LT1 on Nitro=Zoom or Boom!

I am assuming this is advanced tech material, if not, I apoligize.

To start Im considering the use of a nitromethane based fuel additive for the purpose increasing horsepower not octane. Im looking to make another 50 or so HP all the time (unlike N2O) using Problends Fast Forward Nitro additive. Ive done some research and came up with limited information. From what I can tell any more than 1% Nitro by volume will need an increase in fuel by that porportional amount. Seems that Nitro carries its own oxygen in the neighborhood of 49.5% by volume that is released during combustion, similar to n2o. And although it increases cylclic pressure it has a slower burn rate, unlike n2o. The additive though may mix the nitromethane with nitrobenzene or propylene oxide to increase the burn rate.

Now for the questions, since nitro is mixed with the fuel and therefore will be burning all time will the PCM be able to adjust the fuel ratio correctly? The way I see it the o2's should see a lean condition from the extra oxygen and add more fuel to compensate to keep the AFR in check but the MAF will not see an increase in GPS. I know that changes in fuel pressure or an aftermarket MAF can be nulled by the PCM, so is it possible it would correct in the same way on Nitro? The PCM has the power to adjust AFR based on climatic conditions, a 20HP difference can be seen in extreme changes of weather(DA).

If possible I would like this to be a discussion, not, no it cant be done plain and simple.
Check out this link:
www.pro-blend.com/tech1616.html#formulations
Thanks Kevin.

Sure, it probably can be done:

1.25% of this $215.12/gallon (+ shipping) mix probably won't get you 50 hp. How often are you at wide open throttle? That's the only time your engine is making it's max power. All that time you are cruising you are just pushing that stuff out the tailpipe.

Assuming free shipping (of nitro? sure.), your 20 gallon fillup will cost you $35 for gas (@$1.75 per) and about $54 for Pro-Blend. If you use it for 10,000 miles at 20 mpg average, you'll need $1344.50 worth. It won't take that long before you could have built a stroker with a real 50 more hp.


My $.02.

Thanks for the reply Old Stroker. I have considerd the cost and had forgot to mention that I really dont drive the car much, maybe 1000-1500 miles a year and most of it is to the track so the cost wouldnt be all that bad, besides when its all used up there wouldnt be $1000 worth of equipment laying around if I decided not to use it anymore as there would be with a nitrous kit.

Suposedly the amount of nitro in % by voulume increases output in HP by that amount if used alone, so you would be correct that 1.25% would not make 50 HP. But with the addition of accelerators and plastisizors, 1% of nitro "can" make around 20-30 HP.

There's one problem with this that I see other than the cost (It is now $850 a drum for us racers). Nitro will not mix with gasoline. It does mix with methanol, but even if it is premixed with a little methanol, I would bet that it would then pool up and not mix the the gas. Then you would probably get a shot of pure nitro (or nitro/methanol mix) at some point during your drive. I know you are looking at small percentages, but there are lots of little things that you must look at. Nitro requires LOTS of timing. In our race car, we run as much as 60 degrees of initial timing. The burn rate is that slow. Also, it is VERY explosive under pressure. Even in small quantities, your pistons and rods will not hold up very long.

I have heard that it wont mix with gasoline in its pure form but the plasticizors in the additive allow mixing up to 10% total nitro. From what Ive read the plasticizor allows the nitro gobules to stay suspended in pump gas as well as lubricate the top side of the pistons.

Im not sure about the timing issue when used in gas, I would guess it would need to be advanced but probably not as much as when mixed with alcohol. Alky removes alot of heat and is needed in a much higher volume.

Edit:
I didnt really consider the extra pressure on the short block. I guess thats why the bigboys run such heavy weight oil. Do you think it would be much with just 30HP worth?

An interesting subject to discuss, I hope to learn more from any additional posts. I will say that nitROUS is gonna be a lot more practical than nitRO. That stuff VERY toxic, not to mention explosive. I'd prefer not even to handle it, but maybe I'm just a wussy or something.

Anyway, intreresting topic.

Rich Krause

Originally posted by rskrause
That stuff VERY toxic, not to mention explosive. I'd prefer not even to handle it, but maybe I'm just a wussy or something.

