Air Water Liquid Intercooler for LGT

[PhilT]

I love to see how people with no engineering background like to make these statements about what is feasible. Its amazing how wrong they can be.

 

I think we should just make this crazy by showing them just how good it can be. How bout we switch over to an ammonia two phase system (similar to an industrial air conditioner) and drop the intake temperature to 35 F with minimal pressure drop, just to show them what can be done.

 

I guess you could, but the power consumed by the compressor would negate any gains. Ammonia might be a good refrigerant but it operates at high pressures.

[GTurabus]

Some links about the basic principles involved:

 

http://en.wikipedia.org/wiki/Watercooling

 

http://en.wikipedia.org/wiki/Heat_exchanger

 

http://en.wikipedia.org/wiki/Intercooler

 

A little more on topic (Hmmmm, maybe those enginners at Subaru have thought about this in the past)

http://www.wrxtuners.com/forums/f52/air-water-intercooler-11836/index2.html

 

http://www.wrxtuners.com/forums/attachments/f52/1283d1146099530-air-water-intercooler-picture-269.jpg

 

http://www.wrxtuners.com/forums/attachments/f52/1284d1146099530-air-water-intercooler-picture-270.jpg

 

 

Ultimately, as all engineers and most motorheads know, good mechanical design is the result of the appropriate application of science, which is of course, an art, and therefore subjective. All design involves trade-offs and approximations, with a desired goal in mind, and numerous options available to achieve it. In racing, the "best" design, is of course, that which results in winning the race. In the "real" world, the best design is whatever you think it is and can get somebody else to agree to.

 

As a practical matter, I believe there are a number of fellow members of this forum who are looking for increased power without consequences, and if such a device can be produced for the preferred vehicle (which of course would be the spec B, which is why I own one), everlasting riches will result. Short of that, increased power for the least amount of money, and increased power with the least amount of work (i.e., "bolt-on") are high on most peoples lists, unless they have the resources in time and equipment to build to their own tastes.

 

The time honored quotes are of course, "speed costs money, how fast do you want to go" and "performance, reliability, and low cost, which two do you want" are easy to remember, and for most pass for engineering insight. As a former research and development engineer in the aerospace industry, having worked on prototype design and development of some of our most sophisticated defense systems, I do appreciate when someone takes the time to think out a logical approach to a certain area of design seemingly forgotten or ommitted by the factory Subaru engineers, who by the way, are designing Subarus, not Porsches or Ferraris.

 

For anyone with the time, money and energy to invest in perfecting our little machines, I encourage you to use readily available sources that can be obtained from the SAE and ASME websites, both of which I have had longtime memberships in. Using the successful work of others, you can avoid "re-inventing the wheel". Now if I can only work "belt and suspenders" into this I will have used all the pithy engineering sayings I know of.

 

You may now resume the regular goings on, I for one will be entertained just by the fact that people care to become involved with our cars with such a passion.

[GTkansan]

I love the statements made by people about the energy cost associated with compression of ammonia. More lack of any understanding floating around? Care to try and back that up with some numbers? Please guys, lets leave this mucking about and discuss actually relevant information ok?

[PhilT]

I love the statements made by people about the energy cost associated with compression of ammonia. More lack of any understanding floating around? Care to try and back that up with some numbers? Please guys, lets leave this mucking about and discuss actually relevant information ok?

 

 

 

I love statements by people who think they are the only ones who know about a given subject

 

Tell me what temperatures you want to achieve and I'll tell you the power required.

[lookslikeanevo]

[GTkansan]

I can do the calculation of power required to pump the two phase mixture as well. It isn't too terribly involved. The more important/difficult calculation is the power gain from the increased air density, and spark timing advancement available from the decreased temperature. That requires a decent amount of calculation to acquire a reasonable estimate. What im saying is that you cant know off hand that it wont work, so unless you would like to validate your very broad statement "the compression work would outweigh the gain" then it isn't very useful.

 

If you can do the calculation then great, but you must admit that without some verification, anything said by board members must be taken with a LOT of salt, as the number of directly contradictory opinions (by people without any background, or even understanding of the factors involved) is quite large. So if you want your opinion to be taken seriously, back it up.

[rao]

If you can do the calculations then do them and stop giving other people a hard time for not doing them

 

Also, please produce a perfectly operating water to air system in place on a real car (make sure it is the type of car we are talking about, just to be fair ) that outperforms the other readily available proven options and then you can mock the rest of us endlessly. Think of the fun you will have.

[bugblatterbeast]

I love statements by people who think they are the only ones who know about a given subject

 

Tell me what temperatures you want to achieve and I'll tell you the power required.

 

I have to agree with Phil and RAO on this one. I did a quick order of magnitude calculation to see if we were even close to seeing a gain. About the only time running a refrigiration compressor to get better cooling of the IC makes sense is if you can do it off boost and accumulate liquid refrigirant somewhere and/or pre-cool some water. At WOT, you would need to draw off the reservoir and de-clutch the compressor. Even doing so you might have problems as the low side pressure would probably come up too high to get effective cooling unless you dumped refrigerant to atmosphere.

