I thought of something the other day. Forced Induction and Nitrous are a lot alike.

-JUST MY OPINION-
Provided everything is set up and working good, a dry kit would work like a Forced Induction setup. BUT... Would you pray fuel into your intake to add for extra air or would you just let your stock fuel system handle it?... ( about it)... THat's my view on it. Only differance between N2O and FI is the nitrous is injected in the liquid state: VERY COLD. When that gas in the somewhat liquid state enters the hot chamber it expands like crazy. There's your added air and fuel (thru fuel system)... crammed in like usual..

For the Wet guys: I respect your choice and dry doesn't like to work on LT1's, I just don't think it's for me.. Again, the above was just my opinion..



I love this stuff!

 

N2O is basically chemical boost, however, due to its nature of being a temporary use, you are not thinking about the fuel system correctly. Boosted cars are tuned specifically for boost, you cant switch your tune for spraying, then back while driving. I personally don't like the idea of making your injectors work harder, and the MAF to tell them how hard to work. I feel this way because it's not the way the system was designed to work, you are 'tricking' the pcm into dumping more fuel based on temp, where with a wet kit you can tune the fuel jets to get the best possible air fuel ratio.

 

^ but with the wet the nitrous cools the fuel down to a point that it makes it a little more difficult to atomize. The fuel is also heavier than the nitrous. You can ensure proper mixture at the NOZZLES, but who's to say each cylinder is getting it's share of sed' stoichiometric nitrous and fuel (unless you go DPI). As Injuneer mentioned in a previous post, the fuel is heavier and would have a little harder time making the 90* turn to enter the #1, 2 cylinders. -With wet plate, or pre-TB injection.

As with Dry, the nitrous has no problem entering #1, 2 cylinders. Also I personally find it a little unsettling to have raw fuel injected into my intake. -Just me.

My above post was just a funny comparison. I didn't mean it seriously. I am aware that the F.I. is on allt he time and n2o is switched.

 

this is copied from the LS1Tech thread...

Ok,
Sorry I have not had time to sit down and read all of this thread. I have been way to busy. There is a lot of good information in here for guys to read.

Of course there is also some I do not agree with.

I personally have tested and used many different styles of nitrous systems. My opinions are based off of my hands on experience. Not anything else.
We started playing with dry systems years ago. We tested everything from single nozzles, dual nozzles, to our Halo systems. We also have tested many different styles and designs of wet systems. We have tested everything from single nozzles, dual nozzles, plates, direct ports to one off custom set ups. We have a lot of hours and money in doing so. By being open minded we have been able to design and help bring to market some of the best products on the market today.


I try not to station myself on any certain side of the fence when it comes to the wet vs dry arguments that I see posted all the time. The reason why is because I personally believe that one thing that may be great for one application or persons skills may not be as good for another. I feel that you have to look at each application and person individually to give a honest answer on what is best for them. They are spending there hard earned money and they are putting there faith in you to take there best interest at heart. I feel that by having a tunnel vision opinion I would not be giving the customer the service he or she deserves.

With all that said I get irritated when someone tries to place me on a certain side so I will clear it up in this post.

I feel that both wet or dry has there place. One persons knowledge and skills may not be as complex as the next. Some areas where people live have no dyno’s or tunners any where close. One mans budget may not be as big as the next.

I do not feel that one is any safer than the other. I do feel that each has there advantages and disadvantages. You will see people argue that there way is better than the next. This is because it is what they prefer and there is nothing wrong with it. I have yet to see a perfect nitrous system with 0 chance of malfunction. All these offer potential problems...
Anyone that tells you that there is a guarantee that you will not hurt your motor with any certain nitrous system is full of it.
There is always a possibility. That is the chances you take with adding any after market power adder weather its turbo, supercharger, or nitrous.

Here are my opinions on the two systems for the LSX platforms.

WET VS DRY

Tuning Air fuel.
With a wet system tuning air fuel is simplified by changing out the fuel jet. As far as the flatness of the air fuel curve, as long as your NA tune is flat odds are than your nitrous air fuel curve will be as well. In the case of a lean spike on a wet system that is not CAUSED BY POOR FUEL SUPPLY you can adjust in out by shortening the hose from the nozzle to the plate or nozzle.

