[cdb95z28]

Originally Posted by BOSSman760

I installed the ebach pro springs on my 2017 ss 1LE and I hate it, its so bouncy and embarrasing and looks ridicules the way it bounces. These must be some cheap low quality springs, now i need to look for better springs or put back my OEM ones.

They are bouncy because any large deviation from OE ride height will put any of the rubber bushings into a state of bind...this is often overlooked on any drop spring install on any vehicle. The SS 1LE has rubber bushings at the front radius rod and various rear joints. But I believe the biggest impact here is the bonded anti roll bar mounting bushings. One cannot retime the front bushings because they are actually glued to the bar. At the rear, the bar mounting bushings grip the bar super tight, but you can remove and retime the them. On the surface this seems easy enough but GM engineered some preload into both bars. If you can't mimic the preload, you're gonna change the dynamics of everything. Some may notice, others may not. YMMV.

Some of our joints are shperical ball rose joints. They are not affected by static ride height changes. Bind free precision movment. Perfect joints.

This bind effectively changes the OE calculated wheel rate for which the struts and shocks are tuned for. This is the rate or "stiffness" of all the suspension components that the wheel or more correctly what the tire is seeing, not just the springs and bars. Joints are part of the wheel rate. This bind is uncontrolled, undampened.

[DeuceCam]

I overlooked the sway bar mounts when my suspension bushings were timed during my coilover install. To time the rear sway bar mount bushings at static ride height, do you think I'd be able to get away with loosening the bolts to the rear sway bar mounts, jouncing the car (stand in trunk and jump up-and-down), then retighten the rear sway bar mounts?

[cdb95z28]

Originally Posted by DeuceCam

I overlooked the sway bar mounts when my suspension bushings were timed during my coilover install. To time the rear sway bar mount bushings at static ride height, do you think I'd be able to get away with loosening the bolts to the rear sway bar mounts, jouncing the car (stand in trunk and jump up-and-down), then retighten the rear sway bar mounts?

That will not work. The rear rubber bushings have a super tight grip around the bar. They have to be removed then reinstalled. What I would do...

You can remove the bar and then remove the brackets, bushings/resinstall and resest to your ride height or do it all with the bar on the car. Removing the bar sucks unless you do it on a lift.

-Mark the bushings with paint stick or something to make a reference of the OE position.

-Make marks for lateral and radial positions.

-Remove the metal brackets. They are gonna be tough to free from the rubber bushings. swing them side to side while pulling on them. Sometimes it helps to use a flat screwdriver tip or a short pry bar in the bracket holes to kinda pry them side to side. They'll start working off. You don't have much room. But if I recall correctly you can atleast get at the bottom holes.

-The rubber bushings will have a split on their flat area. Spread them here, don't spread more than you have to. They are rubber but have either a metal or plastic core.

-Reinstall at your new ride height. Note that the OE bar has a preload, even at OE ride height. I don't recall which way the bar is preloaded, up or down. It's possible that OE preload may make the bar neutral at your new ride height! You can choose to duplicate this OE preload at your new ride height, but you can only observe the OE amount with an unmodified ride height, obviously. I believe GM adds some preload to add responsivness to the bar.

-When I repositioned the OE mounts on my Gen 5 SS 1LE (same style), I used some hand soap as a lubricant on the bushing to bar surface. This allowed me to easily position the bushing and adjust if nessecary. The Devil's Lube (spit) can also work. Both will eventually dry and allow the bushing to grip as intended. Let both dry before driving.

-Reinstall the bracket. The fasteners are 43 lbs/ft.

There's alot going on with the OE rear bar. Not only do they have an overall preload but a slight twist too, which then adds more (or less depending on perspective). The super grippy mounts add a slight amount of overall rate.

The front bar just has a little preload, a slight twist in the bar. But the front bushing is actually glued to the bar! I half-heartedly attempted to remove the bushings from my front bar once but felt it wasn't worth the squeeze just to understand it further.

When we install aftermarket bars with their lubed poly bushings, there is no grip on the bar.




EDIT: I see your sig says LT1. My observations have been with the SS 1LE, ZL1, ZLE. I believe your LT1 does have the grippy mounts but the OE preloads, if any, may be different.

[Msquared]

The obvious-but-costlier solution to the sway bar bushing dilemma is to install aftermarket bars with urethane frame-mount bushings. The Whiteline rear bar is the same diameter as stock and about the same rate as stock in its middle setting. The BMR front bar is close to stock rates in its softest setting. The bushings that come with the BMR bar are junk, though, so you need to buy a substitute, such as the ones that came on the Hotchkis bars.