Anyway, intreresting topic.

Rich Krause

Nahhhhh, Rich it really isn't bad to handle, unless you hit it with a hammer, or somehow compress it. That's when it gets ugly. You can try to light it all you want with an open flame and it won't do anything. But if you get it in an open cut or in your eyes, then you are in a world of hurt!! It doesn't seem to do permanant damage (I've gotten plenty in my eyes and cuts), but it HURTS A LOT!! Oh, and don't let it get on plastic- it will melt it fast! Other than those things, it's not bad to handle! ;)

Originally posted by Ponyhntr
Nahhhhh, Rich it really isn't bad to handle, unless you hit it with a hammer, or somehow compress it. That's when it gets ugly. You can try to light it all you want with an open flame and it won't do anything. But if you get it in an open cut or in your eyes, then you are in a world of hurt!! It doesn't seem to do permanant damage (I've gotten plenty in my eyes and cuts), but it HURTS A LOT!! Oh, and don't let it get on plastic- it will melt it fast! Other than those things, it's not bad to handle! ;)

Where do you store it? Separate shed or something? When I was running race fuel, it would make me nervous to have a drum in my garage.

Rich Krause

Originally posted by Kevin97ss
I have heard that it wont mix with gasoline in its pure form but the plasticizors in the additive allow mixing up to 10% total nitro. From what Ive read the plasticizor allows the nitro gobules to stay suspended in pump gas as well as lubricate the top side of the pistons.

Well, if that's the case, then that issue won't be a problem.





Im not sure about the timing issue when used in gas, I would guess it would need to be advanced but probably not as much as when mixed with alcohol. Alky removes alot of heat and is needed in a much higher volume.

I would tend to agree, that it wouldn't need nearly the same amount of timing, but maybe a couple degrees.


Edit:
I didnt really consider the extra pressure on the short block. I guess thats why the bigboys run such heavy weight oil. Do you think it would be much with just 30HP worth?

Well, with just 30hp more you probably wouldn't see much wear, but I don't know (What I do know is a cap full of nitro in a scooter will blow it up in less than a minute!!
:D)

I must admit, I am no expert on nitro, I just work on cars that use it for fuel as my day job.

Originally posted by rskrause
Where do you store it? Separate shed or something? When I was running race fuel, it would make me nervous to have a drum in my garage.

Rich Krause

Well, we don't really store it. Because it is so expensive and it is HAZMAT, we try not to haul it in the rigs or keep it at the shop. But if we did have a drum, (we do right now at the shop) it is stored outside) Usually, VP Fuels (the supplier) hauls and stores it for the teams. We usually do have a few gallons of it in fuel jugs in the trailer (already mixed that didn't get used yet), but we don't worry about it.

What about using nitromethane as the wet side to a nitrous kit? Or a lower nitromethane/methanol mix, like 50/50 or 30/70, ect?

Run a dedicated fuel cell in back for the wet side, fill it with the good stuff so you only use it on the bottle. It'd provide extra power and extra octane.

It'd probably just be easier to put bigger pills in and fill the dedicated fuel tank with C16. :D

Top fuel teams carry it all over the country in the same trailer as the cars. Handleing does require care,you dont want to strike it, but it is hardly flamable. If it had just 4 more degrees of flash point it would not need the flamable designation.

I couldnt even imagine the cylinder pressures incurred if used as the "wet" side of nitrous:eek: Though a very small amount may be of some benifit to reduce the amount of pulled timing.

Just a capful belw up the scooter! :eek: :D Nitro R/C cars can run 35,000 RPM on 25% nitro and last quite some time.

So does anyone want to comment on how a factory style EFI system would handle the fuel enrichment needed for nitro?

as far as i know,the stock ecm ignores the O2's at WOT,so im not sure how you will add the extra fuel needed to compensate. Also im not sure how the Orings in the fuel system would stand up to the nitro.

as far as N2O and Nitro,thats something i wouldnt even want to experiment with,way too much cylinder pressure IMO.

