ccage were talking about this earlier today and I was wondering if anyone had any thoughts on these -
LINKIE
The thought is we could just tack weld it together and have a professional welder come in and thoroughly finish the welding.
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ccage were talking about this earlier today and I was wondering if anyone had any thoughts on these -
LINKIE
The thought is we could just tack weld it together and have a professional welder come in and thoroughly finish the welding.
I think you'd probably be better off taking the car to a Spec Miata or other local track car builder and having them design and build a custom cage for you and your car. Probably wouldn't cost much more, and would likely weigh a bit less. I've always been a little leery of "one size fits all" cage solutions, especially in a car where space is at such a premium like the Miata.
good info from MarkP on the :batman: board:
Quote:
Not much is going to get me to post publically around here, but this issue is one that is critical. The design and creation of a safe cage is just not something that anyone with a MIG welder and a harbor frieght tubing notcher should be attempting.
1. There is alot that goes into the proper design of a good roll cage.
2. Heat affected zones must be dealt with appropriately or you'll have a cage that is simply not going to do it's job when it counts.
3. Even the tubing must be picked carefully DOM tubing is considered a must have for uniform wall thickness.
4. Bending hoops is NOT easy, They must be bent carefully without creasing the tubing.
I might, build my own cage, but even then I would run my design by a real Mechanical Engineer with FEA software to insure that I was not doing something stupid as well as every track person I could find.
If you MUST build your own cage, then remember that the triangle is your best friend. It is the strongest structure that you can choose. DO NOT USE UNSUPPORTED SQUARE STRUCTURES. X Brace everything you can within reason if it looks like a square or rectangle.
Your welding must be top notch. YOU SHOULD TIG WELD ANY ROLL CAGE IF POSSIBLE. MIG is acceptable but you better be damn good. Weld Pentration and Heat Affected Zones are critical. Roll hoops should ALWAYS be one continuous loop of tubing consisting of less than 180 degrees of total bends.
When in doubt examine rule books regarding cage specifications. The more rule books the better, find rules for cars that exceed the performance of your car and weigh the same. That may give you a good grounding on why it would be prudent to choose a professional to build your cage for you.
Mark
why are there nascar bars on the passenger side? no form of racing around here allows passengers.... dead weight too.
Some thoughts:
I totally agree with most of the crossposted writer's comments. You do see a whole lot of this "you MUST TIG weld this" stuff around ever since the Discovery channel started running all their popular fabrication shows. There's no doubt that TIG lets you weld with the least additional heat, but there's no reason that a quality MIG, Stick, or even gas weld can't be just as effective in terms of strength. Consider that aerobatic aircraft (and race cars and, yes, roll cages) were built this way for years.
OTOH, I wouldn't be afraid to save a buck by notching and fitting a well engineered kit, then taking it to a professional for final welding. There are some great sites out there regarding notcher designs and techniques. Of course, if *I* (as the newbie I am) was doing it, I'd start with simpler, less mission critical applications first. (Which, incidentally, is exactly what I'm going to do!)
I'm still at the "weld together test stuff and cut it apart" phase -- and having fun learning to measure and plan by building stuff my life doesn't depend on.
As far as Bean's original post here goes, I'd consider a bolt-in, though. It'd sure be a lot easier to deal with if you wanted to change cars, etc.
Chuck
Don't know exactly where this post started or where it's going, but one of the best Spec Miata cage builders just happens to be in our backyard. Todd Opperman has been building cage for about ten years, and has done a large percentage of Spec Miatas in Texas. They are the best designed, triangleted, and braced cages I've been in. He works with Shannon McMasters at Motorsport Ranch. I don't have his number, but I'm sure someone around here does......
This is where I throw my 2 cents in on full cages.
ONLY INSTALL CAGES IN FULL RACE CARS. ONLY GET IN A CAGED CAR WEARING A HELMET and SITTING IN A FULL RACE SEAT WITH SIDE REINFORCEMENT WEARING HARNESSES.
Otherwise you are adding more risk to yourself.
Padded or not, if you head or body come in contact with a bar during a collission, you head or body will lose.
Bean, this is the best nugget of info yet... It seems to me that you're going to want to drive this thing around for fun, and he's dead on -- if you get hit hard in it when not wearing a helmet, you're hosed.Quote:
Originally Posted by Screamin'Screw
This is the tough part, isn't it? A full cage opens up safe "track days" to you, but makes the car unsafe to run around in. A bar (like you have) is more protection than you need autocrossing, but less than you need for safe track driving!
