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
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
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
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.
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
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.
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
|Rob Barack Evo Lancer AWD
|revs. per minute
|| rwhp. - no ice
|| rwhp. - dry ice
|| rwhp gain
|| percentage gain
|| boost - no ice
|| boost - dry ice
|| boost - gain
|| percentage gain
| 8000 rpm
|| 483 rwhp
|| 523 rwhp
|| 40 rwhp
|| 38 open wastegate
|| 38 open wastegate
|| 147.5 %
|| 195.2 %
|| 179.2 %
|Nick Zervos APC (Advanced Performance centre)
Evo Lancer AWD
| 8000 rpm
|| 451 rwhp
|| Broke gearbox
|| 25 open wastegate
|| 488 rwhp
|| 15.9 %
|| 24.9 "
||26 open wastegate
|| 146.6 %
|| 4.1 %
|| 172.8 %
|| 266 %
|| 147.9 %
|| 533 %
|| 600 %
|Richard Anderson ARE (Aluminium Radiators
| 8000 rpm
|| 748 rwhp
|| 109 rwhp
|| 29.5 "
|| 29.3 "
" - "
|| " -
|| 29.4 "
|| 29.1 "
" - "
|| " -
|| 35.1 %
|| 40.5 %
|| 28.1 %
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
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.
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
psi. I kid you not !
||This is our computer file that we sized
the intercooler off & made our prediction to Nick before starting
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
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.
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
||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.
Notes to go with the APC
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.
Kw's @ boost - Rob's
Kw's @ boost APC
175 kw @ 14 psi
90 kw @ 6 psi
275 @ 30
140 @ 13
370 @ 36
245 @ 26
399 @ 36
320 @ 25
- 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
- The best gain is 82%,
which, when you consider the turbo size & only
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
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.
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
It will blister the skin with pressure, so care has to be exercised
to avoid this. Filling is pretty quick with the right pellets.
a shootout run. The ice has melted on the ic. outlet tank & plennum,
but not on the thicker throttle body. Extra return springs needed
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!!
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
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.
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.
intercooler is designed so that the dry ice is right through the
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.
most important component needed for it to operate properly is a 'top of the