View Full Version : Is this enough metal?
ggunter
07-13-2021, 08:00 AM
150776 Does anyone besides me look at this part and realize our lives depend on this tiny amount of metal is all there is between us and crashing? Maybe I worry too much.
You could say the same about any number of parts on a car. As an engineer, I trust that the analysis has been done and that the parts, if properly installed and maintained, will do their job and make the car safe to drive.
Flying in a giant beer can at 500 miles/hour and seven miles off the ground with absolutely zero control ... that gives me pause every time.
flyboyjy
07-13-2021, 08:17 AM
As a retired commercial pilot I can assure you that you really don't want to know just how few bolts are really holding those wings on the plane.
rich grsc
07-13-2021, 08:22 AM
Omg
Not to worry though. The wings on a B-787 only flex about 25 feet….right before they snap off.
In most crashes, the nut behind the wheel is the root cause.
In most crashes, the nut behind the wheel is the root cause.
Roger that!!!
https://www.youtube.com/watch?v=Ai2HmvAXcU0
Sdonnel
07-13-2021, 10:20 AM
As we all know, these cars only function by all the parts cooperating with each other when we turn the key. From paper thin sheet metal to protect our feet, to roll bars we all hope will work if needed. I'm not questioning the engineering of the car or what is supplied by FFR, just making an observation that if we wanted, we could all be worried about more than just that one part. Drive on my friends.
GTBradley
07-13-2021, 10:52 AM
You could say the same about any number of parts on a car. As an engineer, I trust that the analysis has been done and that the parts, if properly installed and maintained, will do their job and make the car safe to drive..
Flying in a giant beer can at 500 miles/hour and seven miles off the ground with absolutely zero control ... that gives me pause every time.
I recognize the benefit, but it always makes me sad to see a perfectly good airplane get tortured to death. Back in the 90s I delivered a brand new Piper to LA for the purpose of destructive testing. I felt like I was delivering a beloved pet to the cosmetic testing laboratory.
Dave, you have to take your engineer’s hat off and put your statistician’s hat on when flying and riding roller coasters. Back when I was flying charter turboprops I had to promote our new, single engine Pilatus to our clients that only wanted two engines for their business trips. The twin and single crash statistics were nearly identical (for different reasons). But the bigger point is that the crash and death rate in planes versus cars is magnitudes higher in the latter…Happy Tuesday;)
ggunter
07-13-2021, 10:58 AM
Not sure how airplanes got into this conversation, unless it is just a comparison, but the part I show is the end of the adjustable upper control arm on a MKIV cobra. Just seems like a tiny amount of metal to play an extremely large roll in the safety of our cars. On the other hand have'nt heard of anybody breaking one either. Just sayin....
GTBradley
07-13-2021, 11:07 AM
Not sure how airplanes got into this conversation, unless it is just a comparison, but the part I show is the end of the adjustable upper control arm on a MKIV cobra. Just seems like a tiny amount of metal to play an extremely large roll in the safety of our cars. On the other hand have'nt heard of anybody breaking one either. Just sayin....
The first thought I have on this question is, how much smaller is this part than on our DD SUVs and trucks? I’m guessing it probably has more to do with the engineering and quality of the part rather than it’s size. Those bolts holding the wing on an airplane are tiny by comparison too.
Railroad
07-13-2021, 01:01 PM
I think Dave Smith rolled a MKIV roadster, dusted it off and went back into the race. Maybe it is strong enough.
On airplane bolts, for larger loads, they sometimes use bottle bolts. They are large diameter, 3 or 4", but hollow and shaped like a bottle. I tried to find a pic, but no luck.
JohnK
07-13-2021, 10:57 PM
I believe that the upper control arms are made for FFR by SPC performance:
https://www.spcalignment.com/race
The description says that they're used for circle track, dirt and drag racing so, yeah... I think they're probably strong enough for our application.
CraigS
07-14-2021, 06:48 AM
The other end of one of the UCA sleeves is the one that bothered. I found a larger clevis at McMaster. It needs a 1/8" washer but it looks much stronger to me.
https://live.staticflickr.com/928/28721573397_bd896ffa8c_z.jpg (https://flic.kr/p/KL2z8k)new clevis (https://flic.kr/p/KL2z8k) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
Jeff Kleiner
07-14-2021, 08:18 AM
When they made a change to these arms 7 or 8 years ago I had similar concerns since their clevis don't appear as robust as the earlier ones shown here:
https://thefactoryfiveforum.com/attachment.php?attachmentid=150841&d=1626268091
That said though after thousands of cars and untold miles miles time has shown that they aren't a problem. I've never heard of one failing. The earlier arms had their own set of problems since some of them didn't want to accept grease into the crossbar links which could lead to galling...and if that wasn't addressed the pivot could fracture (saw it on one that was brought to me to investigate "a strange noise in the front end"!!!!).
Good find on the beefier clevis Craig! You know that if there was ever a weak link (no pun intended) to be found our old friend Wade would find it ;)
Jeff
150841
boat737
07-14-2021, 02:32 PM
Hey, that's my car! I'm famous.
CraigS
07-15-2021, 07:01 AM
Jeff, Wade actually found those for me. I don't think he used them himself but he sent a link in an email. Dang, I miss him.
ggunter
07-15-2021, 07:12 AM
I used your picture boat, it was perfect for what I was trying to show. Putting my car together I was pretty much impressed with everything about the chassis, but the thin side walls on these ends just stuck out to me. As Jeff and others said no one has reported any failures, and I'm sure they would show up here if they did. I really like the one that Craig showed. I believe I will look into those ends. At least it will make me feel better.
rich grsc
07-15-2021, 08:57 AM
Then be sure you replace all the attachment brackets on the frame, because you'll rip them off before you break that piece. :eek:
boat737
07-15-2021, 09:43 AM
I used your picture boat, it was perfect for what I was trying to show. Putting my car together I was pretty much impressed with everything about the chassis, but the thin side walls on these ends just stuck out to me. As Jeff and others said no one has reported any failures, and I'm sure they would show up here if they did. I really like the one that Craig showed. I believe I will look into those ends. At least it will make me feel better.
No sweat. I'm honored.