Going from 8 point roll bar to 10 point roll cage
12-13-2009, 07:23 PM
#22
so is the wolf 6 point and ther 10 point different diameters of tubing?
I was told to buy a 10 point but put in the 6 point of it now, as the track really doesn't check thickness- and when I get fast enough put the rest of it in and be certified to run the #.
Is there any truth to this? If so I will be buying a 10 point after christmas.
I was told to buy a 10 point but put in the 6 point of it now, as the track really doesn't check thickness- and when I get fast enough put the rest of it in and be certified to run the #.
Is there any truth to this? If so I will be buying a 10 point after christmas.
12-13-2009, 08:32 PM
#23
so is the wolf 6 point and ther 10 point different diameters of tubing?
I was told to buy a 10 point but put in the 6 point of it now, as the track really doesn't check thickness- and when I get fast enough put the rest of it in and be certified to run the #.
Is there any truth to this? If so I will be buying a 10 point after christmas.
I was told to buy a 10 point but put in the 6 point of it now, as the track really doesn't check thickness- and when I get fast enough put the rest of it in and be certified to run the #.
Is there any truth to this? If so I will be buying a 10 point after christmas.
12-17-2009, 08:50 PM
#26
it has a higher tensile strength than steel, but thats why people use moly in the 1st place. to save weight with the different wall thickness.
im not a guru on metallurgy, but there are many aspects and advantages/disadvantages to either metal.
you just cant say its stronger unless you are comparing apples to apples.
im not a guru on metallurgy, but there are many aspects and advantages/disadvantages to either metal.
you just cant say its stronger unless you are comparing apples to apples.
02-15-2010, 10:42 PM
#27
Normalized it's not significantly stronger, typically less than 3% difference and their accepted strength ranges overlap, so comparing identical pieces of 1018 and 4130 it is possible for either to test stronger.
Secondly, 4130 self quenches when welding resulting a brittle HAZ around the welds which will tend to crack on impact. It's a stupid rule that I've never heard anyone give a good reason for (if someone knows of one I'd love to hear it). Other sanctioning bodies (for example NASCAR) completely outlaw the use of chromemoly in safety cages/anywhere in the vicinity of the driver. Typcally they're mild steel and MIG welded, another thing I don't get, why do they require TIG welds for "faster" cages? Done correctly, the MIG can be done 3-5x faster, putting less total heat into the metal and still getting complete penetration. Yes, TIG can be more precise, but we're talking about relatively heavy pipe joints, if you can't get precise enough MIG joints on the stuff you shouldn't be doing any kind of welding on anything safety related, period. OTOH, I wouldn't be surprised if someone took a random sample of the TIG welds in roll cages and found that >75% of them either overheated the metal or were just superficially good looking but not structurally sound.
Secondly, 4130 self quenches when welding resulting a brittle HAZ around the welds which will tend to crack on impact. It's a stupid rule that I've never heard anyone give a good reason for (if someone knows of one I'd love to hear it). Other sanctioning bodies (for example NASCAR) completely outlaw the use of chromemoly in safety cages/anywhere in the vicinity of the driver. Typcally they're mild steel and MIG welded, another thing I don't get, why do they require TIG welds for "faster" cages? Done correctly, the MIG can be done 3-5x faster, putting less total heat into the metal and still getting complete penetration. Yes, TIG can be more precise, but we're talking about relatively heavy pipe joints, if you can't get precise enough MIG joints on the stuff you shouldn't be doing any kind of welding on anything safety related, period. OTOH, I wouldn't be surprised if someone took a random sample of the TIG welds in roll cages and found that >75% of them either overheated the metal or were just superficially good looking but not structurally sound.
02-15-2010, 10:47 PM
#28
I just did the upgrade from Spohn S&W 8 point to 10 point. I bought the before dash bars and upper hoop from SW and they fit like crap and gave me no headroom or legal place to mount the window net. I ended up having a chassis guy custom bending bars and upper hoop so I had head clearance and could get in the car (i'm 6'2). Turned out pretty nice and only added 21lbs to the weight of the car. He left the door bars 1 3/4 and made the front bars and upper hoop 1 5/8.
I'll see if I can snap some pictures tonight.
I'll see if I can snap some pictures tonight.
02-16-2010, 02:36 PM
#29
7 Second Club
iTrader: (42)
Join Date: Jun 2004
Location: paducah, ky
Posts: 4,558
Likes: 0
Received 0 Likes
on
0 Posts
Normalized it's not significantly stronger, typically less than 3% difference and their accepted strength ranges overlap, so comparing identical pieces of 1018 and 4130 it is possible for either to test stronger.
