whatset

Thanks for that! Nicely done, have bookmarked your pic set and will forward to my guy for some brain food. Appreciated.

I got the least expensive hardtop I could find - an FRP one.

This does not get in the way of your knees? The business end is a bit lower, but I have to ask. I think it would mess with me mentally, but IDK. I'm 6ft, 230ish and do not fit in the stock configureation of the car all that well. But thinking a hard mounted seat and a Sparco 353 will fix that. Is that the wheel you are running as well or is it the 260? Ergonomically my seating position is very 'mom' like on the track. I prefer an upright position and like a fairly close wheel that I can be strong on. Looks good in the pics.

speedengineer

My cage isn't perfect, but it has quite a few nice features imho. My site has plenty of pics. There are some pics showing another option to make the 'footing box' like Rob was talking about a bit more low profile. My leg/ankle/foot has plenty of clearance there. I also second the method of attaching the footwell bars to the frame rail area in between the brake and clutch. The firewall is far, far stronger there, rather than just thin sheet metal that feels like a pop can when you tap on it. On my car, it also meant that I didn't have to relocate the wiring harness by the ECU. I don't think I have any pics of that bar though on my site.

One thing I might try to do differently if I did mine again is the harness bar for the passenger seat. On the driver's side, it bends back to allow room to slide the seat back all the way. On the passenger side it is a straight bar, so the seat can't go back all the way. However, the main hoop diagonal brace is also prevents the seat from sliding back all the way, so there might not be much to gain by doing the harness bar differently.

If my class rules would have allowed it, I would have loved to tie the forward hoops into the A-pillars. If you can, I recommend doing that as it will add a lot of stiffness, as well as help support the forward hoop laterally in side impact (side bars push inwards on forward hoop).

The weight difference between 1.5 and 1.75 is moot when you consider the wall thicknesses that NASA requires. However, 1.75 will be good bit stiffer, particularly if you aren't planning on adding little corner braces at every tube intersection. The downside to 1.75 is a little bit less clearance everywhere due to the larger diameter (for example, by your head, between the seat and the where the side bars come inside the door frame, etc).

Make sure that you pay close attention to load paths when designing your cage. If you apply a force to the cage somewhere, how will those forces distribute through the cage and into the chassis? Where will tubes be in compression, in tension, in bending, or some combination? That is what is most important to consider when designing a cage to be strong. If you do it right, you won't need to use near the amount of tubing (and weight) that you might see in some cages...


pics: http://www.adrenalineautosport.com/d...d/fabrication/

whatset

Thanks for the info. I like your harness bar design. I've already been in an 'argument' about putting a passenger seat in. LOL, logic won out and I prob. will.

The tube thickness info is well received. This is a toy not a weapon and I'm worth a little overkill in the safety dept., but was mentally leaning towards the 1.5.

krazik

shad always disliked that a box or tube there puts you at risk of breaking leg/ankle in the right impact. which is my old cage/car always had.

dc_s2k

Its not in the way at all, and I am 5'11". It is higher than it looks in that photo.

I don't remember the wheel, but its about 1 inch smaller diameter than the stock, on a QR. if you go too small it will block your view of the stock tach.

whatset

Thanks for the scoop Krazik & DC - looks like that tie in bar position between the clutch and brake should be taken under heavy consideration. I will be sure to note it for my guy. The work will be getting done by JR at Fathead Fabrications. He does a ton of the local cages here in Phoenix; he is even the outsource fabricator for some of the local shops.

A little background - I am a member of a 24hrs of LeMons team (Audi Style Racing - facebook and AudiStyleRacing.com) and we run an '82 Coupe with a 10v T and a short gear tranny swapped in. He did our cage, turbo piping, heat shields and shrouds, custom exhaust and is working now to relocate a big ass radiator in the rear of the car. 24hrs may sound like a joke series to some, but it presents some heavy challenges. Not unlike the Mille Miglia we run against all kinds of cars - there are three main classes on track at once and we all compete for the same overall top spot. That means I'm running against everything from tube framed 5.0 pony cars to bone stock Volvo station wagons and even a ghetto charged Miata put together by Mazda and Garrett engineers. Point is, I've been hit, hard (in turn 3 at Sears Pt.) and I trust my fabricator. Being strapped into that cage is a real confidence booster.

Thanks again all for the insight!

dc_s2k

Ah, we run a Volvo 850 wagon in Lemons and Chumpcar. Its got a strong cage, but not nearly as nice as the one in my S. For what its worth, we've found that the drivers in lemons are much less experienced and prone to doing really stupid stuff and crashing than the drivers in Chumpcar. As a result, the team is gravitating towards chumpcar.

whatset

Who are you guys? Do you run in the west?

dc_s2k

mid atlantic area

bsyeth

Yes Triple check the bar that runs on the left side of your head above the window, put as much curvature in it as possible to keep it away from your head. I am 6ft tall and my head touches it somtimes on bumps, once you get the padding on it, it gets even closer.
I had my main hoop put on the top of the ledge instead of on the floor, that gives me all the room I need to put my seat as far back as I want and room for a passenger. The nascar door bars tie in to main hoop and behind seat.
I will try to get some picks up, but I wish I would have did this same thread before mine was done.