JMortensen

Not your fault. The conduit was right, I guess I just got excited and didn't do a good job measuring it when I did the actual halo. Good news is I was able to get it in there without wasting any material. I probably could have saved 2-3 hours if I had just bent up another piece of tube. I F'd around with that thing for a long time trying to make it work.

Generally a 6mm bolt will have a 1.0 pitch, 8mm will have 1.25, and 10mm will have 1.5 on a Z car.

It's going to be close. What I'd suggest is you remove a spring and jack the current wheel up and down and measure for clearance before you spend $$$ on the new rims and tires.

Holy crap what a day! First thing I did was figure out that the halo was not bent correctly. Turns out the Z roof is narrower in the front than in the back. I had measured the back of my template and made my halo that width, which was about an inch and a half too wide at the front, but fine in the back. So first thing I did was to make the bends in the halo closest to the center a little tighter. Then this moved the ends in REALLY close together. I think they were at something like 36" apart, need to be 41 to fit my hoop. So then I spent hours spreading the ends apart with a portapower. Finally I got it to where it looked like it would work. The bent ends that connected to the hoop were too long (purposely left them long) so I took a couple inches off there, then went to fit the thing. Turns out the ends were still about an inch and a half too close together. I tried some more with the portapower and found that when I spread them apart the front spread enough that it was a real problem. SOOO.... I broke out the bender again and tried my damndest to put a little flare on the ends of the tube to bend them out. This did not work very nicely and I ended up having to use a hodgepodge of parts from my HF bender and the new one, but I got it fairly close. Then started to notch the tubes. Got everything notched and figured I had it pretty well finished, only to learn that my notching had shortened the tubes and they were too close together at the ends again. So out came the portapower and I had to spread the halo while tacking it in. First attempt at that went poorly and the front of the halo was hanging down too low. Took it back off, fixed the notches a bit and tacked it in again, and this is what I was left with. Not the tightest to the roof that I've ever seen, but I think this is pretty close to as tight as you can get with the 1.75" tubing. Also the 1.75 tubing makes it really hard to get the tube above the door frame. I managed to do it, but just barely. With this tacked in place I did find that the drivers side is contacting the roof (first picture shows this). I don't know if this really matters too much, but I kinda figured on taking a hammer to the inside of the roof there after I cut it off to do the tops of the welds, since you won't see that part anyway once I get roll bar tubing on there. Moral of the story: Measure your hoops and halos all the way down, don't just measure at the end. Oh... and buy a portapower...

Is your tach clocked like that because you plan on running 8000 rpm?

Wow... that oughta do it... Thanks for the pics. Looks like I'm headed the halo bar route but I do appreciate it.

The rules change every year, but here is the page with SCCA's current rulebook: http://www.scca.org/Club/Index.asp?IdS=125B8C-71641F0&x=030|057&~= Anyone building a cage really should figure out what type of racing you're going to do FIRST. Many of the rules in the post above only apply to you if you're RACING with NASA (door to door). If you just want to do time trials or track days, then those rules don't necessarily apply. I'm sure they won't allow ANY cage on the track, but there won't be as many limits to the design of the cage if you're not trying to fit a given class. Looking at the rulebook will give you good guidelines for proper cage building, but you might not need to follow them to a T if you're not competing in a given class. For instance, the IT class Z car allows a 6 point roll cage with no bars through the firewall. They do this to prevent competitors from strengthening the chassis and gaining an unfair advantage. A GT3 (I think they moved the Z to GT3 this year) Z car can have a full tube chassis. The weight requirements are also different. The engine requirements as well as the brake requirements again are different. The point is pick what you're going to do first.

Since you're asking for opinions, I have one I'll share. The flare should be convex instead of concave. I think they do that for appearance's sake, but the problem is that there isn't that much room for the tire to move up inside the flare. That said, if it doesn't rub then don't worry about it.

Halo is bent. Came out nice vs the template, I haven't tried to put it in the car yet. I spent at least 5x as much time looking at the stupid thing making sure I was bending in the right place as I did actually bending it, but without actually testing I think I got it right the first time. We'll see tomorrow...

Thanks John. I just needed a little reassurance before I got to it.

Does this look about right for a halo? I don't think I can get it any closer. Using conduit to bend a template per Coffey's previous suggestion...

I drilled holes in the rails on the sides and used sheet metal screws to pull the floor down to the SFC. Worked great. Pics in here: http://forums.hybridz.org/showthread.php?t=106974

I put holes in mine. I'm also going to use those holes to spray Zero Rust in there to seal them from the elements. If you look none of the frame rails on a Z is watertight, so I think trying to make the SFCs watertight isn't really necessary or practical.

The way my main hoop was bent I don't think I could have gone through the floor even if I wanted to. It was very tight in there. Also at the time I was going to do a roll bar and not a cage. Then after a while I decided to do a full cage instead, but the roll bar was already welded in. The plan is to cut the entire roof off at the A and B pillars, after tacking the cage in. Halo vs A pillar bars... I was under the impression that halo bars were stronger. I'm not married to either idea. I know bjhines was worried about putting more than 2 bends in the A pillar bars, but I haven't seen any rule in the SCCA book that says anything about the number of bends in the A pillar bars. On the bender, keep in mind that I'm using about the largest tubing it's made to bend. They say its good for up to 1.75 x .134, I'm using 1.75 x .120. I'm sure if I were using 1.5 x .120 it would be a lot easier. Even as it is, I may have overstated the difficulty if people are getting scared away from it. I don't have the bender bolted down, so I'm able to hold it on the table with my left hand while pulling the handle with my right. I just thought it was interesting that it took so much pressure to start the bend, then once going didn't take as much to keep it going. So far I'm nothing but happy with the bender.

Clean the caliper where the pad hits with an old toothbrush. Get all the dust out of there. Then put a LIGHT coat of synthetic brake grease on the back of the pad where the piston hits it and also on the edges where the pad contacts the caliper. You might also chamfer the leading edge of the pad while you're in there. That should solve the squeak.

I figure since I finally have something more to report here, might as well change the name of the thread and give the update. Just over a year later, I HAVE INSTALLED THE SHOULDER BAR!!! WOO HOO!!! I guess it's not like I haven't done anything else in that time frame, but I did finally get a bender that works from http://www.speedwaymotors.com and I finally got some tube and finished up the shoulder bar. I'm happy with how it turned out, and now that I have the tools I expect to continue on with the cage, trying to get the main part done before I move, but that's going to be tight at best. Some pictures: I guess I didn't update when I did the X brace, so here's that thread for anyone interested: http://forums.hybridz.org/showthread.php?t=119861 Next up, bending the halo. I'm really a little freaked out about trying to bend this sucker, but I guess the worst that happens is I waste a piece of tubing or two or three...