Aluminium Radiators & Engineering Pty Ltd
Unit 11 / 60 Kremzow Rd
Brendale QLD Australia

Ph +61 07 32054620 Email info@are.com.au

      Dry Ice Intercooling 

These are details of the spin off from our high horsepower Research & Development programme.  We tried numerous forms of liquid CO2 cooling with very minimal results & also with block dry ice, once again struggling to get results anything like expected.

Waste of our time. We made this triangular box with a sealing lid & handle for testing block dry ice in water. It's thermal capacity was seriously lacking compared to ?

We had larger fins on the water side.  You can see how the ice 'melted' & formed around the fins, so it should've worked better in my opinion.

Then I hit on an idea that has opened up several very successful adaptations. The first is a straight race application.

Two very similar intercoolers gave three very different results, so please think about your application & work with us to provide a unit that will give the results they are capable of.

This is the first test unit. we fitted bolt on tanks for different applications.

This is inside the core after it had been sitting open on our bench for 30 minutes. Please see note a) below

minus 70°c This is the temp sitting on the bench. 27.5°c is the ambient temp.

Note:- a) - The weather was 27.5°c with 83% humidity. The 'cooler is so cold that it freezes the air & turns it to 'snow'. This does not appear to happen when it is fitted & in use. The air can only come through a couple of intake valves ( the throttle butterfly is closed) & exhaust valves ( where it has to work back along the pipes, turbo).

         Observations after a year of testing. as at march '05
    Uppers
     1) Dry ice really does a brilliant job for dyno comps & drag racing. Because it is so far below any ambient temp., it provides an extremely consistent intake temp, so giving engine power outputs with tiny variances through any ambient temperatures you may run at - consistent higher power output.
        2) It gives a power gain regardless of the level of engine modifications, BUT, the level & type of mods. effects how much power gain you get. Gains are only consistent for your engine - not between different engines.
        3) In my opinion it is very cheap initially to set up, for the gains. In fact, look at it this way, you've spent $30,000.00 on your 4 cyl. engine ( yeh, add it up then) & you've got  800+ fwhp. How much is it going to cost to get that to 900+ hp. It could cost  another $30,000 for that 100hp, or worse still, may be unachievable. Our very best intercooler may be $3000.00 (they start at $900 & go up) & gives this result, so really, it's bloody cheap !!!
        4) The sight of the gasses curling out of the intercooler when filling, has a 'psyching' out effect on the opposition before the run even starts, & also captures peoples attention that may not have taken as much notice of your car otherwise.

     Downers
         1) In Brisbane, dry ice is $3.00 / kg. The burn rate of a 1000hp engine is high (the more efficient our intercooler, the more ice, the more dollars - sorry), so each event can cost $150+ in ice. How much a downer depends on how big a budget you run & how serious your effort is.  A tip - price from an ice supplier that sells to the medical industry - especially Red cross, they buy up to 300kg at a time & so may have a better buying price & pass it on.
        2) Coupled to above, if you go out first round, or worse, break in practice, or even worse still, the whole event gets washed out, the ice can't be stored for a long period, unlike C16 or NOS, so some will be wasted. We have found that if an esky is taped around the lid & placed in a freezer, it will only loose approx 33% over 14 days, so it's not too bad. You can have the coldest drinks (-soft, of course) in the pits though.
        3) To cool a big hp engine properly, the intercooler has to be big. This can be impossible to fit into an existing car & really needs to be planned into a new car. Weight can only be minimized, they will always be heavier than an air-air because of both the weight of the dry ice & the fact that the ic. has to be larger in size. This can be used to advantage in front wheel drive, by being positioned over/in front of the front wheels, or may be back in the passenger footwell/seat area in a rear wheel drive car.
     Cost
        We do not have a fixed part no./price at this stage as they are not high volume & are extremely varied in their requirements, however we do have a very accurate computer programme to size the ic., so you do not waste money, weight & space. To give you an idea, they start at $900 & go up - way up! A 1000hp engine ic. could cost $2000 to $3000, using the exact same core, because of the hours that have to be spent on the tanks. A venturie plate can cost $220 for a large core. A straight forward tank might be $220, or if it's hand shaped, $1100.

                                               
                            First Application - lost  14 %   

Toyota 1JZ 2.5L twin turbo. Rigged up for dyno run only.

The factory ECU could not handle the - 48°c. temps. at all ! It went rich as hell.

This is the dyno sheet from this session.

 

Second Application - gained  98 % 
Rob baracks EVO Lancer - has run in the 9's.

After our fit up in the work- shop. We made it as big as.	During the dyno testing.	This is the dyno graph. No changes were made to the base mapping at all. See notes below.	This graph shows why the big gain. Check how the boost at 100kph goes from 12 to 28 psi.  I kid you not !

This is our computer file that we sized the intercooler off & made our prediction to Nick before starting

Notes:- a) Before we started on the car, I Emailed Nick & said that the charge air temp will not go over 8°c during the power runs. Our computer programme came up with 5°c so I added a little safety margin. To me this is just as important as the results we achieved (if not more), as we can fabricate a 'cooler with complete confidence of it's results - as long as we're given accurate information !!
             b) The dyno runs started with charge air temps. between -55°c to -50°c depending on the time between runs, & the hottest temp into the engine of the 3 runs was +3°c !
             c) There are two points that you have to realize to keep these results in perspective & not be disappointed. 1- The team had just fitted a  larger turbo that depended on a shot of nitrous to spool up at the lights. 2- We fitted our 'cooler in series with their air-air intercooler, so we were only cooling a 78°c intake charge - not 180°c. No loss of boost or power was noticed by having the two 'coolers in line. There would have to be an extra pressure drop.
             d) Nick www.apc.com.au said that it was just like the car had a big shot of nitrous up it's a...e.
                                                                

Third   application - gained  21 %    

In the workshop after fitting up, ready for a dyno run

Coming

This is the dyno chart from Micks car.

