Best place and price for rear lower coil over adapters? Broke Bolt!
04-16-2004, 04:41 PM
#16
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Who says you can't adjust the rear ride height! Looks like you put some airbags and turned it into a lowrider. I bet if you left it like that long enough you'd get compliments from some local street racers 
04-16-2004, 04:47 PM
#17
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Yea, I probably would. I just hope I can get the broken piece out and get the car back together for the remainder of the weekend. We finally have nice weather.
04-16-2004, 05:20 PM
#18
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Dave E:
“Laust, is the spacer resting on the aluminum or the steel insert? Seems like the load on the bolt and the spacer pulling on the insert may eventually pull the insert out of the arm, although I would guess its in there pretty good...”
I don’t know the geometry of the insert, but there is a significant distance before reaching the threads and the hole in the aluminum is very close to the shank of the bolt, so it must either be cast in or inserted from the other side (have not looked if there is a hole). Since it is not pulled out by significantly torquing the bolt and has not loosened in a year, I am quite comfortable with the solution. Good thought though.
“Laust, is the spacer resting on the aluminum or the steel insert? Seems like the load on the bolt and the spacer pulling on the insert may eventually pull the insert out of the arm, although I would guess its in there pretty good...”
I don’t know the geometry of the insert, but there is a significant distance before reaching the threads and the hole in the aluminum is very close to the shank of the bolt, so it must either be cast in or inserted from the other side (have not looked if there is a hole). Since it is not pulled out by significantly torquing the bolt and has not loosened in a year, I am quite comfortable with the solution. Good thought though.
04-16-2004, 10:10 PM
#20
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Wow.
Okay, I'm about to express my own opinions. Flame away.
The correct term is single SHEAR. It has considerably less strength than double shear, like what the top mount for the rear shock is. Consider this: the top mount is an M14 bolt and is plenty strong enough: in double shear.
The lower mount is single shear, and the posts above prove how insuffiicient a similar $2 bolt is for this use. (Opinion here: I think the cobbed up photo is really dangerous, and would seek a better solution right away--YMMV of course). By the way, the nomenclature M10 means a 10mm diameter bolt, and doesn't imply a strength of 10.9.
In the past I used some studs made by KellyMoss of stainless, but they're no longer available. These allowed the damper's eye to be moved away from the control arm, so the coilovers could be easily placed.
When they weren't available, I had some replacements made of stainless with a couple of improvements, including a hex "nut" incorporated so I could use a torque wrench easily, and an integral captive washer.
I'm not interested in distributing these, and they were much, much more expensive than $2. But, I'm interested in "no worries" in this area.
Rear damper lower mount:
So, those are my opinions. They're free, so you know what they're worth.
Okay, I'm about to express my own opinions. Flame away.
The correct term is single SHEAR. It has considerably less strength than double shear, like what the top mount for the rear shock is. Consider this: the top mount is an M14 bolt and is plenty strong enough: in double shear.
The lower mount is single shear, and the posts above prove how insuffiicient a similar $2 bolt is for this use. (Opinion here: I think the cobbed up photo is really dangerous, and would seek a better solution right away--YMMV of course). By the way, the nomenclature M10 means a 10mm diameter bolt, and doesn't imply a strength of 10.9.
In the past I used some studs made by KellyMoss of stainless, but they're no longer available. These allowed the damper's eye to be moved away from the control arm, so the coilovers could be easily placed.
When they weren't available, I had some replacements made of stainless with a couple of improvements, including a hex "nut" incorporated so I could use a torque wrench easily, and an integral captive washer.
I'm not interested in distributing these, and they were much, much more expensive than $2. But, I'm interested in "no worries" in this area.
Rear damper lower mount:
So, those are my opinions. They're free, so you know what they're worth.
04-16-2004, 11:12 PM
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Are the threads rolled or cut, huge difference in strength...I'm well versed in the disadvantages of single shear and I'd like to get something made by SPS or equivalent, Preferably with rolled threads. stainless steel is not particularly strong, BTW.
04-16-2004, 11:18 PM
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Material: - Stainless 13-8-PH, 1300 Mpa strength
Manufacuring: - CNC turned rolled threads
Processes: - Heat treated and shotpeened
There are different stainless alloys, of course.
Manufacuring: - CNC turned rolled threads
Processes: - Heat treated and shotpeened
There are different stainless alloys, of course.
04-17-2004, 12:16 AM
#23
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Julian I hope you weren't thinking that you were going to get flamed by me. My point of the whole thread was that I was mislead by numerous vendors that sell Koni shocks, into thinking a 10.9 grade bolt would be strong enough to support the back weight of the car. Hence the reason I was seeking sources for the Racers Edge adaptors. I too am only worried about making "no worries".
What is your opinions on the Racers Edge adaptors? Why did you not buy those? I can't imagine you having much less then $150 in the ones you had made.
What is your opinions on the Racers Edge adaptors? Why did you not buy those? I can't imagine you having much less then $150 in the ones you had made.
04-17-2004, 01:01 AM
#24
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Julian Allen
“Okay, I'm about to express my own opinions. Flame away.
(Opinion here: I think the cobbed up photo is really dangerous, and would seek a better solution right away--YMMV of course).”
