Water injection vs Intercooler

[Gibbon]

Hi

I'm about to start work on putting my 1jz-gte into my MA61. Yesterday, I was talking to a guy who had used water injection instead of an intercooler in his turbo pulsar.

Searching the forums reveals little on a comparision between water injection and intercooler setups; although it seems that everyone is using intercoolers.

I'm liking the sound of a water injection setup for a few reasons;

- No intercooler hanging out the front of the car attracting attention
- More room in the engine bay without needing the piping everywhere
- It would seem to actually cool the temperatures more than an intercooler
- Better economy and engine cleaning properties (?)

It's available in a kit from from - http://www.coolingmist.com/pagedispl...key=Turbo_kits

The cost would seem to be about the same between both - although the water injection would have a higher running cost (paying for metho etc).

Does anyone have any thoughts on running a water injection setup instead of an intercooler setup?

Thanks

[JustCallMeOrlando]

To be honest, I don't think you'll ever achieve the results of a half decent intercooler setup with water injection. Room in the engine bay isn't really an issue, and you can make your intercooler setup basically invisible with a can of black paint.

[PlacentaJuan]

water injection needs a resivor, what happens when it runs out, are you supposed to check it all the time or is there a warning if it gets low?

when it runs out do you have to stop driving or just not boost it as much?

also from what i have read about water injection in mags like zoom etc, you need to retune your engine or something because the a/f ratios need adjusting (this may not be correct because i wasnt really absorbing it all)

if i was worried about having an intercooler hangint out the fron i would go for a water to air intercooler before considering water injection.

you have to stuff around with extra coolers and plumbing and fans and stuff but at least you dont have to add another thing to worry about or service (filling up water and metho)

[twentyEight]

In my eyes, a intercooler is much more efficient!

But, a setup with both intercooler & water injection would really get those temps down and also keep it cool when your reserve is empty...

["Z" UTE]

Water injection, is commonly used on the Australian Rally Championship cars. Water injection is used in conjunction with an intercooler. These guys only do short legs, maximum 30km's, so keeping the fluid resevoir topped up is not a problem. Then again, they are never off boost, with their anti lag systems.

If I can install a 1JZ-GTE into an RA23 Celica, and have the intercooler system totally concealed, and the car looking as stock as a rock, you should have ZIP problems doing the same with a much larger MA61 engine bay.

If you need pics/ ideas, email me @ [email protected]

cheers Chuck.

[Gibbon]

What size intercooler did you run with to fit undetected in a RA23?

Tah

If I can install a 1JZ-GTE into an RA23 Celica, and have the intercooler system totally concealed, and the car looking as stock as a rock, you should have ZIP problems doing the same with a much larger MA61 engine bay.

cheers Chuck.

["Z" UTE]

Hi mate, from memory 75/100mm thick core, and enough width to squeeze between the headlight buckets with a few minor tweaks. Height wise, enough for bonnet clearance, and tanks to discharge through enlarged bumper mount holes in the radiator support panel.

I am sure the car will be at the Dyno day on the 22nd, so come and have a look.

cheers Chuck.

[thechuckster]

water/methanol won't cool the air-charge down as much and consistently as a cooler - i's primary benefit slow combustion down so the hot air-charge is less likely to detonate.

I think the RWC cars spray water onto the cooler to help reduce heatsoak - they don't spray the stuff into the airflow.

[WindeX]

water/methanol won't cool the air-charge down as much and consistently as a cooler - i's primary benefit slow combustion down so the hot air-charge is less likely to detonate.

I think the RWC cars spray water onto the cooler to help reduce heatsoak - they don't spray the stuff into the airflow.

Ummmm, I am pretty sure you are wrong on both counts there, methanol injection can achieve temps of below zero and cools the air down much better than an air to air intercooler which can only bring temps(at best) down to ambient temps.

http://www.toymods.net/forums/showthread.php?t=1411

And I am not totaly sure about the ARC, but the WRC teams use water injection.

[thechuckster]

unless you are near-constantly spraying in a water/methanol mix you are not going to get the same consistent reduction in temps that a FMIC affords you... unless you carry around a second fuel tank full of water/methanol mix.

I used to use it (water/meth spray upstream of the turbo) on my 18rte as a means of detonation control but it's effect on keeping the intake system (e.g. piping) cool was negligable and i constantly suffered from heatsoak problems. My new FMIC setup still has a compressor housing almost too warm to touch and all the post FMIC piping and the throttle body at 30-35 degrees despite coolant temps approaching 80.


... never knew that about WRC cars - they do a lot of clever, light-weight electrical stuff these days (wastegates, gearboxes, clutches, diffs, engine mngt, etc) and given their fastidious attention to weight management, it seems unlikely that they would carry around unnecessary fluids.