[DeuceCam]

Gents, thx for chiming in!

It's an LTI, so same suspension as an SS. (But, I've got KW coilovers, spl rear toe links, and BMR rear subframe lockout.) Car is roughly 1.5-2" lower than stock. All bushings (aside from sway bar mounts) were retimed at new ride height.

The performance on twisty roads is great; sharp turn in, takes a set, etc. It's the most compliant set of coilovers (or aftermarket spings/shocks) I've had on a car, very refined. That said, I'm a suspension nerd, and it bothers me that there's a potential compromise in the setup that could have been avoided.

Generally speaking, my preference is not having sway bar preload, but it's a subjective thing. I also tend to prefer the feel of stock sway bars over aftermarket. All considered, I'll likely leave it (KISS approach, no can-of-worms) or possibly swap in aftermarket bars.

[sonikk71]

Originally Posted by cdb95z28

That will not work. The rear rubber bushings have a super tight grip around the bar. They have to be removed then reinstalled. What I would do...

You can remove the bar and then remove the brackets, bushings/resinstall and resest to your ride height or do it all with the bar on the car. Removing the bar sucks unless you do it on a lift.

-Mark the bushings with paint stick or something to make a reference of the OE position.

-Make marks for lateral and radial positions.

-Remove the metal brackets. They are gonna be tough to free from the rubber bushings. swing them side to side while pulling on them. Sometimes it helps to use a flat screwdriver tip or a short pry bar in the bracket holes to kinda pry them side to side. They'll start working off. You don't have much room. But if I recall correctly you can atleast get at the bottom holes.

-The rubber bushings will have a split on their flat area. Spread them here, don't spread more than you have to. They are rubber but have either a metal or plastic core.

-Reinstall at your new ride height. Note that the OE bar has a preload, even at OE ride height. I don't recall which way the bar is preloaded, up or down. It's possible that OE preload may make the bar neutral at your new ride height! You can choose to duplicate this OE preload at your new ride height, but you can only observe the OE amount with an unmodified ride height, obviously. I believe GM adds some preload to add responsivness to the bar.

-When I repositioned the OE mounts on my Gen 5 SS 1LE (same style), I used some hand soap as a lubricant on the bushing to bar surface. This allowed me to easily position the bushing and adjust if nessecary. The Devil's Lube (spit) can also work. Both will eventually dry and allow the bushing to grip as intended. Let both dry before driving.

-Reinstall the bracket. The fasteners are 43 lbs/ft.

There's alot going on with the OE rear bar. Not only do they have an overall preload but a slight twist too, which then adds more (or less depending on perspective). The super grippy mounts add a slight amount of overall rate.

The front bar just has a little preload, a slight twist in the bar. But the front bushing is actually glued to the bar! I half-heartedly attempted to remove the bushings from my front bar once but felt it wasn't worth the squeeze just to understand it further.

When we install aftermarket bars with their lubed poly bushings, there is no grip on the bar.




EDIT: I see your sig says LT1. My observations have been with the SS 1LE, ZL1, ZLE. I believe your LT1 does have the grippy mounts but the OE preloads, if any, may be different.

You seem to have a good amount of knowledge on this subject, can you comment at all on the v6 1LE? According to Chevy we have the following the FE3 suspension components, dampers, rear cradle mounts, ball jointed rear toe links, and stabilizer bars.

[cdb95z28]

Originally Posted by sonikk71

You seem to have a good amount of knowledge on this subject, can you comment at all on the v6 1LE? According to Chevy we have the following the FE3 suspension components, dampers, rear cradle mounts, ball jointed rear toe links, and stabilizer bars.

Sorry, I'm not well informed on the V6 1LE package.

[sonikk71]

Originally Posted by cdb95z28

Sorry, I'm not well informed on the V6 1LE package.

No worries thanks for the reply. Finding V6 1LE info is rather difficult. I guess I just need to move up to the V8.

[pbSS]

Originally Posted by BOSSman760

I installed the ebach pro springs on my 2017 ss 1LE and I hate it, its so bouncy and embarrasing and looks ridicules the way it bounces. These must be some cheap low quality springs, now i need to look for better springs or put back my OEM ones.

Sounds like an install issue or wrong part number, lol. The 1LE Eibach Springs, although progressive, have overall the same feel as OEM and almost identical max spring rates. They're very predictable.

[gmansyz]

Mix some key lock graphite in the silicon grease. Stops squeakies.