Hi Guys, I'm a long time reader of the forum, and I've got a C6 Grand Sport for track duty. I recently bought a 9 lives splitter and wing kit. Before buying the kit I searched pretty hard for instructions to know what I'd be getting into - but couldnt find anything for the C6. Thought I'd fix that, and perhaps help out a few people with this guide!
The install is not that bad, and does not cut up the front bumper cover very much.

Note, the splitter fits great with the EOS ZR1 style front lip/splitter!



Step 0: Prepare yourself. Although the parts are good quality, Nothing fits together. Some key issues I faced:
-If you install the splitter with the 9LR supplied hardware, I can not see a way to do up any of the bolts securing the bottom of the bumper to the car. I also do not see a way to tighten the 9LR hardware unless you leave the grill out. Maybe someone smarter than me has a way. Truthfully I didn't spend a lot of time on this problem and designed my on solution seen below.
-Splitter holes drilled in the wrong spots fore/aft, placing the splitter 2.5" to far rearwards

-Mounting bolt pattern of the Sturdy Boi mounts doesnt match the pattern drilled into the splitter. The front holes on the mounts are spread out about 3/16" from the riveting process - you wont get a bolt through them
-Splitter mounts have slots for adjustment, but the holes are drilled wrong and it will not slide. See pic below.


Step 1: Drill holes in the frame. Use the supplied jig, but note the specified hole size is wrong. Use a 25/64" drill bit.





Step 2:
Drill/Grind off the rivet, and use a punch to push the aluminum plate inside the frame about 1/4" away from the frame to allow the rivnut to expand properly.



Step 3: Remove and re-orient the horns. Bolt back on with an M6x40mm bolt. Horns fit back on when you configure them like this:

 

Step 4: Loosely install the sturdy boi mounts. You'll probably have them on/off a few times, no need to tighten the bolts. Note the LH mount has a cut out for oil cooler lines.

Step 5: Cut the bumper. Cut next to the raised mounts, forwards until you're about 1/2" from the crease line in the bumper


Step 6: Re-drill the splitter, or re-mark your holes if you are using a template. I've got 3D print files for a drill jig I'm happy to share through PM, or see the dimensions below. New holes in green make everything fit up. NOTE that every set of holes has a different width spacing...
Quick note. If the first hole from the front of the splitter is roughly 8-1/2" you're going to have the same issues as me. If it is roughly 5-7/8", then 9LR must have fixed things - no need to re-drill


Step 7: Test fit your splitter. Side brackets go to the outermost bolt under the headlight. The round opening on the side brackets goes to the top. Like in the picture below (Except that it will actually fit together once you re-drill the holes )


Step 8: Install your ramps or any other misc parts to the splitter and mount it up! If you are using the 9LR fasteners, pound the nuts into the bottom of the splitter first.

 

This last section is for my personal improvements to the kit. I do not like the top down bolt method for a few reasons. The pound in nuts stick down about 1/8" below the splitter messing up the air flow. I could not figure out how to secure the bumpers lower fasteners. It looks like a pain to do up the splitter hardware.

For these reasons I designed up a stainless steel TIG welded nut plate, and used that to mount screws up from the bottom. I used a counter bore bit, conical washers and flat head screws to keep the bottom totally flush. I can now drop the splitter in under a minute, and re-install it blind from the bottom in 10-15 mins. I'm thinking of making up a few sets of these nut plates, but I am not quite sure - the 9LR mounts seem to all be slightly different from each other - some massaging would be needed to fit the nut plates. I'll think about it for a bit.





Riv nut in side mounts

Second, I didnt like the gap between the splitter ramps and splitter, so I filled it with some body seam sealer.


Third, there was some bare exposed wood from the CNC machining on my splitter, so I hit it with some paint to try and keep moisture out. Also note that when pre-drilling for ramp screws, dont go all the way through. The plastic layer tears away . That one is on me!

 

Any pics with the bumper installed?

Is 1/8" protrusion out of the bottom (the nuts) truly enough to disturb the airflow? Genuinely curious

 

I've only got one pic with the bumper on handy, it is before I re-drilled to get the splitter in the right spot.

As for the 1/8" affecting air flow - I have no idea if it does, but it is within my power to get it flush

 

Nice job making it right! You should just make your own splitter to sell.

 

Nice write up! This mirrors the issues I went through when installing the same kit on my C6 GS. I used the printed template and the location of the holes was off, just like yours. I'm pretty confident they have that designed for a C5 front end and are not changing it at all when someone has a C6.

Those nut plates are trick, do they attach to the splitter mount feet at all? (like when the splitter isn't installed). I'd be interested in these.

Like you, I wanted/needed it to be fastened from the bottom. After some fiddling around, I settled on some J nuts/clip nuts, whatever they're called (pictured below), and put some JB weld to hold them in place on the mount. It's very backyard mechanic, but it works. Would like something nicer though.




Finally, I found that installing two ~5" threaded rods into the mount, then sliding the splitter up the rods and quickly putting a washer/nut on the rod cut install time in half because you don't have to fight to line it up nearly as much. I'll zip most of the bolts in with the rods still in place, then simply unthread those by hand, install the rest of the bolts, and done. Consider some weather stripping to fill the gap between the bottom of the ZR1 lip and the splitter blade. It will flex a little at speed and open up.

 

I like the trick with the threaded rods, I'll have to keep that in mind for the future. I've been balancing mine on 3 jack stands, then lifting it the last inches to get it installed.

The nut plates float on the mounts, if I take the splitter off then I'll run 2x bolts up into each one to stop them bouncing around.