Water/methanol injection question

[KiwiBacon]

methanol will cool within a few inches of where you inject it from. water will do the cooling IN the turbo.
as the air is compressed its also cooled while IN the turbo. the turbo is compressing nice cool air which gives you more output.
maybe efficiency is not the right word. better description may be that it makes the turbo act like a bigger one. more output at cooler temps.
after turbo injection or intercooling will cool but won't give increase in boost.

i'm told temp of water doesn't make a big difference as the bulk of the cooling is done due to evaporation.

To boil the water to steam you need 100C (methanol will lower this a little), that's not going to happen till after it's out of the compressor wheel, so it can't increase the effective size of your turbo or make your turbo pump more than it currently can.
It will increase the mass the turbo is pumping, solely because it's now moving mist which is heavier.
This mist (by now steam) will also cool the exhaust which will mean less energy is available to spin the turbine.

I'm still struggling to see the point of such a system. For a sled puller it'd be fine, but for a 4wd it does nothing an intercooler can't and has many downsides an intercooler doesn't have.

[tweak'e]

To boil the water to steam you need 100C ......

i thought you would say that
i'm not up on exactly why but no you don't need to hit that high.
you have to remember its only a tiny tiny about of water/meth that goes in compared to the large amount of air thats flowing through. (i would assume its bit like getting clothes dry on a windy day with no sun, the clothes are not at 100 degrees but they get dry)
in practice going from after turbo to pre turbo (so no change in the amount injected) you get 1-2psi increase in boost and it comes on earlier (remind me to double check that).

how much cooling compare to an intercooling.....i have no idea. something i would like to find out.

having said that some are running it even with intercoolers. i'm told the water/meth is evaporated so it goes through the IC without condensing on it (don't ask me how that works). remember only talking about a small amount here. the bulk of the water/meth is injected after the intercooler.

while on intercoolers, IC's are fine except where you don't have any cooling air flow, ie going slow or in very hot countries. there is quite a few examples around of them replacing intercoolers (interheaters?) with water/meth because it cools better.

[xenith]

pour some water/meth on to your hand and feel it cool your hand as it evaporates. i have set up injection after and before intercoolers. have even injected after a water to air intercooler and got as much as 60 hp gain (with the water/meth tuned on the dyno ) tuning on the dyno makes a diffrence

[Dzltec]

Don't forget, extra power is made from the methanol, it is another fuel source. Yes it will make power becuase of cooler air.

The tractor pullers in the states use gallons of water per minute to keep egts down, so it works well.

For a 4wd, I got sick of filling the tank up. As a power adder that can be switched on and off, its great.


Andy

[neRok]

i'm not up on exactly why but no you don't need to hit that high.
you have to remember its only a tiny tiny about of water/meth that goes in compared to the large amount of air thats flowing through.

remembering back to high school, i think the reason is based on 'energy'. the meth/water is taking so much out of the air, reducing its temperature. and as mentioned earlier, its not so much the water/meth increasing in temperature, its the 'phase' change from liquid to gas that takes lots of energy. this is why steam at 100° will burn your skin more than 100° water, it has more energy stored. something like that...

also, i couldnt see injecting pre turbo making the turbo more efficient, its still going to push the same amount of flow, i think the difference is how dense the oxygen particles will be, so it would push the same CFM but it would have more oxygen in it. another thing to consider is that the hot air travels faster, so cooling it drastically straight out of the turbo may cause slight problems.

i cant guarantee any accuracy of what i have said but it sounds good to me

[KiwiBacon]

To boil the water to steam you need 100C ......

i thought you would say that
i'm not up on exactly why but no you don't need to hit that high.
you have to remember its only a tiny tiny about of water/meth that goes in compared to the large amount of air thats flowing through. (i would assume its bit like getting clothes dry on a windy day with no sun, the clothes are not at 100 degrees but they get dry)
in practice going from after turbo to pre turbo (so no change in the amount injected) you get 1-2psi increase in boost and it comes on earlier (remind me to double check that).

how much cooling compare to an intercooling.....i have no idea. something i would like to find out.

having said that some are running it even with intercoolers. i'm told the water/meth is evaporated so it goes through the IC without condensing on it (don't ask me how that works). remember only talking about a small amount here. the bulk of the water/meth is injected after the intercooler.

while on intercoolers, IC's are fine except where you don't have any cooling air flow, ie going slow or in very hot countries. there is quite a few examples around of them replacing intercoolers (interheaters?) with water/meth because it cools better.