[Draven]

Gibbon - I've seen plenty of guys run fmic on the ma61. Joorsh gave his a quick spray of black paint and it was invisible. even my fmic on my old ma61 (with a 1jz) was hard to see

[amichie]

water/methanol won't cool the air-charge down as much and consistently as a cooler - i's primary benefit slow combustion down so the hot air-charge is less likely to detonate.

.

This is true.

Water injectors and intercoolers work in deifferent ways.

Turbos compress air to increase the density and pressure of the air but it also gets hotter and that reduces the density. The intercoolers then cool the compressed air and that increases the density again.

Injecting water into the air fuel mixture reduces the peak pressure during the compression stroke just prior to ignition. This reduces the chance of detonation or pre ignition. This has been used for 100 years and was very popular when fuel was very poor quality.

The water also reduces the flame speed and effectively allows the turbo engine to run higher boost without detonation. Some extra ignition advance is sometimes required due to lower flame speed.

[Toysrme]

Very few things can surpass what water injection can do as far as knock surpression.
Water injection by itself will not give better economy. (It could by cleaning the combustion chambers & the IMMEDIATE port area around the valves) Water injection can be used to displace fuel & run signifigantly leaner mixtures as long as you have the effective compression to still support combustion.
Nothing surpasses the "lean out" safety that water injection can provide.

Never use methanol (Methyl alcohol) in combination with water injection on an engine you can't readily tear down & rebuild at any point. Methyl alcohol is quite corrosive to aluminum, and worse health wise to be around. It is highly caustic among other things.
The CORRECT alcohol to mix with water when you are dropping the freezing point is Ethyl alcohol. It poses less of a health risk. Is easier to find, provides the same general benifits (Lower freezing point / atomization), yet does not cause problems with aluminum.

To go along with "The list of things the vast majority of people simply don't know, or understand about water/alcohol injection". Is that neither methyl, nor ethyl alcohol combusts in a gasoline dominated enviornment. Because gasoline requires so much more oxygen to support combustion, the oxygen content drops very rapidly during combustion. The lower explosive limits for both methyl & ethyl alcohol are very quickly exceeded. They can no further combust & simply pass out the tail pipe.
Isopropyl alcohol is the exception. It absolutely should never be used injected into an engine. It remains combustable during combustion with gasoline. Has very little energy & uses alot of oxygen that could otherwise be used to make signifigantly more power combusting gasoline. The use of isoproply alcohol can quickly & unexpectidly (to those not in the know) cause an engine to run almost uncontrolably rich.

Remember... That mixing alcohols with water injection is done to lower the freezing point. The gain in atomization is quickly negatived by the knowledge of - there is no limit to the amount of water you can inject in the first place.
There is also no limit to the size container you can use your water in. There's no reason to run a 1-2 quart container on a street car. Run a gallon...

Also; the charge temp itself is not cooled by the injection of anything (but a gas - say n2o) in it. What is cooled is the combustion process itself & SOME (not ALL) of the combustion chamber related surfaces. The charge temp itself remains the same.




Run an intercooler, run water injection & install a very small nozzle to hit the outside of the intercooler also. There's no reason not to if you already run water injection. There is no excuse for not carrying enough water on your vehicle to support either multiple track driving sessions on a track car, or daily driving.
Between choosing WI, OR and IC flat out. I'd take the IC, but with the understanding an IC won't provide near the benifits than WI can when i comes to combustion chamber temps, clean no carbon combustion chambers, lean mixture safety, or maximum power output passed far the point of detonation of the base fuel.

["Z" UTE]

Also; the charge temp itself is not cooled by the injection of anything (but a gas - say n2o) in it. What is cooled is the combustion process itself & SOME (not ALL) of the combustion chamber related surfaces. The charge temp itself remains the same.

I beg to differ, the atomization, and vapourization of the injected fluid, will extract latent heat from the compressed charge air. This in itself increases the density of the charge air.
The injection point can be anywhere in the induction stream. ie, compressor inlet throttle boby, or intake runner.

cheers Chuck.

[jonra23]

I agree that there is heat extracted by change of state of fluid as Chuck said, methanol much more so than water.

Would advise against running water injection upstream of a turbocharger, the vanes are easily damaged if getting hit by water droplets.

If injecting pre cooler in inlet tract use Demin water with no addatives or will build up a film inside the cooler, dont inject methanol or other combustibles pre cooler for obvious reasons.

Roots style superchargers are generaly OK with upstream water injection as they are running much slower and do not have the thin vanes of a turbo compressor.

regards
jon