MR2 cage; potential woes.

[V6SW21]

I recently had a cage welded up by a fabrication shop that specializes in Honda dragsters and off road racers. I provided rule sheets for NASA and several lesser groups and wanted a cage that met all of their criteria. After I picked it up, I immediately started feeling that the cage was poorly engineered/built and I can't really figure out if I'm completely screwed or not. I just thought some pros could enlighten me on how hosed I may or may not be.

 

 

The diagonal bar on the main hoop doesn't attach to mounting plate as close as practical. Maybe I'm just reading into that too much.

I believe everything is good here but usually I see the diagonal bar start around the driver's head (within 12" of the corner right?)

The a-pillar bars that run back to the main hoop at a taper. (Biggest problem)

The resulting driver's pose. The padding is only 3/8" thick pipe insulation. The certified stuff I've seen is 3/4" thick.

The sweet sweet welds of a trainee maybe? These are the back stay mounting plates. It's also really neat that the tube is only welded 3/4 of the way around the tube because they couldn't access it. I'd believe there are ways to be clever and maybe tack the tube in position, pull it off, weld it in its entirety and reinstall. Maybe easier said than done?

An idea what the driver's door bar looks like.

This is the lower driver door bar. My understanding is that notches are not allowed. Its a pretty clean notch in any case...

 

 

It wasn't a super cheap cage at $2100. I don't feel I received what I paid for. Any suggestions would be greatly appreciated. Thanks!

 

Edit: Not sure why the pictures are so small. I'll figure out how to make them bigger.

[TurboShortBus]

I recently had a cage welded up by a fabrication shop that specializes in Honda dragsters and off road racers. I provided rule sheets for NASA and several lesser groups and wanted a cage that met all of their criteria. After I picked it up, I immediately started feeling that the cage was poorly engineered/built and I can't really figure out if I'm completely screwed or not. I just thought some pros could enlighten me on how hosed I may or may not be.

^^^ IMO, if you are going to blindly allow a shop to build a road racing cage for you, and they don't have any experience in building road racing cages, then you might be in trouble from the start. Any cage shop should contact the owner/driver several times throughout the build to ask questions and test fit the driver in place to make sure the cage will provide enough clearance and protection. Otherwise, a buyer needs to educate himself/herself as much as possible in advance, and visit the cage shop often. It's also a good idea to tell the builder to only tack weld bars into place, and to wait for your approval to fully weld them.

 

With my own cage, the shop owner told me up front that he only built drag cages and had no road course cage experience. This was fine with me, as I told him that I knew the applicable rules and I knew what needed to go where; in turn, he was fine with this. I was at his shop about once a week to test fit me, the seat, and other things in the cage as he was slowly building it (I was in no rush). He would text photos to me if he had a quick question about something ("Do you want it this way or this way?").

 

While this is a VERY long thread, it contains a lot of useful information: http://www.corner-carvers.com/forums/showthread.php?t=27556

 

The diagonal bar on the main hoop doesn't attach to mounting plate as close as practical. Maybe I'm just reading into that too much.

^^^ I can't really tell from the thumbnail-sized photos you uploaded to Photobucket. But, IMO, "as close to the mounting plate as practically possible" is a pretty open-ended statement that is subject to all kinds of interpretation. It is likely fine.

 

I believe everything is good here but usually I see the diagonal bar start around the driver's head (within 12" of the corner right?)

^^^ CCR section 15.6.7 specifically states (bolding mine): "One end of the diagonal brace shall attach to the corner, or horizontal part of the main hoop above the driver’s head, within twelve (12) inches of the driver’s-side corner." If the diagonal is located somewhere within the bend of the main hoop, then it could be considered to be attached "to the corner." Otherwise, if it is below the bend, I would say that it is NFG.

 

The a-pillar bars that run back to the main hoop at a taper. (Biggest problem)

^^^ This is because the builder didn't want to put a slight bend at the back of the overhead side bars, which would have allowed the bars to be pushed further outboard while joining the main hoop slightly inboard (note that a short downward gusset tube would have accompanied this). He/she simply tapered the overhead side bars inward as they went back, which IMO is sheer hack work, especially considering that it gets close to the driver's helmet. These overhead side bars are tough where they meet the main hoop, since the main hoop bend is never right where you want those bars to be. If an additional bend at the back of those bars isn't used, then you have a choice of either 1) making the side bars narrower to meet the hoop at the top of the bend, or 2) making the side bars lower to meet the hoop at the bottom of the bend.

 

The resulting driver's pose. The padding is only 3/8" thick pipe insulation. The certified stuff I've seen is 3/4" thick.

^^^ If you aren't comfortable sitting in it in your garage, then you won't be comfortable in it on track. Try lowering your seat and/or moving it inboard toward the center tunnel.

 

The sweet sweet welds of a trainee maybe? These are the back stay mounting plates. It's also really neat that the tube is only welded 3/4 of the way around the tube because they couldn't access it. I'd believe there are ways to be clever and maybe tack the tube in position, pull it off, weld it in its entirety and reinstall. Maybe easier said than done?

