Meth/E users, how much time?
Was wondering how much distance does the gas need in order to be effective at cooling down the IAT.
I know the carb guys have enough tunnel distance just since the fuel is introduced so far up the manifold, but for us EFI guys the injectors are right behind the valve. Making me believe that there isnt enough track length to get the full benefit.
Any input?
i see carb guys talking about greater cooling effect and you know once someone says it on the internet it becomes a fact,
i believe that you acheive maximum cooling once the air sees the fuel. ie, it the hot air cannot coming from a turbo cannot pass the fuel without turning it to vapor and that action instantly cools the air charge down. its called the latent heat of vaporization.
again, this is my firm belief, not a proven fact.
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i see carb guys talking about greater cooling effect and you know once someone says it on the internet it becomes a fact,
i believe that you acheive maximum cooling once the air sees the fuel. ie, it the hot air cannot coming from a turbo cannot pass the fuel without turning it to vapor and that action instantly cools the air charge down. its called the latent heat of vaporization.
again, this is my firm belief, not a proven fact.
edit: doing some reading it seems that pressure will lower the latent heat but I have not read anything about the time factor. if you have a book on thermodynamics, maybe you can provide some theories on this?
Hi, Im not quite sure I understand the point that you are trying to make. Are you using the fact that EFI intakes dont "sweat" as proof that there is less heat being pulled from the air charge?
Last edited by 71 chevy; May 18, 2013 at 10:39 AM.
Which lets face it...will get skewed readings because of the liquid fuel too.
Even charge temp measured close to a meth nozzle. How much is actually an accurate reflection of charge temp, and how much is simply some cold methanol hitting the sensor ?
Keep in mind I run a lot of meth. Intake sensor reads about 60-80 degree's at the end of a 8 second pass.
edit: doing some reading it seems that pressure will lower the latent heat but I have not read anything about the time factor. if you have a book on thermodynamics, maybe you can provide some theories on this?
.
Hi, Im not quite sure I understand the point that you are trying to make. Are you using the fact that EFI intakes dont "sweat" as proof that there is less heat being pulled from the air charge?
Honestly, I wouldn't worry about it too much. I wouldn't tune a car to be that heavily reliant on a specific temp intake air charge temp. Granted, you don't want 130, 140, 150 degree intake temps, but unless you're running a positive displacement blower, that shouldn't be a concern. The fact that methanol burns cooler, and will no doubt pull out heat from the air charge, is sufficient for a street car running normal boost and timing. So keep your timing in the mid teens, afr in the mid 11s, and you'll be fine.
And personally, I run one nozzle into my blower inlet, and one post blow off valve that's about 8" before the IAT which is before the elbow going to the throttle body.
The carb guys is what got me so fascinated with the eth/meth. They have enough time/distance to cool the charge and remove the intercoolers. I was just thinking of maybe running a pre IAT injector to start the cooling process, but was trying to figure out what distance it would need to actually begin the cooling process.
Alchemist, have you ever had a false sensor reading with little particles of meth/eth touching the sensor?
I'm just thinking that if the engine has a correct temp reading then it can add some more timing instead of being so conservative.
great input from different sources btw!
hard reading, but some will find it interesting (I k now alchemist certainly will)
https://www.google.com/url?sa=t&rct=...JfgXnfCeaXzheA
apparently,
direct injection is ideal
followed by port injection
and worst is into the intake tract before the throttle body.
who woulda thunk. Maybe we can start dispelling this bit of mythology
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