Gt500 Hood vent (on a CIVIC!?!)

Installing a hood vent is an effective way to lower the temperature under the hood and bring efficiency to the cooling system while providing front downforce by evacuating high-pressure air under the hood. Not to mention it looks pretty neat too, but just like everything here on FunctionTheory, it’s all about the function.

My whole Honda life (almost 20 years now), I have always just run a half-sized radiator in all my cars. Five years ago, when I did my K swap, I also installed a half-sized radiator. However, after my first track day with the car, it became apparent that a half-sized radiator wouldn’t be enough to keep my K20 cool. Now, yes, a half-sized radiator will work just fine if you’re only spiritedly driving your K swap around, street racing, or doing some canyon carving. But when it comes to pushing your K swap to its limits for 45 minutes straight on a track, a full-size radiator is necessary.

For the last two years of owning my EK and doing track days with the D16y8, I was only running a half-size. This was working perfectly, and I never once ran into an overheating issue (even in summertime at SOW). Now that the EK is packing a DOHC VTEC powerplant, overheating is on my mind. The increased RPMs on the B16 will no doubt create more heat. While doing my swap, I toyed around with the idea of going full size. However, when a brand-new C&R radiator with a SPAL fan mounted to it fell into my lap (thanks, Royce), I decided to stick with a half size.

Overheating is still in the back of my mind, so to help keep my mind at ease, I am choosing to install a hood vent. When it comes to hood vents, there are many options/styles/brands out there. A few years ago, I saw that someone had retrofitted a GT500 Mustang hood vent, and I thought that it looked surprisingly good. It took me a few years to justify getting this mod, but with the addition of the B16, I figured it was time.

Now, straight away, let me just say that cutting up your hood to put in a vent is extremely dangerous. You see, there is an exceptionally fine line between tasteful and tacky when it comes to doing it. Yes, hood vents can be of great help, but you can definitely do it wrong. I know what you’re thinking, “I put a Mustang hood vent on my car, how can I tell anyone what’s tasteful?”

I’m writing this article because while doing research on how to install a GT500 hood vent on a Civic, there wasn’t much information I could find, and I wanted to show anyone interested in doing this exactly how it goes.

First off, the GT500 hood vent is actually pretty cheap. Coming in at $120 for an actual OEM Ford part, this is actually a pretty inexpensive modification. A word of caution though, there are some knockoff and replicas out there. Below is the part number. It’s for a 2010-2014 GT500.

This is what it looks like stock.

Below are a few snapshots of what the vent looks like out of the box. There are no other parts or hardware that come with it.

First thing you’ll want to do is create a stencil. This is without a doubt the most difficult part. Due to the way this hood vent fits, you’ll have to make the template about 1 inch smaller than the outside of the actual vent.

We chose to make a negative stencil, but you can make it however you choose. Measuring it is very crucial. We used the windshield wiper squirters to help take accurate measurements.

Once we had it centered where I wanted it, we completely taped down the whole paper stencil. It’s recommended that for the vent to work accurately, it should be 4-5 inches from the radiator. It just so happens that it fits perfectly between the edges of the cowl on EK Civics.

Before cutting into the hood, cover the engine with a blanket or similar to help prevent all the metal bits from getting all over the engine bay.

There are multiple different ways to cut it, and I’ll leave that up to you. I’m using an air cut-off wheel. It has a variable speed trigger, so it’s easier to stay on the line when cutting.

There is a skin on the hood, and there is a skeleton. To keep things clean, I cut off the skin part first. There is glue that will hold it to the skeleton. Carefully pry the skin off.

Cut the skeleton from underneath, making sure the skeleton part is wider than the hole cut in the skin. This will allow the vent to fit properly. Ever didn’t have a way to shield my face from the debris, so I guess a helmet will work.

This is what it should look like when its done.

The vent secures with one small bolt in the top center, and two clips on the top side. The bottom side of the vent actually has a groove that slips into the skin part of the hood. Below, you can see how I marked the two areas where the clips lock into. You must make cutouts for the clips to lock into.

You can also see the small hole drilled in the center where the bolt of the vent will go through.

The vent will actually just slide right in, and the two clips should snap into place. It’s just that easy.

Making the template and ensuring it’s perfectly straight is really the hardest part of this whole thing. The rest of it just slips right in. When cutting the small cutouts for the clips, start by only cutting a small amount. If you cut too much, there won’t be enough pressure to keep the vent tightly in place. The downside to this vent is that it doesn’t sit completely flush (this is just due to the nature of how the vent fits into a Mustang hood), so if you’re expecting it to fit flush, then just buy another vent. Overall, for the cost, the ease of installation, and the amount of hot air that comes out, I’m happy. Plus, I feel like the style of the vent matches my car perfectly (not too wild, but just enough).

If like cooling might become an issue for you, this is an easy install, and it’s very functional. There are plenty of people choosing to run this vent on their full-on track cars, so I assume if it’s good enough for them, it should be good enough for me. I figure if they can afford to have a full-on track car, then they could choose any other vent or vented hood for that matter, so this must work pretty well. (I can see a drop of 8 degrees in my IAT while cruising on the freeway)

I hope this write-up helps you see just how easy it is to do this installation hopefully, it will inspire you to make this your next project. As always, thanks for reading my blog, and remember, if you have any questions, concerns, or suggestions, you can always email me at Billy@functiontheory.com, DM me on Instagram @Functiontheory, or just comment below. I truly want to help you and will reply.