looking back over the thread there is a good few paragraphs on page 5.


Drew

Nitro
 

I'd also be inclined to run a separate system for the nitro. Much better control that way, you could only spray the nitro at certain times to cut the costs etc.

I would be inclined to always use a methanol nitro mix for the simple reason that that would give you a handy means to tweak the amount of nitro your using by changing the mixture rather than changing the spray jets.

If I did it I would probably also go direct port injection to ensure the injection rate was balanced between the cylinders. I'd also keep a WI system setup to manage any detonation/ heat load issues the nitro may create.

My instinct would be to trigger an additional WI spray jet along with the nitro until tests show it is not necessary. (I like to take my time and work up slowly and methodically on radical changes like this)

I suspect that at high usage rates detonation could be an issue so would want to keep a little WI reserve capacity available.

Ignition should not be a big issue as you have normal fuel combustion to light off the nitro.

Keep in mind this sort of settup will share some characteristics with a nitrous system. For example if you spray the nitro at low rpm in a simple on off type system you will spray more nitro per engine revolution than you will at higher rpm. That would have the effect of automatically cutting back the flow of nitro at high rpm.

In a system that tracks the injector duty cycle you would have a more rpm independent rate of injection..

Larry

Hmmm...

Wet1, I thought that increasing methanol to more than 50% in a mix with water INCREASES the likelyhood of detonation ?

Hi Joe,
That seems to be the common belief, but I and many others have not found that to be 100% true. Each serves a different purpose to a certain degree and there it some good historical data to indicate that a M50/W50 mix works well, but many of us in the US have found that using more methanol allows us to make more power... maybe just because of the oxygen content of this fuel... I don't know, but we've found that we can maximize a combination to make more power with high methanol concentrations than we can with a 50/50 mix. Unfortunately, many WI systems can't handle the undiluted methanol so a system has to be built around it's use.

Lets try to stay on topic in this thread... if you want to talk more about this, there was another thread on this topic a little while back....
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=673

Interesting...

found this while searching on google...

NITROMETHANE Nitromethane - usually used as a mixture with methanol to reduce peak flame temperatures - also provides excellent increases in volumetric efficiency of IC engines - in part because of the lower stoichiometric air-fuel ratio (1.7:1) and relatively high heats of vaporisation ( 0.56 MJ/kg ) result in dramatic cooling of the incoming charge. The nitromethane Specific Energy at stoichiometric ( heat of combustion divided by air-fuel ratio ) of 6.6, compared to 2.9 for iso-octane, indicates that the fuel energy delivered to the combustion chamber is 2.3 times that of iso-octane for the same mass of air. Coupled with the higher flame temperature ( 2400C ), and flame speed (0.5 m/s), it has been shown that a 50% blend in methanol will increase the power output by 45% over pure methanol, however knock also increased.

Drew

I used to use this stuff in my dragbike. Absolutely gave me 3/10
http://www.pricechemical.com/

Hallo,
i read this thread very carefully because i'am very very interested in the Nitro/Meth/Water inj. issue.
just to get a better overview for myself and maybe to solve some open questions i have made a conclusion
about whats (maybe) facts until now.

If something is wrong, please correct me (my open questions are in brakets behind the statements)
its just not a guarantee, its only what i have understood from reading the thread and maybe there are also
some false informations in it... so please feel free to correct and add som informations.

Thanks
Malte

Conclusion:
-----------

Mixture knowledge:
==================

- 70HP/150Nm gain from mixture: 70/25.5/4.5 W/M/N [without problems]
- unknown but good results from: 34/56/10 W/M/N
- from what we know until now a mixture of: 60/20/20 W/M/N should be possible without causing too much drama
- nobody has results from the snowperformance nitrobooster until now.
Question from me: did someone know how much % nitro / % methanol is contained in nitrobooster? and what mixture will result if using the 8oz on 2-qt as written on the homepage?
- There is a small forum over at snowperformance.net and the folks there say that it will NOT mix with water, and that best bet is 50% methanol 50% nitromethane.

- Hotrod and I (Richard L) both agreeed that you will get about 3-4 hp/100cc/minute

Dissolve knowlegde:
===================

- 33/33/33 W/M/N couldn't dissolve all the nitro
- 50/40/10 W/M/N, no separations - perfect mix
- 50/35/15 W/M/N, very small visible separation (one blob)
- 50/30/20 W/M/N, visible separation
- Acetone and Ethanol doesn't help to dissolve more then 15% Nitro. Maybe reducing the water content helps.


What do what?
=============

- Water has only a cooling effect on the intake air
- Methanol is an additional fuel so it:
- enrich the mixture if no more oxygen is brought into the combustion process.
- has a cooling effect?!? (i'am not sure)
- is needed to dissolve nitro
- brings hp because more fuel can be burned?!? (i'am not sure)
- 50/50 W/M is most effective when used without Nitro (with Nitro -> no info)
- a higher amount of Methanol can cause detonation?!? (not sure)
- Nitro:
- contains aprox. 50% additional fuel and 50% additional oxygen so it makes more hp when ignited.
- knock/pre-ignition ability?!? (unknown for me at the moment)
- cooling effect due to the relatively high heats of vaporisation
- with the higher flame temperature ( 2400C ), and flame speed (0.5 m/s), it has been shown that a 50% blend in methanol will increase the power output by 45% over pure methanol, however knock also increased

- usually used as a mixture with methanol to reduce peak flame temperatures

Open Questions:
===============

- how do i calculate which is the ideal mixture for a given W/M/N mix when i only have a Wideband Lambda meter which is calibrated for normal unleaded fuel.
- what will happen if i mix W/M/N mix together with normal injected race fuel (leaded/unleaded with high octane ratings)
- how do you calculate your WI jet size for a W/M/N mix? same as for Water/Mathanol injection?

Very cool thread, I'm just not very impressed regarding the quantity of fuel needed to make some interesting power. Do I have this right?

100ml/min of PURE NitroMethane will only produce 3-4Hp?


That's the regular size injector for the snowperformance kit. My fuel injectors are 440ml/min so you want me to inject 25% nitromethane with respect to fuel for an extra 3-4Hp? Did you mean 100ml/min of injected mixture produces 3-4Hp?

I'll try to hack the computation from the energy content data given earlier:

50/40/10 W/M/N mixture, assume 100lbs of mixture

0 BTU/lbs * 50 = 0
5000 BTU/lbs * 10 = 50,000
12500 BTU/lbs * 40 = 500,000

Total 550,000 BTU/100lbs = 5,500BTU/lbs

400ml/min*4 = 1600ml/min of fuel and 360bhp

so

1600ml/min*19,000BTU/lbs =30,400,000 (don't care about units ok?)


30,400,000/ 360 = 84,444

Now for the mixture

100ml/min * 5500BTU/lbs = 550,000

550,000/Hp = 84,444 <- Hp is 6.5 Hp

That means I'm getting 6.5Hp for a 100ml/min injector, injecting the mixture, and it looks like the methanol is responsible for > 80% of the power made.

So, again, why add nitromethane? I guess the guy from 2 posts ago said why. The thing is you'll have to inject a lot of it. Let me see what a 50/50 methanol/nitromethane mix does:

50 * 5000 = 250,000
50 * 12500 = 625,000

875,000/ 84,444 = 10Hp with a less than 2.5:1 A/F ratio

That's a cool round number, for every 100ml of 50/50 M/NM you get 10Hp.


It would be cool to find something that would neutralize the nitric acid exhaust. Although I like power, I don't like acid eating up my custom exhaust.

Speedy G