Here are pics of my hood louvers installed on my 03 Eclipse. After doing an engine swap, I was seeing some seriously high under hood temps. After installing the louvers I saw a drastic drop in under hood temps as well as a 20°F drop in oil temps. My data logs also showed a drop in intake air temps.
Brett L. – See his review at www.club3g.com.
Original Article can be found at
After doing my 6g75 swap I was getting some pretty high IATs and under hood temps. My underhood temps were reaching 200F+ and my IATs were reaching 115F.
After looking on the internet I found a website called Hood Louvers | RunCool | Hood Vents For Your Vehicle – | The Most Experienced Hood Louver Company In The World! The Most Cost-Saving Way To Cool Hot Engines!Hood Louvers | RunCool | Hood Vents For Your Vehicle -. They have a pretty good selection of sizes and colors to choose from. I went with the XL size 13″x21″ high flow louvers for this project.
XL (13″ X 21″) Archives | Hood Louvers | RunCool | Hood Vents For Your Vehicle -Hood Louvers | RunCool | Hood Vents For Your Vehicle –
I taped off the hood where I would be working. This would allow me to draw and slide things around on the hood without scratching it. I found hood center line by using the center distance between the washer nozzles and the point on the Mitsubishi symbol (on the bumper) as a reference.
Choosing spacing was difficult but I came up with a number of 2.5 inches from center line. This would allow the most access to the back side of the rivets and minimal interference with the hood bracing.
Let me clarify. The kit is supplied with pop rivets of choice. They are available in either black or silver. From the beginning I planned on using aircraft rivets to secure the louvers and not the pop rivets. This made placement more critical as I needed access to both the top side and bottom side of the rivet. If you ARE using the supplied pop rivets, hood bracing and louver placement is not a big deal as you only need access to the top side of the hood.
I marked off 2 parallel lines 2.5 inches from center line. One 2.5 inches left of center line and one 2.5 inches right of center line. I placed the drivers side louver on the hood where it looked best. Before doing any drilling I zip tied a piece of rubber tubing on the drill bit. This was my makeshift drill stop. It keeps the bit from going into the hood bracing. Being rubber it also doesn’t hurt the finish on the louver when the rubber touches.
BEFORE DOING ANY DRILLING, GRINDING OR CUTTING you must protect the rest of the car. I put a damp shipping blanket over the engine and taped off the rest of the hood before grinding. It’s also a good idea to cover the windshield. I carefully drilled one hole in the hood using the louver as a template, then installed a Cleco fastener (for temporary assy). I continued to drill all the holes that way checking for my proper 2.5 inches from center and installing a Cleco every second hole or so to keep everything in line. Cleco fasteners are spring loaded temporary fastener used in sheet metal work but are not required. They are nice because the louver cannot shift while you are drilling the holes. With a straight edge be sure both louvers are positioned the same distance from the top edge of the hood before you start drilling holes into the hood for the second louver.
After all the holes are drilled through the hood it looked like this.
After getting all the holes drilled, I traced the very outside of the louvers onto the tape. After removing the Clecos and hood louvers you are left with this.
Place one inch masking tape just on the inside of the lines you marked from the louvers. This will provide a nice one inch line from the outer edge of the louver. This will be your guide for cutting. You will be cutting on the very inner edge of the tape you placed down.
It looks like this. You will probably have to enlarge the photo. If you are confused with tape placement, notice that the tape covers the holes you just drilled.
Once the tape is laid down we start cutting into our hood. The corners must be radiused (round) to discourage cracking. I did this by using a 1 inch hole saw at each corner. You drill the hole in the corner just inside your tape lines. In the below pic I also traced my cut line with a cutting wheel so you can see how I placed the tape and cut just on the inside edge of it.
Next you SLOWLY make cuts with a cut off wheel taking small amounts at a time. If you are aggressive or are using a thick cut off wheel, you will generate heat and burn the surrounding paint. Use a very thin cut off wheel and GO SLOWLY.
Here is one complete cut made and border tape removed so you can see the drilled holes again.
Cut out the second hole. Debur and file smooth all the sharp edges you made cutting and drilling holes. Carefully paint the now exposed hood bracing flat or matte so it’s less noticeable through the louver fins. I also used silver touch up paint to cover the bear metal spots from cutting and the drilled holes. Sealing up any exposed steel is important to prevent corrosion. Once all is painted you can remove the tape and allow the paint to dry.
Here is a picture with the tape removed and one louver removed so you can see the black bracing and touched up bare spots.
After paint had dried you can install the louvers with the supplied pop rivets. Again, I used flush aircraft rivets so it looks a little different than yours would.