OK all...so this off season, something I'd really like to do is get a custom, welded roll cage for the GS-R. These are of course very expensive. So it occurred to me that maybe, just maybe, I could use the existing cage (a bolt-in autopower) as a starting point. Was thinking of the following:

1. Weld all the bolted-together joints
2. Weld plates to floor
3. Add additional cross-bracing down low around the rear shock towers
4. Add a petty bar from the top of the main hoop down to the passenger side footwell

As with most shortcuts, there are downsides. Here are some problems with the bolt in cage that welding does *not* solve

1. Headroom is minimal
2. Little to no footwell protection
3. lots - over an inch in some spots - of room between top of cage and roof of car
4. It's heavy
5. Doesn't go through the dash = impacted visibility out side of car
6. Attaches to floorpan (not the rocker sills) for the front four points. This looks like a weakness to me - like it could punch through the floor in a serious rollover.

Anyone gone down this road? Bookler, I think you've done something like this, right? How'd it work out?

 

Great thread, Karl. I was wondering the same thing(s).

Jason-
who also runs an AP 6-point

 

Karl,

We took a bolt in cage and welded into my 240sx. The cage was originally a "custom" bolt in, not autopower, but I don't see any reason why it would work with autopower. We welded the sleeves in place and added foot protection and NASCAR style door bars. As long as the tubing is the correct diameter and thickness it would work.

Here is are a couple pics
Before


After:


Note the sleeves near the drivers head, the passenger door bars and driver door bars were all added to the existing cage.

Hope that helps!

Edit: We also cut the old plates off and sleeved the bottom of the main hopp to snug it up against the roof. The headliner and sunroof left a inch or so of gap once it was removed. I prob have some pics somewhere if you would like.


[Modified by thirstygersty, 3:23 PM 9/13/2002]

 

I went to a cage builder a couple of weeks ago and proposed the same thing to him. This is basically what he told me. It is too much of a hassle and by the time you done you could have spent a couple extra hundred dollars and got a professional cage. Like you said it is a bolt it cage. It is not meant to add chassis strength only rollover protection. You would have to weld plates all over the car not just to the floor if you want to add strength. Here is something else that he said that really sealed the deal. Cages are designed to give on side impacts. Not fail but just bend. The theory is if it doesn't give then you are absorbing the total impact. That isn't good. Adding all the bars is ok just as long as you aren't trying to strengthen the lateral protection. I hope that makes sense.

This comes from a source that I trust but, I suggest to you that you ask a cage builder that you trust and hear it first hand. After all this is your safety were talking about.

 

If you go the route of welding the AP, and/or adding additional bracing, make sure you use the same material. eg Chromoly or not.

Warren


[Modified by Warren, 3:32 PM 9/13/2002]

 

Yes I did. The guy who did mine started out by increasing the size of the plates at the base of the autopower cage. Then he welded the cage together at each connecting pieces by welding the sleeve, not just removing the sleeve and welding the bars together. He also filled in the bolt holes and welded that.

It was very expensive (about $900), and has many of the shortcomings that you mentioned. No door bar, just goes to the floor, no dash bar, etc. If I were to do it again I would sell the autopower bolt-in cage, and get a custom cage welded in. I can tell you though that the welded cage makes a HUGE difference in handling and overall stiffness. I wouldn't even think of racing with a bolt-in cage now.

Hope that helped...

Matt

 

I was thinking about doing something similar with the Kirl bar I have by getting Mark to add the front part, through the dash, and door bars. I was planning to keep it a bolt it though. The more I though about it, and the more custom work I saw come out of Robinson Racing, it was apperent that racing with a bolt in is not a good idea.

Safety gear is not the place one should be looking to save money.

You could get some bigger plates made (the auto power's are tiny) and get a custom front section made that goes though the dash then weld the thing together. Not sure how much that will run you, but I dont' think it would be worth it.

Just sell the Autopower and get one built at K&E -- you are Money after all. If you want to come down to ATL, I would highly recommend Robinson Racing. They did Skultety's RSX (and GSR) as well as Ewan's EG and Sammy's M3. Those guys do an awesome job.

SPiFF, who is holding out for a Robinson cage.

 

Mike (civicrr) customized his AP 6-point in a similar way. I've yet to see pictures of it, but I think he has some. A friend of mine just had a full blown 8-point welded in by Cascade, and it's a thing of beauty. I'll be saving my pennies and trying to sell my AP 6-point this winter to get a Cascade cage.

