Bill Ball

They are OK. The drop links front and rear are intact. Wish it were that easy. However, I will add that when the car wallows under heavy side loading, it leans and feels like the swaybars are gone.

Bill Ball

Mark:

Yeah, it's a mystery. I need someone else to test drive this car. It's so screwed up, I'd be afraid to be in the car in one of the 140 MPH sweepers I went through this weekend. It was hairaising until I just dropped the speed.

I gather no one seems to think too much about the bushings. Mine LOOK good. I don't know how to test the rear ones. The fronts should respond to the wheel grab top and bottom push/pull, but I'm postulating that that turning forces in a 120-140 MPH sweepers are far higher than any hand grab test.

Your car may be old, but it has almost no miles on it. I've got 170K. Has anybody seen decent looking bushings still be a functional failure due to softness?

The alignment should be fine. I was there and watched the whole thing. I checked the torque on the eccentrics too. The car runs down the road straight OK but WALLOWS and WEAVES under heavy side loads. What part of the alignment would affect that?

anonymousagain

Just throwing out a timeline - you try the 1st Koni's and they're under dampened; you install a larger sway to compensate, but it is irregular or out of true, such that it stiffens slower conering, but "would" show inconsistent L/R balance at speed; springs are doing extra duty now and begining to fatigue; time takes it's toll on the 1st Koni's as defective/blown/unmatched, as they just don't work and feel awful at Bonniville; replace with 2nd Koni's that work reasonably as expected, but by now the springs have fatigued beyond acceptance, although initial impression only displaying a softer feel at lower speeds; Pony Express and all things combined, Koni's that are working to hold together springs that can't provide proper rate and a sway that is uneven L/R.

Accounts for all variables, but suggests spring replacement and return to stock sway to create a baseline. Sounds kinda wacked, but regression to the basics of where you were might be the most straight forward approach.

Just a thought....

Bill Ball

I will check the swaybar for R/L balance.

ErnestSw

When all is said and done it's your springs that determine the height of the car. Also, make sure the conical washers are installed correctly in the A arms.

Charley B

Bill - At a 155mm ride height the belly pan might make a difference over 150MPH. Any change there?
You mention the tires are fresh, could you have gotten a bad set?
Some say the Koni's can't handle springs above 600/400, I don't remember which rate your running. Maybe on that first shock change, when you weren't there, they accidently swapped springs fore and aft and that's why it started bottoming after that. I'm just noodling here but I really will be shocked (no pun intended) if the Koni's are the problem.

GlenL

Ok, "bad swaybar" one more time. Sure sounds like it.

Was the stiffness of the Koni's checked for eveness before installation?

How about low or uneven tire pressures? Steering rack bushings sloppy?

Alignment guys are usually really good at spotting bad suspension parts. I'd still jack it up, pull a wheel and use a crowbar to move things.

FWIW: I'm running the Koni's and while the street ride is harsh the track use is good. Set 2/3rds hard. Very smooth and predictable in hard corners and sweepers. My guess is something (or things) are loose or broken.

dr bob

Bill--

Springs are constant rate until they bind. As they age you can predict the rate from the installed height, and assume that the car hasn't gained much weight. So if the spring is 10% shorter to hold the car at the same height, you've lost 10% of your spring rate. Homw much adjuster is used up compared to when you bought the the car? How lond is the spring installed height with the car on the ground? It's short division so even I can usually do the calc in my head.

As springs get tired and the rate decreases, there's more opportunity for punishmnet of the shocks. The shocks really don't care how much the springs are carrying or howe heavy the car is, so long as they aren't bottomed out. If they are bottomed out hard, there's a good chance they are damaged internally. If/when you change to the Bilstiens, maybe a set of springs are in order.

The lower spring rates from worn springs, with a lowered car, makes you a potential poster child for bump steer issues.

On the control arm bushings: There's no way you can manually put enough force on those bushings to move them, certainly not enough movement to notice with the eye as you grunt on the end of the suspension arms. Maybe if the old bushing was 80% missing... Changing the bushings is a chore but not impossible. It's the aggravation of all the other stuff there that makes it fun. If you are going to swap springs and shocks, you might be tempeted to screw the scientific method and do the bushings at the same time.

With the four-post lift you have, you are all ready to test the bushings under lateral load. Dial indicator on the arm, base on the inner fender well. Strap the tire to the lift tray and use a come-along or similar to pull the car sideways, simulating the side loading you experienced at speed. Dial indicator shows bushing deflection. Make yourself some room by jacking the car up and extending the suspension some before pulling. You may also try using an old bare rim (no tire) on the testing side front and have plenty of room. Carpet pad under the bare rim might help.



Just a thought...

greg928GTS

Bill, from looking at your avatar picture, the front end of your car certainly does look higher than it should be.

I had my mechanic check the front A-arm bushings and I watched him while he took a bar and moved the front suspension in such a way that there was movement. It's on my long list.

AO

Just a random thought (ignore if it's not even worth considering), but could the shop that originally put the Koni's in have mixed up the springs by putting front on rear and rear on front? Not even sure if there is a difference, but tought I'd throw it out there.

Vlocity

Bill:

Another shot in the dark...but are you sure they put the rubber snubber back in on top off the shocks?

Ken

Bill Ball

Yes, the conical washers is a good reminder. Fortunately I was careful with that.

Bill Ball

Good shot, even if a miss in this case. The snubbers were there on the first bad set of Konis and on the new ones.

Vlocity

Follow up question......if you have adjustable shocks where are they set. It also sounds like "tramling" from having improper toe or a steering rack that is moving. MK suggested a dry marker test on your driveway...but I use a Sears Laser lined up with the rear wheels and then can break the beam to get measurements at the rear and front of the front wheel. Not perfect, but accurate enough to confirm toe in or out. I actually built a trammel bar to get accurate measurements.

Are you running any steroid bars on the rear?

Lastly what about rear toe. Squating under load will move you quickly to a toe out situation which will also cause the problem you describe. Perhaps you need to add a little rear toe in to the setup.

Ken

Bill Ball

It occurred to me that is possible, although I believe they were only working on my set at the time. The rears appear to be sport springs (2 blue marks). The fronts no longer show an paint marks, so I can't verify. The change in behavior was dramatic, at least in terms of front bottoming.