Need Help Destroyed another shock

[Bow Tie 67]

So I noticed oil on the driver side frame after getting home from Motorstate, it turns out it is shock oil.




http://inlinethumb57.webshots.com/48888/2055733120065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2055733120065608932RikxiQ)
http://inlinethumb27.webshots.com/47514/2645920050065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2645920050065608932cbSdSg)

This is the second shock I have had an issue with. My subframe has no bumpstops, prior to my swaybar upgrade I bottomed one out and it leaked, now this.

The shocks have been on the car since summer of 09 with several track days and no incident. So here are some pics of the suspension and I'm wondering what loads will be placed on the upper and lower a-arms when contacting a stop. I'm running 600 lb springs and still had 3/4" compression available on both shocks. The car was setup right at the midway point of shock travel. Total travel is 4 1/4" with a 1/4" o-ring as a shock compression bump stop. So the effective shock travel is 4" at the limits.

I'm getting tired of shock damage as it gets expensive, not to mention down time on the car.

I'm thinking of adding a bump-stop to the bottom of the frame-rail for compression, and fabricating a bracket with the bump-stop contacting the upper a-arm adjustment turn-buckle. My concern is the loads that may be placed on the control arms when contacting a stop. I think having the upper bump-stop contact the a-arm at the cross-shaft would be better, but then I get into packaging problems with the sway-bar arm's travel and providing enough support for the stops mount. Help .................

Thoughts?

http://inlinethumb39.webshots.com/27110/2477061260065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2477061260065608932MreZTb)
http://inlinethumb23.webshots.com/48406/2130576610065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2130576610065608932QXpRaR)
http://inlinethumb14.webshots.com/15885/2167606880065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2167606880065608932ApLPMG)
http://inlinethumb56.webshots.com/46903/2312585980065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2312585980065608932WMeWaT)
http://inlinethumb06.webshots.com/47429/2159673030065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2159673030065608932KCMexJ)

[Blake Foster]

maybe try adding a bump stop on the shock shaft.
that damage to the shock "looks" like it has Topped out, extended too far???
to pull it appart like that??

[Vegas69]

I agree with Blake, it looks to be under extension. Especially since you said you had 3/4" of shock travel left after the event.(Assuming by the oring position) You really need a stop under your upper control arm that it can rest on around full shock extension.

[Bow Tie 67]

maybe try adding a bump stop on the shock shaft.
that damage to the shock "looks" like it has Topped out, extended too far???
to pull it appart like that??

Yep extended to far? or just loosened up and was pushed out by internal pressure.

[clill]

At full travel you don't want the threads in that shock to have to do the work of holding it together. You need some kind of stop. At full travel is it the shock that stops it ?

[Bow Tie 67]

At full travel you don't want the threads in that shock to have to do the work of holding it together. You need some kind of stop. At full travel is it the shock that stops it ?

Yes it is.

[clill]

Not sure how to put a rubber snubber up top on your setup to limit travel. Early Shelby Mustangs used a cable to limit the travel.

[Bow Tie 67]

Thats what I'm thinking. Currently I'm using AN bolts to mount the shocks. They are longer than needed so I can add a cable or strap between them.

[wmhjr]

At full travel you don't want the threads in that shock to have to do the work of holding it together. You need some kind of stop. At full travel is it the shock that stops it ?

So what about the shocks on the back? The threads fully support everything all of the time, right? And the rear end is far heavier. What makes that different? I realize the spring rates are different.

[Bow Tie 67]

Earlier in the year I took a good look at the new Ridetech coil over shocks and really liked what they have to offer. As your average working stiff I could not justify the cost of changing a component that's doing its job, so it was only a passing thought. Well things change, and now I have a decision to make, have mine rebuilt or try another brand. I made a call to Ridetech and my mind was made up, I decided to try their new coil-overs.

I installed my new single adjustable shocks yesterday and took a short ride. So far so good, the car feels more responsive, the big test will be at the Heidts challenge in two weeks. I will leave feedback once the event is over.

