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Date:         Sat, 10 Jul 1999 01:02:55 -0600
Reply-To:     Carl Hansen <carl_hansen@IEEE.ORG>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Carl Hansen <carl_hansen@IEEE.ORG>
Subject:      Measurements checked, springs, and toys, ahhhh, toys
Comments: To: sxs@concentric.net, drillock@earthlink.net
Comments: cc: "Buettner, Peter" <PGB@dolby.com>,
          Michael Sullivan <sullivan@openmarket.com>,
          "Syncro Shocks - Ratjen, Bjorn, Ph.D." <bratjen@direct.ca>
In-Reply-To:  <37868161.79D226D4@concentric.net>
Content-Type: text/plain; charset="us-ascii"

Steve,

Just double-checked my original measurement, and YOU are correct. Stock spring perch mount location is 2nd from TOP. This gives you 2 lower, and 1 higher spring mounting location.

I also checked the overall length. The full-extended length to the step on the shaft is now at 18 5/8 inches. Stock shocks measurement on mine was 19 inches. This means that the extended length is less by 3/8 inch. This measurement probably does not affect us, and if you want to lengthen the fully extended measurement by a bit, just add a small sleeve.

I would be VERY VERY cautious about cutting another groove in the shock. I'm sure the original was cut in W/O any gas charge in it. It now has a charge, and any error in the depth cut will result in catastrophic results.

The problem will be one of accurately chucking up the shock body. This is a solvable problem, and if it was me doing it to raise the spring mount, I'm confident that I could do it. Just pointing out the possibilities.

I still remember the results when cutting open a pressure sensor at Edcliff in Los Angeles several years ago. The device normally has a vacuum reference inside. As we cut this one open, it suddenly exploded quite violently, parts hitting me in the arm. There had been a leak in a weld, and instead of 14 psi vacuum, the device had been charged with something approaching 1000 psi. It got charged by the pressure applied when the MK50 Torpedo swum to depth (classified) during a range test in the Keyport WA area. No permanent damage to all concerned, BUT I did have a nasty bruise for a few weeks.

Now on to springs and ride height. You realize that there is a limited range over which you can actually lift the Syncro given the design of the assembly, don't you.

The shock/spring assembly is essentially a strut. (Yeah I know, not as in front wheel drive) That strut will only expand to a MAXIMUM length. You can get to that max. in several ways.

1. Stiffen the spring so the van load does not compress the spring as much.

2. Lengthen the spring so that you have to pre load the spring more and more just to assemble the strut. Eventually, there is no vehicle loading of the spring when you install the assembly. This I think would be a very stiff riding vehicle indeed.

The grooves in the shock are equivalent to lengthening the spring. All other things being equal, you could lengthen the spring, at the same rate, or hike up the mount point by the same amount and achieve the same result.

At some point, you reach a point of diminishing returns. Anything that you do in terms of modifying the springs, longer or stiffer, will have the detrimental effect of reducing the upward movement of the assembly, that will make for a rougher ride, and maybe cause the wheel to leave the ground sooner at the extreme? (Not a good thing for steering control and braking.)

It seems to me that the spring thread has focused on raising up the vehicle some. It also seems that no one is talking about large lifts. I expect that must be because you all realize the limitations and drawbacks to pushing up the vehicle with the springs.

At some point, you no longer have any jounce (not sure of he word) left. What I mean is that as you raise UP the van, you are lessening the rebound extend of the system, and at the extreme one can visualize a van that sits on a spring, can compress the spring, but coming back to stock position, has no movement going UP beyond that. The wheel assembly is thus pulled up if the vehicle has any upward movement of the body past normal ride height. This I think is not a desirable thing.

SOOO, not knowing how much the van loads the spring/shock assembly, and not knowing how much UNLOAD movement is needed for the system to work properly, are you compromising the system by trying to raise the ride height by changing the springs????????

Did that make any sense?

It seems to me that the way you really want to raise the Syncro up is to:

o Get your spring/shock stiffness and control right where you want it.

o Change the ride height by modifying the top (or bottom) shock mounting point.

****** ahh toys, aren't they wonderful! I know what I'm doing tomorrow. Going to finish painting the front suspension parts so the front end can go together. If I'm lucky, I can get the front end aligned next week. Dang, sure will be nice to get SyncroBeast running again.

I still have to pull the brake boost assembly, and replace that as well. No fun having to fill the brake fluid reservoir every two weeks!

Ya all have fun now. Later.

on - on.

Ch

Carl Hansen 1.612.440.2899 carl_hansen@ieee.org

Ch

'89 SyncroBeast Vanagon - Soon to come - New Shocks for the Syncro! '87 16V GTI '80 850 Yamaha Special '87 16V GTI w/ hale damage - parting out - body gone, parts remain '89 16V GTI w/ toasted motor '86 Scirocco (8 valve w/ auto) - SO's - now w/ it's own hale damage

Prior Lake, MinneSnowta - Summers here and with it, Mosquitoes!

******************** At 5:10 PM -0600 7/9/99, sxs@concentric.net wrote: >Carl, The stock position is second from top...they >screwed up....we have 2 adjustments below stock and one >above...but I am sure the one above is enough for all >who ordered...plus could get another notch cut...plus >can go lower than stock....plus can use lower notch >with longer springs > >Glad you like 'em. i've been really sick (strep >throat) and really busy, so sorry that I haven't made >more progress on the springs. >steve


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