Well, the odds are in your favor for making more power per amount of nitrous used with the wet system...
however there are more issues to consider, so everyone doesn't prefer wet.
That's how I see it.

For example some people worry about cost and ease of tuning/operation, safety, traction, etc...

IMO the amount of power per amount of nitrous used isn't a real issue at all. Efficient as nitrous is, it's simply not about efficiency when it's so easy to just shoot more in to reach the desired power level.

I look at it as more of a cost/time investment vs power output, and dry simply has that wrapped up and a bag of chips.

 

I totally disagree with that statement. A wet kit is MUCH easier to tune, and diagnose than a dry kit....You cannot always count on either method to add fuel, but with a wet kit it is very easy to check a fuel noid.

 

It's MUCH easier to change the PCM calibration. Let's time it..
Let's say you go and buy some fuel jets, pull the original and install a different one. Well I could have already changed the fuel map within the PCM a hundred times. It takes maybe 20 seconds for me to add fuel and maybe 1 minute to flash the PCM. How long did it take you to buy and install that fuel jet(s)? Exactly my point. BTW, don't complain that everyone doesn't have the equipment and ability. Given enough time and experience, anyone can do it(at least the basics).

With a wet system the possibility of losing a fuel solenoid always remains. Although remote, even new solenoids can fail. Fuel injectors are the most reliable form of fuel delivery on the planet. Seems much smarter to rely on them.

The third reason wet sucks......
It requires the addition of a dedicated fuel system, more or less. Introducing additional fuel lines in the engine bay does increase the possibility of fire. Not to mention the increase time spent installing, maintaining and monitoring the fuel side of a wet system.



...I think that I disagree with White2001S10 about wet having an advantage in lower HP systems. Doesn't the energy used to cool fuel down decrease cooling effect on oxygen molecules? When you introduce hydrocarbons into the intake, doesn't that take away from the amount of total oxygen molecules present? There is only so much space to occupy..

 

>>>>Eh. Thats actually a laughable argument.....I'll race you changing fuel jets to you recalibrating the PCM anytime. Let me know.

>>>>True. But it is easily checked, and poses no more risk than the ECU failing to add fuel for a variety of reasons.


>>>>Good argument there.


>>>> Again wrong.


>>>> Not when installed correctly.

>>>> Simply No.... Your adding N2O remember?

 

Ok try and change 8 jets while I push a few buttons on my laptop.


Fuel solenoids have the same failure rate as PCMs, now that's funny.









OHHH, I shoud of said dedicated fuel setup. Sorry. There is more physical labor setting up a wet system. You can't skate around that.




That's not true. humans are prone to making mistakes. So while YOU might install the kit correctly, there are others that didn't. We could even say that one in ten people might incorrectly install their nitrous kit. That is not what I was talking about though. Sometimes things just happen. For example, one could take several small heater hoses and create a line to reach from the heater core to engine. When installed correctly, there will be no leaks. The reality is that the chance of leaks increase greatly OVER TIME due to the addition of several hose clamps. There are guys out there that installed the kit correctly and still had problems later on.



Ok, then what about the pressure pulse? The fuel adds additional weight and lowers net velocity in the port, yes?

 

I vote dry kit.I run a 5177 kit with a g5x3 heads and bolt ons.made 573 hp tonight.I have run about 10 bottles thru it with my 224 cam it 535hp with it.

 

Well you can scrape together a dry system with under $300 of parts and tape/ziptie it in place operational in about 20 minutes,
blast 150 to 200hp into the engine, fuel automatically compensated by the MAF and run damn fast.
It doesn't get any easier or cheaper than that.

A $30 CTS tricker box (can be done for $15) will change the fueling in about one second turn of a ****.

I don't even see it as a close comparison.

The fuel evaporating in the intake absorbs a lot of heat too, and overall would create a more massive charge in the manifold giving to stronger intake pulses. At a certain power level (don't know exactly where) the dry N2O will surpass the wets advantage by a huge cooling factor.
The vaporized fuel does take up more space in the intake leaving less room for oxygen, and the dry system is capable of feeding more oxygen to the valve.