On a dry system the best way to adjust air fuel is by computer tuning. The dry system can be finicky in this area. The Customers knowledge needs to be a little more indebt on the computer tuning side of things. Some people suggest tuning air fuel by nozzle placement. I am not a fan of this method. I have a hard time trusting a nozzle to stay turned in an exact angle. I have seen to many nozzles and hoses get bumped around or move due to engine torque over of working in the engine bay. This would result in a unknown change of the tune and could lead to engine failure. I feel that it is better to have a safe discharge pattern and tuning to adjust what ever needs to be adjusted from there.(why take the chance) The future may hold some new designs and technology to offer better solutions to this. However there is nothing on the market at this time.

Timing
With the dry system you can tune the cars computer just like a supercharged application removing timing while you are spraying. You can also use the timing tuner.

With a wet system you can adjust timing with computer tuning. However with the timing removed for the nitrous you may be yielding a few horse power naturally aspirated. You can also use the timing tuner and not have to do computer tuning to remove timing for the nitrous.

Advantages of the wet system
Tuning is less complex. The wet system is less finicky than a dry system. The wet system does not rely on the fuel injectors to supply the fuel nor does it rely on the mass air to compensate the added nitrous flow. So no reason to worry about a bad mass air meter, maxed or clogged injectors. You have the ability to run a dedicated fuel system to support the extra needed fuel demand. You can also run higher octain fuel in the dedicated raising the over all octain. Having the option of running the good race gas in the dedicated eliminates most of the concern of fuel solenoid failure do to bad gas causing the fuel plunger to swell.

Disadvantages of the wet system
Bottle pressure is more critical. Your fuel pressure always stays at a steady rate of flow. When the bottle pressure drops the flow rate of the nitrous drops. This changes the tune up causing the car to nose down on horse power and bog due to being to rich. A purge is more critical to keep the car from bogging on the initial hit due to the fuel being at the solenoid and not the nitrous.(air in the line) You are relying on another mechanical to supply the fuel. Some EFI intakes due not flow as well at certain hp levels with the wet system. In the case of a back fire the backfire is more violent due to the greater amount of fuel vapors in the intake. (There are always fuel vapors in the intake. Even naturally aspirated)

Advantages of the dry system
Bottle pressure is not as critical. If the bottle pressure is down the car will not loose horse power. It just simply will not make any added horse power. Purging the system is not as critical. If air is in the line the system will just not hit as fast and hard. In the case of a back fire the backfire is not usually as violent due to less fuel vapors in the intake. With tuning capabilities you can pull timing with out the needed accessories such as a timing tuner. No need to worry about fuel solenoid malfunction do bad gas causing the fuel plunger to swell.

Disadvantages of the dry sytem.
The owners tuning knowledge needs to be a little farther advance. Dry systems normally require a little more tuning and knowledge to adjust the air fuel. The dry systems are finicky in this area. You may have to upgrade injectors to supply the needed fuel that will be required from the injectors. There is a chance that the mass air meter could malfunction.(Not real common but I have seen it happen in person.) All fuel upgrades will have to be done with the cars actual fuel system.


To address fuel puddle
No intake was designed to flow fuel through it. Not even carbureted intakes. They are all test flowed with air design.

Some intakes flow better than others. I do agree that certain intakes have flow restrictions. I do not agree that puddling is possible on a properly tuned application that is not over extending its flow capabilities.

On a properly set up system with in the amount of hp setting suggested the nitrous and fuel mix will flow through the air intake in less than a second. Many super charger companied place injectors before the throttle bodies to add the extra needed fuel. This fuel is flowing into the intake plenum with forced air only. NO NITROUS.. So the FUEL PUDDLING IS NOT WHJAT CAUSES A BACK FIRE.

In the case your system is not tuned to rich the fuel mixture will be to great for the amount of nitrous with it to break it up. The fuel can then fall out of the airflow path into the intake. THIS IS FUEL PUDDLING. This can be avoided with a proper tune and properly designed nozzle or plate.

