CruxGNZ Posted March 30, 2005 Share Posted March 30, 2005 Here is some pictures of my chromoly 6-point cage: Picture 1 In this picture you can see the main hoop and the brace that goes between both sides had to be pushed back a few inches, because I just didn't fit if it was a straight bar. I wanted a diagonal bar in the main hoop, but since that bar was pushed back, it had to be eliminated. Picture 2 Here is another angle. You can see the bars that go from the main hoop to the strut towers. Also, the strut tower brace was tacked in. Now, here is my question about the door bars... you can see the area that is cleaned on the floor for the 6"x6" plate, but what would happen if you were to drill a hole through the floor and angle the bar to the right and weld it to the sub frame right behind the T/C mount? So, in other words, the door bar would start from the main hoop, travel downwards and get welded to the door sill, pass through the floor (floor would be welded around the bar) and have it angle towards the sub frame and attach right behind the T/C mount. Would this add anything? Dumb idea? Picture 3 Here, we deviated from the "box" that I originally wanted to sit over the seatbelt retractor for the main hoop to sit on. What the cage builder suggested, is that the bar sit in the seat belt retractor pocket and have the 6"x6" plate cut in half and cope the plate around the bar and then weld it all together. He says it will not punch through. He a master fabricator/welder and weld inspector, so I trust his opinion. Nothing has not been welded in yet, everything has just been tacked, so any comments? !M! Quote Link to comment Share on other sites More sharing options...
EvilRufusKay Posted March 30, 2005 Share Posted March 30, 2005 Matt, Unfortunately I do not have the experience to offer any valuable input. However i will say that both your idea as well as that of your cage maker sound reasonable to me. Looks great so far! Is it a S&W kit or something eles? Keep up the good work! Rufus Quote Link to comment Share on other sites More sharing options...
Jolane Posted March 30, 2005 Share Posted March 30, 2005 Matt, In response to your question about tieing into the T/C rod mount area, I think that is a good idea. I plan to tie the end of my rocker box into this area on my car. Looking at the load path in the chassis, the engine and front suspension loads (from the LCA, not the spring) go into the lower frame rails, which really don't connect well to the rocker boxes or upper spring mounts. They only connect through the radiator core support, inner fender well, firewall, and floorpans/seat mount brackets. No wonder why the front of these cars are so flexible. I feel that connecting the rocker boxes to the frame rails and subframe connectors can offer a lot in stiffness and rigidity. Maybe I am off base, but is seems like the two frames need to connect better that through 'flat' sheet metal. I will be tieing my rocker boxes into the subframe connectors in both the front and back. I plan to also box in some of the frame up front to help in flexing (hard to explain without pictures). I say tie everything in that you can though... Joshua Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted March 30, 2005 Author Share Posted March 30, 2005 Is it a S&W kit or something eles? It's built from scratch. The guy took measurements and put everything in CAD and printed it out for use in his shop since this was the first Z he has done. We had John Coffee's cage pictures found on his website (betamotorsports.com) to go off of, in terms of where to run each bar, but we had to deviate from John's design a bit. I'll talk to my cage builder tonight to see about running those door bars further forward and tying into the subframe. !M! Quote Link to comment Share on other sites More sharing options...
johnc Posted March 30, 2005 Share Posted March 30, 2005 Since you're eliminating the diagonal in the main hoop, put an X brace between the two rear braces going back to the strut towers. You have to have something keeping the main hoop from racking in case the car rolls hard onto one side. Right now, as built, an impact on the driver's rear corner of the roof can cause the main hoop above the shoulder bar to rack to one side. The X brace I mention is required in FIA legal race cages and should (but maybe won't) satisfy SCCA's main hoop diagonal requirement. The box design in the seatbelt retractor pockets is fine. An inspector will look at the weld where the main hoop goes through the plate and won't even care about the tube projecting into the retractor pocket. PLus, you now have a good jacking point! One of the reasons to build boxes that connect the cage to the chassis is to introduce loads into the cage as normal to the tubing as possible. Its better to have the legs of the main hoop perpendicular to a plate then have it welded into the plate at an angle. I wouldn't worry about connecting the front hoop tot he TC rod area. That whole front corner where the rocker, floor pan, and front frame rails come together is pretty strong and if you span those three areas with plate you'll effectively tie them together. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted April 1, 2005 Author Share Posted April 1, 2005 I was hoping you would chime in John. I didn't want to bother you with another PM. The cage was finished up last night. I was hoping to get it home tonight, but it's now raining, so hopefully I can pick it up on Saturday. The work is awsome! The cage builder and I talked about putting a X brace between the two bars going down to the strut towers, but since the Z will still see street use, I wanted to use my rear view mirror. Also, I didn't extend the door bars per your advice John. The door bars are welded to the rocker panel and then continue forward to be welded to 6"X6" plate on the firewall/floor (where the floor kicks up at like a 45 degree angle). The headliner survived, although it got a little black directly above one spot where he was welding. You can't see it unless you lay upside down in the car and look, so no biggie. Plus it's getting dyed black anyways. After that little "oops", I was holding a plate of metal between his weld and the headliner. One thing I forgot and the cage builder and I had talked about, was welding the top of the main hoop to the roof (where the hatch hinges are). Oh well, I can fab up a few tabs and weld them in myself. Maybe I'll drill a couple holes in them to look a little better than just a few chunks of 1/4" thick metal. I'll post pictures here when I get the car back. !M! Quote Link to comment Share on other sites More sharing options...
