Re: K frame strength
[Re: feets]
#1911519
09/13/15 09:13 AM
09/13/15 09:13 AM
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Joined: Dec 2014
Posts: 6,261 ohio
ruderunner
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Thats what Im getting at. Look at all those right angles just waiting to become 80 degrees.
The factory K had way way more reinforcement around the engine mounts.
Are those the rack mounts just hanging in space? One big [pothole will tweak those in a hurry. Ditto for the control arm mounts. At best the alignment will never hold and after enough flexing complete failure will happen.
For drag only it would likely be ok but I'd not use something like that on the streetor road course.
Angry white pureblood male
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Re: K frame strength
[Re: CKessel]
#1911692
09/13/15 03:07 PM
09/13/15 03:07 PM
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Joined: Dec 2003
Posts: 23,295 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
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Posts: 23,295
Here
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Chris, thank you for chiming in on this with Peter, Feets, JCC etc. You and Peter especially since you have been exposed to the test rigs and stuff with current and former employers and can weed through the feces and shinola. I'm interested in this as I'm not a believer of the A/M units as there is not enough cycle time, miles, crappy roads, Dukes Of Hazard imitations etc on them to prove they are worthy of purchasing and using. I know that eventually we will have no choice when nothing else available to us[ hint, hint for someone to make]. I've been working on the 70 k unit that will be going into my 65 and am interested in where worthwhile improvements can be made as I plan to autocross, road course, drag etc the car. Two of the things I've done are: add in 108 spot/plug welds around the k perimeter compared to 37 factory spot welds, box in the strut rod mount area on the backside of the k instead of just using the 2 attachment spots from Ma Mopar. Salivating on this subject fellas!!!!! Keep at it. Maybe stating the obvious, but if this thread has real data at some point, I bet your proposed solution with come out on top. However we shouldn't completely discount the AF solutions, they do provide some solutions the OEM cannot. On the restraint issue, sure would like to hear some other inputs on whether the test rig should supply any artificial restraint (rigidity), or let the chips fall were they may by having minimal restraint on the tested K. "inconsistent" to me means non repeatable. If the results are inconsistent between K's, that the intention of the test I thought.
Last edited by jcc; 09/13/15 03:12 PM.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: K frame strength
[Re: feets]
#1911801
09/13/15 07:56 PM
09/13/15 07:56 PM
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Joined: Dec 2014
Posts: 6,261 ohio
ruderunner
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ohio
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I took inconsistent to mean non repeatable.
Angry white pureblood male
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Re: K frame strength
[Re: XVracing]
#1912266
09/14/15 03:20 PM
09/14/15 03:20 PM
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Joined: Jan 2003
Posts: 28,096 Irving, TX
feets
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BTW the K does a lot more than hold the frame rails straight. Again, some things you can't measure statically. It has to support the lower control arms as pointed out, and also support the engine as well as counteract the torque.
Just because the aftermarket K frame doesn't look as big as the factory, doesn't mean it's as strong, or stronger...
A Torsional Rigidity test can be done with the K installed or not, the better the rails are without the K installed, the better it will be with it installed.
My suggestion would be to twist the K members out of the car.
CR These are the exact things I was talking about in this thread. What are you getting for your money? Is it any improvement over the stock hardware? What kind of rigidity will it add to your car? I have the tools, material, and metrology to build a rack to use for testing out of the car.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: K frame strength
[Re: GoodysGotaCuda]
#1912586
09/14/15 11:00 PM
09/14/15 11:00 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
About to go away
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About to go away
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...wow, that's pretty impressive. In regards to lack of adequate load paths. Seems fine for a drag car, but I certainly wouldn't spend any money for that.
Oh you ought to hear the praise heaped on that unit. Even here.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: K frame strength
[Re: PHJ426]
#1912646
09/14/15 11:42 PM
09/14/15 11:42 PM
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Joined: Nov 2004
Posts: 4,330 Lynchburg, VA
Leon441
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My 65 cuda is mostly a purpose built drag car that is street legal. Some rules changed in KOS and inner fenders were no longer required. Already had a custom chrome moly tube k member with coilovers and rack, which is light years better handling than stock. But, when the inner fenders were removed the front got flemsy. Then removed the radiator support, including lower support. Thank goodness the k-member is welded in. This stamped sheet metal mentioned earlier in this thread is a huge part of rigidity in your front suspensions.