When a intake meets the point in which the intake can not properly flow the amount of fuel needed to certain runners the fuel will flow to the runners pulling the greatest amount of vacuum. This is common on the ford intakes over a 150 horse power. This may result in a lean back fire up through the intake. If this lean back fire happens the fuel vapors in the intake will ignite fueling the back fire.

This is not fuel puddling.

To some this all up. I feel both systems have there perks and disadvantages. One may meet one persons needs and another may meet another persons better. I stay neutral on what that is and love nitrous in its entirety.

Putting myself in the customers shoes I look at it from the stand point that I would hope that if I was the customer the guy I was looking to for help could maintain a unbiased opinion in deciding what best fit my needs and capabilities. I would hope that the money I worked months to save up was well invested in doing it right the first time.


Thanks for reading what took me an hour to type up. It not easy with A.D.D.. Lol

Dave

 

in response to srsnow

 

Now as far as the fuel having to make a 90* bend to hit the front 2 cylinders.
The LT1 Intake works off of a common plenum, it is designed to be filled with the A/F mixture and each cylinder will draw off the plenum as needed. The velocity inside the manifold will pull the mixture to the cylinders. Typically we see more issues with the back cylinders not the front, so the 90* bend is not as big of an issue.

Reading the spark plugs is the key to tuning a nitrous system, the harder you are pushing the envelope the more crucial this becomes.

 

Excellent info in the last two posts before mine. I personally used a dry kit on my supercharged car. It was easy to bolt on and tuning was just a matter of getting the file changed on my tuner while on a dyno.

I have since removed the nitrous and installed an alcohol injection kit from Snow performance.

 

Are you sure you aren't confusing "atomization" with "vaporization"? Cold fuel is difficult to vaporize. I don't know that cold fuel is more difficult to atomize.

 

Sure you can "switch your tune for spraying, then back while driving".... that's how my MoTeC is set up. When the nitrous switch is armed, the fuel and timing shifts to different tables.

Another way to look at the injectors in a dry system is that they are sized for the full dry nitrous demand. Then when they are not operating with nitrous, they are running at extremely low duty cycles, and working "easier", not "harder". My 78's are loafing under "cruise" conditions .

I don't run an MAF, so I'm not "tricking" anything. But when you are running nitrous through an MAF, it is not the temperature "tricking" the MAF sensor that causes the PCM to add more fuel. It is the MAF sensor sensing a greater mass of air/nitrous flowing through it. The MAF sensor compensates for temperature, by always heating the wires to a fixed number of degrees higher than the incoming air temperature. In that way, it calculates mass flow based on the electrical power required to keep the hot-wire at that fixed number of degrees above the incoming air temp. What is slightly "off" when you are flowing a combination of air and nitrous through the MAF, is the fact that the specific heat of air and nitrous are not the same, and the MAF bases its mass flow calculations on the specific heat of air.

 

The MoTeC setup is hot, I haven't seen that. I think that would actually be nice to run in the wet kit as well, to run a specific tune vs just pulling timing.

With the MAF, I thought it measured the density of air based on temp. I'll have to do a little more research on that topic. I knew you could run a larger injector than needed, so you wouldn't have them running at a full load while running n2o.

 

Well using the term tricking is just that a term. Whether spraying or n/a the MAF works the same. So your tricking your MAF anytime you do any mods that increase VE, and/or actual/percieved air flow increase.
The MAF wire is heated, and the cold nitrous is measured as temp/density-through the voltage difference seen at the wire which is then in turn converted to measurements we use in our MAF tables.

