Mid-Engine Cooling

[WillH]

Maybe off topic but my old aircooled Duc would boil the hydraulic clutch when stuck in stop and go traffic at 40C. Made for some interesting rides...
I would assume the aircooled 911s ran rich to keep cool. Emissions probably put and end to that.
Nice and cool 34C with humidex in the 40s this week here at least it's not snowing...

[jaykay]

Originally Posted by WillH

Maybe off topic but my old aircooled Duc would boil the hydraulic clutch when stuck in stop and go traffic at 40C. Made for some interesting rides...
I would assume the aircooled 911s ran rich to keep cool. Emissions probably put and end to that.
Nice and cool 34C with humidex in the 40s this week here at least it's not snowing...

Yes just keep in mind that that a major part of the air cooled senario is oil cooling.....this is probably the best answer for the Boxster

[GaryMulcahey]

I was thinking about the temps of the engine over the last couple of days also. Very hot and humid out here. I brought the car back from buying it in Toronto yesterday and all I could think was, "this car is just not happy in congested city traffic".
But out here in the country on the twisties with no traffic lights in sight, it was very happy and didn't run too hot.

G

[j.fro]

I'm also concerned about how hot the 986 engine can get. Not suggesting these to anyone, but I have bypassed the fan relays and wired a switch for each fan so I can manually control them. Why two switches?? Each fan draws 40 watts. When I tried a single switch controlling both it got so hot it melted.
I turn the fans on when the water temp gets to about 170 (low temp T-stat is open). The car never gets above 190 now.

[alm001]

Originally Posted by j.fro

I'm also concerned about how hot the 986 engine can get. Not suggesting these to anyone, but I have bypassed the fan relays and wired a switch for each fan so I can manually control them. Why two switches?? Each fan draws 40 watts. When I tried a single switch controlling both it got so hot it melted.
I turn the fans on when the water temp gets to about 170 (low temp T-stat is open). The car never gets above 190 now.

On my Audi s4, there was an after-run circuit that would circulate coolant and run the fans for up to 10 minutes after the car was turned off. Some people would change the temperature sensor so it ran more often, however I jumped the sensor with a switch so if I knew I wanted the car to run the fans for the full 10min, I would just flip the switch before turning it off.

I wonder if we can change the sensor that turns on the engine bay cooling fan, or if there is a similar timer that if the sensor is jumped, wouldn't just run forever.

[jaykay]

Yeah....I had my carpet off and man that firewall gets pretty toasty. Has anyone put insulation/gold leaf on the backside of the hatch...? If my engine comes out I think I might foil up the whole engine bay.


Back on topic: Assuming that engine oil cooling is the way to go ( for a dedicated track car: transmission?), I had envisioned a duct incorporated in the right side vent that directs cooling air to shrouded oil cooling heat exchanger. If there is enough room you could put in a duct for the trans. as well.

You would fashion an opening the side vent shroud to accept a bell mouth / velocity stack with a duct leading to the shrouded oil cooler. I think setrab makes some small stuff that may fit in the engine bay and I believe I have seen them used for Boxster trans coolers.

With this arrangement you would get a seamless cold air intake for oil cooling. The engine bay fan along with ram air from the side vent would provide for superior heat exchange.

Not sure about how to properly mount the heat exchanger in the bay....without welding mounts. Unfortunately all this may have to done with engine out

[Deadeye]

Originally Posted by jaykay

Yeah....I had my carpet off and man that firewall gets pretty toasty. Has anyone put insulation/gold leaf on the backside of the hatch...? If my engine comes out I think I might foil up the whole engine bay.


Back on topic: Assuming that engine oil cooling is the way to go ( for a dedicated track car: transmission?), I had envisioned a duct incorporated in the right side vent that directs cooling air to shrouded oil cooling heat exchanger. If there is enough room you could put in a duct for the trans. as well.

You would fashion an opening the side vent shroud to accept a bell mouth / velocity stack with a duct leading to the shrouded oil cooler. I think setrab makes some small stuff that may fit in the engine bay and I believe I have seen them used for Boxster trans coolers.

With this arrangement you would get a seamless cold air intake for oil cooling. The engine bay fan along with ram air from the side vent would provide for superior heat exchange.

Not sure about how to properly mount the heat exchanger in the bay....without welding mounts. Unfortunately all this may have to done with engine out

I have installed an oil cooler as described above into my track car to keep the trans oil temps under control. I ran a 3" flexible brake duct from the right side vent scoop to a small heat exchanger with a 5" Spal fan attached. It is mounted directly to the rear trunk floor in a small space next to the gearbox on passenger side. I will post pics when I get the car back on the lift.