Problems intercooling?

[kelley]

we will see ciper

[ciper]

Do you disagree with what I say?

[kelley]

no, you have valid points.
we will see and I will leave it at that.

[ciper]

I want everyone to distinguish between the function of both types.

An air to air setup is active cooling, you only get benefits when air is moving over. If your at a stop light and take off the intercooler doesnt start working until your speed is great enough. The cooling effect increases with speed so you have to tune for the average (low) cooling effect. If airflow over the intercooler isnt great enough (you are drafting another car) then you get no benefit.

The water setup stores "cold energy" for use at any time. I could sit still spinning my wheels and the intake charge would still be cooled. The cooling effect is stable over any speed and you can recharge the system once off boost. Its easy to tell when you are running out of cold water, and the heat increase is gradual and predictable.

The reason you see these insanely large Air intercoolers is to grab as much air as possible. With the water setup and an apropriate sized tank you could use a 6x6 heat exchanger in the front (size of an average transmission cooler).

I thought Id post this page http://www.panhandleperformance.com/intercooler2.html
which counters my argument. Its completely wrong.

For some good information about water vs air cooling just look at overclocked PC's.
Also know that originall aftercooler means it cools the air after leaving the final turbo and intercooler usually means its between two turbos.

The information you read about water getting too hot and preventing the car from running is because the system hasnt been sized apropriatly. It would be like saying "My Saab intercooler cant support 400HP, that must mean air to air sucks." You can build a relativly small AWIC setup for the HP compared to AAIC. Its just that the water system needs recharged between runs

[BAC5.2]

Ahh, I didn't see the part about the Legacy AWIC, I thought you were agreeing with DLC that the AWIC kits cost upwards of 3k.

What do you mean the AWIC's have to be recharged between runs? I'm not building a race car and DEFINATELY not building a drag car.

[ciper]

Meaning you can build a SMALL AWIC setup that willl support high HP. When you do air to air its all or nothing, the size of the intercooler directly dictates the maximum power that can be produced.

If you AWIC setup is too small you are relying on the buffer effect of the water. In order to use it again you have to wait for the water to cool down, which can take along time.

[kelley]

does anyone watch the screensavers on techtv?
they built a computer last week utilizing water cooling. I am trying to find a link

[kelley]

http://www.techtv.com/screensavers/howt ... 13,00.html
I wouldn't mind haveing this computer.
the danger den link sells the water cooling kits.

[BAC5.2]

So, a FMIC would be an inefficient choice in terms of cooling?

Basically, here's my plans and you can recomend whatever you feel is necessary.

I don't plan on running any more than 350 to 400 horsepower at the crank. I was planning on overbuilding the engine for reliability (I don't want to be at the brink of explosion making 350hp, I wan't to make that power without breaking a sweat).

I guess what I don't understand is, if FMIC's are so inferior, then why are they even used?

I have no problem running an AWIC if one will fit my needs and not require me to stop driving or ice the IC just to keep driving on boost.

It would seem to me that through conduction, the water in the AWIC would heat up and lose it's cooling efficiency the longer you boost. If I am driving across the country, I don't want to have to stop every hour or two to ice down the intercooler.

So, that clarified, recomend away.

[THAWA]

I dunno if ya know this or not, I didn't a lil while ago, but an AWIC usually has a heat exchanger or radiator attached to it. That's what keeps the water in there cool.

[BAC5.2]

I dunno if ya know this or not, I didn't a lil while ago, but an AWIC usually has a heat exchanger or radiator attached to it. That's what keeps the water in there cool.

Really? I never knew that. I don't know jack about AWIC's, lol.

[vrg3]

Yeah, in the end you always need air to cool it. Just like water-cooled engines still need air to cool the water.

[ciper]

BAC5.2: You didnt know there was a front heat exchanger? Dangit! Thats what I get for asuming you knew.

AWIC and front moun AAIC work the same way, except instead of moving the entire intake to the fron of the car you only move the heat energy to the front of the car.

[evolutionmovement]

Think of it as a duplicate of the engine's cooling system, but used for the intake charge.

Steve

[BAC5.2]

BAC5.2: You didnt know there was a front heat exchanger? Dangit! Thats what I get for asuming you knew.

AWIC and front moun AAIC work the same way, except instead of moving the entire intake to the fron of the car you only move the heat energy to the front of the car.

Haha, nope. I have zero experience beyond basic things with turbo/FI cars.

So, lol, sorry for the confusion.

Got pictures of a complete AWIC setup?

How much am I going to be looking to spend to get an AWIC capable of handling 500hp?

[ciper]

500hp? The most expensive part is the intake heat exchanger, otherwise its cheap.


Here is a picture of a kit to give you an idea from http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... gory=10416

[BAC5.2]

Well, how much do the heat exchangers run? Lol.

I have a feeling it's going to be much more cost efficient to get a FMIC than an AWIC.

[ciper]

Have you taken into account the modifcations needed to fit the front mount that isnt a problem with the water setup? Its NOT cheaper to run front mount, I just need to find an apropriate core for that much power.

Here is an idea on pricing, a complete s2000 air water intercooler kit retail for 1000$ http://www.superchargersonline.com/prod ... CT-350-047

Also remember that its possible to convert an air to air unit into a water unit. Im going to do this with a SAAB intercooler for someone.

[BAC5.2]

An entire WRX FMIC kit runs about 1k.

I would have a core custom fitted to the car, and was told that it would be comprable to the cost of the WRX, if not a bit cheaper (because labor is included with custom fit parts).

I'll have to get a real estimate some time though, and then compare that with a AWIC setup then go with whichever ends up being cheaper I guess.