Your statement on "what is slightly off" really makes no sense. The link I posted earler on, you can see compared dyno sheets of dry hits set-up different on the car/system. One reads n2o with nozzles close, and an instant hard hit with mucho torque. The second dyno shows nozzles a little different location, and a slower progressive hit. What does this mean, well it means the MAF will read just fine whether you have lots of nitrous hitting or a diluted mix. Think about the cars up in Alaska, their MAFs read sub 0* temps fine, then go to the Texas desert, once again, the MAF reads/works fine. To many people want something, somehow, to be wrong with the MAF, but the facts speak for themselves. We all depend everday that our MAFs will do what they were designed to do, and adding a dry hit is really noe different. Think of it as the Alaska/Texas comparison, they both work fine, as will n/a and the dry hit. Do you realize that on a cold day your MAF is increasing your inj DC just as on a dry hit, compared to a hot day?
Robert

Edit: Here's the link again for the wet vs Dry thread, if ya haven't read it you might be able to get some good insight. LS1Tech Wet vs Dry thread

 

Huh? How is measuring an actual mass flow change "tricking" anything?

The "temp/density" is not measured directly through voltage difference. Its measured through a power comsumption calculation, using a Wheatstone bridge. You've got to understand how the sensor works before you make statements like this.

It makes perfect sense if you truley understand how the MAF sensor measures mass air flow. It measures mass Air flow by measuring the power input to the heater wire, and the power input is a function of the BTU's being lost from the wire, and the BTU's lost from the wire are absorbed by the mass of air, which can only be calculated by knowing the specific heat of the air.

Sure, the MAF sensor works exactly the same on air in Alaska as it does with air from Texas.... because air has the same specific heat, no matter what "State" its in. But nitrous does not have the same specific heat as air, so the whole basis for the "mass" calculation is thrown "off".

The issue with locating the nozzles "close" starts to bring into consideration the direct impingement of liquid nitrous with the heated wire. Now you have the combined effects of a colder gaseous mixture, and the heat of vaporization of the liquid nitrous impinging on the wire. Remember.... the MAF caclulates the mass air flow based on the BTU's being lost, and it will be more accurate with a homogenous gaseous state mixture than it will be with liquid nitrous impinging the wire and vaporizing.

Sure... colder air is denser, PCM sees more mass, adds more fuel by extending the injector pulse width. Longer pulse width at any given RPM = higher duty cycle. Nothing surprising here.

 

Another dry fan here. Now I dont have a MOTEC (wish I did), but the stock PCM and MAF are more than capable of very reliably handling dry nitrous. I use a bone stock 99 MAF/Computer along with 42 lb injectors and a special dry nitrous tune to swithc the tune for spraying dry nitrous. it will pull timing and add fuel ONLY when the dry nitrous is spraying. Similair to your MOTEC except isnted of an arm switch to activate a seperat table..it uses the MAF tables to add the fuel and retard timing.

Obviously on a 400 hp car the PCM will only access certain cells on the pertenant tables all motor. When you spray a healthys dose of dry nitrous the MAF senses is and sends the higher freq signal to the PCM. This is in an area that the PCM would never acces NA. So you can change those cells to suit your nitrous needs without ever affecting your NA tune. Both fuel and timing.

I ran a 300 shot right down the MAF for 2 years without having a single issue. Operating in the 700-725 rwhp range.
As a matter of fact we copied that setup for many local cars with great success. To me its more reliable and less finicky than even the direct port wet stuff.

All fueling, and timing requirements where programed right into the PCM. And it left the NA tune intact. Very simple and removes alot of additional parts that may be failure prone. And of course the dry nitrous setup consist of only 1 solinoid. And if it fails shut...no biggie. IMO the dry is the way to go until you reach that barrier of Maxing the MAF. Of course we are strictly talking LS1s here.

Now I would still certainly take the MOTEC setup...lol. But we all cant be that lucky, and the LS1 stuff works darn good with the dry.

 

Sorry to offend you by commenting to a post you made, that wasn't my intent. However, with your double talk and over top tech jargon it seems you want to have a confrontation of some sort. Well I am up to the challenge in a friendly manner only.
Well I am not reg over here, but you can check my threads and posts out over at ls1tech if ya think I am full of it, or at the vetteforum.
Robert

 

Hey Al, well said as is preusual. One thing to add on the tune. Running a dry on the lsx platform affords a truly two in one tune. This means that your dry tune will not effect your n/a tune concerning timing and fueling. Furthermore, it's all automatic, meaning nothing to worry about, no sws to flip, no tune to load re-load, no aftermarket pcm.
Robert