Hood Scoops/Vents

[Toledo FJ]

Anyone seen any custom hoods for the FJ? Something with a functional scoop or some vents. I don't understand why they put that little scoop up front but then blocked it with a piece of plastic. Isn't the point to increase airflow into the engine compartment? The only thing I've found are these vents from OK Offroad (go to "stuff" in the menu bar. They are called the run cool hood vents. http://www.okoffroad.com/ Does anyone have these or have you seen them? Pics? Do they look good, or like s***?

[Lovey]

Originally Posted by Toledo FJ

I don't understand why they put that little scoop up front but then blocked it with a piece of plastic.

I always thought that was just another "copy" like the headlight bezel.
see the similarity?
my $.02

[Toledo FJ]

Right, but isn't the scoop/hood vent on the old FJ functional? I mean, doesn't air flow through it and into the engine compartment to help cool it? I understand the retro styling, but seems dumb to make it purely aesthetic. Unless there is some reason that it would be bad to have that scoop functional. I don't know....I'm no expert....Just wondering.

[FirstToy]

You could make the stock hood vent functional with some modding. Not sure how functional it would be but ... also the additional question always comes up: do you even need it? It's not like a Jeep where they had some overheating issues... however, I am tempted by this topic as well!

search the 80s tech forum for lots of discussion on the topic and links to other hood vent ideas

[Toledo FJ]

I probably don't NEED it but I can't see how it would hurt. Correct me if i'm wrong, but anything that reduces heat will improve engine performance and longevity. Also, I have a lot of armor on my rig, and when its full of gear, I'm carrying a lot of extra weight. I'm guessing that makes my engine work harder and run hotter so I figure it wouldn't hurt. Not to mention the aesthetic factor.

[tddfj]

no i dont think the scoop on the front of the fjc is functional it is just for looks. i am amazed that some company hasnt made a replacement scoop that is functional to replace the stock one.

[Toledo FJ]

Thats what I'm saying. I'm wondering why nobody has come out with a complete hood replacement. Could look really nice.

Regardless, has anyone looked at those vents I mentioned from OK Offroad? They would be a good option if they work well and look nice. I just have no idea if they will look good or like crap. Also, you'd have to figure out where to place them, and that could make all the difference with regards to function and aesthetics. If they do work and look nice, they would be a hell of a lot cheaper than a new hood or even a nice scoop.

[mirfjc]

This is something I posted up over on the blue forum. My engine bay was getting so hot my compressor for my front locker was refusing to work.

This is the "finished product" from the outside:


The main idea here is to get more exterior air into the engine bay, and then to get the warm engine bay air out.

The stylish air intake on the hood, above the main grill is a fake plastic cover. But, this would be a good place for a real air intake. The plastic cover can be removed, but one gone, you have two problems: 1. You now have a big open hole in the hood, 2. The hole only goes in abit, and then you hit a layer of hood sheet metal (and then another) - the air still won't go into the engine bay.

The grill
On Air2Air's suggestion, I got some nice sturdy metal mesh from industrial metal supply, which is just a sheet metal store. I tried Home Depot, and couldn't get anything decent. It has been pointed out to me that the pattern I chose is a little BBQ or screen door. I know But it was by far the strongest piece available, and I took strength over matching aesthetics... ymmv.

The metal mesh is cut to the size of the hole left by the plastic faux intake mesh. In order to retain structural strength, we did not cut out all of the first layer of sheet metal. Instead, we left support pieces every few inches. Some of these residual pieces were used to bolt the metal mesh into place.

The stock hood, prior to the cut. Note the support ridges - these were left in tack as we cut holes in the panels around them:


The "mesh" in the upper air intake in the stock hood is a plastic faux mesh - no air will get through (and if it did, it wouldn't get far):


The metal mesh in place in the intake:


The support pieces left in the first layering of sheet metal cut are evident (note that this photo has the second layer cut, also, else you couldn't see the first layer):


These images show more of the bolting of the metal mesh:





The secondary (inner) layer of sheet metal also needs to be cut to allow air flow through. Like the first layer, we left support beams in the sheeting at "reasonable" (i.e. guess) intervals.

