Are water-to-air intercoolers greater super better than air-to-air?

One would automatically think so, cause i did. and there are two setups available at the moment on ebay with pump, radiator and intercooler. Only issue is greater bulk.

but history, particularly with my celica background, is that some manufacturers went from water-to-air to air-to-air in their later models while still having greater hp output and more aggressive tuning setups.

maybe just the companies cutting on manufacturing costs on the later models i spose?

Or particularly just the question of whether its actually necessary to go even that far...

Hi

An effective intercoooler is hard to package in rear engine car, the problem is airfow unless your willing to have an air 2 air hanging out your decklid.

Steve

hmm yea your absolutely right there. Thats going to be my major hurdle... cause being a baja i don't want the intercooler to be picking up air from all the crap and rocks below.

and up above... well then issue is room and air flow. Particularly when i don't want one of those baja scoop style decklid covers... i got a modest, oldskool one that sits flush with a pops nose that i really got my eye on using. I got both styles... but would rather a 'neat' setup.

ah wells... plenty to keep my busy on the holidays no doubt!

it was cost cutting that the manufacturers dont use h2o coolers

air to air is a very simple primative peice compare it to how much more complex a water intercooler is plus add in header tank, pump, radiator, water lines etc its easy to see why there not standard equipement

that siad theres a pretty big aftermarket for barrel coolers and they're much better suited to a rear engined vw

air2air can be made to work in a bug, ians WRX bug uses one and i was watching the inlet temps alot and was surprising how low they stayed even with some heavy boosting

i started setting up one on my old turbo setup just before it died and i threw in the towel

it was a stock WRX TMIC sitting between the decklid hinges catching all the air coming over the roof with decklid stand offs

never got the chance to test it

Hi

The bits needed for the air 2 water system can be scrounged around for or you can just buy all big dollar name stuff.

A good system that usually wont beak the bank is one from a turbo liberty, I think I paid around $150 for a pump, radiator and intercooler. Then you will need some hoses etc and triggering device, aftermarket ECU can do this or a Hobbs switch with a delay circuit would work as well. The intercooler radiator can be fitted at the front of the car in the air stream but out of the way of rocks etc.

Steve

There's a really really interesting article by Julain Edgar over on Autospeed. He tests the thermal characteristics of intercoolers and basically deduces that most of the heat from the air stream goes to the intercooler under boost (and heats up the intercooler core itself) and then quite a lot of that heat soak actually goes back into the airstream (heating it up) when the car is not on boost or at idle. It seeps back into the airstream a little at a time which doesn't really affect the running of the engine. So he thinks of it mainly as a heat sink for the inlet air, that gains and releases heat to the airstream, not so much releasing it to the cooling water. (whether that's true or not I'll leave up to you to interpret, have a read).

So he looked at the properties of heatsinks and found that wax (parrafin wax basically) has an interesting thermal property. It takes lots and lots of heat energy to turn it from solid into liquid. Once it's liquid, it can then dissipate the heat, and also slowly release it back as it turns to solid. So he got a water/water intercooler and filled the water areas with liquid wax, sealing it all off so it's a closed system.

This then takes heaps of hot boost, takes the heat energy out of the air to turn the wax inside the intercooler to liquid. It's still contained within the system. Now as he drives around off-boost, it slowly releases energy back until the wax is solid.

I reckon this would make for a very, very compact intercooler system that doesn't require pumps and external radiators and so on. Perfect for the back of a bug or buggy.

that sounds pretty interesting

is that julian edgar the bloke who started zoom magazine?

what engine are you running it onand i am guessing its in the Baja???

water to air is more affective on a small cooler as it keeps the temps down more than an air to air. A big air to air can work almost as good as a small water to air.

The down side of water to air is all the extra parts and if something lets go its harder to find the fault in the system where as air to air is simple and easy to fix.

there is another simple option and its what i have done. Use a small top mount air to air cooler with a water spray directly onto the cooler with a 8inch thermo mounted underneath drawing the air through. I have a duel stage boost controller set up in my baja and on the first stage its just 6lb of boost with out the water being sprayed. when i switch over to second stage its 12lb of boost and when it hits 4lb the spray comes on so that it will only fire under hard driving and not when idleing.

We did a heap of testing and the water drop the temps massivly it also droped the engine water temps as my rad is mounted in the rear with a draw through fan that sucks the air and water thats fallen from the intercooler which was an added bonues

its removed at present and i dont have pics but i hope to have the work i am doing at presant done in the next couple of weeks and i will re install it. when i do i'll take some pics so u can see how i've done it.

mine is mounted central from the rear bar work to under my rear scoop and gets a fairly good air flow, the 8inch thermo makes it very good flow.


its not fitted int he picture but u can see where it would fit going in the middle with the center of the rear sccop higer


steff...

thanks for all the help guys, alot of ideas here and good advice. top stuff. paraffin wax is pretty orig! i will have to definitely find that article.

Hi steff, yea its for a the baja, its for a s/c 1600. Yours sounds like a very simple and effective idea. for the spray over the intercooler you just have a windscreen washer pump or sumfin coming from a reservoir?

It would be more trusting then a 23 yr old water to air intercooler setup i'm seeing on ebay. They have a few from the old st165 3sgte gt4 celicas, pump, intercooler and front mount radiator with the bid at $99. But your right, with wats involved, and particularly if i'm driving in the middle of no where, i want something thats the most reliable... and therefore will be looking for something newish, simpler and the most inanimate. I like your idea.

I plan on driving through the outback and don't want a major breakdown lol.

Hi

I have the wax article as a PDF file, drop me an email and I will send it to you. info@clubvw.org.au

The air 2 water is not that complicated, I have personally used one on my 1302 for many years, Jak has one on his WRX bug that been trouble free for years.

Steve

yea useing a crapodore washer bottle with windscreen pump. It has a low level switch so i know when its nearly out. It only get power on the second stage as it has a pressure switch only going on at 4 and above.

I wasnt saying a water to air is complicated if anything its more basic than mine but if u have problems, leaks etc is mush harder to find/fix on water to air coolers where as a air to air its a simple thing and normaly u know straight away if its playing up. I wouldn't mind useing water to air on mine but the more i looked i found it really wasn't suited to my car and what its used for.

I dont run mine on the second stage very offen but the set up has a hidden advantage that i never thought about when installing it. We put ice cubes in the tank 10 minutes before i run down the strip and the water temp being sprayed onto the cooler droped by just over 3/4's from what it had been before(basic temp probe just to get an idea)

when i get it al sorted and back on the car i want to install a temp senser just before the turbo to mesure the air, hopfully it will show some very good results from standard to the air passing through the cooled cooler. in fact thinking about it i should install it now with no cool fitted so i can see an over all affeact from a standard set up.

steff.............