Coilovers install question

[16g-95gsx]

I'm changing everything, control arms, ball joints, sway bar bushings, sway bar endlinks, tie rod inner and outer along with boots, and then also the coilovers. Hopefully it just refreshes everything to OEM+ and eliminates failure modes of the factory system

[E34Play]

Originally Posted by Joshdub

Mine is completely stable. It's likely from worn bushings, a poor alignment, an issue with the tire, or any combination.

Thanks, that’s what I’m thinking and my money is on the alignment. It only shows these symptoms when the ride height changes so drastically (bags deflated previously, and coilovers installed now). Tires would have shown symptoms regardless, and I’d like to think the bushings would have as well.

[E34Play]

Late update for anyone who may search the issue. The ball joints in my rear upper control arms (all 4 arms) were bad causing excessive play, and a very bad alignment to top it off. The back end was dangerously unstable, a bump in the road and I could jump over a foot. New arms and an alignment and all is good!

[16g-95gsx]

Knock on wood I should be done with everything tonight after a replacement front driver's axle arrives. I removed the rear airbags and plugged the rubber cap with a nut/bolt with a washer under either side. The washers squeeze onto the rubber in the cap and seal off the hole. I have the coilovers on full soft for the time being and will adjust ride height to be comparable to where it was OEM (I measured 31.5" ground to wheel arch height on average all around). I may lower it a tad, but likely not much more than an inch or so if I do as it's an SUV and slamming it would ruin the utility. I'll report back my opinion on the ride quality, but I doubt that I'll get true feedback until it's aligned as every suspension component was replaced so it's guaranteed to be totally out of spec.

[16g-95gsx]

And she's back together. I gotta say the ride quality is surprisingly good, not in any way harsh almost stock on the softest setting. Can't wait to get it aligned and play with it a bit

[16g-95gsx]

After driving it with a proper alignment I am fairly impressed how much tighter the truck is with no adverse harshness on the softest damper setting. On the firmest (32 way adjustable) it is noticeably firmer but I still would say it's about as harsh as most oem truck suspensions. Very impressed and glad that I made the switch, having been skeptical at first I would highly recommend the swap to others.

[PropellerHead]

Originally Posted by 16g-95gsx

After driving it with a proper alignment I am fairly impressed how much tighter the truck is with no adverse harshness on the softest damper setting. On the firmest (32 way adjustable) it is noticeably firmer but I still would say it's about as harsh as most oem truck suspensions. Very impressed and glad that I made the switch, having been skeptical at first I would highly recommend the swap to others.

The best thing ab coilovers is being able to set the weight balance to perfect 50/50- 'corner weighting'. I did this on my E39 540. Basically, we used scales under all four tires and set it so each read exactly 25% of the vehicle's weight. Put a couple hundred pounds of sand in that front driver's seat when doing this for absolutely perfect results.

On the E39, this made the big sedan move around like an E46. Yes, they're *supposed* to be 50/50 from the factory, but we all know those big ole 315's are heavier than the fronts. And there is no way they accounted for a driver. On my E39 in particular, they didn't plan on a huge aluminum radiator (with twice the fluid weight) and a big ole supercharger up front. On my E53, I could balance out the heavy under ride protection up front. But I wont. I like and I have used the ability to raise and lower the suspension enough that I will keep it.

For the 'stance' crowd, this will upset the perfectly even height at all four corners. For the 'coil overs is for slammed' crowd.. well.. you can have a lower ride height that is also balanced. But the key for coils is balance- not looks. The performance reward is totally worth the little bit of 'off-balance' look.

[oldskewel]

Originally Posted by PropellerHead

The best thing ab coilovers is being able to set the weight balance to perfect 50/50- 'corner weighting'. I did this on my E39 540. Basically, we used scales under all four tires and set it so each read exactly 25% of the vehicle's weight. Put a couple hundred pounds of sand in that front driver's seat when doing this for absolutely perfect results.

On the E39, this made the big sedan move around like an E46. Yes, they're *supposed* to be 50/50 from the factory, but we all know those big ole 315's are heavier than the fronts. And there is no way they accounted for a driver. On my E39 in particular, they didn't plan on a huge aluminum radiator (with twice the fluid weight) and a big ole supercharger up front. On my E53, I could balance out the heavy under ride protection up front. But I wont. I like and I have used the ability to raise and lower the suspension enough that I will keep it.

For the 'stance' crowd, this will upset the perfectly even height at all four corners. For the 'coil overs is for slammed' crowd.. well.. you can have a lower ride height that is also balanced. But the key for coils is balance- not looks. The performance reward is totally worth the little bit of 'off-balance' look.

The capability for easy corner balancing is great, but even the premium version is subject to the laws of physics.

You will not be able to change the front/rear balance or the left/right balance. Those are determined by the location of the center of mass (OK, slightly adjustable if you purposely tilt the car forward, for example).

You will be able to make them balanced though, within the constraints of not changing front/rear and left/right.

So
..........15..........35
<<==
..........35..........15
with F/R = 50/50 and L/R = 50/50

can be balanced to
..........25..........25
<<==
..........25..........25
There is no change in F/R and L/R, since that would require a special waiver from the laws of physics and those are not being given out right now ;-).
When you dialed in 25/25/25/25, this is what was being adjusted, giving a great improvement in handling. If you got to 25/25/25/25, you must have started with 50/50 F/R and 50/50 L/R, since that's what you ended with and the mass properties did not change.

But I could adjust my 911's torsion bars all day long and not change the 41/59 F/R weight distribution, even if I wanted to.

[PropellerHead]

Originally Posted by oldskewel

There is no change in F/R and L/R, since that would require a special waiver from the laws of physics and those are not being given out right now ;-).

Thanks for alll that!