JMortensen

OK, so is there a reason why you attached to the tower rather than the bar on that roll bar you did? Is there another advantage to one over the other? I can see one advantage as far as installation in that it would be easier just to notch the tube on each end and weld it than to make a plate and weld the plate to the tower then weld the tube to the plate.

I looked long and hard at that picture, but I have already welded in my strut bar and it is .095 wall based on John's and Drax's previous suggestion in a long ago post. Maybe that doesn't matter, but it seems strange to use .120 and then attach it to .095.

That sounds like fun. Just did the Hwy 1 from San Luis Obispo to Monterey a couple months back. Great drive. Have fun.

It's been discussed before Alex. You can search and find it in greater detail. Bottom line is removing the springs from the suspension, disconnecting the sway bars, moving the suspension up and down in the normal travel range, and measuring the toe change that happens while the suspension moves. I measured mine with a makeshift bumpsteer gauge. I used 2 dial indicators, one at the front of the rotor and one at the rear, and I jacked the body of the car up and down, not the suspension arm.

No, I just remembered learning what they were for, and who told me.

Thanks John. The more I look at it the more I like your design over all the others I've seen. Any idea how straight the supports have to be? I suppose if I weld to the top they can be pretty damn straight, just curious if there is a rule. BTW for anyone else looking at NASA's rules pretty much says "refer to SCCA's rules".

Read zcarnut's post #10 on this thread: http://forums.hybridz.org/showthread.php?t=101811

Oh yeah. Forgot about that. Weld in. I've got the hoop covered. 4 bends, 180º. That part I'm not worried about. I think I'm just going to plan on making some platforms to set the hoop on and weld to it there. I like John Coffey's bar that he did for a customer. He scooted the front legs of the hoop forward then leaned the whole hoop back so that there is more seat clearance. Plus I am going to get a 10º layback seat, so I think I'll do OK on seat clearance. That's the type of info I guess I need. I'm not going to be racing with SCCA most likely though. I guess I should check with NASA. This is going to stay an autox/track day car for a while, but I'd like to build something that I can use later on if and when I do decide to do some door to door stuff. Maybe I should just build what I want then screw with it later if some sanctioning body says it's not appropriate. Diagonal crossbar and horizontal brace are also part of the plan, BTW. Definitely planning on attaching to the roof and sides, not planning on an X just due to the extra weight.

Nobody has anything on this for me? I did see a roll bar in a pickup truck today where these supports were clearly angled. Not sure how pickup roll bar relates to car roll bar...

"Education" is code for "Socialist". Sheesh, I thought you knew that already.

OK I think I might have figured out part of the answer. If you brace on the sides then the brace is way out wide on the bar, and when you tie that into the strut tower, the bar will either have to be angled inwards quite a ways, or will have to tie to the top of the strut tower to be straight. Is there any problem with it being angled? Seems like that would make it weaker in case of a rollover. I did already weld a tube between the strut towers, would like the braces for the main hoop to attach near that other tube if possible.

I've looked at quite a few different designs for roll bars and cages now, and I have a question or two. I intend to do a 4 point bar with the two supports attaching to the strut towers. My question is this: Is it better to attach the supports to the TOP of the main hoop, or to the SIDES of the hoop, or does it even matter at all? I've seen em both ways, just wondering if one has an advantage over the other. It seems to me that it would be a lot easier to weld everything if the supports went to the sides of the hoop instead of the top. It could be easily welded inside the car by popping out the quarter windows. If it needs to be on top then it's a little trickier. I've seen 3 solutions, and if anyone has any feedback on these that would be appreciated too. 1. Cut holes in floor with hole saw, slide hoop down into holes, weld the supports, lift back up, slide plate over hole and under bar, weld bar to plate and plate to floor. This was a method used for cages, not bars, might not apply to what I'm doing. 2. Cut hole in roof, weld bar, weld patch in roof. 3. Tack everything, take out of car, weld, put back in car. I guess sometimes this is pretty difficult to do depending on the design of the bar. I think this would be pretty easy to do on mine, especially since the car has no interior right now.

Have you seen http://www.picklex20.com? The more I learn about it the more I like it. I have ordered some for my car but haven't received it yet. What it does is coats the metal and leaves a light protective layer. It isn't a final coat, just a treatment for the metal. The thing I like most about it is that it actually IMPROVES weld strength, because it removes all the rust so that you're weld doesn't have any rust in it. Also, welding doesn't remove the coating. I'm going to use it on the rest of my project, then cover that with Zero Rust, then paint on top. I'm pretty confident that should do the trick. In the hard to reach spots, I got a blaster thingy from Eastwood. It's like a little paint pot with a 3' tip on it and you shove it into holes and blast the inside of the frame rails, etc. So I'm going to blast the picklex20 in there, then weld what I have to weld, then blast Zero Rust when I'm done.

Have you tried cutting some length off the little spacer in between the bushings and get a shorter bolt? I don't know how much "extra" thread there is on the bolt when everything is tightened down, but you might be able to just cut the bolt a bit for a little more clearance if that's what rubs. Also, I don't think this will affect the clearance much if at all, but did you space the bar away from the uprights? Supposedly 1/2" spacer in there prevents the bar from binding. My plan on mine is to cut the end of the bar off and weld a vertical plate to it and run heims joints. That should make the end link even shorter, but that's a whole lot more work.

Isn't this kind of a pointless argument to be having here? We aren't building ships, we're welding .120 wall tube. Mig should be more than sufficient if its done properly.

Agreed. Doesn't matter as long as you're not sucking air back in. I prefer the open and pump it method just because it takes quite a bit less time to bleed.

It really depends on what kind of driving you're doing. Running a quart low on a drag car isn't going to cause any problems, but running a quart low on a road racer isn't the best idea. PeterZ has it right. When my buddy lost a main bearing in his 510 it gave no signs other than starting to lose power. After a couple turns the lack of oil pressure showed on the gauge, but by then it was too late. This was on a stock L18 pan and slicks, FWIW. We both got baffled pans after that incident.

Anybody besides me ever actually see a Monster Miata? The only thing monstrous about the one that I saw was the understeer. I just can't imagine that this thing would be any better. I suppose if you only like to drive straight though...

My friend welded the leaf spring perches for his Toyota 4x4 with a flux core welder. The welds were ugly, but he took me through the Rubicon trail with that truck just fine. It just seems a shame in your case to have such nice machining be stuck together with such ugly welding. I'd suggest you see how much a professional would charge to weld it all up for you. You could even tack it all together then have a pro finish it.

Everyone I autoxed with ran wider front track, except the 911s. When I first heard about it I thought it was a FWD thing, but nope. From Mustangs to Ford Fiestas to 510s to Z's everyone ran wider front track. Nice thing for me was with adjustable front control arms I was able to screw them out to get the wider track instead of using wheel spacers and this also gave more available negative camber. The combination of track and camber definitely made my car turn in better.

Didn't you also run like 5º of timing at idle Bastaad? That would be about 22º timing with all the mechanical advance in on a ZX dizzy, so if that is right, then you also had to cut down the total timing to keep it from pinging. There's a lot of power in that last 10-13º