The WOT issue is what Im having trouble with (In my mind anyway) In closed loop the PCM should be able to modify the AFR without much trouble with constant feed back from the o2's, but this is where Im confused, with certin changes such as increased fuel pressure the PCM will eventually correct for it even at WOT or open loop based on cell 16 (I believe) information in closed loop. Kinda like if you parked your car after running in 100deg temps with a baro of 29.30 then running it the next morning with a temp of 40deg and baro of 30.40. The PCM would be lean at WOT untill it relearned. So would it be safe to say that it would eventually learn the fuel curve at WOT on nitro? I know Fred has a really good grasp of how this works....maybe you could chime in?
:)

In the new version of LT1_Edit you can lock the BLM's in cell 16 (or is it 18, or both, I forget) and avoid the issue you raise. But the bigger issue is "are O2 sensors an accurate way to read AF ratio with a mixture of nitro and gas"? I doubt they are, and it leaves open the question of what the right AF ratio for that fuel combo would be. Who knows?

Rich Krause

Yes the air to fuel ratio would definitly be different, but i don't think that would matter. The O2 sensor is not measureing the the mixture before combustion, its measureing the results after combustion.

For a stoichiometric mixture the composition after combustion should be the same regardless of the fuel and its appropriate ratio.

I think that if your running it all the time you'd just need to start from scratch and create a tune for it.

-brent

Originally posted by rskrause
In the new version of LT1_Edit you can lock the BLM's in cell 16 (or is it 18, or both, I forget) and avoid the issue you raise. But the bigger issue is "are O2 sensors an accurate way to read AF ratio with a mixture of nitro and gas"? I doubt they are, and it leaves open the question of what the right AF ratio for that fuel combo would be. Who knows?

Rich Krause

Well, I'm not sure what the AF ratio would be with the mixture, but I do know the stoich AF ratio for nitro is close to 1.8:1- NOWHERE near gasoline's 14.7:1. Also, as somebody pointed out, the nitro would eventually dissolve the o-rings in the fuel system. It even dissolves the o-rings in our oil system over time (because of the amount of nitro that ends up in the oil).

Kevin-
The R/C cars are built for nitro for one, and from what I've been told, the % listed on the fuel for those is not nitro:methanol. It is actually much less if you figure it like that. DISCLAIMER: I do not know that for a fact, someone just told me that.

I imagine the reason the scooter blew up is that the nitro didn't mix with the gasoline and it all of a sudden got 100% nitro in the carb and it turned the motor internals into paperweights.

Originally posted by Kevin97ss
The WOT issue is what Im having trouble with (In my mind anyway) In closed loop the PCM should be able to modify the AFR without much trouble with constant feed back from the o2's, but this is where Im confused, with certin changes such as increased fuel pressure the PCM will eventually correct for it even at WOT or open loop based on cell 16 (I believe) information in closed loop.
As a simplification, if the PCM is "adding fuel" in Cell 15 in closed loop, its going to continue adding the fuel in PE mode using the BLM's in Cell 15. If the PCM was "subtracting fuel" in Cell 15 in closed loop, it will default to Cell 18 and lock the BLM's at 128 in PE mode.
Kinda like if you parked your car after running in 100deg temps with a baro of 29.30 then running it the next morning with a temp of 40deg and baro of 30.40.
This has nothing to do with A/F ratio or O2 sensors. This is taken care of by the MAF sensor, or by calculations made based on the MAP and IAT readings in a speed-density system. This isn't "learning"... this is simple data processing - it sees a different air mass flow and it adds the proportional amount of fuel.

The PCM would be lean at WOT untill it relearned. So would it be safe to say that it would eventually learn the fuel curve at WOT on nitro? I know Fred has a really good grasp of how this works....maybe you could chime in?
Are you saying that you are running this "nitro" additive all the time? I'm not sure that the O2 sensor even responds as indicated in the post by 94formulabz.... The O2 sensor "infers" A/F ratio based on the residual O2 in the exhaust stream. Does a motor running on a fuel other than gasoline produce the same residual O2 levels as gasoline when the A/F ratio is correct to prevent detonation? I don't think so.... but Rich and I have debated this issure with regard to nitrous, without resolution. My point with nitrous is that you are combining 2 different combustion processes... At peak power, you are running the air/gasoline portion at 15% richer than stoichiometric (12.8 vs. 14.7:1), and the nitrous/fuel portion is typically running 35-40% in excess of stoichiometric (7:1 or 6:1 vs. 9.6:1). Does this combined combustion process produce exactly the same partial pressure of O2 in the exhaust gas as a strictly air/gasoline process? Wouldn't it be possible that O2 partial pressure would be even more disturbed by combining two processes... one with a 14.7:1 and the other at 1.7:1.

