Andrew Bayley Posted November 7, 2000 Share Posted November 7, 2000 S&W supplies all the plates needed to weld the cage to the body. These pieces made my installation MUCH easier. Do yourself a favor, invest in a really nice gasket scraper. This will be needed to remove the insulation material off the floors. I started off with a large screwdriver and that just didn't cut it. It was tempting to use an air chisle, but I kept reminding myself that I was working on Japanesse sheet metal from the 70's. As for Gusset's, I believe S&W will sell a bag of twenty or so for cheap. Try them first. Again, good luck -Andy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 7, 2000 Share Posted November 7, 2000 Search for 'dry ice' - it takes tar insulation off fast-n-ez. My cage is just bars, no plates or anything. Are they just square plates of mild steel? Nothing special about them is there? ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted November 7, 2000 Share Posted November 7, 2000 quote: Originally posted by Morgan: Any comments on gussetting the cage? like little triangular pieces of plate welded at the inside angle of every joint? Is there a danger of making a cage too stiff(I can't imagine that) or anything like that? Any suggestions on attaching it to the body? Just nice big plates to weld to, nothing special? I haven't done it yet but did all my background for it. You won't typically see my suggestions done as they're not common knowledge. My advice and drawing came from an ex Nascar chassis/cage builder and current member of another race team under confidence. You can make your connections too stiff...YOU want the car and cage to behave as one. Connected well their strength is far greater than sum of two parts. He rec'd a full weld of your tube ends to your anchor plates. (here's the switch) BUT your anchor plate to car welds he rec'ds staggered welds of (I'd have to look up my dwg) ~1" weld 1.5" gap and 1" weld etc as you go around the plate perimeter. This allows this connection to flex WITH the car keeping max strenth (cage alone or car alone is no good to you). If it were too stiff it could be inclined to separate from a flexing car. Other v. important point he stressed was having your main hoop as TIGHT to your body as POSSIBLE. Even if you have to winch it together with a cum-a-long to get it inside the car/into position and then when it relaxes it's tight to your outer pillars. You then want it TIED IN to your pillars and roof every 18-24" with a small tab welded to hoop and roof/pillar. This again combines the cage/chassis strength for a greater sum. Keep in mind that's my version of what he stressed but I feel I relayed it accurately and it makes total sense to my engg mind. PS he mentioned many rear tower connections are done v. poorly and will punch thru their tower easily (ie. tower approaching your head!)when done with a fwd facing plate on one edge of tower. I'd have to check the dwg for detail on this connxn. AIR a top integral cap was preferred. Hope that's discernable...He hit a wall with just a race rollbar at 140mph and walked away so has benefitted from his attention to detail (since then he won't do motorsports w/o a full cage) There's more than one way to meet a spec, Mine will be done locally by a guy I trust who agrees with my expectations. ------------------ Of all the things I've lost, I miss my mind the most. Quote Link to comment Share on other sites More sharing options...
Owen Posted November 8, 2000 Share Posted November 8, 2000 My S&W kit definitely has a seam in it. I knew from the beginning it would be ERW, electric rolled weld??? Mine is the 14point kit. Roof halo is too wide to be mounted up high without cutting a portion out of the middle. Door bars won't fit, mine are straight btw, because my Corbeau seats are in the way. Same problem with the rear braces as mentioned above. Frame supports will have be cut shorter if I want them to land on the subframe connector. Anyone else having issues? I'd like to "work together" on this installation. Maybe a new thread? I need suggestions and solutions for where the main hoop feet will be located, etc. Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 8, 2000 Share Posted November 8, 2000 Owen, I have the S&W 10pt cage and was out in the garage late Saturday evening/early Sunday morning placing the cage in the car trying to get some ideas. I was armed with printed out pics from MikeKz's site and the printed thread from Andy back on June 19th. I have come to the conclusion that the main rear hoop is going to have to mount in the seat belt cups. What I will probably do is fit the "footers" in the cup first then remove them and weld the hoop to the "footers". Then place that assembly back into the cups and weld the "footers" into place. I believe it would be easier welding around the perimeter of the footers than attempting to weld around the perimeter of the tubing placed in the cup. I will probably do a modification to the cage much like MikeKz's to move the bar running across the main hoop back three inches. I knew the first day I received the cage I would not be able to run door bars so that really did not bother me. I believe you could have some custom bars made up if you really need them. The top "halo" on my cage seems to fit fine. The one portion of the cage that concerns me are the front support bars that meet the front of the "halo". They appear to be ~3" short of optimal. Once again I am not really concerned as I will just butt weld a small piece of tubing to the bottom or just contact S&W and have two new ones bent. I don't know how Andy mounted his main hoop above the seat belt pockets as on my car there is only ~1" there and it would not support the diameter of the tubing. I have a 280 so maybe this is the difference? It seems that if there were room to mount it up there it would be easier than mounting it the seatbelt cups. By the way, what model Corbeaus do you have? How do you like them? How do they fit? I am 6'2", 210lbs and am looking at seats now. I want to get my seats mounted in the car before doing the cage (Thanks Mike Kelly for SAVING me on this!!) to make sure there will be no interference. I agree, maybe we can "work together" on this as the more input we have the better. I hope to start the project this weekend or next. Thanks, Chris Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted November 8, 2000 Share Posted November 8, 2000 Dry Ice, hmmm... I'll have to try that next time. I received eight 4" x 6" plates of 1/8" thick mild steel with my cage. Your right, they are nothing fancy. I think even Home Depot carries this stuff if you didn't get it. Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted November 8, 2000 Share Posted November 8, 2000 Oh my god, Someone is actually using what I said as an information guidline... Seriously though, Chris, I'm not surprised to hear that you've only got ~1 inch above the seat belt pockets. There are a lot more subtle differences between the 240/260 and the 280 than most people think. My ledge is about 3 inches wide. I did the same thing you mentioned where I welded the tubing to the flat plate then welded the hoop w/ attached plate to the car. The way that the main hoop was sized from S&W it appears that they intended the main hoop to sit in the vacinity of the retractor pockets. However in my 260, the loop would have been at a slight angle to the B-pillar (due to the 3 inch ledge above pockets) if I decided to go this route. Also, I was interested in retaining the passenger seat belt. Very interesting thread we got going here. I'm wondering if we could at least put together a FAQ and put it up in the technical documents section of this page. -Andy P.S. I'm going to try like hell and get some digital pictures of the cage this weekend (in storage at Dad's place). Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 8, 2000 Share Posted November 8, 2000 Andy, I think you are right regarding the rear "ledge" in front of the wheel wells. If I remember correctly, when Pete was over he looked at my car and said that he had more room up there. I would really prefer to mount it up there but there simply is no room on my car. I am going to run race harnesses so the seatbelt cups being "used" does not concern me a great deal. My Dad has a buddy that he works with that builds race cars, maybe I can get him to come up one weekend and give some advice on the best way to install the cage. I will then pass on the info to all interested. Has anyone extended the cage through the firewall to tie into the strut towers? This is something I want to do but I can't decide if I want to create the triangle by the tubes running towards the center of the car through the firewall or outwards to tie into the "halo" supports of the cage. Those of you who have Bob Waar's book "How to Hotrod and Race Your Datsun" take a look at page 133 and 134. Thanks, Chris Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 8, 2000 Share Posted November 8, 2000 The term ERW stands for Electric Resistance Welded. Its just the method of welding the tube as it comes from the roll dies. As you all probably know, it starts from flat sheet, is rolled into a tube, then welded as it passes through the machine using high frequency electricity. It uses no filler rod like traditional arc welding. Here is a picture of the process: DOM tubing is basically ERW tubing that was then cold drawn (over mandrel) to a exacting inside/outside wall thickness dimensions. I believe it is also x-rayed/analyzed to look for any potential weaknesses in the seam. To quote a site on its uses: "D.O.M. is used for a tremendous variety of machine parts where closer tolerances and higher mechanical properties are needed. Hydraulic cylinders, spindles, office chairs, jacks, printing equipment, rollers, motor housings, elevators, air hammers, fans and shafts are just a very few of the applications utilizing D.O.M. tubing." There are like 6 different types (grades) of mechanical tubing, the three most commonly used in auto applications are: ERW,DOM and 4130. Erw being the weakest, DOM being stronger and 4130 being one of the strongest and is used mainly for suspension applications. As Mike pointed out, DOM is lighter (and cost 3 times more generally) and many racing bodies allow a thinner tubing if DOM is used. Also as stated above, Nascar's are setup to flex and are not as stiff as some may think. They actually have to include the chassis flex into they're handling setup. A quick word on 4130, it usually requires special welding techniques (ie, preheating) and its generally only used sparingly because of the expense and hassle of joining it. To quote a extremely good metal fabricator: "My suggestion on 4130 use is don't." By this he meant only use in some applications ( like the cool looking tubular control arms and suspension pieces we see used in alot of the racing cars). Oh well, thanks for baring with my long post. You have now passed metallurgy 101, go out and amaze your friends and family. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Owen Posted November 8, 2000 Share Posted November 8, 2000 Chris, I have the Forza model Corbeau in the driver seat, and the Clubman in the passenger. The Clubman has a better angle on the back but is too narrow at the shoulders. The Forza shoulder supports are pretty wide and almost hit my door panel. I am only 5'6" so I will not move the seat crossmember back any further, I won't even use sliders for the seat because it is as far back as it can go already! If you are bigger than me, I recommend a bigger seat. Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 8, 2000 Share Posted November 8, 2000 Lone, THANK YOU! I love it. Technical content from someone in the know. PLEASE keep it up! I had no idea DOM was ERW tubing taken over a mandrel. I didn't know how it was done, but supposed it was hot solid bar taken over a mandrel. Duh. Thanks for setting me straight! I think if we ever do get an FAQ going on this site (Hmm.) this post goes in straight away. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com - Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 9, 2000 Share Posted November 9, 2000 Not to run it into the ground, but there is also seamless tubing. Its made like Pete was saying. Heres a quote on its manufacture: "A heated billet moves through pressure rolls as it is driven over a stationary mandrel to produce a hot finished seamless tube. This hollow is then cold drawn through a die and over a mandrel to precision finished dimensions." This is called cold drawn seamless tube, and it supposedly machines better than say DOM at least thats what I read. To make it all the more complicated, some of these tubings can come in different 'chemistries' as they say meaning different tempures etc. For our uses, we just need to worry about the three I mentioned earlier. Now... Back to roll cages! Lone [This message has been edited by lonehdrider (edited November 09, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 9, 2000 Share Posted November 9, 2000 I have no worried about using welded seam tubing now, considering it appears that all tubing is welded! Picking it up this weekend! ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
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