^^^ I can't tell what's happening due to photo size. But, from your mention of the tube being welded 3/4 of the way around, this falls short of CCR section 15.6.13 and is NFG/insta-fail. My cage guy has fixed this condition on other peoples' "Club S approved" cages with a very small TIG torch.

 

An idea what the driver's door bar looks like.

^^^ Do your class rules prevent the use of short vertical bars to connect the lower door bar to the OEM rocker sill beam? You might want to consider taking advantage of them if you are permitted (not a huge advantage, but I would use any line of defense for a side impact bar).

 

This is the lower driver door bar. My understanding is that notches are not allowed. Its a pretty clean notch in any case...

^^^ While CCR section 15.6.12 specifically says that the B-pillar shall not be notched, I am of the opinion that a slight notch in the sheetmetal to accommodate a door bar is a better alternative than a double-S bend in the same door bar. This could now be a case of "asking for forgiveness instead of permission." Contact your regional inspector to see if it's a big deal or not, as it may not be. In your case, it looks like there is a pretty sizable gap between the notch and the door bar; a suitable clearance might have been gained with judicious use of a hammer to dimple the B-pillar, which would have avoided the notch situation.

 

 

It wasn't a super cheap cage at $2100. I don't feel I received what I paid for. Any suggestions would be greatly appreciated. Thanks!

 

Edit: Not sure why the pictures are so small. I'll figure out how to make them bigger.

All may not necessarily be lost in your case; I was very picky when it came to my cage. While I see many things that could have been done differently with yours, some of them don't violate anything in the CCR, while others do. At the very least, this cage is fine for NASA HPDE and TT use.

 

I highly recommend that you get a full head, shoulder, and hip containment seat. If you spend $900, then IMO you didn't spend enough. I was looking at a $1200 Kirkey before I eventually went with a $1600 LaJoie. With your current arrangement, your helmet won't have to go far to the side to get outside of the cage envelope in a driver's side impact (with a wall, another car, etc.). At that point, you will be relying on the window net to contain your helmet, and that is not its job. If you can't fit a full head containment seat in the car and still easily get in/out, then use a pair of properly installed triangle center nets, one on each side of your helmet/shoulders (as is commonly done in pro racing).

 

Also, make sure that any aluminum or non-FIA/non-SFI seat has a wide bracket that rigidly connects it to the harness bar behind it. While it's a debatable topic, I recommend attaching FIA seats to the harness bar as well (since the FIA seats and FIA brackets are only as rigid as the 20 gauge floorpan they are attached to).

 

Mark

[V6SW21]

I appreciate your response. This was exactly what I was looking for. I'm going to get it teched soon and get a list of discrepancies. I like your opinion on the seat too, I will look into more head support. Thanks again.

[kbrew8991]

these are difficult cars to cage as your pictures demonstrate.

 

Definitely get yourself some more head clearance, even if it means getting that bar redone by that guy or redone elsewhere.

[TurboShortBus]

Even a seemingly minor impact isn't so minor on the body:

 

That was just a cheap aluminum seat with added "head rests" and "shoulder rests."

 

Mark

[V6SW21]

 

 

Sorry it took so long but I added new pictures, apparently emailing them to myself made them small. I'm not very tech savvy. I appreciate everyone's input, hopefully I can get the cage fixed so I can get back out on the track. It's the better part of undrivable even if I try to move the seat around; it only becomes an enduro kart.

[TurboShortBus]

^^^ Did somebody use a can opener to trim the metal out of the inner door panel? Clean all of that up so that you aren't snagging your expensive fire suit on it or cutting your hand. Lay out nice, straight lines with tape and use a cheap "metal air saw" from Harbor Freight (currently on sale for $18.99) in order to have less flying shrapnel than a cutoff wheel produces. Hit it with some sandpaper to take off any burrs and to round off the corners a bit. Rattlecan to taste.

 

^^^ If you're uncomfortable in the car, then it's going to bother you, and you won't be focusing as much on your driving as you should.

 

Also, that looks like the el cheapo foam padding that you should not be using (although this isn't to say that you can't use it, but it is safety gear). See CCR 15.6.4 for what you "should" use.

 

Are those rear kickers perfectly straight from the main hoop back to their mounting pads?

 

Mark

[V6SW21]

Thanks for your response. The cage guys are going to fix everything but I agree with you, it's very crudely done. I was disappointed with their performance in nearly all aspects of the cage. As for the foam padding, it is just pipe insulation. I mentioned it in my first post that it was just to add to the dimension of the cage to show how much more kicked out the header bar really is. I don't have the real deal stuff just yet. This post was to just get people's opinions on the cage and to help show the cage builder that it's not just my opinion. Between this and the responses I have received from lesser groups, the cage builder I believe has seen/will see that his performance was subpar and that a business that prides themselves on building quality cages shouldn't be putting this type of stuff on the track.