SBC_400 Posted April 1, 2005 Share Posted April 1, 2005 I would be a little hesitant on blading the cage to the body at his point, if the car is going to see any serious stress, or tortional load on a road course, you will be twisting the body alot, and if you still have all the glass in, and not lexan, you might have soem problems Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted April 1, 2005 Author Share Posted April 1, 2005 But... the chassis is a unibody. The cage is already attached to everything in that respect. With the cage installed, the chassis will twist/bend quite a bit less than stock. Unless I'm misunderstanding what "blading the cage" is? !M! Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted April 2, 2005 Author Share Posted April 2, 2005 Here she is, all done. The guy that did it does a GREAT job! If anyone in the area needs a cage, any kind of cage, this guy said he can do it. You should see his 7 second race car! . $800 for a chromoly 6-point cage, you can't go wrong. If you want the guys number PM me. Picture 4 Picture 5 Picture 6 Picture 7 If you're wondering, the passenger seat isn't bolted in, that's why it looks crooked. !M! Quote Link to comment Share on other sites More sharing options...
Chewievette Posted April 2, 2005 Share Posted April 2, 2005 Here she is, all done. The guy that did it does a GREAT job! If anyone in the area needs a cage, any kind of cage, this guy said he can do it. You should see his 7 second race car! . $800 for a chromoly 6-point cage, you can't go wrong. If you want the guys number PM me. Looks like he does good work! Your quite a ways from me, but you never know how far you have to go for good work. Let us know how it works out for you! Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted April 3, 2005 Author Share Posted April 3, 2005 Let us know how it works out for you! Jacked up the car under the retractor pocket and the whole passenger side of the car came up off the ground. I was able to open and close the passenger door with ease! Do I even need subframe connectors? I was going to do them Pete Paraska style, but if this cage is enough, should I bother? I did search on the subject of subframe connectors with a cage and the answers were mixed. !M! Quote Link to comment Share on other sites More sharing options...
EvilRufusKay Posted April 3, 2005 Share Posted April 3, 2005 Do I even need subframe connectors? I was going to do them Pete Paraska style, but if this cage is enough, should I bother? [/b']!M! I was wondering the same thing. I also got mixed results when I did a similar search. The cage looks great, thanks for posting the pics. My plan is to buy either a S&W or one from JohnC, tack it in place then take it to a local weld shop to do the proper welding. Your pics will help with that a bunch. Rufus Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 3, 2005 Share Posted April 3, 2005 Jacked up the car under the retractor pocket and the whole passenger side of the car came up off the ground. I was able to open and close the passenger door with ease! Do I even need subframe connectors? I was going to do them Pete Paraska style, but if this cage is enough, should I bother? [/b'] I did search on the subject of subframe connectors with a cage and the answers were mixed. Here's my take on this, and I've done absolutely NO testing. A roll cage that attaches to the suspension pickups or strut tower bars keep the chassis from flexing where the TOP of the suspension mounts. So the top of the struts aren't leaning out on corners, etc. Subframe connectors will work to keep the BOTTOM suspension mounts from twisting. So you brace the top of the strut and brace the subframe where the control arms bolt on and the frame rails in the front and now you've added more strength than either would alone. Again, no testing, but seems reasonable. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted April 3, 2005 Share Posted April 3, 2005 I don't know that Matt's substantial door bars aren't going to do what's needed. I for one have to wonder if "subframe" connectors in this application won't be adding more weight than performance. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted April 6, 2005 Author Share Posted April 6, 2005 I'm excited that it is all finally finished, so I had to take some pictures. Everything was cleaned with Marine Clean, then washed down, then painted with POR-15. This was my first time working with POR-15, and I have to say that stuff is EVIL! I'm glad I wore an old longsleeve shirt (which happened to be a stupid black turttle neck... did I mention is was 73 degrees today!), because I got a bit on my arm. When I went inside to wash up, I looked up into the mirror, only to see a black dot right above my right eyebrow. My jaw dropped. I didn't have any cleaning solvents around and I didn't want to scrub the crap out of my forehead with steel wool, so I grabbed some Astringent from the bathroom closet and a cotton pad. It came off with about a dozen wipes! Man, am I lucky or what? My forehead is the only spot I got some of that POR-15 on my skin. Still don't know how it got there. Anyways, here she is all pretty: Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 Picture 6 !M! Quote Link to comment Share on other sites More sharing options...
2126 Posted April 6, 2005 Share Posted April 6, 2005 Looks like a real nice job you did there Mat. I don't see any cross bracing on the main hoop. Isn't it important to have some sort of triangulation to prevent the main hoop from collapsing, in the event of a serious roll-over? Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted April 6, 2005 Author Share Posted April 6, 2005 I couldn't put a cross brace in the main hoop, because I would not fit in the car if it was there. That's why the brace that goes between the two sides of the main hoop was pushed back. John C. said it would be best to put an "X" between the two bars coming down from the main hoop to the strut towers, but after thinking about it, this car is still going to see the street, so I decided to not put them in because of visibilty. From what I understand, NHRA doesn't require a diagonal bar, so I'm okay there. SCCA I believe does require one, so I might miss out on some fun. I can still hit Road America twice a year, take it to the 1320, and have a ton of spirited driving on the street. So, I'm happy. !M! Quote Link to comment Share on other sites More sharing options...
Mike C Posted April 7, 2005 Share Posted April 7, 2005 Looks great Mat. I'm glad you are keeping its street manners in mind! Quote Link to comment Share on other sites More sharing options...
chucky Posted April 7, 2005 Share Posted April 7, 2005 looks great hope to see ya at RA Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted April 7, 2005 Share Posted April 7, 2005 Matt, Looks great man. The main hoop fits like a glove.. Might have to get your mesurements on that !. Great job Quote Link to comment Share on other sites More sharing options...
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