When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Thus why phrased it specifically: "the largest mass of hot as possible air" I thought it was fairly clear. Also I am not sure you can go 1:1 air mass to fuel mass ratio that way (I am not sure, you might be right but I have not attempted the calculation) don't we normally say there is some mass:mass of air/fuel ratio? 18% more mass of air with an 11:1 air fuel ratio is not 18% more fuel is it? You threw a wrench and I am not sure I am awake enough to catch it.
See that little squiggle in front of the 18% -- it is shorthand for approximately.
It will not be exactly 18% since some of the extra fuel volume will displace some of the extra air volume. But close enough.
But what are you arguing here? Are you saying that you think hot thin air makes more power than cool dense air? If you think my numbers are wrong, provide your own instead of hand waving.
See that little squiggle in front of the 18% -- it is shorthand for approximately.
It will not be exactly 18% since some of the extra fuel volume will displace some of the extra air volume. But close enough.
But what are you arguing here? Are you saying that you think hot thin air makes more power than cool dense air? If you think my numbers are wrong, provide your own instead of hand waving.
No, I am saying that 10lb of 200*F air will give you more power than 10lb of 100*F air, in theory.
I am working through your calculations but there is some black magic I need you to explain,
I see how you get kg/s air mass and kg/s of methanol, and then you provide a ratio, great. But where is the calculation for decreasing or increasing air temp? You need to use a specific heat capacity somewhere. Also, you are neglecting the combustion process where methanol surely surpasses 60*F at some point.
I think we need to take the specific heat of methanol and figure out how many joules it will absorb moving from -40*F (or whatever) to ambient temp of say 150*F, first. Then I would like to compare it to water, as water should be almost twice as good at doing this. Then we should be able to, by using your calculation for kg/s, and how many joules of energy in temperature (and entropy? this is physical chemistry now?) the air will absorb as it changes temperature, to find an instantaneous relationship (by creating a model. Sigh) between the two. It will require some programming but it could be done. I just have a **** load of homework already like this... making models and output graphs for differential equations... so I am not too crazy about doing one for "fun" anytime soon.
In any case. You saying that injecting super cold methanol is not going to drop IAT much is only more fuel for the argument that its not all about the IAT drop. Methanol doesn't suddenly get better at cooling IAT when it is warmer.... does it?
Last edited by kingtal0n; Jan 20, 2016 at 05:22 PM.
I think we need to take the specific heat of methanol and figure out how many joules it will absorb moving from -40*F (or whatever) to ambient temp of say 150*F, first. Then I would like to compare it to water, as water should be almost twice as good at doing this. Then we should be able to, by using your calculation for kg/s, and how many joules of energy in temperature (and entropy? this is physical chemistry now?) the air will absorb as it changes temperature, to find an instantaneous relationship (by creating a model. Sigh) between the two. It will require some programming but it could be done. I just have a **** load of homework already like this... making models and output graphs for differential equations... so I am not too crazy about doing one for "fun" anytime soon.
You are over thinking it. Just because you have a hammer...
ok, let's do it another way. Specific heat of methanol is 2.533 J/g*C
We are talking 3 grams per second of methanol flow. 60F to -40F is a 56C difference.
3g * 56C * 2.533 = 426J/s extra that the -40F methanol will take out of the IA vs being at 60F.
What does that mean to air temp?
E =mc(delta T)
Air mass is 0.35kg/s as previously calculated. c = specific heat capacity of air (at constant pressure) = 1005 J/(kgK)
426J = 0.35kg x 1005kgK x delta T
delta T = 426 / (0.35 x 1005)
delta T = 1.21C
i.e. on the order of magnitude of my other calculated estimation.
Note that the "magic" of cooling power of water/meth is in the phase change. Cooling to -40F will not affect that part.
You are over thinking it. Just because you have a hammer...
ok, let's do it another way. Specific heat of methanol is 2.533 J/g*C
We are talking 3 grams per second of methanol flow. 60F to -40F is a 56C difference.
3g * 56C * 2.533 = 426J/s extra that the -40F methanol will take out of the IA vs being at 60F.
What does that mean to air temp?
E =mc(delta T)
Air mass is 0.35kg/s as previously calculated. c = specific heat capacity of air (at constant pressure) = 1005 J/(kgK)
426J = 0.35kg x 1005kgK x delta T
delta T = 426 / (0.35 x 1005)
delta T = 1.21C
i.e. on the order of magnitude of my other calculated estimation.
Note that the "magic" of cooling power of water/meth is in the phase change. Cooling to -40F will not affect that part.
Ah! Very nice. So then we are NOT injecting methanol primarily for its IAT cooling effects, but rather its ability (like water) to change to a gas an absorb energy... then why use methanol at all? because of it's octane rating presumably, which is another factor that will contribute to the overall result in the combustion chamber (which we cannot calculate or deal with easily).
