Engine Bay Cooling

[iblackwe]

I was wondering if anyone has come up with an idea to remove the hot air from the engine bay. Would installing a fan somewhere near the side vents? If anyone has an Idea I am all ears. I am going to install a water meth kit and my concern is heating up the water methanol in the tank. I wouldn't be surprised if the engine bay gets to around 80 degrees celsius..

Any ideas would be much appreciated!

[Real time recon]

Hot air rises.A fan near,or pointed at, the hood scoop would remove engine heat a lot quicker than one @ side vents.

[Real time recon]

...

[GoDadGo]

Some Shelby Cobra's Had Heat Extractors!
Search the web to find some pics of Shelby CSX3243.

[07FIREBLADE]

I'm doing fans at the rear to pull air out. My whole rear end is going to be open though with perforated grills though so I will have a bunch of open surface area.

[iblackwe]

ah okay, I would like to do the same but I am going to be installing a trunk that would botch that for me...

As for a fan above the intercooler intake, aren't those hood scoops blocked off by aluminum? Or does anyone have a picture of the finished rear hood with the aluminum to see what it actually looks like because the factory five one looks like there would be no air flow over that area. Screen Shot 2016-07-23 at 1.22.07 PM.png

[STiPWRD]

ah okay, I would like to do the same but I am going to be installing a trunk that would botch that for me...

As for a fan above the intercooler intake, aren't those hood scoops blocked off by aluminum? Or does anyone have a picture of the finished rear hood with the aluminum to see what it actually looks like because the factory five one looks like there would be no air flow over that area. Screen Shot 2016-07-23 at 1.22.07 PM.png

Those aluminum panels are meant to channel the air from the top scoops to the tmic. As the air flows in from the scoops it will want to take the path of least resistance so unless you block off the top of the engine bay, it will not want to flow through the intercooler. You can certainly make something more custom that will do a better job of channeling the air. With that said, there is probably very little air flow coming into the top scoops to begin with compared to the side scoops. I'd focus on directing the air from those and creating lots of openings in the rear and top rear of the body. The trunk will probably be very toasty.

[Bob_n_Cincy]

I'm doing fans at the rear to pull air out. My whole rear end is going to be open though with perforated grills though so I will have a bunch of open surface area.

Fireblade,
I attempted this with my rear radiator. It did not work out as there is a high pressure eddy up against the back of the car.
I think this is what is happening to some that are getting exhaust fumes coming back into the car.
Bob

[Frank818]

I have a 7" fan on the lower left side to push air through my oil cooler, which I plan on directing air from some place in the front of the engine bay. Then I will have Craig's humps' louvers which will help get the hot air up and out by itself and I plan on installing a 7" fan in the right hump to push the hot air out. If there's no space, which I think there isn't, I will locate the fan at the top of the rear bumper where my exhaust is and push hot air through. I also have a few ideas of NACA ducts in areas no one mentioned yet in order to direct colder air through the engine bay, forcing hotter air out. We'll see.

[jaw777]

Frank - Any chance you would be willing to posts some pics of your set-up? I am kicking around ideas as to how to get more air moving through the intercooler using a fan(s). Maybe your setup will give me inspiration.

[Frank818]

Hey jaw, absolutely I can man. I'm currently in the process of building it, though, so I can only get draft pix of unfinished product. I think within 1 to 4 weeks it should be done, apart probably from the ducting of fresh air to the oil cooler. That one will take me more time to design. Let me know if you want draft pix or prefer to wait until I have all together.

[jaw777]

Frank - I'll take them whenever you can get them. I am stalled out for a couple weeks. Thanks.

[Canadian818]

Fireblade,
I attempted this with my rear radiator. It did not work out as there is a high pressure eddy up against the back of the car.
I think this is what is happening to some that are getting exhaust fumes coming back into the car.
Bob

So what can we do to relieve pressure behind the bumper? My plan was a mostly open rear bumper, but if there is in fact a high pressure zone behind the car this won't help. When you tried your rear radiator, did you have a diffuser installed? Any spoiler? I'm thinking the diffuser with significant stick out would push that zone rearward.

[Mechie3]

The low pressure zone is caused by lack of air. If you ram more air through the engine bay you fill that low pressure zone, but that means opening up the front. Of course you'll always be fighting low pressure because of how aero works with square ended cars.

[UnhipPopano]

I wonder how the side scoops would change the overall drag on the car? Would the increase in air flow reduce the drag from the back enough to offset the increase in drag the scoops add? Also, if the low pressure zone in decreased, would that reduce the effectiveness of wings?