This image shows some of the support pieces we left in the inner layer of hood sheet metal:


The Louvers
We had two approaches to getting engine bay air out: the louvers were our better idea. These are parts that MAF have put on various Toyota 4WD vehicles. The louvers come in different shapes and can be found on the MAF website. They come in long, wide, or square sizes. The one I have on right now is a long. The hood panel beneath the louver location was cut, without cutting the support structures below. This reduces the amount of air going out the louver, but strength is probably key here. The louver is placed with the air intact back-to-front, such that driving in rain doesn't pound water into the engine bay. Rain will come in, though, fyi.

Marking out where the hood louver shop will go:


View from inside after chop with louver on:


View from the outside:


Details of the pins used to hold the louvers in place:



Amount of open air via the louver:


Ducting to the Meshes Below the Wind Shield
Large meshes sit below the wind shield that are used to duct air into the cabin air system (the a/c when vented). We decided to try using these for engine bay air outlets. Obviously, they can't really work for both, so if you want outside air coming through your cabin vents, then you probably don't want this mod (or you for some reason like sucking on dirty engine bay air).

Basically, we cut holes in the plastic "firewall" that separates the engine bay from these mesh outlets. The driver-side wall was not cut because the air intake plumbing connects there. This is just a basic plastic cutting exercise, nothing fancy:

Holes cut in the barrier that ordinarily stops engine bay air and cabin intake air from mixing:

[Toledo FJ]

Dude! That is EXACTLY what I was looking for. Awesome job. This is going on my to do list for sure. Thanks so much. Awesome rig.

[mirfjc]

Originally Posted by Toledo FJ

Dude! That is EXACTLY what I was looking for. Awesome job. This is going on my to do list for sure. Thanks so much. Awesome rig.

Glad it was of help. The one thing I wouldn't do again is cut the "firewall" between the bay and the cabin intake meshes. It does work great as an engine bay coolant, but if you're just a second late hitting recyc on the AC, you get a nose full of nasty :P

[cowboy4x4]

Hello this is my first post here I just joined up.
Here is what I did.
my factory scoop is now a functional scoop remove the entire front plastic piece from the hood, remove the black fake grill note:the clips will break off when you remove them you will have to buy new ones from dealer they are cheap. I drilled out every single diamond shape in the fake grill then cut out bigger openings in the back side of the hood. reinstall everything presto functional hood scoop, and it still looks factory'.

[Toledo FJ]

good thinking. Now why didn't toyota think of that?

[uphill]

Mark, do you end up with more "mud" coming through that louver? I know you did the mod - but now you've had it on the rig for a while are you happy you did it? What have you noticed most about it?

[mirfjc]

Originally Posted by uphill

Mark, do you end up with more "mud" coming through that louver? I know you did the mod - but now you've had it on the rig for a while are you happy you did it? What have you noticed most about it?

Most mud, muddy water, and dust makes it in via the bottom (i.e. up past the skid tray and spraying up into the engine bay), almost nothing makes it down. I've not driven in heavy rain yet, so I don't know what that will do. The only impact so far has been positive: my compressor is MUCH happier with the very much lower temps (this I've experimentally verified with my hand-as-a-thermometer: previously the compressor radiator fins would get too hot to touch after even a few mins of engine idle, whilst after the several hours of Odessa crawling a few weeks back, the compressor fins remain cool to the touch).

The only thing I need to figure out is how to stop my truck from keeping switching the air recycle off. (Whatever happened to the old levers where you just set it at recyc and it stays there? And why does my truck seem to think it knows better than me where I should be getting my air from? - if I want outside air, I'll open a window ). Since I cut the engine bay rear plastic wall, the old cabin air intake is now my engine bay air exit. Which works GREAT for the engine bay, if only I could keep my air on recyc...