[NuwanD]

You can argue AWIC vs AAIC 'till you are blue in the face, with that being said i feel that it really depends on each specific application.

If you run your car hard on boost for very short periods of time ie; drag racing, it would be of benefit to have a system which keeps the intake charge cool while the car isn't moving... advantage AWIC

However, if you are on boost for long lengths of time and therefore running at speed a AAIC makes more sense as there is no need to store "cold" for times when you aren't moving (like the coolant in the AWIC). The maximum efficiency of the AWIC cannot be any better then the core size of its heat exchanger assuming you haven't built up a "cool" charge earlier. So if you get a AWIC with a heat exchanger half the size of say a WRX TMIC then the maximum amount of cooling you will get (assuming you haven't built up a "cool" amount of coolant earlier) will be half that of a WRX TMIC. This works vice versa as well. If you do assume that you have built up a cool charge with the AWIC its cooling capacity will be great than the size of its heat exchanger or a comparative AAIC but this effect is only temporary.



The model of AWIC pictured above will work fine for short bursts of high boost / large HP, but with any prolonged time on boost you will run out of a cool charge and run into intake air heat issues. You would need a AWIC with a larger heat exchanger and an appropriately sized pump to run high boost for prolonged periods of time, the same goes for AAIC... size is proportional to cooling capacity.

Other items that haven't really been addressed are water sprays and other cooling systems for AAIC. When not moving a waterspray or likewise system will drastically reduce the temperature of the IC and the intake charge, so it is possible to keep a AAIC cool without moving air. TMIC suffer in this department since they are exposed to the heat of the engine bay and are therefore more likely to suffer from heat-soak. You need quite a bit of water to undo heat-soak so a better system would be more useful. Some aftermarket systems spray nitrogen or CO2 onto the core of the AAIC to dissipate heat.

Also you should take into account the lag created by extensive intake piping. This is the single most reason i don't have a FMIC at the moment. Having driven many WRX's with varying intercooler setups i find that the lag created from a frount mount is unacceptable for what i want to use my car for (rallying). In this area the advantage is for TMIC and AWIC where the intake path from the turbo to the throttle body is the shortest. Remember that every time you let off the gas (ie shifting) you release much of the compressed air in your intake system via your BOV (atmospheric or recirculating), and your turbo has to re-fill your intake tract with compressed air once again before you can feel the gains. There is a way around this but i doubt many of us could afford a decent anti-lag system and the expensive inconel exhaust and turbos required to run it.

AWIC and AAIC are not your only options, you can also look into a internal waterspray system such as ones made by aquamist, which as far as i know work amazingly well but realize that you must always have water in the reservoir for it to work, no water = no safe boost. From systems i've seen depending on how you drive, mileage, and the size of your tank you can go for a month or two without refilling the tank, but i'm sure that figure was taken from some granny driving.

Well I hope this long post helped somone with there decision, and I hope I didn't come off as being biased to any particular system. That being said I tend to follow what motorsport uses. Rally cars use AAIC, drag racers use AWIC as well as some larger vehicles which use large amounts of boost to just get moving (trucks).

[BAC5.2]

That helped a lot!

I won't ever really be drag racing (because it's expensive in an AWD car, lol).

I just enjoy driving, spirited back roads and the like. I'll have to try to get behind the wheel of a car with an FMIC to check out the lag time. I hope it isn't TO bad, but I'll see.

Thanks for the info!

[ciper]

I want to say part of your explanation in other words.
"An AWIC will overheat if you dont use a large enough front heat exchanger or a high enough volume pump. You could always upgrade them but lets forget about it for the moment."

That doesnt make sense. The air water setup allows you to upgrade in small steps as needed. Monitoring your water temperature time to increase and time to cool allows you to decide when parts of the system need upgrading.

The Water spray setup is applicable to AWIC as well, dont speak of it as if only an air intercooler can take advantage of it.

"if you are on boost for long lengths of time and therefore running at speed a AAIC makes more sense as"
I can turn that on its head. If you are on boost for long lengths of time then an AAIC makes no sense because it has to be too large. With the air to water setup you can have a large tank of water to match these extended boost runs. This lets you run a vehicle with stock looks and equal performance to one that has a huge intercooler on the front.

[NuwanD]

BAC 5.2 .... i don't mean to say "no, don't use an AWIC" but think about what you need for your particular goals for your car. For example the JDM AWIC is a great system, but has its limits like any other system, so be aware of that when setting your goals and choosing appropriate parts. You stated 500HP earlier which is lots of boost...........

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Ciper...
yes you are correct, one can upgrade parts of the AWIC system as needed, just like any other system, depending on boost levels upgrades are eventually neccessary to any system

sorry, i should have stated that the waterspray can be used for AWIC

large tanks of water weigh quite a bit , anything is possible if you want to stick to a certain method. However, say you are on a high speed race course or rally stage, you would need a very large heat exchanger on a AWIC set-up, after an hour of lapping you'd need a jagnormous water tank to still have cool water if you don't have an adequate heat exchanger. If you did have an adequate heat exchanger, its size would rival that of a FMIC, so it wouldn't look stock either. Not everyone does hi-speed lapping for 3 hours straight as myself, so once again this doesn't apply to everyone.

I completely agree with you that an AWIC is great but it has its place just like a AAIC, and depending on what you want from a car it may or may not be the choice for you.................

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From an efficiency standpoint no system is 100% efficient, the internal-combustion engine has an efficiency of somewhere around 30%. I feel it is pretty inefficient to transfer hot air --> liquid --->air when it can be done air ---> air. But as stated earlier there is much more to take into account when choosing a system.

I'm not trying to be 100% pro-AAIC just stating the pros and cons to both systems. I think this is a pretty good discussion however.