Some of you may have seen that Nine Lives Racing recently released a wing kit for C5/C6's that uses their popular aluminum wing (9.5" chord length, 71" wing span). It's quite a cost effective kit, coming in at <$1,000 for everything from chassis mounts to wing endplates. I liked the kitfor the cost and since it uses 2-piece wing mounts that I can either mount a spoiler for CAM class autocross to, or the wing for track use. I believe the mounts are a GoodAero design which is a proven product.
Tools needed: Drill and 3/8" or slightly larger drill bit Angle grinder or air grinder with cutoff wheel Measuring tape Painters tape and sharpie Centerpunch or sharp drill bit for marking hole centers Assorted metric tools including torx bits to remove rear fascia 1/2" wrench and 3/16" hex key for wing mount and wing upright bolts.
The first step for installation is to remove the rear fascia. You can access all the bolts by removing the rear wheel well liners, the rear lights and licenseplate, and opening the trunk. You'll also have to remove the foam bumper from the steel bumper beam. My car had a bunch of dirt and junk on top of the foam bumper and between it and the beam, so I spent some time vacuuming it up and cleaning the general area.
The wing has mounts welded to it at 22.5" spacing, so you want to have the same 22.5" spacing between the chassis mounts the you bolt to the rear bumper beam. I measured the length of the rear bumper beam so I could get the center of it, and then placed painters tape on the beam under where the mounts will go and used a sharpie to mark where the edges of the mounts need to end up. I then held them in place and used a centerpunch to mark the hole centers for drilling the beam. The bolts are 3/8" diameter so I drilled them a bit oversize to allow me to tighten the mount down in the correct location.
Here you can see the chassis mounts bolted down in place.
You have to reach inside the bumper beam to get the nuts on the back side of the bolts and hold them while tightening. I recommend bolting the wing uprights and wing to these mounts as a check when you are at this step to make sure the spacing is correct, before calling it good.
You'll notice that the mounts have some slight interference with the fiberglass trunk flange that will keep you from tightening them down all the way, so you will have to notch the trunk flange to allow the mounts to sit flush. I recommend making this notch a decent amount wider than the mount itself to allow for some wiggle room and since there is no negative impact from doing so. A cutoff wheel on an angle grinder makes quick work of the fiberglass.
The next step is to notch your rear bumper foam to allow it to bolt back down over the new wing mounts.
Congrats, now you get to re-attach your rear fascia. Before we do that we need to make some room for the wingmounts to poke through though! Don't worry, the downforce is worth cutting up your bodywork.
I started by holding the rear fascia up to the mounts and putting some painters tape down so I can mark lines on the bodywork where I need to cut. You can then start the notches on the inner lip of the fascia, then re-check their positioning on the car by holding it in place against the wing mounts. You can also measure distance from nearby holes on the trunk flange and rear fascia to get more accurate dimensions for the cuts. I then finalized my lines on the painters tape and made the cuts. I recommend cutting the notches twice as wide as you need to account for things moving around as you tighten down the rear fascia. You can seal the gap back up with some trim rubber if you want. You have to cut all the way to the edge of the upper face:
Congrats! Now you can tighten down the rear fascia.
For me, the next step was to build a rear spoiler for autocross using the chassis mounts. I used sheet aluminum and aluminum angle, riveted together, and then bolted it to the wing mount holes. It worked really well and is only held on by four bolts so it's easy to remove. I can even boltit on parallel to the trunk lid for low-drag transport, then stand it up at the autocross site.
Final results with the CAM spoiler bolted to the car. I really noticed a big difference with this spoiler at autocross speeds.
Installation of the wing itself is just bolting it up and selecting an angle of attack. My first event with the wing was a tracksprint at ViR Patriot course last weekend and I beat a bunch of cars on Hoosiers and some open-wheel things, just on my leftover Michelin PS4S tires. I highly recommend getting yourself some downforce!