injection. A well set up water injection system will allow you to run the chemically correct nitrous to fuel ratio, so the system will be more fuel-efficient. If you don't try to over do it, and keep the hp levels within reason, running slightly richer should be all you'll need to control detonation. Water injection and running richer will both reduce the power output, but raising the detonation limit will allow more nitrous to be used to get more power.

Nitrous-to-fuel Ratios
The chemically correct nitrous to gasoline ratio is 9.649:1. If a nitrous engine runs lean, it can destroy the engine in a matter of seconds. There must be enough fuel for the nitrous to react with, if there isn't, temperatures rise rapidly. The oxygen that couldn't react with fuel will oxidize any parts that get hot enough. So don't run lean.
 

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thats right
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1,399 Posts
oxygen burns. thats the whole process of combustion. the N20 just adds more oxygen to the mix, so when your fuel ignites, it burns ALOT more oxygen with it. it leans out your mixture because you add a ton more oxygen, but you cant add more than your fuel system can compentsate for. nitrous rules :head:
 

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fullthrottledan said:
ok, before the track opens in the spring, i am planning on having a nitrous system. i am getting a Nitrous Express Wet system and running a 100 shot. i want to know how long to hold the button and when to first push it. i dont want to blow up my engine but want the best time.
*edit* if anybody want to get rid of their NX kit. let me know
If you're just going to run a 100 shot, just go with a dry system. The NOS 5177 kit is perfect for our trucks and is what I will run once I get all my priorities straightened out.
If you're thinking of just having a button to spray when you push it, and stop when you let go of it, that's a ghetto ass setup. Don't do it, you will most likely fuck something up.
There are things that do all that for you, totally automated setups.
1)WOT switch: Will spray only when you floor it, which is what you want. If you spray at half throttle you could fuck your shit up, especially with a wet system.
2)Window switch: What this does, after you activate the nitrous (turn the system on) is sprays only after a certain RPM. So...you turn it on, and the nitrous will come on at 3000RPMs for example. Also, it will stop spraying in between shifts if you want it, in case you don't have a built tranny. Spraying through shifts will kick your stock trannies ass.
There's other stuff too but I'm too tired to think anymore.
 

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GMFS Senior OG Member
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3,511 Posts
droppedgmc said:
well if you have traction, spray away!! i've got a a/f guage so i can watch to make sure the engine doesn't go lean. so far so good.
Can you explain what is a a/f gauge?
 

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GMFS Senior Member
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so what kind of switch does the NOS 5177 kit come with. Or what do I all have to do to prevent my truck from leaning out?
when sprayed in front of the maf, it freezes it making it think it's running cold so it dumps more fuel in. i don't think you'll have a prob. when i spray, it goes 2 more bars into the green on my a/f
 

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droppedgmc said:
when sprayed in front of the maf, it freezes it making it think it's running cold so it dumps more fuel in. i don't think you'll have a prob. when i spray, it goes 2 more bars into the green on my a/f
Actually, when you spray in front of the MAF, the PCM reads that there is more air going in, and the EFI adds fuel to compensate. That is basically what a dry setup it, allowing your fuel injection add the necessary fuel needed. There IS more air going in because N2O is denser than regular O2.
With a wet setup, you spray nitrous and fuel AFTER the MAF. So you need things like an A/F ratio gauge, fuel pressure safety switch, etc. because you can fuck up your engine easier if you don't watch it (e.g. if the nitrous solenoid gets stuck, fuel will puddle in the intake manifold and BOOM! If the fuel pressure is shitty, you will get too much nitrous and run lean...and BOOM!) The advantage of a wet kit is that you don't have to rely on the stock injectors to add fuel, you add it with a fuel solenoid, so you can run a bigger shot.
Are you the same guy who is spraying dry right in front of the MAF? Have you tried running it yet?
I would personally not spray that close because you will freeze the MAF and most likely fuck it up. You do not want those sensors freezing. Even though I have no personal experience with nitrous, I have researched and asked on other boards. Everyone I have asked who has a dry setup has said to spray AT LEAST 6 inches or more away from the MAF.
Again, I don't have personal experience, I'm just telling you what I've read. :D
 

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GMFS Senior Member
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Are you the same guy who is spraying dry right in front of the MAF? Have you tried running it yet?
i am the guy, i haven't had any probs at all
LEAST 6 inches or more away from the MAF
i moved back to 7" where i had it when i sprayed with my edelbrock kit
 

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Ok, so which is it? Are you spraying right on the TB or 7" before it?
*edit*
I see what you're saying. So how many times did you spray with the nitrous right on the TB?
And why did you decide to move it 7" back like with your Edelbrock kit?

Which Edelbrock kit did you have?
 

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GMFS Senior Member
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Ok, so which is it? Are you spraying right on the TB or 7" before it?
i never had it right in front of the t/b, it was about 4" away from the maf, now it's 7". the first kit i had was a 70001 kit. i converted it to a "dry". it's a good cheap first kit.
with the old kit, i went through about 25 10lbs bottles in 6 months :D
 

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droppedgmc: Are you running on stock internals? If so...so far so good? Will you be throwing in some forged rods and pistons, etc. or anything like that?
 

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GMFS Senior Member
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all stock internals. so far so good. hasn't missed a beat on the ole 4.8. has 73,000+ on it now also. still spraying away:head2: but for my next trick, rims, then my ls1 thats sitting in the garage
 
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