This engine has a street sized turbo & needs to go up in size to get the true gains that are possible.
The engine started to 'lift' the head @ 20psi & the session had to be stopped. Unfortunately this project has gone flat  with Mick opting for a NOS setup.
                                      

  Others
APC  Lancer  Evo - 83% gain

 

This is how the car came to us	This is how it left our work -shop. Mega hours,  mega cramped,  mega good !	First tuning session. Broke the gear box on this dry ice run.  Note @110 kph,  kw jumped from 135 to 245 & boost 11 to 26 psi.	On display at the '04 Jamboree. 2 broken boxes inside 8 hrs - on the dyno in 4th gear !
Yes it's big, but it absorbs 150 kw's of heat @ 1200 cfm.			Looks quick standing still. Feb.'05 ran 9.01 & 162.8 mph (262 kph).

Notes to go with the APC Application.
- This is APC's own shop car, built in house. Exhaust & cage by Trev @ Custom Exhaust. Cooling by Richard @ ARE.
- Nick (proprietor) built & tuned Rob Baracks engine & of course this one. The above dyno chart is the first tuning session, cut short by a second broken diff.  He was nowhere near finished mapping the Haltec E11, so there's more to come. Fuel is VP C16.
- This engine is upgraded  in most specs. from his previous builds, especially turbo size, as can be seen in the following chart.

- The same tyres were used on both dyno runs, & both four wheel drive.
- At 25 psi Robs engine made 250 kw, where as Nicks made 300 through to 366 kw, so they certainly are different animals.
- Robs engine only made 8% more power at the top of the curve, remember the tune was not changed. However Nicks engine made 16% more power. It will be interesting to see what happens when the tuning is completed. Rock on the new Phizner gearbox.
- The best gain is 82%, which, when you consider the turbo size & only 25 lb boost, is a very good result. It could go either way when tuning is complete, but when the boost is wound up to the mid 30's & the outlet temp possibly doubles, the % gains should increase.
                                                                             More info here
                                                                 

ARE's own Test Bed -  30% gain *

Not the monster gains of some, but what a fat power curve, & gains will probably increase with more boost as the charge air temps. rise.	Third power run on dry ice & we've just started to put some in the second chamber. 785hp was made next run & with the second chamber only half full.	It will blister the skin with pressure, so care has to be exercised to avoid this. Filling is pretty quick with the right pellets.	After a shootout run. The ice has melted on the ic. outlet tank & plennum, but not on the thicker throttle body. Extra return springs needed here.

    Some details
During the power run above we ran the Toyota 3RZ engine too 8000 rpm & at 30 psi., the intercooler was absorbing 130 kw (7399 btu/m) of heat, so no wonder the ice  burn rate is high. However, when we step up to 9000 rpm & 40 psi, later in the year, we are going to have to get rid of 220 kw (12522 btu/m) of heat !! Man, that 'coolers gunnu smoke as much as the rear bags!!

    * A) This gain is over having iced water ( we filled the top with party ice & then poured tap water over it) in the 'cooler, then draining & adding the dry ice, so the gains over an air-air would've  probably been around 45%.
              B) It shows how accurate Brett (GCG Turbos) recommendation for turbo size was, because at 30psi the turbo is right in it's efficiency range & not overheating the charge air. I'm sure the ice will give a better result when we step up too 40psi., or if we went to a larger turbo, will help spool up earlier.
                                                                                                             More info here
                                                                                   

Why buy our  intercooler ?  
Unfortunately you're going to have to buy a unit ( or look at someone elses) to see why because I'm not showing pictures, but the difference between our unit & the others I've seen & seen pics of are:-
     1) We have developed our own computer programme for sizing our 'coolers so you can buy with the confidence of knowing that it will do the job within ± 5% ( & closing as we get more data) of the heat value of what we give.
     2) Our intercooler is designed so that the dry ice is right through the whole core - not just down both sides. All of both side walls of all tubes are in contact with the dry ice & that's all I'm saying !
     3) Due to my near 30 yrs around a flow bench (on & off), our tank shapes are second to none.
     4) We are not limited to shape or size. They can be square or rectangular, small or gigantic - but not round !
     5) We can alter the internal specs for a particular application if needed - & we know exactly what the results will be.

The single most important feature of this product is not only the power gains achievable, but the fact that engine performance is going to be pretty consistent between a 36°c day & a 10°c night run.  That's not only what wins races,  but intimidates the opposition during qualifying, especially for a Rotary (or any engine) that has trouble spooling up.  This is because our cooling medium is almost constant @ minus 79°c, not plus 1°c like ice water or ambient that can be anything from minus 4° c to plus 54° c.

     the single most important component needed for it to operate properly is a 'top of the range' ecu.

© Aluminium Radiators and Engineering Pty Ltd (ARE Cooling)
 While every effort is made to ensure details and information is correct at time of publishing Sunday, 05 August 2012
please contact ARE by phone, fax or email to confirm prices before order.