I still need to work through it myself, but for now, since i have tried a few of your other calculations and came up with the same result, I have no reason not to trust this one.
Thanks for doing all that math, I am very rusty on this front.
Last edited by kingtal0n; Jan 20, 2016 at 05:54 PM.
Ah! Very nice. So then we are NOT injecting methanol primarily for its IAT cooling effects, once and for all this is settled then. Thank you
Firstly, it's for 2 reasons. Octane enhancement and IAT cooling.
Secondly you are missing a massive piece.
The cooling effect comes not from the temperature of the water/meth, but from the high amount of energy needed for the phase change to vaporize water/meth.
My point was that cooling the methanol is minuscule compare to that effect.
I don't have the numbers handy for methanol, but the heat of vaporization for water is 2260 kj/kg.
So for our 4GPH = 3 g/s that works out to be 6780 J/s. Cooling the mixture gives as an extra 426J/s or ~6% cooling effect.
This post isn't directed at anyone, I just wanted to highlight something I think is interesting.
The benefit is to injecting water OR alcohol (as you are able to inject 100% water or alcohol) is not directly due to the IAT (you are not seeking an air density benefit) but rather its ability to hold down EGT (combustion chamber temps) which directly influence detonation/octane threshold.
IN other words, the power of injecting water is in it's heat capacity of vaporization, that is, its ability to absorb and carry away temperature as it evaporates. Any IAT drop is just a coincidence/icing on the cake.
Ah! Very nice. So then we are NOT injecting methanol primarily for its IAT cooling effects, but rather its ability (like water) to change to a gas an absorb energy... then why use methanol at all? because of it's octane rating presumably, which is another factor that will contribute to the overall result in the combustion chamber (which we cannot calculate or deal with easily).
I still need to work through it myself, but for now, since i have tried a few of your other calculations and came up with the same result, I have no reason not to trust this one.
Heat energy is heat energy, regardless of where it is in the induction & mixing cycle. What do you think happens when heat energy tranfers from one molecule to the other? They work towards an environmental homiostasis, correct? That means something is getting warmer while something else gets cooler... The vaporizatio in that process. Of course it isn't going to impact it all right away because the process takes time for the heat energy to be absorbed. It isn't going to be right at the turbo. The atomization isn't the best, niether is homogenization needed for uniform energy transfer, but the time all depends on the mass ratio being injected & available heat energy.
Of the math shown of 100:1 (Which I doubt is a static number at all mass-air flow rates) the mass is not all that substantial for the benefits accomplished, as said above of octane as well... So if a 50/50 mix is used in this calculation, then the actual mix ratio of meth would be 200:1 A/F... correct?
I think you need to step away from the internet a while and go put some of these great ideas of yours yo use. Let us know how the super heated forced induction setup works.
Heat energy is heat energy, regardless of where it is in the induction & mixing cycle. What do you think happens when heat energy tranfers from one molecule to the other? They work towards an environmental homiostasis, correct? That means something is getting warmer while something else gets cooler... The vaporizatio in that process. Of course it isn't going to impact it all right away because the process takes time for the heat energy to be absorbed. It isn't going to be right at the turbo. The atomization isn't the best, niether is homogenization needed for uniform energy transfer, but the time all depends on the mass ratio being injected & available heat energy.
Of the math shown of 100:1 (Which I doubt is a static number at all mass-air flow rates) the mass is not all that substantial for the benefits accomplished, as said above of octane as well... So if a 50/50 mix is used in this calculation, then the actual mix ratio of meth would be 200:1 A/F... correct?
Right I was just trying to get people to think. I didn't actually ask myself those questions, they are rhetoric for those trying to learn.
To elaborate a tiny bit, the phase change everyone is talking about is a sudden one time thing in this scenario. the molecule gradually ramps up in temperature, gaining little by little energy, and then finally it hits the point of a phase change, and THEN it carrys away a MASSIVE amount of energy as it "frees itself" from it's partners various kinds of intramolecular forces.
Ah! Very nice. So then we are NOT injecting methanol primarily for its IAT cooling effects, but rather its ability (like water) to change to a gas an absorb energy...
Where do you think the energy for the phase change comes from?
It comes from the air.
What does that do to the air?
It cools it!
When it's cooler it is denser. Not linearly but exponentially.
Which means more O2, which means we need to add more fuel to maintain our A/F ration. Which means more power.
So yes, injecting methanol can mean more HP.
Look at the video you posted at 3:19.
As far as water vs meth - water is denser and has higher heat of vaporization. But also doesn't burn. So displaces some amount of A/F. Methanol has the advantage of reducing IATs (though not to the same extent), increasing octane, and burning to get back some of the A/F it displaced.
