Re: Cm vs Ms
[Re: MattW]
#2464775
03/11/18 03:18 PM
03/11/18 03:18 PM
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Joined: Dec 2005
Posts: 11,552 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,552
Fulton County, PA
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Pounds per foot
1.675x.134 ERW 2.134 1.625x.120 DOM 1.929 1.625x.083 CMY 1.367
Last edited by CMcAllister; 03/11/18 03:22 PM.
If the results don't match the theory, change the theory.
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Re: Cm vs Ms
[Re: MattW]
#2464786
03/11/18 03:43 PM
03/11/18 03:43 PM
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Joined: Jan 2003
Posts: 19,363 Las Vegas
Al_Alguire
I Live Here
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I Live Here
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Posts: 19,363
Las Vegas
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IMO in a 10/12 point typical 8.50 cert cage you will likely see a 30-35lb weight savings with moly over mild steel. I think many people go Mild for cost reasons. The material is less money and in some places easier to come buy and also can be mig welded. Which means less fitment time and a lower cost. I know you didn't want that but for a typical 8.50 cage it is not a ton of weight but in racing weight is weight
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Cm vs Ms
[Re: MattW]
#2464812
03/11/18 04:53 PM
03/11/18 04:53 PM
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Joined: Dec 2005
Posts: 11,552 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,552
Fulton County, PA
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I'm anal about weight. Beyond that ERW is not good unless you're building a swing set. DOM and CM have been pretty close in price. 100' of CM is 56# lighter than the same DOM, and 77# lighter than the ERW. Value of the car is higher. And IMO is a better car.
If the results don't match the theory, change the theory.
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Re: Cm vs Ms
[Re: MattW]
#2464819
03/11/18 05:15 PM
03/11/18 05:15 PM
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Joined: Jan 2003
Posts: 19,363 Las Vegas
Al_Alguire
I Live Here
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I Live Here
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Las Vegas
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Definitely way better resale
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Cm vs Ms
[Re: MattW]
#2466506
03/14/18 06:02 PM
03/14/18 06:02 PM
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Joined: Jan 2004
Posts: 4,566 Motor City
6PKRTSE
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master
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Motor City
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If I remember correctly when we cut the M.S. 12 point cage out of my buddies G Body (GM) & did the 25.5 cert C.M. cage upgrade when all said & done it was 25-28 lbs lighter than the old cage.
1963 Belvedere 440 Max Wedge Tribute 1970 Charger R/T S.E. 440 Six Pack 1970 Challenger R/T, 528 Hemi 1970 Charger 500 S.E. 440 4 BBL 1970 Plymouth Road Runner 383 1974 Chrysler New Yorker 440 1996 2500 RAM 488 V-10 4X4 2004 3500 Dually Cummins 4x4 2012 Challenger R/T Classic.
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Re: Cm vs Ms
[Re: 6PKRTSE]
#2466541
03/14/18 06:48 PM
03/14/18 06:48 PM
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Joined: Jan 2003
Posts: 19,363 Las Vegas
Al_Alguire
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 19,363
Las Vegas
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If I remember correctly when we cut the M.S. 12 point cage out of my buddies G Body (GM) & did the 25.5 cert C.M. cage upgrade when all said & done it was 25-28 lbs lighter than the old cage. Basically the same thing we have found depending on the car being done. Thus my 30-35 guesstimate
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Cm vs Ms
[Re: 6PKRTSE]
#2466906
03/15/18 02:14 PM
03/15/18 02:14 PM
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Joined: Jan 2004
Posts: 8,254 fredericksburg,va
cudaman1969
master
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master
Joined: Jan 2004
Posts: 8,254
fredericksburg,va
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If I remember correctly when we cut the M.S. 12 point cage out of my buddies G Body (GM) & did the 25.5 cert C.M. cage upgrade when all said & done it was 25-28 lbs lighter than the old cage. So, how many more feet of CM tube did you use over the 10 point?
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Re: Cm vs Ms
[Re: MattW]
#2466960
03/15/18 04:45 PM
03/15/18 04:45 PM
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Joined: Jul 2008
Posts: 361 Canada
onig
enthusiast
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enthusiast
Joined: Jul 2008
Posts: 361
Canada
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Any truth that CM joints need to be "stress relieved"? Read this many many years ago. If true, how is it done?
69 Dart
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Re: Cm vs Ms
[Re: onig]
#2466975
03/15/18 05:14 PM
03/15/18 05:14 PM
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Joined: Dec 2005
Posts: 11,552 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
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Posts: 11,552
Fulton County, PA
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Any truth that CM joints need to be "stress relieved"? Not in thicknesses typically used in race cars. Proper TIG techniques to keep the heat affected area to a minimum and getting tight fits at joints is needed though. As per Lincoln Electric: Q. Do I need to heat treat (stress relieve) 4130 after welding? A. Thin wall tubing normally does not require stress relief. For parts thicker than .120", stress-relieving is recommended and 1,100ºF is the optimum temperature for tubing applications. An Oxy/Acetylene torch with neutral flame can be used. It should be oscillated to avoid hot spots.
If the results don't match the theory, change the theory.
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Re: Cm vs Ms
[Re: MattW]
#2467091
03/15/18 09:40 PM
03/15/18 09:40 PM
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Joined: Jan 2005
Posts: 4,243 Charlotte, North Carolina
sgcuda
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master
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Charlotte, North Carolina
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I thought I heard somewhere about 500 years ago that at some point, C/M tubing became available annealed and that stopped the need for stress relieving. Since then all C/M tubing is annealed.
[image][/image]
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Re: Cm vs Ms
[Re: MattW]
#2467147
03/15/18 11:44 PM
03/15/18 11:44 PM
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Joined: Dec 2005
Posts: 11,552 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,552
Fulton County, PA
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4130 tubing is available in different conditions. SFI specs call for Condition N or normalized for anything used in the structure of a chassis. Sheet is also available in Condition A or annealed which is not as strong and easier to form. There is also a hardened material that was talked about a number of years ago after some well publicized problems but hasn't been talked about for awhile.
Years ago I saw a car that wrecked hard, came apart and hurt the guy pretty bad. Nothing was bent, everything that came apart looked like broken glass. And this was not a backyard car. You have to pay attention to this stuff and where it comes from.
If the results don't match the theory, change the theory.
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Re: Cm vs Ms
[Re: onig]
#2467211
03/16/18 03:30 AM
03/16/18 03:30 AM
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Joined: Aug 2003
Posts: 43,163 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,163
Bend,OR USA
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Any truth that CM joints need to be "stress relieved"? Read this many many years ago. If true, how is it done? I remember the same thing but I think that was way back when NHRA allowed any type welding of C.M. I don't think that is needed with Tig welding as already mentioned Airplanes C.M. fuselages used to be welded with Oxy Acetylene gas welding a long time ago, I'm sure they needed it also
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Cm vs Ms
[Re: cudaman1969]
#2468312
03/18/18 09:28 PM
03/18/18 09:28 PM
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Joined: Nov 2004
Posts: 4,330 Lynchburg, VA
Leon441
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master
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Posts: 4,330
Lynchburg, VA
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Chrome moly if welded with 70 S2 filler will not form a carbon line.
Some folks weld with 4130 filler. This produces a carbon line a couple inches from joint.
It best to keep welding area warm with cage warm. This reduces flash temperature. And do not cool welds.
Every broken tube Ive ever seen was welded with hard filler rod. They all broke in carbon line. If welded correctly you can bend into a pretzel and not crack.
Career best 8.02 @ 169 at 3050# and 10" tires small block power.
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