[Mark R]

There have been a couple recent threads on BMR suspension upgrades, so I wanted to share my impressions of the particular upgrades done on my car, a 2018 A10 Coupe.

I had the BMR cradle lock-out kit installed, as well as three suspension arms replaced on each rear wheel. BMR recommended this combination as best for my purposes, which is street use, and not so hardcore that the components would ruin the ride or increase noise, vibration, or harshness. Additionally, I also had the BMR mid-chassis brace installed, just because I wanted it.

My main handling complaint was the rear end wag when quickly changing directions, and the slight squishiness back there. These components really improved the total feel of the car. I am very happy with the increased tightness in the feel and handling of the car. It does ride a bit more harshly, but there is no big increase in NVH.

Overall, I am very pleased with the outcome of these modifications, and can recommend this combination for anyone looking to significantly improve the handling of their car, without diminishing its overall ride and comfort.

Mark R.
Albuquerque, NM

[TRZ06]

Nice. Good to hear.

I am going down a little different path, but trying to achieve the same thing as you.

I am having the ZL1 1LE solid cradle bushing kit installed on my SS 1LE on Wednesday.

I was originally going to do the rear lock-out kit, but I figured if I am going to do it, lets do it all the way and go for the full solid bushing kit from GM Performance. I am going to see what that gives me, and then move to the BMR arms if needed.

From what I understand, the biggest culprit of the rear-end side to side sway and the squishiness back there is the rear cradle bushings. Which is why I decided instead of only getting rid of 80% - 90% of the movement , I wanted 100% of it gone, hence the solid bushing kit.

Also, when I test drove the ZL1 1LE, the rear-end was solid, and with the exception of the front toe links , I believe the ZL1 1LE shares the same arms and bushings as the ZL1 and SS 1LE, so it makes sense that the main issue is the cradle bushings.

[Mark R]

I can see the desire to rid the rear of 100% of that flex. I can't do the work myself, but I would like to try both setups to see which I like better. For now, the spending has to stop.

Mark R.
Albuquerque, NM

[JDP Sales]

Good stuff! Thanks for sharing. I went with the rod end stuff and I don't think the ride quality difference was too crazy either. We jumped from stock to full blown race mode though so its hard to tell just how much each modification affected it.

This is good to read. Thanks again!

Jared

[Torquem]

How much unsprung weight does this add?

[TRZ06]

Originally Posted by Torquem

How much unsprung weight does this add?

I'm sure it adds a little, but the benefit of the tighter, more controlled rear-end would be worth any weight penalty.

That is the only real issue with the ZL1 and SS 1LE from a performance standpoint.

Coming directly out of an M3 (which had the rear-end hard mounted to the frame) into my SS 1LE, it is a HUGE difference in rear-end stability and rear-end confidence when doing any aggressive left to right maneuvers or any high speed driving.

I guess GM needed to differentiate the ZL1 1LE from the rest, but in my opinion both ZL1 and the SS 1LE should have had hard mounted rear-ends from the factory. It is a noticable difference when really pushing the car.

[TRZ06]

Originally Posted by Torquem

How much unsprung weight does this add?

I just realized though that you are probably talking about the arms, which is where 99% of the weight added would be.

I will report after I get the ZL1 1LE solid bushings put in on Wednesday. If that takes care of the issues in the rear, then there would be zero weight penalty, just the pain of the labor involved with having the bushings removed and installed.

[Pollock]

My rearend does not move at all with the factory solid bushings when compared to my old 1SS 1LE

[TRZ06]

Originally Posted by Pollock

My rearend does not move at all with the factory solid bushings when compared to my old 1SS 1LE

VERY good to hear this, as my solid bushing install is tomorrow, FINALLY.

I SO can't wait to have that solid feel in the rear again.

[Mark R]

"I SO can't wait to have that solid feel in the rear again." Yikes! Maybe re-word that a bit!

[wlsmoku]

[TRZ06]

Originally Posted by Mark R

"I SO can't wait to have that solid feel in the rear again." Yikes! Maybe re-word that a bit!

LOL, yeah, I guess I should have proof read that before posting.

Ah well.

[TRZ06]

Ok, solid rear cradle bushings are in.

The bad news, it is a PAIN IN THE ASS, it took my performance shop 10 hours.

The good news... IT WAS WORTH IT. The rear-end feels so much better. It now has that planted feel. It even makes the MRC shocks feel better, without any rear-end play back there, you can see that the shocks are better then they appear to be when you have the rubber bushing body motions getting in the way.

I don't even have a good alignment yet, as there was no time to get it done last night, so it will feel even better when I get a track alignment done and all the parameters where they should be.

I see no need to do the BMR arms.

[Mark R]

Sounds like you got right to the root of the problem.