You asked for some flaming, so here we go:
Assuming that you are referring to the picture I posted, maybe I can alleviate your fears by informing you that I have a Masters degree in mechanical engineering with numerous courses in machine-elements, stress analysis, material science, metallurgy and many others not so relevant for this discussion, so in spite of my somewhat nonchalant approach, I do know what I am talking about. There are two aspects that I respect in terms of reliability of modifications, namely a thorough analysis and historical experience.
Going through a formal analysis on the stresses in the bolt (FEA or treating it as a single ended solidly mounted beam) still leaves a lack of knowledge of the actual forces that it is exposed to at the end.
I compared my (granted simple) solution to the prior one, which broke the bolt and it is my judgment that the peak stress and therefore the strength has been reduced by a factor of about two.
Attached is a quick drawing of a future spacer that probably is only slightly better than my current pipe converter spacer and likely (with a standard bolt) would be as strong as yours if yours had the same moment arm.
I have to admit that your bolt looks certainly looks pretty. Additionally the integral hex portion is at the right location, increasing the effective diameter where the bending moment is at maximum, thereby reducing the stress and the arm for the bending moment is also shorter than my set-up allows. It would have been even stronger if the hex had tapered down to the OD of the integral shock mount washer.
I too could induce a little fear in your solution (in addition to mentioning the cost) by asking questions like: Do you know the yield and tensile strengths of the material used? Do you have a material certificate for the specific steel used? What are the fatigue characteristics of the material used? What is the maximum force needed to bend or break your bolt and are you sure that your shocks are soft enough not to create such a force?
I obviously would never ask such nasty questions, because I am sure you have used that bolt for a while without failure. Similarly I find it strange that you characterize my solution as “really dangerous” when I have successfully challenged it for more than a year.
Yes, you did step on my “engineering toes” and I kick back.
Laust
“Okay, I'm about to express my own opinions. Flame away.
(Opinion here: I think the cobbed up photo is really dangerous, and would seek a better solution right away--YMMV of course).”
You asked for some flaming, so here we go:
Assuming that you are referring to the picture I posted, maybe I can alleviate your fears by informing you that I have a Masters degree in mechanical engineering with numerous courses in machine-elements, stress analysis, material science, metallurgy and many others not so relevant for this discussion, so in spite of my somewhat nonchalant approach, I do know what I am talking about. There are two aspects that I respect in terms of reliability of modifications, namely a thorough analysis and historical experience.
Going through a formal analysis on the stresses in the bolt (FEA or treating it as a single ended solidly mounted beam) still leaves a lack of knowledge of the actual forces that it is exposed to at the end.
I compared my (granted simple) solution to the prior one, which broke the bolt and it is my judgment that the peak stress and therefore the strength has been reduced by a factor of about two.
Attached is a quick drawing of a future spacer that probably is only slightly better than my current pipe converter spacer and likely (with a standard bolt) would be as strong as yours if yours had the same moment arm.
I have to admit that your bolt looks certainly looks pretty. Additionally the integral hex portion is at the right location, increasing the effective diameter where the bending moment is at maximum, thereby reducing the stress and the arm for the bending moment is also shorter than my set-up allows. It would have been even stronger if the hex had tapered down to the OD of the integral shock mount washer.
I too could induce a little fear in your solution (in addition to mentioning the cost) by asking questions like: Do you know the yield and tensile strengths of the material used? Do you have a material certificate for the specific steel used? What are the fatigue characteristics of the material used? What is the maximum force needed to bend or break your bolt and are you sure that your shocks are soft enough not to create such a force?
I obviously would never ask such nasty questions, because I am sure you have used that bolt for a while without failure. Similarly I find it strange that you characterize my solution as “really dangerous” when I have successfully challenged it for more than a year.
Yes, you did step on my “engineering toes” and I kick back.
Laust
Last edited by Laust Pedersen; 01-14-2013 at 03:32 PM.
04-17-2004, 06:40 AM
#25
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Hi Guys,
Yes, Laust has the solution. I been
running my Ledas with a spacer
cone like Laust design for 3 years
using the standard bolt without any
problems. The cone set up actually
strenghten the bolt loading & moves
the stress & load point very near to
the spherical bushing. In fact, I think
this is an even stronger than Racers
Edge design because it's a solid one
piece bolt instead of a two piece
design.
Yes, Laust has the solution. I been
running my Ledas with a spacer
cone like Laust design for 3 years
using the standard bolt without any
problems. The cone set up actually
strenghten the bolt loading & moves
the stress & load point very near to
the spherical bushing. In fact, I think
this is an even stronger than Racers
Edge design because it's a solid one
piece bolt instead of a two piece
design.
04-17-2004, 02:28 PM
#26
Nordschleife Master
I guess a spacer in a cone shape might alleviate the problem to some extent, but I don't see how you can say there's a even a single sheer force on the bolt. Not when the shock is mounted an inch away from the hole the bolt threads into.
I'm not really familiar with this connection, but that's what it looks like to me.
No wonder they are bending and breaking. Not a failure you'd want to have happen in a high speed corner, that's for sure.
I'm not really familiar with this connection, but that's what it looks like to me.
No wonder they are bending and breaking. Not a failure you'd want to have happen in a high speed corner, that's for sure.
04-17-2004, 02:57 PM
#27
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Single shear refers to the fact that there is no support for the load carried on the other side of the shock, when a bolt is used this way, as opposed to supporting both sides like the upper shock mount, it is single shear. Where the load is applied, or how far from the threads, on the length of the bolt doesn't matter.