This is what's always kept me away from track days. All reputable road racing organizers have much higher safety equipment requirements than do the track day organizers, but you're driving on some of the same facilities at similar speeds. Sure, it's tempting to say, "I won't be driving at race speeds" or "most shunts come from going wheel to wheel," but both of these are not really true.
Anyway, sorry to rattle on... I think the tough question here is, "What do you want to do with it?"
Chuck
Sounds like it's time for someone to make a quick release roll cage kit. I am sure that would cost a pretty penny! :shock:
That's where I'm torn... do I want to dedicate this car to track days? or will it be used on fun runs...
Obviously, the safety features inherent in a full cage are also a huge cause for alarm when not using a helmet. So the debate continues... :)
Hey Sparky have you done a track day yet? :wink:
It's hard to ignore the following! :shock:
Quote:
Originally Posted by Screamin'Screw
No I have not attended a track day yet. I would like to in the near future. One of my original ideas was to make my little BUR a track car.Quote:
Originally Posted by POS Racing
I think SS made his point quite well -
I have a racing seat that was going to, someday, hopefully sooner than later, be installed in a full caged car made for and used at track days. Perhaps even Spec racing (I can afford to move in that direction)... my goals as such are still undefined... I find I'm having too much fun AutoXing for now. Perhaps that will change after I've tried a track day.Quote:
Originally Posted by Screamin'Screw
But, for now, the question was asked just as a point of reference. I don't intend to have a cage put in anytime soon... I was just wondering if there were any benefits to purchasing a pre-built cage versus a custom built.
I've been doing track days for a couple of years now. Because passing is in limited sections of the course and nobody is out there to trade paint, you have a very little chance of needing the protection level offered by a full cage. In a full out race situation, YES, you need a full cage and all the safety equipment prescribed in the SPEC manual (probably more), but for the street - no.
However, I see accidents on the streets all the time and the results would normally be death or very serious injury caused by the cage if installed. So for regular drivers education weekends, a simple rollbar extending 2" over the driver's head is generally considered enough protection.
If your waffling, I would go with a regular roll bar. You can always go back later and put a full cage in. It's real difficult to go the other way. The choice is obviously yours, but keep in mind a car with a roll cage has no trade in value.
Just to keep perspective, a competitive Spec car is going to run in excess of $15,000 and it will take about another $5000 in support stuff to run one car. That's before you have even entered a race. I would get REAL sure you want to that before you toss your hat in the ring.
Your first year in SPEC expect to be bringing up the rear. After that you got a SHOT at being competitive if you can keep your car running. To be top 5, expect to be shelling out $8-10K per year to keep one car for a whole season.
Track weekends on the other hand are about $400 - $500 per weekend all included (track time, Parts, Tires, Hotel, Transportation, beer). A whole lot less stress and just about as much fun.
Trade in value? You've obviously never laid eyes on my car.Quote:
Originally Posted by Screamin'Screw
I appreciate the comments about the street use... but again, if I did have a cage built for the car, it would leading to time in Spec racing... (lofty goal for now, but I'd like to say that I tried it...)
I have a roll bar now... and I enjoy its protection. However, if I did go to a full Spec Miata, obviously, it's days on regular surface streets will have come to an end. Again, as for now, I'm enjoying the AutoX... the eventual fate of the BUR (read $$$'s) is still in the air...
You may not be aware of this but take a look at NASA's drivers education. www.nasatx.com You will start to progress towards your competition license without needing a SPEC car. Frankly, it's cheaper to buy a used SPEC than to try an build one.
Have fun!
This is the exact argument I mentioned... Many track shunts are not caused by "trading paint" but rather by driver error or mechanical failure. I can attest to this as my one big track accident involved no other cars, and a bar wouldn't have been enough to protect me.Quote:
Originally Posted by Screamin'Screw
Don't mean to offend here -- hopefully everyone has that alligator skin I see mentioned in the forums... 8)
FWIW, I totally agree that street driving with the cage is unsafe, and I'm truly glad you brought the point up.
Chuck
ccage,
I am sorry to hear that you were in a situation where the cage helped. I can only imagine how scarey that must have been. I will agree there are situations where the full cage is the way to go. I just can not imagine that being the entry ticket to drivers education weekends.
