Horrible ride quality and can't figure out why

Ralphatron

So I'm out of ideas on why my ride quality is pure garbage and hoping you guys can help me out...

Here is my setup:

- BR series BC Coilovers (NON true rear) - Dampers set to FULL SOFT
- Swift coilover springs in the fronts at 10k (same rate as the default springs on the coilover kit)
- Hotchkis Front Sway bar
- NO rear sway (have hotchkis installed but currently not connected to one endlink)
- Z1 rear camber arms
- 20mm Z1 hub centric spacers in the rear
- Only lowered enough to eliminate the wheel gaps, but not tucking at all and only had visible negative camber in the rear before my alignment.

I can't imagine the ride quality im experiencing is normal. I've got the dampers set to full soft and im not running stiffer springs than what the kit comes with (10k Front/8k rear on the divorced spring). Spring preload is separate from ride height on this kit, and was installed properly.

Before my alignment I was getting bad darting/tramlining from the rear toe being off pretty bad. As you can see, the camber is still not in spec, but only out of spec by .3 degrees in the rear and .8 degrees in the front. Even with the adjustable camber arms installed, toe can't be dialed in if camber is, and vice versa, so I obviously opted for toe to be in spec for now.

The car doesn't dart around *as much* anymore but I still feel a ton of instability when going over certain bumps at certain speeds. Nothing crazy, just regular street driving.

I know coilovers are naturally stiffer than stock struts, but I'm still feeling a lot of energy transfer into the body of the car and its borderline unbearable.

Before the coilovers, I had swift lowering springs with stock struts and it pretty much felt identical to stock ride quality if not better. I'm about to pull the trigger and just revert back to that setup but I'm still unsure if the there's a different culprit here. Could the amount of negative camber be the entire reason for the instability over most uneven surfaces? If it is, do I just need to get adjustable traction arms to let them get BOTH the rear camber and toe in spec?

The car feels fine when going over forgiving larger bumps, but its the smaller jagged divots and pot hole type imperfections that it absolutely hates.

Here are the final Alignment Specs:

Attached Images

alignment.jpg (72.4 KB, 120 views)

cv129

...is BC supposed to ride like stock...?

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Spooler

First of all, you alignment is jacked up. Camber is no where close and the toe is horrible. Toe should be set to dead middle of spec for front and rear. The next question is what spring rates did you get?

Ralphatron

... um no....

what I'm trying to figure out is if coilovers are supposed to ride like ****

I was not happy about the toe either, but the "tech" told me I'm fine as long as its in range and the 7/100ths of a degree wouldn't be noticeable.

Camber on the other hand is obviously out of range, but its not even visible, and I've driven cars with worse negative camber before that did not feel as bad as this. I understand every car is different though so if I can be convinced that getting everything green will solve my problems I'm willing to chase that result. The question is what parts will I need to allow it? My spring buckets are still housing the springs so I don't think I can get actual toe arms, which leaves me with the traction arms but I've heard that they shouldn't be used to adjust the toe. I also don't think aftermarket eccentric toe bolts will do the trick either but that's just a guess.

Spooler

You need SPC toe bolts to get the rear Toe in spec with the proper camber. Excessive camber will cause the Tramline to be worse. You need front camber arms or FUCA. Get SPL, they are easy to adjust. Set the camber to -1.4 front and -1.5 rear. As I said before, set the toe to dead middle of spec. The next thing to do is to properly setup the dampers. You want the dampers to control the compression and rebound. Full soft does nothing. You have to dial the dampers in to absorb those impacts. Set it in the middle and adjust until the car is more stable on a bumpy road. If it is still bouncing around, add one more click positive to make the dampers work more. It takes time to dial in the dampers. I tuned mine in on I-16 which is bumpy as hell. The ride is just about perfect now.

Spooler

Where are you in Florida. If you can drive up to the Savannah, Ga. area I can set them up for you in about 30min. once you get the alignment set properly.

Spooler

PM and ask Elmo370z how my car rides. It is easy to set them up when you get the hang of it.

Ralphatron

This is super encouraging and it definitely gives me hope. What I still don't get though is if all these extra parts are needed to get coilovers to sit and feel right, how the hell is everyone else thats just running them alone getting away with it? The only explanation would be I'm too low which is causing all the negative camber, but I'm almost maxed to the highest setting in the rear and the fronts are probably just a tad lower than lowering springs which is like 1.5 - 2 inch drop.

Definitely going to look into some upper control arms and the toe bolts in the mean time, thank you for the direction!

South east coast but I'm almost willing to take a trip just to see what a tuned suspension is actually supposed to feel like on this car lol.

I actually had no idea the damper settings were actually meant to fine tune the ride quality. I always assumed stiffer = track, softer = street.

Ralphatron

oh, a thought I just had was worn out or damaged control arm bushings in the rear where the spring bucket and shock connects to the rotor. I must have removed and reinstalled the entire suspension about 8 times already and the the bushings that the bolts go through may have potentially gotten worn or damaged. Just guessing though, I don't have any other reason to think they're messed up. Would the symptoms of that potentially cause what I'm feeling?

These specifically...

Attached Images

rear-suspension.png (45.3 KB, 103 views)

Ralphatron

crap on a stick, the spc bolts require cutting the hole bigger. I have no idea who to trust to do that right around here

Spooler

Where do you live on the east coast. Maybe someone could recommend a shop. You really need to have the car corner balanced to get the most out of your new suspension.

Rusty

You can do it with a Dremel tool. I believe you get a template with the toe bolts.

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Spooler

The damper are to absorb unwanted energy. What you will feel in the car is a bounce when you hit a rough spot. You want to tune that bounce out by stiffening up the damper setting so it can absorb that energy. It will dissipate it as heat. So in the summer time, you may have to run one more click on the dampers because the fluid is warmer. Your ride may be a little stiffer but the end result is a more compliant car that sucks up those bumps with no bouncy feeling. That intern keeps the wheels on the ground providing more traction.

redondoaveb

^^^^^ this

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Ralphatron

I'm in greater fort lauderdale area. I wouldn't mind going as north as west palm beach, or as south as miami.

yeah, I'm just worried about messing up since its the actual subframe I'm cutting away from. Unless a lockout kit would be able to fix a hole that 's too big or not exactly the correct shape?

But wait a second, are you guys telling me that every single Z that's on coilovers at the very least needs to get FUCAs, rear camber arms and spc toe bolts if they want to get their alignment in spec and/or get their ride quality right? And based on it being due to the lower ride, wouldn't this apply to lowering springs too ? would I be able to avoid all this if I just raised the car about half an inch ?