I honestly do not know whether the O2 sensor will read correctly, unless it knows the fuel stoichiometry... I believe a wideband works on units of stoichiometry (lambda) rather than absolute A/F ratio... but when you tune an alcohol engine do you have to calibrate the wideband for the fuel?

In any case, the issue is not so much the adaptive learning of the PCM/O2 sensor feedback in closed loop.... the real issue would be establishing the proper target A/F ratios for PE mode. That would take care of the need for a possibly much richer A/F ratio at WOT.... not relying on the adaptive learning.

Originally posted by Injuneer
As a simplification, if the PCM is "adding fuel" in Cell 15 in closed loop, its going to continue adding the fuel in PE mode using the BLM's in Cell 15. If the PCM was "subtracting fuel" in Cell 15 in closed loop, it will default to Cell 18 and lock the BLM's at 128 in PE mode.

This has nothing to do with A/F ratio or O2 sensors. This is taken care of by the MAF sensor, or by calculations made based on the MAP and IAT readings in a speed-density system. This isn't "learning"... this is simple data processing - it sees a different air mass flow and it adds the proportional amount of fuel.


Are you saying that you are running this "nitro" additive all the time? I'm not sure that the O2 sensor even responds as indicated in the post by 94formulabz.... The O2 sensor "infers" A/F ratio based on the residual O2 in the exhaust stream. Does a motor running on a fuel other than gasoline produce the same residual O2 levels as gasoline when the A/F ratio is correct to prevent detonation? I don't think so.... but Rich and I have debated this issure with regard to nitrous, without resolution. My point with nitrous is that you are combining 2 different combustion processes... At peak power, you are running the air/gasoline portion at 15% richer than stoichiometric (12.8 vs. 14.7:1), and the nitrous/fuel portion is typically running 35-40% in excess of stoichiometric (7:1 or 6:1 vs. 9.6:1). Does this combined combustion process produce exactly the same partial pressure of O2 in the exhaust gas as a strictly air/gasoline process? Wouldn't it be possible that O2 partial pressure would be even more disturbed by combining two processes... one with a 14.7:1 and the other at 1.7:1.

I honestly do not know whether the O2 sensor will read correctly, unless it knows the fuel stoichiometry... I believe a wideband works on units of stoichiometry (lambda) rather than absolute A/F ratio... but when you tune an alcohol engine do you have to calibrate the wideband for the fuel?

In any case, the issue is not so much the adaptive learning of the PCM/O2 sensor feedback in closed loop.... the real issue would be establishing the proper target A/F ratios for PE mode. That would take care of the need for a possibly much richer A/F ratio at WOT.... not relying on the adaptive learning.

Fred: I still asking around to try to find the answer to the question re: conventional O2 sensors and nitROUS. Obviously, the same issues would apply to a nitRO/gas mixture. As you point out, we don't know how to measure teh AF ratio or what it should be. It would take time, money, and probably more than a few motors to figure it out. The info is probably out there. But I don't even know anyone to start asking. I did talk to a guy at Electromotive who basically supported your point that a convention O2 sesnor is not accurate when running nitROUS, that's as close as I have come.