[JB91710]

Look at the engine for a Porsche 917K to see how they cooled their air cooled engine. Their fan was shaft driven off the crank but you can use a electric fan to push or pull the air out and mount it in the engine cover. It would make a cool visible, active feature.

https://youtu.be/vawGm4PBKrY

[Bob_n_Cincy]

So what can we do to relieve pressure behind the bumper? My plan was a mostly open rear bumper, but if there is in fact a high pressure zone behind the car this won't help. When you tried your rear radiator, did you have a diffuser installed? Any spoiler? I'm thinking the diffuser with significant stick out would push that zone rearward.

Here is an 80 mph picture of our configuration: good flow.jpg

also my yard stick cam with radiator fan on.

[Canadian818]

Looks like lots of airflow out the back.

[Bob_n_Cincy]

Looks like lots of airflow out the back.

Not really, With the car sitting still and the fans on. I got 10mph air through the radiator.
With the car going 65 mph and the fans on. I got 10mph air through the radiator and it got close to overheating after 1/2 hour on highway cruise.
Note: I did not have belly pan installed.
Bob

[lance corsi]

Has anyone considered opening the leading edge of the side sails just behind the front wheels? It already resembles an air duct and with some clever work, could be made to deliver fresh air to the engine compartment. I may look into this myself. Of course, you would need some sort of dirt\water exclusion due to the road trash churned up by the wheels.

[Frank818]

Frank - I'll take them whenever you can get them. I am stalled out for a couple weeks. Thanks.

Will do man, gimme a couple of days to gather some pix and write up something.

Look at the engine for a Porsche 917K to see how they cooled their air cooled engine. Their fan was shaft driven off the crank but you can use a electric fan to push or pull the air out and mount it in the engine cover. It would make a cool visible, active feature.

https://youtu.be/vawGm4PBKrY

That is exactly what I'm doing. Smaller fan of course but same concept.

Has anyone considered opening the leading edge of the side sails just behind the front wheels? It already resembles an air duct and with some clever work, could be made to deliver fresh air to the engine compartment. I may look into this myself. Of course, you would need some sort of dirt\water exclusion due to the road trash churned up by the wheels.

Yes, FFR did. I read some threads about that, not sure they actually did it but they thought of, or someone did think of.
I'm just concerned about the hot air of the hot pipes from hot coolant routing into the engine bay. We want fresh air not hot in there. The cooler side of the pipes might be ok.

[Frank818]

Bob, Adam, I'm pretty sure with belly pan and with diffuser the airflow will change in the back. How, I don't know. Only theory knows.

[Frank818]

Hey Jaw, here's what I got so far. More to come once I build it.

These pix are posted for the 1st time, they're not even on my build thread yet and won't be for a couple of weeks, until I have all of my cooling design completed. I wasn't planning on posting them until all done, but I'm doing it for you, hopefully it'll give you ideas.

I'm pretty sure there is air flow in that area, maybe not a lot but to take the most of it I'm using NACA ducts. Also my filter is right at the outlet of that duct. So far I've seen no one testing air flow in that area. Too bad, I've done it anyway. Besides it's going to look cool, the cover will be blue and duct black. Cut both sides.

2016-09-06 06.44.29_1.jpg



These are the cuts for Craig's great humps' louvers. You can see where I plan on locating my 80w fan, right above the turbo.

2016-09-06 06.44.40_1.jpg2016-09-06 09.15.22_1.jpg



This is a NACA duct on the belly pan. It will suck up air into the engine bay and swirl it where ever, as long as I got air moving in there. Should be just under my hot side coolant pipes and right under the down pipe. I will fit another one on the other side of the pan.

2016-09-06 11.01.16_1.jpg2016-09-06 11.01.25_1.jpg2016-09-06 11.01.36_1.jpg



Craig's louvers and my fan. I tested the fan very close to the hole and it works very well. I thought the air would hit the cover and bounce back in the engine bay but in fact the air flows out of the louver for at least 80% of it. I will fit brackets on the round tube to hold it in place. It will be controlled by the push of a button on my tablet and also at engine shutdown when I push a button it will run for 5mins, along with my oil cooler fan, rad fan and aux coolant pump, to kill as much as possible the heat soak.

