Here are some shots - I tried to make them instructive in content and angle. It's not the perfect cage, but it's a decent IT style cage.























Scott, who apologizes for so many pics....but wanted to show enough detail....



[Modified by RR98ITR, 12:25 AM 2/10/2002]

 

here it is..

 

 

Can't tell from the pictures. How many square inches are the mounting plates that sit between the roll tubing and the frame of the car??

 

It looks pretty good, but it doesn't look like he used enough plating at the attachment points. You're allowed up to 100 square inches, which is what's in mine, and it looks like I have ALOT more plating than you do.

Also, is that 1.75 .095 wall tubing?

 

I worry about the cage punching thru the floor. The bigger the plate the less chance of that happening. The rules specify no minimum size.

Grumpy

 

We're not done with the plating. My welder is kicking and screaming because the floor and rockers are so thin, and there's unremovable glop here and there that erupts during welding - something closer to the 100 sq in WILL be there in the end (the bottoms of the main hoops will be boxed in after everything else is done - capturing the tubes at both ends of the cubular structure. The top of the rear tower/wheelhouse is done though - that section is pretty thick and 3D so there's no good reason for mega armor there.

I think you guys are worrying too much about the proverbial "punching thru the floor". Imagine a scenario where that could happen - the only one I can think of would be another car landing on the top. In a violent enough general deformation of the whole structure 100 sq in's at the bottom of the main hoop might not be enough anyway - the floor, rockers, and rear seat tub are EXTREMELY thin. Per SCCA Pro Racing World Challenge and Grand American Rules the A and B pillars will be stitched the cage too - I could (but won't) leave it as you see it and I'd bet my life on it performing satisfactorily. In talking with some of my very experienced friends I've been told that three plates (floor/rocker/rear seat tub) and the hoop being only welded to the floor plate was entirely satisfactory - I'm not content with that though, and as I said will essentially box them to distribute the load more widely.

The worst part of this cage, or any IT type cage, is it's protection in a mega side impact. Because I'm leaving the doors intact, there's not alot of room between me and the cage - the door opening cross bracing is my last line of defense and there's alot of deformable structure outboard of that, but real NASCAR door bars would be more reassuring. The inability to run another tube or two laterally below the driver with seat mounting is also sub-optimal. But this is all still much better than an Autopower bolt in cage - both in terms of protection and contribution to chassis rigidity.

I could have carried the door bracing higher, but I wanted to leave room for seat mounting height reduction and clearance for my left elbow while steering - I think that's probably a minor deviation from what others have done - and there will always be a scenario (hopefully theoretical only) that defeats any reasonable structure.

And, yes, 1.75 in 0.095 wall DOM - lovingly Tig-welded by a two man team (the idea of Lee working the pedal for Steve just cracks me up). If any of you saw "The Road to Wellville", you may remember a guy "therapeutically" hooked up to some wires saying "More amperes!". I guess you'd have to be there.

Scott, who thanks you East Coasters for your remarks....do you think I'll ever be able to get my heater/blower assembly out?.....oh, sure, ONE time......


[Modified by RR98ITR, 8:23 AM 2/10/2002]

 

nice cage!!

 

Additional design comments:

The lateral tube at the bottom of the main hoop was done on recomendation of Scott Zellner. Alot of G3 cars DON'T have a tube here, and I at one point decided to omit it, but in the end I decided that thin sheet metal of the area under the passenger seat recommended such a tube (especially considering how many pounds of heavy steel the factory originally bolted in to buttress this area).

The lateral knee tube was angled slightly to allow for dropping the steering column. This was a concern for service and positioning change reasons. Viewed from the rear that angle turned out to be very slight. The large bolt on steering column support bracket will get a tab and a linkage mount to the top of the lateral knee tube. This doesn't seem to be necessary at first, but Wade Gaughran(?) was seriously injured in a rental ITR last year in Grand Am and it involved the steering column in some way reportedly.

The particular angle the front down tubes make in their path from the front of the halo hoop to the floor was forced by my desire to have the floor location be at the turn up from the flat floor to the firewall. Wiring on the drivers side and heater/blower on the passenger side looked restrictive, but worked out in the end. Steve chanced to position these tubes further inboard than I expected - I got over any concern since it was only about a half inch inboard below the cowl height and this allows use of the stock outboard dash mount brackets (the left one has to have the hood release mounting cut off). The amount the tube is inboard of the A-pillar is greater, but only affects line of sight a little - it will require the stitching gussets to be longer, but a little more section depth here won't be a negative.

I didn't run tubes from the rear tower/wheelhouses to the bottom of the main hoop because I figured that there was enough structure and 3D along that path to do the job already. I notice that King does put these tubes into their cars, and so do others, but of course there are yet others who don't. At some point I went from lotsa tubes to minimal tubes, and I just didn't want to do another lap of that.

My harness is an Autopower 5-point (which I'll replace upon expiration with a 6-point), with shoulder belts that wrap around the harness bar. Lap and sub belts will be remounted to the floor with big doublers. I ordered four 3-foot lengths of Simpson half-section SFI padding.