Rich Krause

I know this is under a bit different situation, but..... a few years ago i inquired about using nitro in my GN over on the turbo buick boards. I had an alcohol injection system for 100% enthanol mix already on the car and set to inject above 15psi boost. The plan was to switch the pump in the kit to a methanol compatible pump and run pure meth with nitro mixed into it (~5-10% by volume). I can't remember all the details and the old thread has fallen off the server so.... basically some of the bigger name guys [like Jason Cramer, Carl Ijames(engineer i think), etc] said that i would have problems keeping my O2s under control when the system started to inject since nitro is a "heavy" fuel and also would require different timing tables. Under boost it would give huge gains though. If i had an aftermarket computer to tune it for the times when the injection is on or off it probably would've been more feasible. The end result of the discussion was that the mix i intended to use would give gains like that of a healthy nitrous shot but would involve much more trouble to use and set up. So in light of that, i just left the idea alone and stayed with ethanol. If you have a dedicated race car nitro would probably be the hot ticket, but for everything else nitrous would be better. Just my $.02

I have often wondered about using nirtomethane in a road car, after research I realised the basics involved.

As someone said earlier about using it as the wet side of a nitrous kit, if you ran two additional fuel cells in your car, one for additional petrol and one for nitro, they could be premixed in the correct ratios by a couple of well chosen fuel pumps and then shot into the intake by a 9th injector by way of a solenoid with a dash mounted switch.

By using this method you have horsepower on tap and one gallon of the nitro would last you a long time. No neat nitro hitting the chambers as the correct amount of additional fuel would be added.

Something to think about, anyone else think this might work out?

Originally posted by Injuneer

Are you saying that you are running this "nitro" additive all the time? I'm not sure that the O2 sensor even responds as indicated in the post by 94formulabz.... The O2 sensor "infers" A/F ratio based on the residual O2 in the exhaust stream.

I was in a rush for work, but thats exactly what i was trying to get at by my statement that it was measureing the results after combustion, it's measureing the partial pressure of the residual o2 compared to the atmosphere.

Originally posted by Injuneer

Does a motor running on a fuel other than gasoline produce the same residual O2 levels as gasoline when the A/F ratio is correct to prevent detonation? I don't think so....

Thats a good point that i didn't have time to mention, but don't know the answer to either. I have some emmisions residuals data for different fuels, but it doens't list the o2 residuals :( Its quite possible with the increased burn time there would be considerably more(or less) o2 residuals at an appropriate AF ratio for that fuel blend. However, he was only talking about trying to add about 30 hp, so its not quite as drastic as someting like Fred's nitrous motor.:)

Considering the fact that he is going to be blending this fuel in his garage, its not like he is going to find any information on a target AF ratio for his particluar blend.

-brent

Originally posted by Kain


Run a dedicated fuel cell in back for the wet side, fill it with the good stuff so you only use it on the bottle. It'd provide extra power and extra octane.

It'd probably just be easier to put bigger pills in and fill the dedicated fuel tank with C16. :D

Nitromethaine will not increase octain it will decrease it. Nitro burns much more violently than gas. Thats why top fuel runs them so rich. So the engines can live. Infact the engines are so rich that they are on the verge of hydrolock.

The AFR for 90% nitro will be any where between .5:1 up to 2:1 depending but Im not looking to run anywhere near that amount. I think what Brent is saying about the AFR not mattering makes sence, at least in closed loop operation. The o2's arent looking for a specfic target, they are comparing. If the PCM sees that more fuel is required it will add it regardless of its actual ratio.

The after combustion residual should not change except for the addition of nitric acid. In small amounts nitric acid should not harm or effect the o2's. This is only information I have read and have no first hand experience.

Fred, I see what you are saying about having two different combustion proceses but Im not sure the end result would be any different because in effect just the ratios change. More oxygen is helping burn more fuel.

Josh, your friend is somewhat correct in that the ratio isnt nitro:methanol. A combination of lubricants is also included. The nitro content in % is still there based on total volume of the container.

Brent, finding the correct AFR is next to impossible for a certin blend its strictly trial and error or should I say a lot of plug reading. All of the information I have found for running nitro in gas is based on carb induction and is hard to translate it to EFI.

Originally posted by ASRoff
Nitromethaine will not increase octain it will decrease it. Nitro burns much more violently than gas. Thats why top fuel runs them so rich. So the engines can live. Infact the engines are so rich that they are on the verge of hydrolock.

Nitromethane does not have an octane rating. So actually it would not change the octane of the mixture. Because it is violent is not why we run them so rich. We have to run them that rich because the cylinders will not fire with less fuel. That is one reason why you see cars 'drop holes'. You are right about the hydrolocking, though.