 

If you want a roll cage and do not have a lot of room, you can try going through the dash with it. Mine is like that and it is great. I have tons of room and it is easy to get in and out also.

I got pics here: http://evillinux.mine.nu/~ed/warrior/11-8-01/

 

I am having several modifications made to my cage when Mark Stewart builds it. I will also probably end up welding it together in the car this winter.

The additions will be:
- Petty Bar
- Second door bar
- "X" the back
- Crossbar between the 2 back feet
- Crossbar between the 2 B-pillar feet in the main hoop

Any cage builder could probably do those additions for $300-$400. That puts your total cage expendature under $1000.00. You won't find a GOOD custom cage for much less than $1500.00. There are still some inherent flaws that the custom will cure ie: tubes down through the dash, closer tolerances to the roof and better floor mountings. I doubt the custom will do much for your headroom issues. That is more of a function of roofline and seat placement. To fix that you will probably need to:

A) Lower the seat
B) Shift the seat inboard slightly

To fix your footwell concerns you just need to weld some tubes in from the front cage foot to the firewall. You are allowed 8 points so use the other 2.

I am hoping to have the facility and resources this winter to do all of my mods myself. That will save a few $$$s.

 

My Teg had an Autopower bolt-in when I bought it. Instead of ditching it I went the weld/add-to route and have been pretty happy. My modifications:

1. Added Petty bar from main hoop to pass footwell mounting point
2. X-brace between main hoop and rear brace lower mounts (Autopower cage alone had bends in rear braces, of questionable legallity for w-t-w comp.)
3. Added 2 passenger side door bars where AP cage had none.
3. Removed single driver side door bar and replaced with 3 NASCAR style bars w/ vertical bracing.
4. Added horizontal dash bar.

You could go further and add 2 additional mounting points on the firewall connecting the main hoops to the firewalls. You could also replace/add to the mounting plates to make them larger, and do it in such a manner that you weld the new plates/additions to the rocker sill in addition to the floor. For better details of this, check out http://www.improvedtouring.com/images/special/crx_build/ - although this is not a bolt-in cage, there's no reason this same sort of mounting plate couldn't be used for replacing the standard mount for a bolt in cage in order to tie it to a larger area of the unibody.

Also, AFAIK, it is legal to mount the rear braces to the rear shock towers in NASA, and to add a horizontal tube tieing those two plates together.. I DO KNOW it is perfectly legal to do so in SCCA. See that same series of photos for how that was done. Remember, you can attach as many tubes to that mounting plate as you like, going anywhere you like, attaching to anything you like (as long its another tube or mounting plate, not some other part of the car.) as long as you don't have more than 8 plates and none of them exceed 100 inches square.
With enough well-thought-out adding to a bolt-in cage you get make it pretty close to the rigidity and level of protection of a custom job.

Karl, take a look at my car when we're at VIR. For the time being I'll try to get some decent digital shots of it in the next few days and post them so you can see what I did.

I'm not the person who skimps on safety and I'll put my cage up against 90% of them you'll see in IT cars. It is not as high speed looking as a lot of the custom ones but I'd bet it's every bit as safe. And it cost me about $350 in tubing and welding (the AP cage was already in the car so I didn't shell out for that), although I did get the "special labor rate" from a friend who did a lot of the work. Figure someone else would have an investment of less than $1000.

Good luck---

-Floyd, who has so damn many bars in the rear of his car that it looks like a prison cell view out of that big NASCAR rear view mirror!

 

I just recently finished adding large floor plates to each of the attachment points of my Kirk cage. I have a bunch of pics, and I will post them once I finally get a finished picture of how they look now that they are done. I will also be welding door bars, a dash bar, and all of the seams. Total cost will be under $800.

 

Not legal to have a 'strut tower bar' that isn't removable with NASA according to the regular rules. It is in Pro Compact or USTCC.

Johng is right. I ended up with a AP again but I had it welded & some other work done. I have some pics but no were to host them.

1st stage. I started off with it bolted because I didn't know when my friend would be able to weld it. Here are the things I did to it. I cut approx. about 2" of dash away. I got longer sleeve material for the part that goes along the door/a-pillar. I moved that section forward. (Make sure the tubing is 1020 DOM) I had stupid heavy plates made out of 1/2" steel which is releaved on one side. The side against the floorpan is solid. This allowed an extra 1/2" of height. I checked this out with Jerry K. & Ali A. as to legality before doing it. No problems.