Painting....ughh. We've discussed spraying and brushing, where and how I can do what, and I still don't know what I'm going to do beyond the color - Black.

Scott, who has a long summer of incremental progress ahead....I don't want to bury myself before the first school date.....


[Modified by RR98ITR, 10:06 AM 2/10/2002]

 

From the pictures I'm staring at, it looks like the forward most lateral brace goes under the steering column. I don't know how your driving position/seat/height are, but won't your knees get hung up under that? In the big nasty worst-case wreck (not saying it'll happen, but that's what you're building this cage for) won't your knees/thighs be jammed up against a lot of hard metal? Padding would further compound the interference issue. What was the reason for not running that lateral brace up behind the dashboard and using a bolt-on or welded loop on the steering column?

As for spraying the cage... wow that's a lot of masking work I'm thinking high-temp or something so you don't contend with molten paint if your ITR happens to be in flames.

 

There's lots of room above my knees/legs - significantly more than on many other cars I've seen and or been in. I MAY pad it, we'll see.

Up behind the dash? Above the column the only available room would be above the top of the dash. Alex Long did that on his T2 M3, but that's no good for me. I wanted that tube in that general location (right below the column) since that's about the height of the most likely impacts, and I want to support the impact side A-pillar/door support with the opposite side thru the stitching. Any impact that takes that tube into any part of my body is going to be hard to walk away from for reasons beyond just that tubes performance. I suppose I could run a strut down to the top of the tunnel to prevent it buckling in that direction - but I probably won't.

You very funny.....high temp paint . So does that mean you wouldn't think me a clod if I found a way to brush paint it real nice?

Scott, who so wants to get rid of that heavy dash.....but can't.....



[Modified by RR98ITR, 11:50 AM 2/10/2002]

 

There have been a few cases (I've heard, not witnessed) of knee bars bending downward, pinning or breaking drivers legs in hard left front impacts. Most builders around here run that bar above the steering column these days.
My bar runs from the base of the A pillars and is designed to bend away from the driver and through the windshield if it starts to bend.
I realize that I'll have much bigger problems in an impact that big, but the idea of that bar bending into my shins and snapping my legs wasn't very comforting. The problem with adding a brace to the tunnel is that it creates a 9th attachment point, which isn't legal for what I do.

 

Say I'm looking forward from the drivers seat - where is your lateral tube relative to your instrument hood?

Clearly I'm fortunate(?) to have an ITR for which there is no real home in SCCA classing. 9th point indeed! I....must.....resist.....the.....urge......to..... ..rant......about.........rule.......nincompoopery .......(no offense....I KNOW that you gotta have rules)....it's just that were talking about "bending into my shins and snapping my legs".....yeah, I know - I coulda run the bar higher (to the detriment of another aspect of safety)......

Scott, who wonders: "what about a chain from near the base of the windshield under the dash to the top of an under column front lateral tube?".....dooohhhhh........

 

heh, you're supposed to paint the majority of the bars beforehand, and touch them up after welding. It's the easiest way to get full coverage on the bars.

Warren

 

Great! I mention chains and now I've got weirdo's asking me about my back seat

Speaking of which: there are two tires that won't fit back there any more. Have I mentioned my plan for a hidden hitch receptacle that will likely go right thru the middle of the rear plate? Complication: I hear that a nicely equipped version of that little track trailer goes for about $1500. Well, it looks like I'll have to build my own.

Scott, who's watching Ronin, enjoying it, and thinking that: yes, street racing is bad.....back to the show...

 

Looking from the drivers seat, the "dash bar" bends away from the A Pillar, behind the gauge pod, and across the dash at the base of the windshield. Don't ask me how my builder got it in there because I have no idea (the windshield was still in the car as I didn't have time to take it out). He's just that good.

I assume that limiting the number of cage attachment points in IT has something to do with costs. Thats all I can come up with.
But yeah, when you're talking safety, more is typically better. Nincompoopery indeed.

There's lots of "nincompoopery" in SCCA. For instance...
An ITS Integra GSR would do well to get 175 to 180 whp in full IT trim. 130 lb/ft of torque would be about tops.
List weight for this car... 2690. Huh?!?!?!
The Speedsource RX-7s from Florida are getting over 200hp at the ground and are listed at about the same weight. I don't get it. I guess I never will.

Scott, who weighs 225 pounds and still has to add 70lbs of ballast to his GSR to meet ITS minimum weight. BAH!!!

 

Heh . Yeah, we thought about it, discussed it, etc. Cranky fabricators and eccentric engineers are hard to deal with. They sometimes leave the really nasty bits to last hoping that it will become your problem and not theirs.

Scott, who shrugs and says: "It don't have to be perfect".......

 

My cage builder doesn't like painting beforehand either, but since I was footin the bill, it got painted. I think he charged like an extra $50 for painting.

Warren

 

Very Nice.
A bit naked looking, though!