The wet systems tend to hit harder for a couple of reasons. First is the fuel vapor in the manifold. Second is that the wet system doesn't automatically pull spark advance like the dry does. Going rich and pulling advance make for a softer hit.
If you tested a 100hp pill dry for wet on the dyno, you're actually really comparing the wet against a more conservative tune, so not exactly fair unless you equalize the tune.
This does explain a lot of claims that wet simply makes more power because it's better.
I'll never agree that it's better though.

 

Ok a little example of why this is false.... Take a sealed container with 100% percent oxygen. Now inject said container with fuel vapor until it is 20% fuel vapor. Guess what? You still have the same amount of oxygen molecules which is all that matters....

The simple fact is both kits provide the same amount of oxygen molecules to the engine per X amount of N2O. Introducing the fuel earlier in the process does not alter that fact.

 

Ok, I can agree with that. Both kits provide the same amount of oxygen molecules. So. then it comes down to installation. Dry kits are faster to setup than a wet system. I'm talking about the physical labor.

I just tuned an LT1 that moved from direct port to a single, smaller dry shot. The car went faster. MPH went up from 126 to 129(w/o my help). Now with my calibration it should go 130mph+ on the dry 100hp shot. I know there are more faster cars (in STL) that are using dry. Most of the cars with a wet system gets waxed. We can BS about theory all day. Real world results speak for themselves.

 

I won't agree with that.
Injecting extra mass & volume into a given space would increase the pressure and that doesn't happen in an operating intake manifold.
The entire system will equalize pressure-wise which means simply that less ambient air will be injested by the engine using the wet system.
This shows up on dyno air-meters all the time and is the norm.
Having less space to injest ambient temp air is one of the reasons that smaller wet systems can provide a cooler charge.

 

In a wet hit where several hundred psi of N2O pressure is introduced just inches from the intake the pressure will increase.....

All of this is really a moot point anyway. Im done here.

 

Sorry, a nitrous nossle does not create positive pressure within the manifold. Nitrous is not forced induction. The nitrous line pressure is no different with a dry shot.


Judging by your last post, I would have to agree.

 

An increase in pressure in an enviorment does not mean you have positive pressure.

 

No, the intake has negative pressure. Pressure will equalize across the intake manifold, not build up. I will say this again, nitrous is not a form of forced induction. It does not introduce positive pressure across the manifold. Ask any nitrous user, they don't get 2lb, 10lbs or 1000lbs of positive manifold pressure. If you think that, then you must be using a two bar map sensor.

I thought you was done?

 

Ok let me say this slow for you...Im not saying you have POSITIVE pressure in the intake....Geez. Example you go from -.2 to -.1... Get it now?

The simple FACT is a dry hit DOES NOT provide more oxygen molecules to the engine. Both kits provide the same amount of oxygen and thus create the SAME amount of power....

It really is that simple.

 

No, there are more things going on. First thing is that N/A engines at sea level/0 DA can have zero pressure at WOT. Given your example 0psi+N2O=positive pressure or boost. I don't think so, nice try. You know....the engine also draws in oxygen molecules on it's own. That ability to do so gets kind of "choked off" by all that gas going into the manifold. This happens because molecules take up space. The oxygen molecule is relatively light compared to a complexed hydrocarbon such as gasoline, the atomic mass of oxygen is WAY lower. That means you can pack more oxygen in an equal space, give the same pressure. Please don't argue the engine is drawing AIR, not just oxygen. The mass of AIR is still a ton less than vaporized gasoline.


Gasoline takes up more space than oxygen, given the same pressure. Flowing fuel through an air intake system does hinder the ability for air to equalize pressure, or at least give more resistance to motion(IE pressure pulses and drop). This resistance is due to the atomic weight of gasoline. The pressure drop might be greater with a wet system, but the duration increases. Slowing down the pressure equalization negates any gains from the additional weight. Less weight and more oxygen molecules will release more energy than a slighty higher pressure drop, I would think...


Gasoline absorbs more energy in order to cool it down vs oxygen. That energy could be spent cooling oxygen molecules.
For example, it takes X amount of energy to cool one hydrocarbon chain. Take that same amount of energy and it could be applied to 1000 oxygen molecules (in order to cool it to the same degree). The cooling effect of nitrous is more efficient when the energy is used on oxygen (vs oxygen and gasoline). That's why you get a denser charge with a dry shot.

 

Not just that, but oxygen can squeeze together more tightly w/o those bulky a$$ hydrocarbons in the way.