Depends if DF sent you a left handed one, or a right handed one.Does it matter which port is IN and which port is OUT in the heat exchanger?
I would have said that you don't want air on the outlet of the heat exchanger/return to motor. Aren't most car radiators top hose hot/from the motor and the bottom cool/return to the motor?I don't think there's an IN and OUT on the HX, but if you're not mounting parallel to the ground, you will want to put the inlet closer to the ground to ensure it's full of coolant and not air.
haha I was so confident and proud in my answer, and in an instant you've brought me back to my great consternationI would have said that you don't want air on the outlet of the heat exchanger/return to motor. Aren't most car radiators top hose hot/from the motor and the bottom cool/return to the motor?
I started to go into the trapping of air, but I'm not sure how much it matters whether it's top or bottom fill. If the HE is the highest point in the system it will trap air either way. If it's not the highest point air will still try and leave the system to reach it. But if the system gets low on coolant you want to still suck fluid gathering at the bottom instead of air at the top. At some point the pump will loose it's prime. Of course this is all a general discussion and will depend on the details of where it's mounted.haha I was so confident and proud in my answer, and in an instant you've brought me back to my great consternation
I am confident in saying you don't want the inlet and outlet both facing towards the ground. I can't imagine how that results in anything except for an air bubble across the top of the HX.
I think radiators tend to have the outlet mounted below the inlet as they have enough volume to actually allow for the cooler fluid to sink to the bottom in low-flow scenarios.
But for a small heat exchanger, as in our application, I think filling from the bottom allows trapped/entrained air to escape through the outlet better than flowing top to bottom. This might not be an issue if can bleed the system of air really well while the pump's not on, but still suffers in instances where air is picked up from the small pocket at the fill point as in a stock Cobalt HX system.
No, the fan is not used. The duct shroud takes the place of the fan. Just tie the wire up out of the way somewhere.Potentially silly question related to this topic - if I’m using the heat exchanger duct kit and mounting the heat exchanger below the radiator (as it’s shown in Adam’s photos), would the fan still be used? Assuming it would be as there is a wire in my harness for it, but I do not see one depicted in Adam’s picture
Figures - So now of course I'm brought to the question of: Which option is more effective? I don't particularly love the look those nostrils in the sides of the hood, but I also feel like the area where the heat exchanger will be mounted will harbor quite a bit of heat from the radiator...and then you just have a fan blowing hot air over the heat exchanger. Thoughts?No, the fan is not used. The duct shroud takes the place of the fan. Just tie the wire up out of the way somewhere.
The heat exchanger fan is a puller (or at least mine is), so it'll pull air from below the car adding some downforceFigures - So now of course I'm brought to the question of: Which option is more effective? I don't particularly love the look those nostrils in the sides of the hood, but I also feel like the area where the heat exchanger will be mounted will harbor quite a bit of heat from the radiator...and then you just have a fan blowing hot air over the heat exchanger. Thoughts?
The answer here depends on the circumstances. At higher speeds, the NACA ducts will be more effective. Ramming air directly into the nostrils at 100 mph is pretty darn effective at cooling. Sitting at a traffic light, those nostrils do nothing, and the fan is far more effective. So, when do you need to cool the intake charge? For me, it's at 100 mph. I don't care about intake temps while idling.Figures - So now of course I'm brought to the question of: Which option is more effective? I don't particularly love the look those nostrils in the sides of the hood, but I also feel like the area where the heat exchanger will be mounted will harbor quite a bit of heat from the radiator...and then you just have a fan blowing hot air over the heat exchanger. Thoughts?
The good ole fan car. I always thought that was the coolest thing (no pun intended lol). Shame they DQ'idThe heat exchanger fan is a puller (or at least mine is), so it'll pull air from below the car adding some downforce
There was a racecar in the 70's that used this concept to such great effect that it was banned. He used two military grade fans that together could pull almost 10,000 cfm. He mounted them at the rear of the car and ducted them to draw air from beneath the car and blow it out the rear. Claimed he could generate almost 2000lb of downforce at any speed. Here's an article about it.
So this was my exact thought as well - I would also like to have air flow while I'm not moving, but fresh air at speed. How did you deal with the fact that the fan pulls air in the opposite direction of the duct flow? I was thinking maybe there is a way to flip the fan blade around.I ran the NACA ducts in conjunction with the fan because I wanted to get fresh air over the heat exchanger but I also wanted to move air while sitting still. It was a tight fit but it does fit!
I flipped the blade and swapped polarity to make it a pusher fan. I also have a floor up front to keep the air from dumping under the front of the car.So this was my exact thought as well - I would also like to have air flow while I'm not moving, but fresh air at speed. How did you deal with the fact that the fan pulls air in the opposite direction of the duct flow? I was thinking maybe there is a way to flip the fan blade around.
What is the benefit of moving air while sitting still? Is there a concern of heat soak from the engine raising IATs while sitting idle?I ran the NACA ducts in conjunction with the fan because I wanted to get fresh air over the heat exchanger but I also wanted to move air while sitting still. It was a tight fit but it does fit!
There is a modern version of a fan car here. The McMurtry Speirling is a carbon fiber car with 1000hp electric drivetrain. Active suspension is able to keep the vacuum box close to the ground, so it only needs 70hp to get 2000kg of downforce for the 1000kg car.The heat exchanger fan is a puller (or at least mine is), so it'll pull air from below the car adding some downforce
There was a racecar in the 70's that used this concept to such great effect that it was banned. He used two military grade fans that together could pull almost 10,000 cfm. He mounted them at the rear of the car and ducted them to draw air from beneath the car and blow it out the rear. Claimed he could generate almost 2000lb of downforce at any speed. Here's an article about it.
This is also a good point about the fan impeding airflow. I may actually start a chart as soon as I get mine finished up - I can post it when that time comes and we can get others' info in there.What is the benefit of moving air while sitting still? Is there a concern of heat soak from the engine raising IATs while sitting idle?
I can't think of a use case where I'd be raising IATs sitting still or any issues with leaving from a stop with IATs a few degrees higher that wouldn't immediately drop once I start moving.
I'm thinking about it from the standpoint of being a few degrees cooler at a stop versus running a few degrees warmer under load due to the fan impeding airflow from the NACA ducts. I could be underestimating how much IATs rise sitting still or overestimating the drawbacks of a fan in the path of the ducts, but it seems that the numbers I've seen posted in various threads show that NACA duct setups have lower IATs than those with just fans.
Maybe we can chart intercooler configs and IAT temps like we did with tire setups.