Yes the water will evaporate below 100C, but you can't make use of the huge amount of latent heat (the energy required to boil it to gas) which gets sucked up when it boils.
How much water you can evaporate depends on the humidity of your intake air and how much capacity it has left to hold moisture. I have a relevant text book behind me, but I'm not opening that one today.

With evaporative cooling the coldest you can get it is the wet bulb temp (stick a thermometer in a sponge and see how it reads compared to a dry thermometer).
Someone want to do that with a water/methanol sponge and tell us what the result is at room temp?

At 100% humidity (basically where I"m living now) the dry and wet bulb temps are the same and evaporative cooling doesn't work.

As for intercooling going slow, that's why they make fans.

Water injection and water/meth injection aren't quite the same thing either. One is just cooling, the other also adds fuel.

[tweak'e]

also, i couldnt see injecting pre turbo making the turbo more efficient, its still going to push the same amount of flow......

well the way i see it is its like driving on a nice cool night.
eg i went for a quick hunt last night and the ute was cruising at 3psi less than normal. it was loving the cool temps.

the thing with turbo's is the denser the air the more MASS they can pump for the same work. turbo's hate hot or thin air. cooling the air going in the turbo is just like driving on a nice cold night.

certainly it could change a lot with humidity, i will have to ask the guys who run it in the tropics.
however i can see that the meth side will still continue cooling (meth will still evaporate even in 100% humidity). what may be a worry is if the water doesn't evaporate. mind you its still a small amount and the turbo and pipes are still fairly hot. if it doesn't take heat out of the air its certainly going to be taking it out of the turbo itself.

[KiwiBacon]

if it doesn't take heat out of the air its certainly going to be taking it out of the turbo itself.

There's the rub, water and water/meth injection don't take heat out, they just absorb some of the energy in boiling the fluids you've added.
An intercooler actually removes the heat energy from the charge air.

The reason you have less boost is because the water boiled to steam inside your cylinders which cooled the exhaust.

[tweak'e]

The reason you have less boost is because the water boiled to steam inside your cylinders which cooled the exhaust.

i'm not running WI just yet. that boost drop (at cruise not full noise) was just from the better efficiency due to cooler air temps. just an example if how much difference you can get due to air temps.

dollar kinda sucks for bringing stuff in at the moment which is why the project is on the back burner.
i was looking at intercooling but cost, the tricky route to fit a front mount or even tricker to fit a top mount, which makes the WI look like a cheap easy option. for me i can fit 20-40l tank easy enough but cost of alcohol is a sticking point.

[KiwiBacon]

The reason you have less boost is because the water boiled to steam inside your cylinders which cooled the exhaust.

i'm not running WI just yet. that boost drop (at cruise not full noise) was just from the better efficiency due to cooler air temps. just an example if how much difference you can get due to air temps.

dollar kinda sucks for bringing stuff in at the moment which is why the project is on the back burner.
i was looking at intercooling but cost, the tricky route to fit a front mount or even tricker to fit a top mount, which makes the WI look like a cheap easy option. for me i can fit 20-40l tank easy enough but cost of alcohol is a sticking point.

Is this a ZD30?
How close do the pathfinder/terrano intercoolers match up to the terrano front end?

[tweak'e]

Is this a ZD30?
How close do the pathfinder/terrano intercoolers match up to the terrano front end?

yeah navara ZD30.
i'm not sure there is room to fit the patrol top mount.
i see the terrano's have top mount but i also see a pic of one with factory front mount.

most of the IC fitted to the navara that i've seen have been front mount but they remove the pre cleaner so the intake pipe goes through into the wheel well and goes down and around the chassi. gets a little close to the ground which is not good if you bottom out the front.

the WI would be almost worth it just for cleaning out the crap in the intake ! getting the boost up quicker also has a big apeall on these as they don't get full boost to mid rpm.