Where do you think the energy for the phase change comes from?
It comes from the air.
air that raises in temperature and becomes exhaust, and thus has an EGT associated with it. I said several times that water/meth will reduce EGT. You are just pointing out that before it was exhaust, it was air, and that anytime before combustion or during combustion is fine for the phase change to occur (but certainly not afterwards, it would be too late).
You are right to point to this out, and I will take it one step further and point out that many folks are measuring their IAT after a meth/water injection and correlating that IAT in the plumbing (before much phase change has occurred) with the performance of their systems, which is not the case as we have seen several times., and perhaps this was/is my main reason for posting to begin with. You can't go by IAT data to find out how well your meth system is working, you really need to look at the final product (EGT).
I think you need to step away from the internet a while and go put some of these great ideas of yours yo use. Let us know how the super heated forced induction setup works.
It would be really nice if you would share your pictures of a compressor wheel you have run for 50k~miles while injecting a liquid into it. You would be the first source for such information I have ever found across 30 forums and 15 years of data collecting who has attempted this. I am sure it works etc... I am simply interested in the shape of the wheel itself, does it show anything besides normal wear. I love injecting water/meth but I have always been afraid to do it pre-turbo. I am curious what kind of nozzle you are using, if any, what sort of atomization precautions you are taking, etc..
What real world experience do you have with a turbo ls motor kingtalon? I mean first hand own drive and built by you experience. Not something you read somewhere.
It would be really nice if you would share your pictures of a compressor wheel you have run for 50k~miles while injecting a liquid into it. You would be the first source for such information I have ever found across 30 forums and 15 years of data collecting who has attempted this. I am sure it works etc... I am simply interested in the shape of the wheel itself, does it show anything besides normal wear. I love injecting water/meth but I have always been afraid to do it pre-turbo. I am curious what kind of nozzle you are using, if any, what sort of atomization precautions you are taking, etc..
I'm 35 and have probably owned 30 "toy cars" or so over the years. I've never put 50k on any of them, turbo or not. If I get 2-3 race seasons of drag racing/street duty out of a JY motor I count myself lucky. The reason you haven't found information about compressor erosion is because it doesn't exist when used in an application like this. Which I explained already.
I literally sprayed tons of cars pre-compressor and never had an issue. I've done so on my current LS turbo for 3 seasons or so. It's billet and a little tougher than a cast wheel, but it still looks like new.
The worst application I can think of was my 93 talon. I used about 3gph of water pre-turbo at about 250 psi. This was on a tiny 16g mitsu turbo I put a "special" port job on with the gate basically pinned shut. It would spike to 35lbs of boost and settle to 25 or so by 7k. Easily cranking out over 100k RPM on that poor little turbo I'm sure. Ran it this way for about a year before the motor let go. Then sold the same turbo to Kevin Jewer, who set the record (which I believe still stands) for a 16g turbo. Using it. The blades were just fine near as I could tell. I rebuilt it before I sent it to him.
Your experience brings a tear to my eye. thanks for sharing it. I will now use this exact thread as a reference anywhere anybody asks me about injecting water pre-compressor- I will say "He did it! and although he beat those engines/turbos severely, the wheel looks decent after 2-3 seasons..." (not sure how long a season is, do you mean actual seasons like summer/spring/fall so 6-9 months? Or is a "racing season" a whole year, I get confused easily with things like that)
Well i decided and went ahead and ordered a ebay intercooler with piping kit. 31x12x3. Same one i had on my gto. My gto made 720whp on 17psi with a 4.8/e85/precision7675 /ls9 cam with the same IC. So it should work well.
I would hate to crack a ring land due to heat. If this motor grenades i would prefer it grenade the rods and know that power killed it than heat on the stock pistons.
the reason the pre-turbo injection is improving mass flow of the turbo better (more power) than when we inject it in front of the throttle body is because the IAT reduction is greater before the charge hits the cylinder, as more of the water/meth is able to change phase before it reaches the engine. Once the liquid is inside the cylinder and the valve closes, phase change can no longer influence air density after the compressor in the plumbing. I can imagine (guess) that passing through the compressor wheel would have a major influence on sending them to a gas phase as well. In fact, I am now thinking I would want to spray wayyyyy before the turbo even, perhaps 3 to 4 feet before the turbo in fact, as fine a mist as possible. There is some finite distance (it might not be so far. but I would want to test it) at which the final IAT at the cylinder is best just before the valve.
Just thought I would share that realization, if you already had it figured out well I was the slow one.It just hit me, I was standing there thinking of what the new user had put into perspective for me. It was like re learning it in a new way.
Last edited by kingtal0n; Jan 21, 2016 at 12:00 AM.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
