dry nirtous ??? how long will 20oz last

[brent9k]

I have a 20oz bottle and all the the hardware. I want to put it on my pol 800 twin. Im not looking for big HP, I just want a little extra. 100-300 RPM gain. how long will (sec/min) this 20oz bottle last. (10-15 HP gain max)

I would like to end up with about 2min of run time.

 

[snownman]

nitros

a 20 oz. bottle wont last 20 seconds, and your engine wont last much longer if you dont add fuel with it.

 

[brent9k]

Is that fact or your own uneducated theory?

I just ran a test in my shop with a pill that is rated at 20hp

I did 5 , 15 second passes. I also made sure the bottle was warm.

Im still intrested in geting more info on the subject, but please Don’t try to be noticed by making stupid comments that are not fact!


Has any one tryed to just shoot nitrous gas into the air box?
I know the power would go way down but my run time is almost 5 min if i hold my bottle upside down.

 

[Heavysledz]

I have a 2 1/2lb bottle and a 40hp shot (2-20hp nozzles) and I can only get about 55 seconds out of a full bottle before the bottle is empty. So doing the rough math, a 40oz bottle -> 40hp shot = 55sec. This would equate to a 20oz bottle -> 10hp shot = 110 sec....

So it looks like you are in the right ball park for a 10hp shot lasting around 2 minutes. I don't think you are going to get anywhere near 300rpm out of a 10hp shot though.

I do have to side with snowman when saying that you are not doing your motor any good by adding the NOS without any additional fuel. When the N2O breaks down the additional oxygen will act as a blow torch in the combustion chamber without the addition of more fuel.

 

[XC700116]

^^^That and without the fuel added you don't get any HP increase other than creating a lean condition while on the button. NO2 is not combustible without fuel added with it.

 

[EVANEZER]

XC700 is right on fact!!

 

[rockin rmk]

^^^^^ as said above no extra fuel = no extra horsepower and that is a fact.
So the real question shoud be how long will my engine last with 20oz of nitrous?

 

[Perk]

Don’t try to be noticed by making stupid comments that are not fact!

Easy cougar, you asked for help and you were getting some. You might not agree with him, but remember, you're the one that asked

He is right, you can't inject nitrous without fuel (if you are jetted right) without damaging your motor. I don't doubt that you did an experiment and did not burn your motor down, but you would eventually. I expect that the motor that you were testing on was already running too rich and that is why you did not have a problem.

Nitrous info to help you -

1. You can run nitrous without "injecting additional fuel". However, you do this by jetting ~2 steps richer (for 30-40 hp) and run your sled that way all of the time. A guy on here use to sell those kits many years ago. I think his company went by the name of Scott Performance. They did a lot of early work on the Team Thunderstruck sleds. Anyway, the downside of running this way is that you are running rich all of the time so when you are not using nitrous, you are not making peak power.

2. The preferred way to run nitrous is to inject both fuel and nitrous together at the same time. This is done in two ways - WET or Dry.


Wet Systems:
- The key component in a wet system is a nozzle/manifold in which both fuel and nitrous are injected together. This is typically done post the carbs (in the boot between the carb and the reeds). It can also be injected directly into the case, but this is typically done on drag sleds only. That is because the nozzles don't hold up well when hard mounted into the case (they break after being exposed to vibration for extended periods of time).

Wet systems are renowned for making more horsepower than dry kits. I don't know if that has ever been proven. I can imagine that it is true on really high output kits (automotive application) but we are only shooting for 30-50 hp on mountain sleds so it is a moot point for most of us.

Wet systems are more complicated to install. There are two solenoids (one for fuel and one for nitrous). You will have to run lines for both fuel and nitrous for each cylinder, connect into the stock fuel system (for high hp applications it is recommended that you run an aux fuel pump). Most people run a battery if they use a wet kit because of the power demand to kick two solenoids.

The biggest problem that I have found with wet kits for sleds is that the same amount of fuel is delivered every time you hit the button. The problem with this is that depending on the temperature of your bottle, the nitrous pressure will vary....that is a big issue on a sled. Too cold and your nitrous pressure will be so low that you will not get enough nitrous for the amount of fuel being injected. When this happens, you'll know it because you actually lose power. If the temperature is too high, the pressure can be high enough that you inject too much nitrous for the amount of fuel and you run the risk of burning down. Running egts will help you keep an eye on this. If you start seeing temps above 1400 (typical but has to be benchmarked to your motor), you'll know you are injecting too much nitrous for the amount of fuel you are injecting.

I ran two different wet systems in the past. They work, but I don't recommend them.

Dry Systems:
- A dry system injects only nitrous through its manifold/nozzle AND uses other methods to supplement fuel while it is being injected. Nitrous is injected into the airbox and fuel is added using the stock fuel injection system or carburator.

The Boondocker system is one of the most popular sled kits on the market. For carbed sleds, the additional fuel is supplemented by using the nitrous pressure from the injection manifold to pressurize the carburator float bowls. By pressurizing the carburator float bowls, you increase the amount of fuel delivered to the motor. The advantage of this design is that as the nitrous pressure varies with temperature, the float bowls are pressurized in direct proportion. This insures that the proper amount of fuel is injected with the amount of nitrous that is being injected. Boondockers also sells the Synergy regulator. This insures the same nitrous pressure at the manifold at all times. This makes running nitrous a no brainer. I run this kit and would not do it any other way. Consistency and reliability are incredible.

For fuel injected systems, a control module is placed between the injectors and the stock ecm. When you are on nitrous, the duty cycle of the injectors is increased to add more fuel. This is the most controlled way to supplement fuel when on ntirous, but the box is not cheap.

Your hardware -
20 oz bottle = 1.25 lbs. Typicaly, we use a 4 lb bottle and can play for a day on it. But I am not an over user, and I still empty the bottle every ride. I am jetted for a 50 hp increase. I'd say for the cost of a bottle (you can get them on ebay for $100 (5 lb bottle)). You would be better off to go bigger here. At 1.25 lbs of nitrous, I am betting you can get 60 seconds at 30 hp.

15 HP hit - I remember on my first wet kit I was told to jet it for 20 hp and make sure everything was working as planned before going to 40 hp. If I had to run at 20 hp, I wouldn't bother, it just isn't worth the hassle. 20 hp just doesnt make a difference in most situations. I say shoot for 30.

So the only way I can see to run your kit would be to do it the "quick and dirty way". Make sure you are jetted two steps rich and inject it into the airbox. Be careful though, if you inject too much nitrous (nozzle orifice to large) 2 steps wont be enough and you will burn down. Also, you can get into trouble on cold days or at low elevation. General jetting principles apply. You'll want to be two steps rich for your typical temps and elevation, then don't use your nitrous unless you are in that neighborhood.

Good luck,
Chris