Michael Dene

Timeline......
2007 coupe M6 Base 1LT
*New front Z51 bar and Moog links about ten days ago. REMARKABLE improvement, still absorbs bumps but was way flatter in most corners I attempted at a faster than normal rate, (I’m old). Huge improvement.
*Five days ago new Bilstein B6 on the rear. Stock shocks with 75,00O miles squished easily but didn’t spring back worth a damn.
New B6 squished by hand pretty easy also, but came back to full length quicker. Zero difference in ride quality over bumps IMHO, zero.
*Yesterday new rear Z51 and Moog links. Rained so put to bed.
This afternoon test drive. Noticibly stiffer, remember just the front netted still a cushy, stock ride. This is now unbelievable. So stiff thinking going back to stock bar.
New front B6 will be here Wednesday.
Now those are my findings, but the big question, is it my imagination but is the ****-end about 3/4”-1” higher?
Car seems to have a bigger rake to her?
Thanks

rkj427

if you had the car lifted with the rear wheels off the ground to install your rear bar, the ride height will appear higher, as it takes some time on the road to get the suspension to settle back into place more than a typical quick road test

Michael Dene

Valid point indeed thanks for that.
I did roar around for about 40 mins in it this afternoon over some pretty crap roads. I should measure fender to wheel clearance now and see.
The Bilsteins wouldn’t raise it a bit would they?

rkj427

Potentially, if there are differences in the length of the shocks between the ones you removed, and replaced them with.

Also, if the old ones were weak, they may have allowed the suspension to settle into a lower position over time.

Just my thoughts. Either way, after accumulating a couple hundred miles AFTER all your work is completed, you could adjust the ride height to OEM specs.

wayback

The old shocks can cause the suspension to settle lower over time. New shocks will increase ride height but it won't stay that high very long.

I'm not sure how to take that new sway bar and bushings made the ride harsher. Swaybars can't do that, only control body movement during cornering.
Maybe your feeling bumps transmitted from one wheel to the other side?

I felt a more centered weighted steering when I had Z06 bars. Have since changed the rear to Z51 sways and steering is less center weighted. Z06 and Z51 front bars are the same only rear bars are different.

Hitman227

Should not - they are just shocks, not struts, which has some load bearing action like a spring.

With shocks, your springs will control the ride height.

Michael Dene

I know the spring is still the same, but I agree, it would set the height.
Next Wednesday the front shocks will arrive and I will measure the before and after on the front fender height.
I went for a good 300 mile drive today and it was great. Bad roads and the jarring was really bad on me and my lady. I’m thinking I should’ve just stuck with the front Z51 bar.
We stopped for a bathroom break in the country, and while I was in the ditch, I looked at it from a low angle and man, the back end is sky high. I’m sure I didn’t install airbags for towing haha.

Iceaxe

Out of curiosity what center bushings did you use on the swaybars? If the swaybars are binding it will cause issues. The swaybars need the ability to rotate in the center bushings. The other reason I ask about center bushings is properly installed Z-51 swaybars should not cause a harsh ride.

Did you start with the new endlinks adjusted to the same length as stock? Also you could unbolt the swaybar endlinks or center mounts and put the car on the ground and see what happens. That should take about 15 minutes and greatly narrow your search for what is causing the issue.

Michael Dene

I used new, stock GM bushings lubed with die electric grease, new Moog greasable links that have no adjustments, stock length. The bar bolted up with ease, ( same as the front, and the car rode the same as stock with just the front bar on for a few days, still cushie).
Thanks!!

Michael Dene

I’m just thinking out loud this morning.
So there is over 400 miles on the suspension mods, and even though installing the rear sway made it unbelievably ridged, I’d like to ask you the question....
When your car is on level ground, is the bottom rocker parallel to the street?
Mines up quite a bit in the rear.
Thanks