Last edited by Leon441; 09/14/15 11:43 PM.
Career best 8.02 @ 169 at 3050# and 10" tires small block power.
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Re: K frame strength
[Re: PHJ426]
#1912665
09/14/15 11:51 PM
09/14/15 11:51 PM
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Joined: Dec 2003
Posts: 23,295 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
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Here
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I don't think years of use will effect the test results, assuming all welds are intact, there are no fatigue cracks, etc
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: K frame strength
[Re: ThermoQuad]
#1912719
09/15/15 12:42 AM
09/15/15 12:42 AM
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Joined: Dec 2003
Posts: 23,295 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 23,295
Here
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Regarding welding everything, no real downside. The problem is that I see, and another member has already mentioned increasing the oem spot welds from mid 30's to over a hundred, the spot welds are structurally located better then edge welding, IMO. And the problem with spot welding 40+ years later, is getting reasonably clean metal inside for quality spot welds. Edge welding has this problem to a lesser degree. Doing both of course is also a solution.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: K frame strength
[Re: PHJ426]
#1912793
09/15/15 03:49 AM
09/15/15 03:49 AM
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Joined: Dec 2010
Posts: 12,375 SoCal
MuuMuu101
I got lucky at Woodward!
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I got lucky at Woodward!
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SoCal
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So are you only testing factory stock K frames that have many years of abuse or only NOS units that have been stored in an oxidation free environment?
Or will the K frame be a reinforced K frame by someone like Firm Feel?
Just those 3 examples of factory K frames will yield varied results.
Better yet lets dig up a K frame from an Original Dukes of Hazard jump car....... Well, let's face it, we can't turn back the sands of time and 99.9% of people out there are not using a NOS K-frame that have been stored in an oxidation free environment that's also never seen the road. Personally, I think it's 100% ok to use factory, used K-frames. Just test a larger sample size instead of testing one. It will help smooth out any variation in the data. I'd test both a stock OEM one, a stock one that's been welded up more, a reinforced Firm-Feel (or similar), and any aftermarket tubular setup that could be borrowed.
Last edited by MuuMuu101; 09/15/15 05:08 AM.
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Re: K frame strength
[Re: feets]
#1912809
09/15/15 07:20 AM
09/15/15 07:20 AM
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Joined: Dec 2014
Posts: 6,261 ohio
ruderunner
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ohio
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Since most folks don't have a stockpile of NOS K frames, a good used unit makes the most sense to me. If not tested to the point of failure that stock K can be reinforced and retested to see if the common tricks actually help or not.
Angry white pureblood male
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Re: K frame strength
[Re: PHJ426]
#1913024
09/15/15 02:43 PM
09/15/15 02:43 PM
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Joined: Jan 2003
Posts: 28,096 Irving, TX
feets
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OP
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So are you only testing factory stock K frames that have many years of abuse or only NOS units that have been stored in an oxidation free environment?
Or will the K frame be a reinforced K frame by someone like Firm Feel?
Just those 3 examples of factory K frames will yield varied results.
Better yet lets dig up a K frame from an Original Dukes of Hazard jump car....... I would test the stock K frame I have on hand. In my opinion it is a fair example of what is in use on the typical car today. It has no heavy rust or damage. A pretty paint job on a restored K frame will not make it any more structurally sound. After testing the stock piece I can weld it up like so many others do and test it again. That would be a fair test of what welding does for a K frame. I haven't seen that tested either.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: K frame strength
[Re: XVracing]
#1913033
09/15/15 03:02 PM
09/15/15 03:02 PM
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Joined: Jan 2003
Posts: 28,096 Irving, TX
feets
OP
Senior Management
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OP
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Chris,
I'm ready to go when you guys are.
Can you send me a K-frame? If so, I'll get the ball rolling with the other guys too.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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