Millsy Motorsports
HomeCatalogFree PartsBlog
C5/C6 Center Hood Vent
2026-08-21 | 10 min read

C5/C6 Center Hood Vent

Beat the heat with a big hood vent!

C5 Center Hood Vent - DIY!

A center hood vent is an excellent way to extract a ton of heat and high pressure air out from under the hood!

Features

  • Reduces fluid temps
  • Settles front end of car somewhat at higher speeds
  • Easy to install
  • 3 available styles

As you can see, I went with the small louver/gurney style, and thus, that's the only one I've tested. The larger vent style may work better or worse, I just haven't gotten around to finding out.

HOOD VENT 1HOOD VENT 2HOOD VENT 3

Where to get

This kit is open source and licensed under CC-BY-NC-SA. You can download the .DXF to cut it out yourself, upload it to SendCutSend or other machining service provider, or purchase a ready-to-go kit from me directly. Link to the vents: millsymotorsports.com/free-parts Aside from the plates themselves, you will also need:

  • 20x 3/16 tri-split rivets OR you can use bolts/nuts!
  • Sharpie marker for layout
  • Tape measure for layout
  • Cutting tool (I used an oscillating multitool)
  • Straight edge of some sort
  • Saw horses

Sadly, these do require a bit of welding. I include 2 spots for some cross slats that support the middle sections of the louvers. I TIG welded mine but a small MIG welder would work great too. You just put a tack weld at every louver-slat connection. The slat DXF provided needs to be extended another 2 inches for the SMALL louver version. The instructions are post-assembly of the hood vent. See step #2 for template advice. I actually used steel to make these, .074" thick. The twisting stress between the louvers and the frame around them is pretty high, so I went with a material that's a bit more fatigue resistant in that area.

HOOD VENT 4

Installation

Wear a particulate mask to protect your lungs!!!

This installation isn't bad at all.

  1. Place your hood on some saw horses. Makes it easier to work under if necessary.
  2. I suggest using the flat steel hood vent, pre-bending, to either make a template in cardboard with your sharpie. You can also use the vent itself as a template!
  3. Using the tape measure, find the center line of your hood and mark it in 2 spots.
  4. Using the straight edge, align it with your 2 marks and run your sharpie between them, making a line.
  5. Place your cutting template center on the marker line, and trace out what hood material needs to go. I believe the general suggestion is to make the edge of the hood vent between 16"-20" up from the leading edge of the hood, but double check me on that.
  6. Using the oscillating tool, start cutting out the material.
  7. After you remove the center portion of material, try to fit the hood vent in the new hole. At this point, I would carefully bend the louvers up, decreasing the angle of each subsequent louver as you move towards the back of the vent.
  8. Align the 2 rivet holes that are placed in the center around the edge of the vent with the remaining marker line.
  9. Clamp, tape, or have a friend hold the vent down while you drill these 2 holes. Make sure it doesn't move! These are pretty important for alignment.
  10. After those holes are drilled, you can rivet the hood vent on and drill the rest of the holes.
  11. Clean up and enjoy your new hood vent!