2016-09-14 16.25.35_1.jpg2016-09-17 06.05.45_1.jpg

[FFRSpec72]

You may be creating more problems than solving. I have not had heat issues with just side venta ro IC and large rear louvers and large exit out rear

[Hindsight]

Frank: Couple things:

Where you put the naca duct on the engine cover: I'm pretty sure there is actually some flow there. I didn't think there would be due to it being behind the windshield but I cut the front "legs" of my engine cover off yesterday so they can be screwed into the body and stay put, while I open my engine cover on it's hinge. I notice while driving that the engine cover wants to left out at the edge on top of those intake vents which means there is air blowing on it.

I like the nacaduct idea on the bottom pan - that is similar to what I've been thinking of doing, though I wasn't going to use a nacaduct - I was just going to cut a little "tab" that I could bend up a bit. Air will want to stay attached so some of the air from under the car will be drawn into the engine bay. I was going to make it nearly the width of the belly pan and about 1.5" to 2" deep.

[JB91710]

You could use a wheel like the C4 Corvette's to suck air out of the engine bay.

http://imgs.inkfrog.com/pix/LAMBERTS...WHEELS_002.JPG

[tmoretta]

Now that I have given up on trying to get enough air to the intercooler, my WRX orig. intercooler with 2 (5 1/2) inch Spal fans mounted is available for sale - cheap! IC is already drilled and tapped for temp. sensor. PM me if interested. Maybe someone is more enterprising and persistent than I. I am going AWIC.

[Frank818]

You may be creating more problems than solving. I have not had heat issues with just side venta ro IC and large rear louvers and large exit out rear

Yeah, no one knew when I asked, so I'll be the tester of that next summer. That's the kind of R&D I have a lot of fun doing. If it works so bad that it provides negative feedback, I'll simply just block off the holes, really easy.

But rest assured all these little (and I have more) changes haven't been done here and there just cuz one morning I woke up and said "Nah, why not man?". I did all the search I could before to have some reasons to do it and more than the possible negative effects.

Frank: Couple things:

Where you put the naca duct on the engine cover: I'm pretty sure there is actually some flow there. I didn't think there would be due to it being behind the windshield but I cut the front "legs" of my engine cover off yesterday so they can be screwed into the body and stay put, while I open my engine cover on it's hinge. I notice while driving that the engine cover wants to left out at the edge on top of those intake vents which means there is air blowing on it.

I like the nacaduct idea on the bottom pan - that is similar to what I've been thinking of doing, though I wasn't going to use a nacaduct - I was just going to cut a little "tab" that I could bend up a bit. Air will want to stay attached so some of the air from under the car will be drawn into the engine bay. I was going to make it nearly the width of the belly pan and about 1.5" to 2" deep.

Good preliminary news on the top openings. Couldn't be worse than in the Corrado where the filter was very close to the engine and the headlight quite tight around the body, you remember that. Now, with the sort of box I'll build around it, the filter will suck up from the side scoop and top opening. Even if no air pushed to it at least the filter has colder air to suck up from than the one around the engine.

It's actually 2 NACA ducts on the belly pan but I have not received the 2nd one yet. The only prob with those ducts is I have to go by their sizes. Need one big enough, not too big, long enough, not too much, etc. I do have 2 tube frames welded for my engine mounts which limit my choices but you guys have the engine taking the place. Cutting an opening is easier to control but the ducts were cheap and they are easy to install so I went with that. I also think a NACA duct would flow better than just a tab.

[Frank818]

I am going AWIC.

Not sure Jaw knows but I'm also AWIC.

[UnhipPopano]

From the info available on NACA Ducts, they work best when you have High Pressure and High Velocity on one side, and Low Pressure on the other side. So, If the area under a car was high pressure, the care would tend to lift up. Based on a body design that flows the air over the car, the pressure under the car would be considered a low pressure zone.

But is the pressure in the engine compartment Greater or Less than the pressure under the car? With Side and Top Air Scoops, you would think that the engine bay is pressurized. In addition, people have noticed the smell of exhaust and fuel coming back into the cabin. This too supports the notion that the engine compartment is pressurized.

Is there a way to verify this? If you turn the NACA duct around, will it suck the hot air out?

[Frank818]

After reading a lot of people's experiences and seeing some tests, I believe there is high pressure (and high velocity) under the car (with belly pan and diffuser), medium pressure inside and behind the engine bay, low pressure above and very low in the cockpit.

In which case my belly pan's ducts would suck air in the bay and my hump fan would suck air out the engine bay and above, hopefully the same as with the rear deck lid opening that most people found the air was flowing out of it and not in it.

