I have been trying to figure out where to put my conventional 10x30x5 cm Setrab oil-cooler for the Rotrex unit and avoid having to stack 3 coolers (oil, IC, coolant) in the grille opening.
Both my fog-light openings in my bumper are already occupied for the engine oil-cooler and CAI.
I have heard of water to air intercoolers but did not know there were water to oil coolers available for automotive use before reading about laminova coolers from www.laminova.se :
This looked like a major win: No airflow needed, the amount of oil from rotrex will not tax water cooling much, clean install etc.
After ditching AC I have enough space ato add a ~ 20 cm long C43 Laminova unit in the hose going from rad to engine block. Problem solved ?
The Rotrex inlet oil temperature should be max 80 C which is quite cold when dealing with petrol engines where optimal coolant/oil temp are around 90-100 C. My oil and coolant temps can reach as high as 120/105 C on track days.
According to testing done by Flyin Miata the temperature drop for a radiator in a Miata is only around 5 C when inlet coolant temp is 105 C --> http://www.flyinmiata.com/tech/rads.php
|radiator||Ambient temp||Rad inlet||Rad outlet||Improvement over stock||Temperature drop||Time to temp||Outlet temp compared to ambient|
|Brand X aluminum race radiator||38º||105º||101º||+1º||4º||15:44||+63º|
That means a laminova cooler would act as a heater instead of cooler if used with the Rotrex.
But what about using it as regular oil-cooler for the engine and use my current engine cooler for the Rotrex ?
Here are some graphs from laminova.se for the C43 with 120 c oil inlet temp and 85 c coolant temp:
As for coolant flow I don't have a clue. I found an example here where a 20 gpm water pump actually delivers 0 gpm at 6psi pressure drop. Lets just say the miata pump can deliver 160 litres/min to make it near optimal for a laminova cooler with a bypass.
A C43-182 would then cool my 120c oil down to 116 given my coolant inlet temp was 85C.
However my coolant temps are most likely 100+ C which I'm afraid would make this cooler useless as anything other than an oil heater.