I've had a set of Koni Sports for my 2008 C6 sitting on the shelf for a while that I finally found time to install this weekend. For the most part the install went fine. It took me a while since I didn't know what I was doing, but I eventually got them in. I have the Lisle tool which made removing the original shocks MUCH easier, I was glad to have it.

I used the zip-tie method, the rears were definitely easier than the fronts, though I found the zip-ties I had only have a 50lbs breaking force and that was weak enough that the force of the shock extending was enough to break them. I had to run two sets of zipties down the shocks to hold them compressed. Zip-ties also stretch on first loading, so I had to compress the shock, tighten zip ties, release force and let them stretch, then compress again and tighten them up. After that the shocks would stay compressed for me to remove or install them. I also found it easiest to compress the fronts for removal to unbolt the top mount, leave the bottom bolted, then use a jack to lift the control arm and compress the shock. Then install my zip ties, do the stretching routine, lower the jack, and the shock would drop right out.

The one issue I ran into is that at first I installed the fronts and torqued the top nuts to the factory spec of 21ftlbs. I was able to do this without the nut shaft spinning so it was really easy to just use a deep socket. I went for a test drive and everything seemed good, but I remembered the little scrap of paper "instructions" that came with the Koni's listed a torque spec of 33ftlbs for the top nut. I went home and tried to torque the nuts up to 33ftlbs and while that worked fine on the driver's side, on the passenger side the nut shaft started to spin at something like 25ftlbs and I couldn't get all the way to 33.

The Koni's use a larger 17mm top nut that the Lisle tool doesn't fit, so I'm not really sure how to tighten down the top nut the rest of the way. There isn't much room in there to get a box wrench on the top nut and vice grips or something on the shaft. Does anyone know if there's a larger version of the Lisle tool out there for a 17mm nut? How would a shop handle installing these shocks? Some sort of crow foot socket?

The car seems to drive just fine, no clunking or unexpected noises. The rubber bushings seem to be adequately compressed by the washers (they're squashing out just slightly past the lip of the washer), so maybe it's good the way it is? I'm not really sure how precise the torque needs to be on something like this given there's a rubber sandwich of bushing involved.

 

no precise TQ, sounds like you have them perfect, just don't want to squeeze them till they split, there is enuff room for an open end and a little baby 1/4 inch socket of the right size and an extension, my first set of Bilstein's I didn't get the rubber had to use the stock ones.

 

Thanks! I appreciate the confirmation.

As a shot in the dark I tried using the "contact" form to ask Koni themselves and actually got a response right away. Since the Sports are inverted shocks the entire shock body is what is spinning, not the piston shaft. They say you can hold the shock body itself while you tighten the nut, which I didn't even realize. I'm thinking to try a strap wrench or something to make sure the body isn't damaged. I'm going to adjust the rebound on the shocks anyway so maybe while I have the wheel off for that I'll see if I can get the extra ftlbs on the passenger side to match the driver's side. I agree that it's probably fine the way it is, but I'll sleep better knowing the torque on both sides is exactly the same.