legacycentral bbs

I have a water to air i/c on my 92 suby legacy turbo.. does anyone no if there is a to cold temp 4 the air temp?? or has anyone tried this?? Im makeing a container that goes in be the radiator return and the header tank.. that will hold dry ice and realise pressure.. done the intercooler need pressure? as some of you no the dry ice sits at around -70digrees c and sublimes from a solid to a gas.. creating pressure.. is relising it gona be a prob if i just have a tape at the top and leave it open while i have dry ice in it? it will be above water level of course..

The ESX WRX drag car uses a dry ice intercooler setup. It can be done but it's a little more complicated.

Oh ya, and if you're going with dry ice then you really shouldn't need a heat exchanger so the 'air' part is taken out of the equation.

trying to read your post just gave me a headache...damn

yeah but i dont wana be runing dryice all the time you no wat i mean.. its cheap but i cant buy it every day.. heat is wat stops you from putting your boost up right? i mean if you could keep the boost cold how high could you put it?

it's a little more complicated......

and it's not really keeping boost cold.....it's the compressed intake air charge that you want to cool.

When air is compressed it heats up. The molecules are packed closer together. The more you compress the air (more boost) the greater the temps will be.

The issue with hot intake air temps is the following. As the piston is compressing the air, it's heating it up even more. The temp will rise further. At this point the fuel has already been injected into the combustion chamber and atomized into the intake air charge. The fuel has a certain temperature that it will ignite at. If the temperature of the intake air charge equals that. The fuel will ignite by the intake air charge, rather then by the spark plug.

This is called pre-ignition. It's very bad.

So yes....if you can keep your intake charge temps down, you can run more boost. Another option is to run higher octane fuel, which requires more energy to be put into it to ignite.

After read the post, I just pop up an idea, does anyone use the solid dry ice put it on top of the air to air intercooler and the air filter box while racing? since its a dry ice and it won't leave any liquid to damage your engine.... but how much for a dry ice????

Ben

hack0r wrote:I have a water to air i/c on my 92 suby legacy turbo.. does anyone no if there is a to cold temp 4 the air temp?? or has anyone tried this?? Im makeing a container that goes in be the radiator return and the header tank.. that will hold dry ice and realise pressure.. done the intercooler need pressure? as some of you no the dry ice sits at around -70digrees c and sublimes from a solid to a gas.. creating pressure.. is relising it gona be a prob if i just have a tape at the top and leave it open while i have dry ice in it? it will be above water level of course..

holy run-on sentence/barely even english

magicmike wrote:trying to read your post just gave me a headache...damn

word

what would you want to relieve the pressure for? Dry ice and water in a soda can is always fun, i wonder how that'd work with and intercooler.

well its kind hard to explain.. so i drew a pic lol and now i cant work out how to add it.. grr... email me if you wana c and think you can help thanks. CJE@xtra.co.nz

All i no that if the pressure dont relise and there is enought dry ice in there it will blow something apart by pressure..

and when its relised .. will it push water out or air.. its hard to no untill i test it..

Dry ice turns to gas, not a liquid.

Steve

yeah i no.. but i will be cooling the water in the intercooler. if i accelerate water will be water where the relise valve is and i assume it will pust it out under pressure

A pic of my idea.. lol just a quick one.. wat do you think?

http://get.yourfile.net/?us1989

How much boost do you plan on running that you are going to be overpowering the AWIC?

What turbo are you running?

More importantly, why do you want to do this? The dry ice would last 2 seconds before it completely turned to gas. It would be effective for 1 pass at a time.

If it's THAT important, I'd just adapt a CryO2 intake cooler to help dissipate heat.

BAC5.2 wrote:How much boost do you plan on running that you are going to be overpowering the AWIC?

What turbo are you running?

More importantly, why do you want to do this? The dry ice would last 2 seconds before it completely turned to gas. It would be effective for 1 pass at a time.

If it's THAT important, I'd just adapt a CryO2 intake cooler to help dissipate heat.

i dono how much boost yet but even if i dont change it my car will still run better wif cooler air. the dry ice last longer than that. i have made a container that would hold about 2 kgs and in boiling water that takes about 5-10mins to completely turn to gas. keeping the intercooler water that cool 4 that long has to do something good.

i mean i dont even no wat temp the intercooler sits that.. oh by the way im from new zealand.

i just assume from wat i understand. that it would make my car run better

So you get 20 minutes out of the dry ice. 20 minutes. What good will that do? You've still gotta stop and refill the container every 20 minutes if you wanted to maintain the effects.

I'd think you'd get better results with a bigger radiator for the water. At least that would be a permanant thing, instead of a temporary and complex, and expensive setup using dry-ice to try and cool the water to cool the air. You could just as easily, if not moreso, adapt a Cry-O2 intake charge cooler, and use Nitrous Oxide or compressed CO2 to cool things.

Question for you.....does the A/W intercooler setup have a pressurized water system?

I don't think you really want to be pressurizing this water, and I don't see an easy way to relieve the pressure in the system unless you run a tube from the highest point in the system into a volume bottle and have a vent at the top of that bottle. Basically a similar setup to how the radiator overflow works, except you would not have a pressure control device like the radiator cap. The vent would more or less be open all the time.

If the stock A/W setup does contain some pressure, you'll need some sort of pressure controling device that will open once pressure reaches that set point and relieve it into the volume bottle/overflow.

The stock AWIC setup does have a ~13-psi radiator cap on the heat exchanger, but I don't believe it's actually pressurized normally.

I mean, think about it -- the only way for it to be pressurized would be for the water to be ridiculously hot, right?

I think the cap is there just as an emergency thing; it acts as a relief valve if somehow the system does pressurize and the water increases in volume.

Many AWIC reserviors look essentially like a radiator tank..with an pressure blow-off cap (the crude but effective pressure-control device) and an overflow bottle...they are built to withstand some minor pressure but aren't really supposed to hold much. Obviously the circulation hoses and the heat exchanger hold pump pressure, but that should be pretty low. It would be higher for those who choose to use small hoses and higher pressure flow, like if you use an air conditioner condenser that has small fittings. In that case you need strong hoses and a positive displacement-type pump, one that can push good volumes at higher pressures, but again the reservoir would not hold much pressure, just the portion downstream of the pump, through the HX and IC and back to the reservoir.

Let's face it, dry ice will not do too much better than one or two runs, so why not just fill the reservior up with ice-cold water, and make it easy to drain and refill the tank as needed.

yeah only 20mins.. that ages.. 1/4 mile over in 15s!!! lol i not making it to run all the time. but yeah pressure is wat i have been worried about.. maby i should put the dry ice a different container to the water.. and have a good heat exchange inthe middle.

I think regular ice would probably be the best for the amount of hassle.

but normal ice isnt anywhere near as cold! and wouldnt work as well.. i have come up wif a better idea wif heat tranfer wif a tini radiator.