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section 8
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Discussion Starter · #1 ·
Spell it like they say it! Anyhow nearest I can figure, the reason for the "body up " orientation on the front bilstines I think would be due to the movement of the spring upon compress and rebound . Next time you jack up your car by the frame notice that the rear spring is captured (still compressed) while the front you can grab the spring and slam it where ever you want to specifically up. With the hat on the bottom there is less opportunity for the spring to come down Misaligned and break the shock. However , I feel that the cheesy adjuster that slides up and down on the shock may Cock enough on compression to cause shaft breakage in some cases. I'm no genius or scientist , heck I cant even spell my name sometimes, but this makes sense. Gordon Levy sells Koni's with a threaded shock body thus eliminating the sliding "mess" . Anyone got a different theory! Bob
 

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FFCobra Fanatic
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If you're right Bob, that means the new FFR Koni's will be susceptible to the same failure ... although the shaft diameter is larger.

It really seems to me that a group of engineering types should be able to figure this out relatively easily. The failure happens at a weak point and it's always the same place. Either the shaft is too small in diameter for the application or some other stress factor is causing the failure.

Maybe someone could mount a bullet cam down there and do some jouncy road testing?

I dunno. All I DO know is that I'm very reluctant to put my car on the road with these shocks. I'm not thrilled with paying $800 for a set of (marginally?) better shocks either.
 

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section 8
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5,136 Posts
Discussion Starter · #3 ·
I see "The Reaper " every time a see a bump in the road or see the speedo near 100 while turning. If I had the technology I would try the camera. I'm sure monroe or some other big company has a shock tester . I watched ,long ago, how Edelbrock tested their products it called A SHOCK DYNO, DONT NEED AN ENGINEER TO FIGURE THIS OUT. I just emailed Gordon Levy to see if changing to just the Front koni's he sells would be a good Idea. His have a threaded body and not an adapter . I also emailed FFR last week for their blessing on these 590 dollar bilsteins that they would last 50k miles of street driving There has been no response yet. They also have not offered to take back my shocks that have only 500 miles on them. I may call bilstein personally and ask for their help . I am not interested in being hurt or damaging my vehicle , or God forbid injuring someone else. Someone HAS To care. We have a great product here in the Roadster but the safety of the occupants has been compromised .
 

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Premium Member
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5,825 Posts
Bob,

I have Pro-Shocks up front because Canadian customers don't get the Bilstein (or any other) coil-overs included in their kits.

Pro-Shocks have a bit of a bad rap from some of the high-performance autocross guys, but they are at least a 'purpose-built' coil-over. The shock body is threaded for the adjusters like Gordon's Konis, and the shaft diameter is a slight bit larger than the Bilsteins as well.

I know this because I tried to slip on the 'upgrade' hardened washers FFR provided, and they wouldn't fit. It's probably only a 16th or so difference, but they ARE larger. In addition, Pro-Shocks use a larger diameter spring like the Konis as well, and so rubbing on the shock body does not appear to be an issue.

Although I currently have them mounted 'body-up' as per FFR's latest tech update, I checked, and I can mount them in either position (newer version FFR tubular LCA's) without interference.

All this being said, Pro-Shocks have failed in the past as well. Most of the shafts that broke were identified as clearance issues with the older style FFR tubular LCA's, but there were other failures where the shock broke/failed internally and the shaft came away from the body.

One thing I have not heard others mention is that Pro-Shock (the company) will work with you to build/re-build the shock and components if necessary as well as valve it to your particular specs. If you've got some miles on them, you can send it to them, they'll dyno the shocks, determine wear and give you options to re-build or replace. I have found them very good to work with and quite helpful to a novice like myself.

Don't get me wrong, these are NOT EVEN CLOSE to what Gordon Levy is selling. These are still non-adjustable, light-duty coil-overs, but I think they may (?) have a margin of safety on the Bilsteins.

P.S. I always get a good laugh out of your posts!


Not for the content (you're obviously a knowledgable guy), but your down to earth humor is always good for a smile or two!

Cheers,


Sean
 

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Senior Charter Member
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646 Posts
Bob and others:

I feel for FFR every time I see one of these new shock threads start. I'm not sure that anyone can conclusively say that any of the shock failures are the fault of the design/ implementation of the shock itself.

Of the threads that I read ( I must admit they get to me a little so I don't read them all), it seemed like failures were due to incorrect installation and the spring issues. If I had to guess, I'd say the majority were due to springs landing wrong on the lower or upper seat after jacking, thus causing an excessive bending moment in the shock shaft.

I am not sure that designs that offer a threaded body ( vs. a separate or sliding body cover) provide any improvement in spring location as when the suspension is at full droop ( full rebound), the spring will be completely unloaded and thus could potentially come unseated.

This is definitely an interesting issue due to the large number of people ( spec racers as well)that are using the Bilsteins that have not had an problems.

Flame away...

-Matt
 

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master craftsman
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5,597 Posts
The reason for the body upor body down has to do with srung and unsprung weight. which way is which and why I don't know for sure but it is important for handleing, especially in the front. It has been disscussed in previous posts..........steven p
 

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section 8
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5,136 Posts
Discussion Starter · #7 ·
Sean , Thanks for the complement , if I couldn't make jokes of potentially dangerous situations I would have stressed myself to death long ago. Presently I'm just at the gray/bald stage!!! Bob
 

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Originally posted by steven fort lauderdale:
The reason for the body upor body down has to do with srung and unsprung weight.
Steven,

While I know about the unsprung weight advantage of mounting the body of the coil-over up, the FFR tech update (which was in response to the last rash of Bilstein failures) instructs everyone to mount their (front) shocks in this fashion.