[justin85-60]

You shouldn't need extra cool air in to help cool the engine compartment. Barring some other mods that is. The engine was designed the way it was for a reason. A modern engine's performance will be increased by pulling more air into the engine, but not the compartment ie a freeflowing intake system. The FJ 40 scoop may have been fiunctional as it was carborated and those get hot. Hence the carb cooling fan up until the FJ62 when FI was introduced. Functional air scoops are necessary when you have a turbo or SC. In the above case, witht the compressor, it was the compressor that needs the lower temps the engine is fine, so if you don't have a compressor or a turbo or something; that seems like a lot of work for little or no gain. My .02. Thanks for listening to my ramblings.

[Toledo FJ]

Your ramblings are very sensible. I do plan, however on running the TRD or URD supercharger sometime down the line. Other mods are more important and will come first. One of those mods will be the addition of an air compressor for tires, tools, and eventually an ARB front locker. I don't know if I will put the compressor in the engine compartment or somewhere else. Regardless, I really like the looks of hood scoops or louvers. I went ahead and ordered the Run Cool Hood vents from Okoffroad. They are a little more than the MAF louvers, but I like the angular shape of them better than the straight ones offered by MAF. I'm going see how they look before I commit to cutting into my hood. If things look good, I'll post up some pics when Its all done.

[alaskacruiser]

Has anyone who has done this mod recorded OBD-II readings for intake air temp and coolant temp before and after this mod? Would be very interested in these readings.

[Toledo FJ]

yes, I did see a post on the blue forum where someone had posted before and after temps. Im pretty sure there were significant drops.

[targa88]

Originally Posted by Toledo FJ

yes, I did see a post on the blue forum where someone had posted before and after temps. Im pretty sure there were significant drops.

Don't mean to hijack but what is the "blue" forum?

[Toledo FJ]

fjcruiserforums.com I hope I didn't just break some rule by posting that link. If I did, sorry.

[ATTILLA]

Doesn't matter, same owners and a lot of the same people anyway.

[Niner]

Originally Posted by ATTILLA

Doesn't matter, same owners and a lot of the same people anyway.

ih8mud and FJcruiserforums are not owned by the same folks.

but mud doesn't have a link rule like the blue forum.

[Manhattan]

Just letting "random" air in through the vent or scoop seems like it could do little good or even some harm. The air is not directed - it simply comes in and creates positive pressure under the hood. Couldn't this reduce the "ease" at which air is flowing through the radiator(s) and other places the Toy' engineers intended to have air flowing?

[FJTex]

wow.. been hangin out in the blue forum for a while and i'm startin to miss this place... seems like a lot of the anti FJc crowd has coold off a little

[Toledo FJ]

I haven't heard of anyone who had done this mod who has any regrets or damage as a result. I'm going to hold off on the front scoop for the moment and see how things work/look with just the Raceace hood louvers. If they are sufficient, I probably won't do the front scoop.... at least not now. As far as the Louvers go, I'm very happy. Good quality, etc... The instructions are very good. Even though you have to take a cutting wheel to the hood, it looks like an easy job. I'll let you all know once I get them on. I'll post some pics. I've almost figured out how but if any mac users out there can tell me how to shrink the photo, I'd be much obliged.

[mirfjc]

Originally Posted by Manhattan

Just letting "random" air in through the vent or scoop seems like it could do little good or even some harm. The air is not directed - it simply comes in and creates positive pressure under the hood. Couldn't this reduce the "ease" at which air is flowing through the radiator(s) and other places the Toy' engineers intended to have air flowing?

In the case that I showed in the earlier post, the air flow is pretty well directed: we wanted air to flow over the compressor, and also to simply convect out when stationary, so one outlet is the louver. The larger idea is to cool the whole engine bay, and we made outlets at the very back of the bay by converting the cabin air intakes into engine bay outlets. So the flow is from the front to the back over the top of the engine and with enhanced flow over the compressor. Use of recyc vs. vent with the A/C is the only work around we had to implement for the air intake issue.

[Trollhole]

This would look kind of cool.