Secondly, 4130 self quenches when welding resulting a brittle HAZ around the welds which will tend to crack on impact. It's a stupid rule that I've never heard anyone give a good reason for (if someone knows of one I'd love to hear it). Other sanctioning bodies (for example NASCAR) completely outlaw the use of chromemoly in safety cages/anywhere in the vicinity of the driver. Typcally they're mild steel and MIG welded, another thing I don't get, why do they require TIG welds for "faster" cages? Done correctly, the MIG can be done 3-5x faster, putting less total heat into the metal and still getting complete penetration. Yes, TIG can be more precise, but we're talking about relatively heavy pipe joints, if you can't get precise enough MIG joints on the stuff you shouldn't be doing any kind of welding on anything safety related, period. OTOH, I wouldn't be surprised if someone took a random sample of the TIG welds in roll cages and found that >75% of them either overheated the metal or were just superficially good looking but not structurally sound.
Secondly, 4130 self quenches when welding resulting a brittle HAZ around the welds which will tend to crack on impact. It's a stupid rule that I've never heard anyone give a good reason for (if someone knows of one I'd love to hear it). Other sanctioning bodies (for example NASCAR) completely outlaw the use of chromemoly in safety cages/anywhere in the vicinity of the driver. Typcally they're mild steel and MIG welded, another thing I don't get, why do they require TIG welds for "faster" cages? Done correctly, the MIG can be done 3-5x faster, putting less total heat into the metal and still getting complete penetration. Yes, TIG can be more precise, but we're talking about relatively heavy pipe joints, if you can't get precise enough MIG joints on the stuff you shouldn't be doing any kind of welding on anything safety related, period. OTOH, I wouldn't be surprised if someone took a random sample of the TIG welds in roll cages and found that >75% of them either overheated the metal or were just superficially good looking but not structurally sound.
02-16-2010, 06:26 PM
#30
my exhaust guy can throw a mig weld down that looks like a row of nickels.
there are too many damn rules is what it is.
moly can crack at the weld.
some chassis guys wont weld until they heat the pipe up within a given percentage between the pipe and the heat of the torch.
there are too many damn rules is what it is.
moly can crack at the weld.
some chassis guys wont weld until they heat the pipe up within a given percentage between the pipe and the heat of the torch.
06-02-2010, 12:18 AM
#31
the problem is you make too much sense and we want to pay $15k+ for our chassis... lol.. me and my friends have discussed this many times.... its not the welding process thats the problem... its the weldor. some people would be real dissapointed to find that many of the cages that were suposed to be tig'd were in fact mig'd and didnt even know it... a skilled weldor > process
I've put down some pretty MIG welds before, but this is one of the few close ups that I have and it's the worst possible combination of conditions, flux core (not cleaned off yet) welding cast to mild steel (in other words, roll cage tubing welds would be much easier to make much better looking, even wire brushing/polishing that up a little bit would make it look better):
06-02-2010, 05:55 PM
#32
That raises another question that I've considered... I've seriously considered MIGing a cage and trying to pass it off as TIG before (long story for the reason, I do own a TIG so it's not that I couldn't do it), but have wondered if the average tech inspector would figure it out.
I've put down some pretty MIG welds before, but this is one of the few close ups that I have and it's the worst possible combination of conditions, flux core (not cleaned off yet) welding cast to mild steel (in other words, roll cage tubing welds would be much easier to make much better looking, even wire brushing/polishing that up a little bit would make it look better):
I've put down some pretty MIG welds before, but this is one of the few close ups that I have and it's the worst possible combination of conditions, flux core (not cleaned off yet) welding cast to mild steel (in other words, roll cage tubing welds would be much easier to make much better looking, even wire brushing/polishing that up a little bit would make it look better):
Mike
06-02-2010, 11:18 PM
#33
Well, it's not really stitched mig... it's a continuous weld (well, 3 of them to prevent cracking with the cast, you can see where the individual weld beads overlapped in 2 places). (the only reason that is important to me because I can't stand the deal that some "fabrication" shops are doing with stacking spot welds done with a mig to make them look neat, really only creating a stress riser/inclusion at every single spot)
Although I agree with what you said about it's appearance otherwise, I'm not sure that would be the case steel on steel, shielded MIG and a little bit of clean up with a wire wheel/scotchbright wheel (get rid of any signs of unevenness or spattering) and then painted, I'm not sure that it would look that different.
Oh, and before you say it, I know that it would look wrong to me and I would spot it from a mile away, but a lot of people that act like they know can't seem to tell even if I'm not trying, and I've seen a lot of total junk that doesn't meet the rules get certified/pass tech, which is what makes me wonder about it.
Although I agree with what you said about it's appearance otherwise, I'm not sure that would be the case steel on steel, shielded MIG and a little bit of clean up with a wire wheel/scotchbright wheel (get rid of any signs of unevenness or spattering) and then painted, I'm not sure that it would look that different.
Oh, and before you say it, I know that it would look wrong to me and I would spot it from a mile away, but a lot of people that act like they know can't seem to tell even if I'm not trying, and I've seen a lot of total junk that doesn't meet the rules get certified/pass tech, which is what makes me wonder about it.