That being said there is a VAST difference in safety between DE weekends. NASA weekends are designed to produce racers and they take more risks. I think DE weekends put on by manufacturers like Ford are the riskiest because they offer so little education and really just tell the drivers to go out there and test the limit. My favorite for beginners is The Drivers Edge (TDE) because you MUST have an instructor in the car until the instructor feels you are ready to solo. BIG difference. Does TDE have incidents - yes, but I feel like they likelyhood of a bad incident is greatly reduced. Yes, mechanical failure and/or driver stupidity can be a significnat risk factor, but since over 90% of beginning DE drivers drive their car to track and plan to drive it home, I think there is a balance of risk there erring on the side of getting them to the track and back home in one piece.
Thank you for your insight, there are not that many people that have actually had to use their rollbars or cages. Your kind of in an elite club. :thumleft:
I guess I brought it up, so I have to now admit my stupidity.Quote:
Originally Posted by Screamin'Screw
Actually, it wasn't as scary as you'd think. Getting hit on the road with only a lame three point shoulder belt -- that's scary. One time my Dad and I (this was quite a while back) had pulled off the road in his '86 Mustang convertible to look at a map. A guy came barrelling down an onramp, drifted off the road, and creamed us going about 60. I still don't remember it, but my Dad says I rotated around the belt and whacked my head on the dash hard. He said I wandered around asking over and over again what happened because I only had about 2 minutes worth of memory. (Insert "now I know why you're the way you are" jokes here.)
OTOH, the track incident wasn't so bad as far as personal injury is concerned. I was doing my second SCCA driver's school at Charlotte, NC. We used the oval start/finish, then turned into the infield, ran the full infield, then back out into the start of turn two and around the oval.
I had figured out that slow and tight into turn 1 and 2 (as opposed to fast and to the outside) would give me a much better setup for 3a and 3b which meant carried speed down the short chute -- and much faster lap times. Well, eventually it got away from me and the tail end came out in 2. My instructor says (in hindsight) that I should have turned into it and allowed it to spin up the middle of the track which would have slowed me down and made it a zero-impact or low-impact incident. But being the vastly experienced racer I was -- one other school -- I straightened it out... not thinking about how I *really* needed all that space for braking.
I shot off 3a at an angle, rolled across a ton of wet grass (which has a negative coefficient of friction, I believe :roll: ) and hit the concrete at about a 45 degree angle going about 50 mph. I hit hard enough that the car rotated in the air and the back end of it hit the barrier as well.
All of this surprised me because I was expecting to fly around and get the crap knocked out of me like a street accident. Not the case at all. It was just a big BANG and my arms moved a little. I remember thinking, "Wow, that wasn't bad -- the car must not be that damaged!" Wrong. It rolled, which made it easier to push on the trailer. Truthfully, riding back to Florida with the guy I'd rented it from was WAY more dangerous...
I was in an RX2 with a full cage, a halon fire system (thankfully not needed), and a six-point harness. I was wearing an approved fire suit with Nomex long johns, socks, and balaklava. And, of course, a Snell SA approved full face helmet. We determined that I did indeed whack my head on the cage (by finding black cage paint on my helmet in a matching gouge).
More like that "dumba**es who can't stay on the track and had a short road racing career because they spent the next year paying for the car they wrecked" club. Doh.Quote:
Originally Posted by Screamin'Screw
Chuck
:shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock:
That's the most amazing story I've heard all month.
S.
It's interesting that you point that out. A couple of years ago I was hit on the track by another car at a lapping event. I remember feeling the same way you did about the accident - at the time I had on a Nomex driver's suit, full-faced SA helmet, arm restraints, a 6-point harness, and a rigidly mounted FIA-homologated track seat. Thankfully I didn't need the roll bar, as the car stayed on its wheels the entire time.Quote:
Originally Posted by ccage
It is amazing how much less brutal an impact is when you've got the proper safety equipment.
There are a couple of things to take away from that story. First off, harnesses, helmets and Racing seats do wonders. The ability to firmly plant you ass in the seat and keep it there during high G impacts should not be underestimated.
Secondly, even with all that restraining equipment, your noodle still managed to find the bar. Your soft tissues and neck in particular can stretch and contort in amazing ways in a high G impact. Hence the need for a good full face helmet.
You neck is holding up a 10 lb bowling ball plus a helmet. In a collission G forces can exceed 100Gs making your head the equivalent of 1000lbs.. Protect the noodle out there boys.