2nd stage. Parts that could be welded 360*, bolts were eliminated. Other parts, bolts stayed in & sleeves welded as much as possible. A 'plate' was welded to the rocker near the front plate. The two were welded together. This was to address the fact that in my rollover, the floorpan & rocker spot welds started to tear. The rear was left alone since there are four areas of support. There is also quite a bit bigger gap between the rocker & the AP plate.

3rd stage. A passenger side doorbar is added. It goes from shoulder height to just below the dash. The driver's side doorbar is cut out. Two NASCAR bars, as required by the GCR, are installed.

What would I change? If I had time & knowlege, I would have removed the cage. Cut off the AP plates. Drill holes with a holesaw in the floorpan. Let cage slide down in holes. Weld everything, eliminating all the bolts. Make perches ala Roger Foo style for the four front 'plates'. This would allow max. height & tie in the rocker & floor. Make a spacer out of al for the rear stays, or better yet, new stays to the tower area. If I had the cage out, I could have taken the dash back out. Dash bar.

You know what? Next time, I will probably go custom. Doing all that work costs a butt load of money & time.

Sorry for the long post.


[Modified by civicrr, 5:36 PM 9/13/2002]


[Modified by civicrr, 5:38 PM 9/13/2002]

 

Karl,
Talk to Sam Neave down in Franklinville ( near Liberty ) a straight talker, good fabricator, and best bang for the buck! His # is 336-824-1605.
Good luck,
David
HC4 #50
"speed makes me horny "

 

Just went back and re-read the rules and the part about "Any number of additional bars are permitted within the structure of the cage as long as they are installed strictly for safety and do not violate CCR Section #15.6.2 Intent." Ah hah.

The intent part is what differentiates NASA from SCCA, whereas in SCCA you're completely free to add as many bars between mounting plates, as long as you have used no more than 8 points, regardless of their purpose.

For the record, because I added to a bolt-in cage that was already in the car and the rear mounting points are on the rear floor, not the shock towers, I have not / can not add these bars. HOWEVER, they are legal per SCCA ITCS and NASA CCR Section #15.6.1 does allow for all SCCA cars (and others) to participate in NASA events while complying to their own respective sanctioning body's rules, as long as they have those rules in their possession to prove that they are legal. Solution? Want a little better cage design? Build it to SCCA spec, keep a current SCCA GCR, and then get an annual SCCA tech each year and get a logbook. Then get your NASA logbook. The reality is, a lot of the ECHC cars alreay have this as they're SCCA IT cars. You're talking about one peice of tubing so cost can't be the reason NASA doesn't allow it. I know the reason is they have to draw the line somewhere to keep it under control.

Like I said, this is all just my pondering and it's probably not worth the trouble for one additional bit of support. And yes, it is a little underhanded, but then again, you take advantage of every possible opportunity withing the rules, correct?

-Floyd, who has probably got a few people upset now.

 

Just like NASA GCR says that you the engine must be 'stock'. You can have an IT legal motor built & it would be ok since IT cars are welcome to race with NASA. I wonder how much power I am giving up?

We don't make the rules. We just have to make them work for us.

 

Good information everyone, exactly what I was looking for. Rhodes, you read my mind - I was gonna call you to get Sam's number tomorrow

I'm leaning towards punting and getting a custom one done up this winter. Have a few leads on people who can do one for reasonable (mostly circle track folk). Obviously I'll make sure and look at sample work before I pull the trigger.

I figure if nothing else I can probably sell the autopower for a couple hundred bucks.

 

You probably already thought of this stuff......I would have good pics & be really clear as what you want. People who don't 'roadrace' have different ideas about cage construction & design. Also make sure that you leave a copy of the rules with the builder. eg tubing diameter, wall thickness, etc.

 

Some cage pics can be seen here. http://www.mobrep.org/modules.php?se...view_album.php

Thanks for hosting them, Matt!


[Modified by civicrr, 10:21 AM 9/14/2002]

 

Very cool civicrr - thanks. Gives me a good idea what I can expect

 

One thing I forgot to mention - I *heard* that there was new cagebuilding information in the latest Fasttrack. No idea of NASA will run with this as well, but I assume they will. I'll put this in a different thread.

Edit: URL for new thread is here


[Modified by krshultz, 2:21 PM 9/14/2002]

 

Karl... weld in.

You know better. If you need any ideas... you know you can inspect my CRX thoroughly

Pete