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Discussion Starter #1
Absolute boatload of great info on this site - nice one guys.

But cant find anyones experiences good/bad/indifferent on charge cooling (maybe I'm looking in the wrong place?), with mist spray, before or after the intercoolers inlet. Obvious benefits are cooling the inlet charge and therefore helping detonation probs.

Anyone tried it with realworld results ie consistent performance at trackdays, more torque/bhp?

Andiroo
 

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Andiroo,

Some of the guys have experimented with water spray systems in front of the intercooler and they seem to work. I don't think we have the capabilities to actually measure the performance improvement but it does seem to make a positive difference.

The good thing is it is cheap to do and easy to do yourself

John
 

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PACE do a nice line in Chargecoolers (air-water intercoolers) although they are quite bulky and I'm not sure where you would inslall on on a skyline

I have one on my coupe, it was custom built to replace some of the intercooler pipework, plus you need another small radiator and a coolant tank installed so it gets a bit cramped
 

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Discussion Starter #5
Thanks for the replies guys.

Sorry, not water injection, not IC(s) sprays, and not a seperate chargecooler rad. Although it can use the same equipment as the water injection, but its less dangerous to use......

The charge cooling described and being developed for me is maapped and driven by several inputs - boost, IC(s) internal temp (before/during/after), and intake temp. Using these variable inputs it predicts when the IC(s) charge needs to be cooled in real time (rather than an IC spray which can be inefficient and also too late). As per water injection it then mists either the IC(s) input or output to control these values back down to ideal setup. Will supposedly cover all eventualities of the air charge needing to be cooled.

With a lot of you guys running 550bhp +++++, I'm surprised it isnt used more. Our calculations indicate not only real bhp at the wheels at all times, which is especially handy on trackdays, but with its detonation curing properties, maybe even extra torque/bhp - and its not very expensive.

Andiroo
 

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if it is, then its going to be similar to the top model Aquamist system which is mappable on boost and a few other parameters from the ECU
 

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Discussion Starter #8
Hi mate,

I thought water injection was misting along with the fuel mix on the intake, not the IC(s)? I know its confusing (maybe I am) but you are right in that mostly the same parts are used for both techniques, however the charge cooling doesn't go near the fuel mix, therefore taking away the dangers (and associated ECU mods) associated with that.

I am led to believe this is why they differentiate the two techniques by using two different terms (theres probably other terms as well just to make it more fun!)

Andiroo
 

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Discussion Starter #10
Hey there Big Lad, you are spot on.

Its ERL's mappable system with a electronic twist in terms of the inputs. Supposedly they call the technique Charge Cooling, although as DCD pointed out it still uses Water Injection bits and bobs, but the technique is not called Water Injection.

So I take it nobody is using this technique?

Andiroo
 

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wow..this is confusing!!

If you spray water in before or after the IC that air/water mix will eventually be mixed with the petrol..right?? :confused:
 

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Discussion Starter #12
You're right, it is confusing mate.

Again, I'm led to believe that the charge cooling effect, with it being atomised or whatever, will only result in the fuel meeting colder air, ie the water will have vaporised/evaporated before it meets the fuel. Also with direct Water Injection, ECU parameters have to changed to account for atomised water in the combustion chamber, whereas Charge Cooling you dont - it doesnt get that far.

(I'm slightly less confused now!)

Andiroo
 

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I thought that was just water injection???

you are not actually cooling the air intake temperature but the addition of water to the air/fuel mixture you are cooling the cylinder temprature, allowing you you run higher boost due to the lowered detonation point.

probably not a totally correct explanation but you get the jist :)
 

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Discussion Starter #14
Thats what I said,

What you've just described is what I've been told is water injection ie cooling the cylinder combustion temp by spraying mist with the fuel.

The cooling of the air intake pre and post intercooler, directly with mist, is charge cooling.

So I take it nobody has used this?

Andiroo
 

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dunno if its used much on skylines, but aquamist have been used on loads of other cars with success.

I think the confusion is due to the terminology, I have only ever heard of this described as Water injection. While chargecooling / coolers generally are associated with air to water intercoolers.

the effect is slightly different as chargecoolers make the air dense i.e cooler and water injection cools the cylinder through evaporation (I think)
 

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Discussion Starter #16
think your right about the confusion.

Definitely the air cooling technique rather than the cylinder though.

Andiroo
 

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Water Injection

OK I'm confused, seems like 3 systems are described:

1. Water is sprayed on outside of i/c to evaporate to atmosphere - result cooler intercooler and lower air intake temp = works

2. Water is sprayed into intake charge, evaporates in cylinder and cools charge = more power = works

3. Water is sprayed into intercooler? It cannot evaporate to atmoshere and is probably not hot enough to evaporate fully into charge, result intercooler/pipes full of water? Doesn't seem logical to me.

I would have thought that you either want to cool the charge with water in the cylinder (2) or by increasing efficiency of intercooler (1) - I don't see the point of option 3.

Guy
 

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Discussion Starter #18
Check out ERL's site mate, all three are on there.

http://www.aquamist.co.uk

it goes like this;
-BY LOWERING THE INLET (INTERCOOLER) AIR TEMP, POWER GAINS CAN BE EXPECTED EVEN WHEN THE TURBO CHARGER(S) ARE OPERTATING OUTSIDE THEIR NORMAL PEAK EFFICIENCY RANGE.
THE LOSS DUE TO HIGH TURBO DISCHARGE AIR TEMP AT HIGH ENGINE SPEEDS CAN BE COMPENSATED BY THE EFFECT OF HEAT DISPERSION PROPERTIES OF WATER SPRAY AND RESULTANT CHANGE IN CHARGE AIR DENSITY THUS INCREASING TOP END POWER. ARMED WITH THIS INFO ABOVE, A SUTABLE MAP CAN BE CONSTRUCTED FOR YOU PARTICULAR APPLICATION.

They seem to think it makes sense

Andiroo
 

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Guy,

This is where I'm getting confused also as I think 2 and 3 are the same, but 3 will not cool the air charge temprature

As I understand it water injection can do two things -

- Lower charge temperatures. If this is what you want to use it for the jet should be positioned as close to the the throttle body as possible.
- Det reduction. If you want det/knock reduction put the injector as far away from the throttle body to get best water atomisation.

I don't think there is anything to be gained by putting the injector so that it goes through the IC as I'd imaging you would fill it with water over time??

certainly all the installs I have seen have been after the IC and within a few inches of the throttle body
 

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Andiroo,
I think you must be refering to Water injection, (No 2 on Guys list), but are refering to it being located further up the intake path i.e. at the intercooler rather than the manifold.

This will give the same result. But where as the water in the manifold will be completly injested and burnt, adding it to the intercooler will allow water to collect and corode from the inside out. NOT good. The biggest danger with water injection is ensuring that nothing is left after the engine has switched off.

As for your referance to the water mixing with the fuel and giving you problems, it won't.

You can run up to a 50/50 mix of fuel and water under full throttle conditions with no desernable effect. When I say 50/50 I mean backing off the fuel 50% and adding 50% water. This obviously will reduce the intake temperature, but will also incerase economy.

Something that was found out on WWII spitfires.
 
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