In the mean time here are some pics. Due to the difference in shock design, the Ridetech shocks were more difficult to install. For one they actually have a nitrogen charge, so the shock wont stay collapsed and the mount bolt center line to shock body is a shorter distance. At first I thought I might have to grind for clearance on the lower control arm, but soon found if I pushed the suspension down as far as it will go I could set the shocks in and install the bolts. I double checked full suspension travel without the coils to make sure no binding would occur. SCORE !! there is enough clearance.

I'm still working on some suspension stops, but have faith in these shocks as they have real bumpers vs a 1/4" o-ring!!

clearance to lower control arm
http://inlinethumb18.webshots.com/48465/2313350930065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2313350930065608932oPRiFz)
http://inlinethumb19.webshots.com/46098/2263636690065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2263636690065608932XUNtuh)

Installed pic

http://inlinethumb02.webshots.com/49153/2545694700065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2545694700065608932rKVwNM)
http://inlinethumb15.webshots.com/47822/2611638340065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2611638340065608932MbHtQc)

[wmhjr]

Matt, I don't think the 1/4" o-ring is a bump stop. I considered it a travel measuring tool and nothing else. You can see how much compression you're getting based on how far up the 0-ring gets pushed up on the shaft.

But I'm still curious as to why there should be a difference front to rear. I have Varishock double adjustables and was also a little concerned about the shock having to support the full extended spring rate in the front since the shaft isn't quite long enough for the a-arms to be fully extended (ie, car on left with wheels at full droop). I asked, and got the question - "what do you think happens in the back?" which made me realize what was going on.

The only thing supporting my rear axle when the car is on the lift (or if a wheel comes off the ground while driving) is the rear shock. That's the normal mode in an a-body coil spring suspension. The spring rate is roughly 1/3 of the front spring rate, but the weight of the rear assembly, etc probably compensates quite a bit.

[Bow Tie 67]

I never considered the o-ring one either, but that is what CW called it.

As far as the rear / front shock supporting weight at full droop, its ok for the shock to do that you just dont want violent crashing events at either extreme.

[Vegas69]

The spring rate difference is a good point. I really don't think the rear sees full extension near as often either. It's not independent like the front. Bottom line, a bump stop should've been engineered into that frame.

[wmhjr]

Yeah, I'm not saying I know the answers here - just what I thought about myself and what I was told.

So far, I really like the quality and the performance of the Varishocks. I did find that there were some interesting parts of the install. However, I was concerned when I installed the front ones in particular because of how I needed about 10 hands to hold the coil maintaining the index, keep the shock centered, make sure that the shaft was going through the hole in the upper coil perch (which it wasn't directly aligned with) and the shaft was slightly too short, requiring the springs to be compressed a bit for the shaft to get through the hole. So, as soon as I installed the upper bushing and the washer/nut, obviously that was the component taking the stress of slightly compressing the coil when there was no weight on the front suspension.

I talked to Mark at SC&C and AC. Both said it was a non-issue and reminded me how the rear was that way no matter what. They said if I was running the car at the drags and the front end was coming up and down hard on a consistent basis, I'd need something to limit travel. I've only had the shocks on for about a month, but thus far (including extensive time on a 2 post lift where the suspension is at full droop) I've encountered no issues.

Just my 2 cents. Nothing more than that.

[Bow Tie 67]

http://inlinethumb26.webshots.com/35865/2641957040065608932S600x600Q85.jpg (http://good-times.webshots.com/photo/2641957040065608932XrIZkz)

Heidts challenge results

5th auto-cross
7th road course

5th over-all event

I'm going to say, I LOVE the new front shocks.

I have never been very good at the autocross, now the car transitions much better allowing me to learn to drive the car and not fight it.

On the road course she was very predictable and had no problem handling the large rumble strips when I was to wide or pinched a corner.

Street manners are vastly improved, the new shocks can be dialed down and give me a more sedate ride.

All in all I'm very happy and dont believe I need to worry about bump-stops. I have set the compression bumpers down on several occasions and only had them show contact once ( railroad tracks ) although I did not feel any harsh compression.



Plane and simple RideTech coil overs work!!!

[Vegas69]

Congrats, sir...