[latetobolt]

I had these rear shocks installed today: Bilstein B6 Performance Series 24-171687. $131 each shipped from Summit Racing, arrived the next day: Bilstein B6 Performance Series Shocks and Struts 24-171687

A local shop installed them for me for 1.5 hours labor - very reasonable. They do require several washers to fit the Bolt, as the bracket on the swing-arm of the Cruze was apparently considerably narrower than that on the Bolt. It took eight 9/16" stainless washers at the bottom of each shock to fit properly on the Bolt - see the image.
http://oi65.tinypic.com/3343v2q.jpg

The resulting change in handling of the Bolt is very gratifying. Where my unmodified 2019 always felt reluctant to turn into a corner during enthusiastic driving, the car now feels much more willing to take a corner, there is no longer a need to adjust the line in mid-corner while the car rolls back upright, and on corner exit you just straighten out smoothly.

There is very little difference in ride - bumps are really no more noticeable. I credit Bilstein for this, as their gas-pressurized shocks are known for taking small pavement irregularities in stride, and the result is generally a better ride than Koni Yellows I've installed over the years.

Because these shocks are gas-pressurized, they do increase ride height slightly. I measured the rear wheel arch height before and after, and found a negligible 4mm increase, as I expected.

It's a great mod - makes the car feel almost BMW-like - highly recommended.

A very late reply, but a note about the Koni yellow adjustable substitute (looking for a softer ride) that also requires washers on the sides. The Koni and maybe the Bilstein has a larger hole than the OEMs. Is this not considered a problem or will good bolt torque keep the shock from jerking up and down in the, now oversize, shock hole?

 

[latetobolt]

Koni’s have to be adjusted before install, part # for Cruze is 8240 1293 sport yellow. Shockwarehouse $125.24 each with free shipping. Up to 5 days delivery.

 

[latetobolt]

I had a test street. At legal speed with perfectly good original rear shocks the milk crates in the back would bounce off the floor. With the Koni's set on max soft rebound they would not. And my 83 year old neck joints felt better with the Koni's. That's my version of the scientific method. The milk crate bounce test.

 

[latetobolt]

It's a continuous adjustment. You have to compress, and hold, the shaft down until it engages an adjustment slot inside the shock then turn it left or right (can't remember which way) until it stops to get the least rebound dampening effect. If possible you can then compress them both together and release to see that they expand/rebound at about the same rate.

When reinstalling be sure to use max torque on the bottom bolt to reduce chance for up and down movement since that hole in the Koni is larger than the original shock hole, or shim up the hole to fit better. FYI the bottom bolt screws into a captive nut, so don't bend any tools trying to loosen the nut.

 

[latetobolt]

No, Koni is too narrow. You need 8 9/16" washers at the bottom of each to fill the space. May be hard to find. I had to order a bag of the things.