 

What would probably make more sense is a hybrid air-air-water IC. You would use the water to increase the effective thermal mass of the IC. Off boost, you would use the same assembly to cool the water (by dumping heat into the ambient air and the intake charge). Taking things one step further, why not just build a box around the TMIC and fill it with some low melting point solid. Heat of fusion is a much larger number per unit mass than heat capacity for most materials I can think of.

[ClimberDHexMods]

Also, please produce a perfectly operating water to air system in place on a real car (make sure it is the type of car we are talking about, just to be fair ) that outperforms the other readily available proven options and then you can mock the rest of us endlessly. Think of the fun you will have.

 

Working on it

[biz77]

This should be interesting.

[Rika]

Working on it

You dont have a clue do you? Let me guess first year out of school with an engineering degree? An Air to water has been done and it wasnt great

[NSFW]

Are you all assuming that the turbo is blowing hot air for a large portion of the time or are we assuming that the turbo is mostly freewheeling with occasional bursts of hot air? In other words, is this for road racing or is it for daily driving?

 

It seems to me that for road racing you'd want it to continuously be transferring heat from the IC to the radiator to the atmosphere. Whereas for daily driving you could rely on thermal momentum to do most of the work - the transfer of heat from the IC to the water would be key, but the transfer from water to atmosphere could be relatively slow since the off-boost periods would be relatively long.

[ClimberDHexMods]

You dont have a clue do you? Let me guess first year out of school with an engineering degree? An Air to water has been done and it wasnt great

 

K who made it?

[mwiener2]

^ U serious?

[mattg]

strange that nobody has made one of these that has worked well and been affordable for the masses in a street application.

 

lazy vendors.

[rao]

I have one

 

[Rika]

My lawnmower has one

[norbs]

Subaru Rally Team thought about using water/air intercoolers but the added complexity over a FMIC with waterspray made them drop the idea. Sometimes there are simpler solutions ;-)

[ClimberDHexMods]

Spent half the night researching this. Really interesting stuff. The GM cars with air-to-water intercoolers are not all GM junk. The Corvette ZR1 LS9 uses a really simple internal one.

http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com//media/il/features/tech.center/09.chevrolet.corvette.zr1.engine/08.chevrolet.corvette.zr1.intercooler.500.jpg

 

A scattered group of guys in Australia are using these. I found a guy who built one for his 4x4 roughly a year ago, and is still having excellent results. He used 4 Laminova tubes to make a custom core. He's been creating a lot of buzz; I'm trying to get in touch with him.

http://www.fj40-2f-eti-locked-n-loaded.com/images/gallery_five/bits_11.jpg

 

http://www.fj40-2f-eti-locked-n-loaded.com/images/gallery_five/bits_10.jpg

 

A good summary of the Laminova application is in THIS LINK

 

As for the overall system, the reliability isn't going to be like an air-to-air, but with people going stage 3 with high boost, air-water may not seem so unreasonable. It is still one of my top concerns though.

 

As for the criticism here, if your cautioning is objective and constructive, feel free to keep it coming I'm having fun with the beginnings of this project, and if it doesn't end up working, that's fine too. Please try to keep this thread more than "it won't work, I have no concrete evidence or examples, give up". Or don't; I'm still having fun

 

Also thanks for all the extra information and offers to help. You guys are awesome

[ClimberDHexMods]

Matt in Australia got back to me real quick, included a link for his project. He's building cores with Laminova heat exchangers. Really interesting designs. And he posted up a few air temp numbers, though his 4x4's engine is a far cry from our LGTs. Some good ideas.

 

http://www.r3vlimited.com/board/showthread.php?t=126703

 

Again, if anyone else knows of people who have done this or are working on it, success or failure, it would be really helpful to post the details or even communicate with them directly.

[NSFW]

Food for thought:

http://www.google.com/search?q=awic+site%3Anasioc.com

[NSFW]

http://forums.nasioc.com/forums/showthread.php?t=1603700

http://forums.nasioc.com/forums/showthread.php?t=1254416

[GTTuner]

What do you estimate the increase in spool to be, between a TMIC and FMIC.

 

(This is a trick question, as I have had both on the same turbo, and already know the answer)

 

Barely measureable.

 

This is the set up of the future...http://www.speedmaxperformance.com/

 

click on products and ck out the intercooler cores.

[WhatV8]

You have all kinds of options, some better than others in specific applications. Don't knock someone because they want to try something different. Let the development happen and see what the results are on a Legacy GT application...no skin off anyone's nose other than the folks that do the development if it flops. I would be interested to see what comes from it.

 

Don't forget looking into other boosted air-to-water heat exchangers...since I am also a 'blue oval' fan you can check out the 2nd Gen Lightnings and supercharged Cobra Mustangs for ideas. A fellow SVO Mustang owner has created his own air-to-water intercooler using a Vortech aftercooler, now called a "Power Cooler", from a 5.0L Mustang application, which could work on a boxer as well. Here is a link to the kit Vortech sells:

 

http://www.vortechsuperchargers.com/product.php?p=19

[praedet]

Rao, just let it happen, you and I don't have enough engineering degrees to understand why when you compound efficiency losses, your efficiency goes up

 

I am not taking away from this idea folks, I just want to point out one flaw in the logic of the defenders...

 

Just because someone is doing it, and getting good results, does NOT mean that it is the best way, or even a good way. When you look at mainstream solutions, they are mainstream for a reason