Originally posted by ASRoff
Nitromethaine will not increase octain it will decrease it. Nitro burns much more violently than gas. Thats why top fuel runs them so rich. So the engines can live. Infact the engines are so rich that they are on the verge of hydrolock.

Originally posted by Ponyhntr
Nitromethane does not have an octane rating. So actually it would not change the octane of the mixture. Because it is violent is not why we run them so rich. We have to run them that rich because the cylinders will not fire with less fuel.

Ahhh, that makes sense. Since nitromethane has a low flash point, it would want to predetonate under compression more than the regular fuel around it.

What about this:

Instead of using it as a dedicated wet side for a nitrous system; just use it by yourself. Have a gallon gas tank in back, a alcohol fuel solenoid and a sprayer hooked up as a 9th injector. Take a 10-25% nitromethane and corresponding number methanol mixture and spray that? It'd take awhile to figure out the math and what jets to use.

Nitropropane appears to be the chemical you should add, it mixes with gasoline, nitromethane does not. Hot Rod magazine has done some excellent testing with nitro on a couple of engines, search their website.

They had a 388 test engine that made 25 additional hp on race gas with 10% nitropropane. They used race gas to control the wild detonation. But, as mentioned in other posts there are many problems created by leaving nitro in the fuel system.

As far as tuning goes they suggested one jet size on all four corners per each percent nitro added. With LT1 edit you should easily be able to add fuel, and/or the stock WOT programming is so overly rich small percentages of nitro may require no change. Although Hot Rod's experience shows that a small percentage of nitro isn't worth the effort.

I have no idea how the o2s will contol closed loop operation.

Another excellent source of information is Hot Rod's Anvil engine series, search "anvil" on their site. This engine ran on methanol, which is a little different, but it still provides some excellent insite.

we have expereimented with nitro in race engines. only about 5% max and there was No gain to be had.

I always hate to leave no alternative, so if it's just 50 hp you are looking for, here's what I did, almost (I made my own).

Get a purge or powershot solenoid and a used nitrous tank. Hook the solenoid to the tank and run poly line to the intake track. Use a micro switch on the pedal and away you go. Insert a .037" orifice for a jet (verify for yourself, I can't remember). The stock programming and knock sensor will do the rest. I can't quite remember but I think I dry sprayed 80 hp without problem.

Smokey Unik (sp?) wrote an article on using a 5% or so nitro mix with gasoline in roundy round engines resulting in a little edge over the competition. What didn't he do to get a little edge over the competition?

Perhaps the increase was to small to measure in your application, 93z286speed.

You'd really have to average several before and average several after runs to measure that small a delta.

Thanks for the info tips Andy, I'll check those out:)

Edit: The first two links didnt work.

Just some interesting stuff, not real impressive though. The below link is about Nitropropane.

www.hotrod.com/techarticles/42018/index.html

You bet. As you can see the learning curve can be expensive.

So, boom is the answer to your question.

Yea, I couldn't get them to work.

There you go. There is another source of infomation I found, Ray Hall the famous turbo guy. Use Google and Search nitromethane.

You could always use a seperate fuel system with an alcohol compatable pump and spray a mixture of methanol and nitro off of a solenoid at WOT. The methanol would likely help alleviate the detonation. Certain comercially available mixtures already have lubricatants and other additives that may increase your chances of success. That's what I was interested in trying. Just to cheap to buy the pump. Plus with the inherent danger, I'd seriously compromise my ability to drive to work (daily driver). I've given up on nitro in favor of more traditional power adders.

Yea, I think I'll just leave this idea in the dust. Not enough information for EFI engins out there. I dont have the doe to fix a shattered piston and cracked cylinder walls:eek: Oh well, maybe I'll consider nitrous or better heads/cam package, or like OldStroker suggested, stroke it.

Thanks all
Kevin

Bringing this thread back to life.....I ran across this over on TB.com:

http://www.turbobuick.com/forums/showthread.php?s=&threadid=118269

Just with a 6% mixture that engine gained over 50rwhp.... makes you wonder.