They do not make it clear why it must be so, but the implication is that this mounting position (as well as the addition of the hardened washers under the spring hats) is necessary to reduce the potential for shock shaft failure.

Originally posted by mjlangley:
I feel for FFR every time I see one of these new shock threads start...
Matt,

I'm not one of those people simply bitching about a poor or inadequate design. I have wondered myself about why we don't hear more about broken shocks from within the racer community. I do want a certain degree of security that I am doing the right thing and I will continue to read each of the various shock topics as smarter types than me continue to brainstorm the solution.

I don't know how confident you feel, but the number of failures to this point (it's been more than 5 years since the first reported broken shock) and each iteration (QA1, Pro-Shock, Bilstein) has had multiple failures reported.

I only have one other seat in my roadster and the odds are the passenger will be someone very important to me. I could not live with myself if something within my control was responsible for loss of life.

Sean
 

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section 8
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5,136 Posts
Discussion Starter · #9 ·
all facts considered we have beed provided band aids for a potential beheading. In other words probably aint gonna work.Very well put Sean, no-one I don't like gets in my roadster.Perhaps FFR would like to offer an extended warranty on the shocks if they think they will last .I'm still waiting for a reply to a similar question from last week. Bob
 

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Junior Charter Member
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1,053 Posts
I was hitting 90 to day and some decent bumps
and I have to sat thay I was worried about the
front shocks (I have bilstien fronts and proshock
rear).

Last week I removed the wheel and completely compressed the spring by jacking the lower control
arm... I can clearly see that the spring bows
and chafes against the threaded sleeve.. The threads are worn off.. I am not sure if this is
related to the breakage problem or if it is
a seperate problem.

I have also seen worn thread probem happen to Proshock on another car..

In any event, I will probably eat the $$
and go for Koni on the front at some point.

I am still satisifed in doing bussiness with
FFR so I won't complain.. I am very happy
with their product.

Dan
 

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section 8
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5,136 Posts
Discussion Starter · #11 ·
Yep me too , can't enjoy the ride if your scared ! The only issue is the good Koni's are almost 2k for the set. the product is great it's just some of the bits need help . Safety issues should not be ignored . Bob
 

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FFCobra Craftsman
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24,707 Posts
My MkI had the old ProShocks on the front w/ the 2.5 springs.I bought Levy's Konis cause i autocross.Then I got a late mkII and it had ProShocks all around. But they are little skinny things.I haven't measured but a lot smaller than 2.5 inches.And that means much less clearance shock to threaded part.I wonder if all springs,except ones for NASA, bow some and the reduced clearance is just too little to accomodate it.I have never had any contact w/ several Eibach and several QA1 springs from Summitt(all 2.5 inches).
 

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That's interesting Craig,

I must have the older generation Pro-Shocks I guess, since my springs and spring hats etc. are all 2.5" stuff.

I didn't know there was a 'skinny' spring version.

Sean
 

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FFCobra Craftsman
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24,707 Posts
I was surprised too.My FFR5353 is a very late MkII. The original owner said the kit was on sale cause the mkIIIs had just come out.
 

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section 8
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5,136 Posts
Discussion Starter · #16 ·
They look kind of small . I haven't gone out and measured but the shaft does not look any bigger than a regular light truck shock and they never break . 20+ years in the auto business and never seen one break . So I do not think the shaft diameter is an issue it the way it is loaded. Bob
 

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1,668 Posts
Bob,
In a car they are not carrying the weight of the car or have the spring applying side loads. Look at the diameter of a strut, that would be a better comparison.
 

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section 8
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5,136 Posts
Discussion Starter · #18 ·
Ahhh master of the golden sawzall you are correct! At my age its tough to remember what stuff looks like when your not looking right at it not to mention how it works . Here is something interesting . Ibought Bilstein struts for my 87 Mustang and the piston was more than twice the diameter of the stocker. Forgot suspension 101 The coil over acts as a strut and absorbs any abuse the spring generates . Senior moment. Sorry . Hows the car coming pm a recent pic what I've seen looks great Bob
 

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Here are my thoughts:
The lower "A" arm is not only subject to vertical motion when motioning over a bump or dip. It is also subjected to horizontal forces when the tire impacts a bump or pot hole. In a perfect world the tire would gently rollover all obstacles, this is not real life. There are some very violent impacts that really shudder the whole car think about the what the lower "A" arm is experiencing.
Now think of the motion ratio of coil-over lower mount versus the upper mount. Let's say the there is an impact that compresses the coil-over and also shocks the lower "A" arm back 1/8", if the coil-over was compressed to 10" the upper coil-over rod end would pivot back 1/10 as much. Pivot, not be impacted rear ward, simply pivot.

The lower mount is subjected to too many forces acting in different planes at the same time and to a greater degree of movement.
This is why I have flipped my coil-overs body down. To put the weaker end up and out of harms way.
I have donor lower "A: arms and there is no clearance issues whatsoever. I feel very confident this is the right thing to do.

Michael S.
 

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Bob,
In a car they are not carrying the weight of the car or have the spring applying side loads. Look at the diameter of a strut, that would be a better comparison.
 
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