mark kibort

Glen,

Just found the pictures, and it is more like 2-3:1. dont think its 2:1, as you can see, when jacking the car up and having the tire at full droop, it moves about 3" from where the tire normally sits near the fender at rest. it does this with about 1" of movement. I have a shot somewhere taking under the car at rest, where the shock body is just touching the bumpstop. the bumpstop is part of my suspension and the total travel upward is around 1.5 to 2" max. (over 5 " of wheel travel as shown by my Laguna corkscrew compression. )

mk

https://rennlist.com/forums/928-foru...servation.html

GlenL

Jacking introduces other motions. Like flex in the rubber bits.

2-3:1? Sounds like you're agreeing with me.

Look at the shock mount on the lower arm. It's roughly half-way down it. How could it not be about 2:1?

Bill Ball

The Bilstein part numbering is a bit obscure. They have an explanation on their website, but it doesn't match up. The final portion, H00X, is variable. I've seen H001, H002, H004 and H008, H1, H2. There's no explanation for that.

Anyway, your fronts match up with the standard Bilstein PN. I recently bought a used pair of fronts that are marked 4200966H004 instead of F4 B46 966 H004. They sure look the same but are OLD, probably before they redid their PN system. And I got a pair of rears that have a 928 PN (92833305112) which doesn't quite match up with the PET PN in the final 2 digits. They also are stamped 4310974W008, strangley similar to your 4190974W008. These must be obsolete Bilstein PNs. I haven't called tech at Bilstein to try to decipher this.

Anyway, with your extra inch or so in the rear, I wonder about your springs. The WSM is very confusing, but notes in one spot that the higher tolerance group (3 paint stripes) will raise ride height by 10-15mm. Also, the notes mention that the adjustment collars for Bilstein verus Boge are different, both front and rear. They also mention the lower perches are different, at least for the front. Here is a pic of my fronts assembled and it is clear those are fresh perches and nuts that came with the shocks.

Landseer

Thanks for that information, Bill.

Both front and back of this vehicle have 3-stripe springs.
Front left shock adjuster is immobile despite best efforts.

I just put the front left wheel back. Need to settle it out and establish the front baseline, checking it against Jim's last records. Should have done that to begin with, but I think its pretty high.

Rear adjusters show only a thread or two beneath them. Ride height is 210 (was at least 225 to start, I think). Tires are +30mm diam, so that accounts for about 15mm. So equivalent ride height is approximately 195 from that perspective.

Both front and rear adjusters are cast material. I have the rear suspension out of a boge-equipped car to compare. Cursory look suggests the subject car has Boge adjusters, front and back, but that's not confirmed.

Stuff gets switched around over the years and that might have happened along the way.

Interesting day with 928's, as usual.

soontobered84

I didn't see if earlier in the thread you used all parts from your previous strut assemblies. Springs from an older car with non adjustable spring perches have an extra coil. If you used other springs, do you think these springs may be from an older non-adjustable car? Just a thought.

Landseer

That's a good question.

I guess I'm fixin to take some baseline measurements and try to identify what exactly we have.

Sure helps to have everybody's input.

Can you imagine not having a place to discuss this stuff with other serious enthusiasts?

Jadz928

I just don't get the talk of different springs or different perches.

This exact same setup, with a bilstein-to-bilstein swap in between used to be set a a low ride height, both front and back. We're talking like 140-145 front, 165 rear.

The only variable I see is my mechanic. Is it possible to mix up parts front to back and yeild different results?

I'm going to stop by my mechs on the way home and ask what he may know.

soontobered84

You should be able to just count the number of coils and compare that number to your other cars.

Landseer

Thanks, Jim.

I probably should have done my normal deep reading on the subject before even posting.

Could just be me, keep that in mind!


Will-do, regarding counting coils.
Unfortunately I've been totally ignorant of ride height and shocks until now. Everything I've got is running Boge, most of which is worn-out.

soontobered84

Jim,
He posted that he didn't know where the springs came from. If he accidently used springs from a non-adjustable model year car there would be that extra coil mashed down into the smaller space that is now the adjustable type springs. That would give the effect of raising the car and keeping it raised because the spring would be under additional tension

Landseer

Well, everything is as-received from Jim. (As-is deal, BTW, no obligations to investigate this ride height whatsoever!!!)

Jim's mechanic swapped Bilsteins for a new set a few thousand miles ago and said the ride height was as low as it would go.

Its possible that swap got complicated somehow. Or that I'm doing something wrong. Or both.

Bill's information is also interesting regarding heavier-duty springs, as is John's regarding the subtlty of very early cars and coil count. Plus the Bilstein company footnotes. Nothing's ever too easy on 928's

soontobered84

okay, I think I got it now. These springs and shocks came as a package deal from Jim and they were put directly on your car from his. Sorry. I didn't understand that part. I was thinking that you had changed springs independently of the Bilsteins. Seems like if they worked on his car, they would work on yours.
Jim, sorry if I was explaining something of which you would have already been aware. Just trying to help.

mark kibort

Yep, I am agreeing, but it does seem like more, when you look at that picture of the rim below the fender at laguna. I guess all that rubber is compressed as it rides on the bumpstops. lots of force, for sure.

anway, carry on!

mk

Jadz928

No worries, John.

Actually.... I sold the coilovers to Chris, and told him he could have the car to which they were attached. It was more of a 3200 pound package deal.

I hope I'm not being testy... I'm just trying to think from the POV of what are the true variables and what variables can be eliminated.

Landseer

Well the coil count, front and back, matches the USA car next to it. It even has the same 3 blue stripes on the rear left spring. Unfortunately, no ride height baseline is available on that one.

On subject car, now on the ground, after bouncing on the back a bit,
Rear measures 195 or so. I don't see it settling much more. The stance looks good in visually assessing the back fenders.
Front is also 195, but it hasn't settled from being lifted.