But the main purpose of my hump fan is when the car stands still, to suck very hot air out. That will work no matter the aero.

According to what you say, as long as pressure differences are high enough, it seems NACA ducts would work either side, provided the opening faces the low pressure area.

[DMC7492]

Hi guys food for thought,yesterday we were at 80F. I took the 818S for an 11 mile jaunt. Country roads up to 80+ MPH. The AWIC was showing up to 148F going in boosting10-11 PSI and the max outlet temps were 87 that was sitting still in the drive way. While cruising the outlet temp sat right at 84 which was probably very close to the road surface temp.
The body is on but there are no cut outs in the rear bumper, no belly pan on the engine. Only increased side scoops.
Just to show how well the AWIC works.

[Frank818]

Yeah the AWIC works in almost any situation if designed and installed properly. Nice to see you got great results! Where's your HE located?

[DMC7492]

Yeah the AWIC works in almost any situation if designed and installed properly. Nice to see you got great results! Where's your HE located?

The Heat exchanger is in the front normal location no splitter or ducting at all just the 1 inch exchanger open on top, sides and bottom.

[Frank818]

Tnx DMC, that's the same as me.

Jaw, still on your question, I also have a wide opening in the top back and 2 smaller ones in bottom back, damn license plate.

2016-09-18 06.24.52_1.jpg

I also have Kurk's shark-like side scoops to let more air in, although they seem to be efficient starting at 50-60mph, which tells me the FFR scoops are probably not that efficient, otherwise Kurk's scoops would probably have helped even at lower speeds...

[DMC7492]

The Heat exchanger is in the front normal location no splitter or ducting at all just the 1 inch exchanger open on top, sides and bottom.

My plan is to do all the sheet metal work after fitting the body this includes isolating the air going in the exchanger, the exiting air will not be able to get back in the inlet.
I think any design including the air to air intercoolers or oil coolers or radiators need to isolate the incoming air so it cannot be mixed with engine compartment air.
I wonder if Bobs rear radiator design even though it had 10 mph air flow if it was recirculating the hot air from behind the car and eventually continued to increase temp? Ducted cold air inlets may have helped...

[coloskydiver]

I figured I would post this here as it is on the topic. One of the key things to keeping the engine bay temps down is the keep the engine cool. On my car I have the hump vents installed and the larger rear louvered vent mentioned earlier in the thread and all the vents cut out. I am also running a water to air intercooler so the vents on the engine cover simply pull air into the engine bay. With that being said, I was still running a bit hot and really hot out at the track. After taking a look at what air was making it through the radiator it became very clear that there is a a ton a space where air can spill over or to the side of the radiator. I also have two radiators that i need the air to make it through. The gap on my car from the top of the radiator to the hood was a little over 3-1/2 " which is actually quite a bit of volume of air that should be going through the radiator. Also right after this large gap we have vents in the hood that the air can exit out of and air will move through the path of least resistance. There is also a decent gap on each side of the radiator the air can go around. So as a test i made some shrouds to force more air through the radiators, one for over the top of the radiator and the one for the passenger side of the radiator. The driver side was a bit tougher as I have a second over flow tank for the inter-cooler. I simply used some of the metal that took off the car when updating to the new nose and some cardboard to make a template. It may not be pretty but made a huge difference. During normal drive it would average 195 degrees ish (currently only have one fan working) but after the shrouds, my mountain drive i posted was the test run and the car literally ran 15 degrees cooler averaging around 180 degrees and sometimes even lower (cruising consistently at 55 MPH). I do think this system does need a helper pump up front and plan on doing one over the winter but more air moving through the radiator is always good.

[JB91710]

if you want to get radical you could make your car like a Porsche 908/3 or maybe the 908/2 would be more accurate. You would have no heat problems that way

tumblr_louf56FCkX1qhfyzfo1_1280.jpgPorsche-908-3_17.jpg porsche-908-2-spyder-37219.jpg.

[Bob_n_Cincy]

if you want to get radical you could make your car like a Porsche 908/3 or maybe the 908/2 would be more accurate. You would have no heat problems that way

tumblr_louf56FCkX1qhfyzfo1_1280.jpgPorsche-908-3_17.jpg porsche-908-2-spyder-37219.jpg.

Our 818 looks like that. And yes, we were out on the road today driving it like this.
We did add some magnetic trailer lights and zip tied on a license plate.

bumpless.jpg

[JB91710]

I don't think you'll have any problem staying cool with that configuration!