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Sports Cage Design

Posted: Fri Nov 07, 2008 4:30 pm
by greg
Hi All,

Firstly - let me state that this is a "sport cage" - not a roll cage.

Here we go...

So i have been checking out this thread here on Pirate where the fellow has built the rear part of the cage to sit on the "sill" of the rear corner of the car.

http://www.pirate4x4.com/forum/showthread.php?t=645247

That had me thinking that perhaps the whole cage could be built in this manor. Sort of - not an inny, and not an outy...

E.g.
A Pillar is bolted to where the windscreen comes from (not the cowl)
B Pillar replaces the current suzuki pillar or sits just behind it
C Pillar comes from the rear corner of the car (per the pirate build)

I'm kind of hoping that the car would end up with a wide and low sort of look to it.

I'm thinking it could be bolt on / bolt off for semi regular vic roads appearances.

Other Comments to consider:
1. The car would not run a proper windscreen (if you can't get over this, stop reading now and go back to your air conditioned and carpeted vehicle).
2. The car would not run the suzuki b pillar. i would plan on running the seat belt off of the cage b-pillar. I expect it would be easily as strong as the existing suzuki setup.
3. It is not a roll cage. It is a "sports cage". It will be designed to improve the ruggedness of the car in a "flop", and would also remove the windscreen frame from the car - which we all know is the most worrying thing about putting a car on its side - damaging that windscreen frame.
4. A "plastic" windscreen might go into the cage for wind protection. I know this is not ADR1.2.3.4 approved, but i also know that i can run a sierra with no windscreen at all and get approval under ADR5.6.7.8

My Question(s):
1. has anyone got any photos of a cage that has the A-Pillar coming from the point mentioned? Obviously it has to be cosmetically pleasing before i would do it.
2. have i got enough SMS talk in this to confuse people?
3. is this idea wrong enough to be right?

Posted: Fri Nov 07, 2008 5:12 pm
by Gwagensteve
I like the sound of this so much it must be wrong.

It could be totally removable with basically no visible bolt holes if you really wanted too.

You might not even need a whole windscreen - a deflector across the bottom 4" of the cowl might be all that's required to keep the wind/bugs out of your teeth.

You could even do the evil eyebrow thing (the dip in the front hoop) to make it look even lower.

Steve.

Posted: Fri Nov 07, 2008 5:20 pm
by greg
Gwagensteve wrote:You could even do the evil eyebrow thing (the dip in the front hoop) to make it look even lower.
OMG!!! That's exactly what i was thinking... :D

I think will full doors it would look ridiculous, but for people who are half door inclined, it could work ok too.

Posted: Fri Nov 07, 2008 5:31 pm
by Gwagensteve
The B pillar would have to go.
you could pick up ALL the b pillar mounting bolts. Bolt to the rear corner in more than one plane - ideally 3, or run puddle welded 50X25X3 U channel onto the tub tops like on Noel's car.

Material choice could be important - lightish wall to not add huge weight etc.

You could also maybe run a double B pillar hoop with some sheet between (like the early avalanche sniper chassis from memory) to build strength and some visual weight and hide the seatbelt mount.

The stock B pillar could be used as a template with maybe a 2-2.5" "chop" to give the right squat look.

Steve.

Posted: Fri Nov 07, 2008 6:34 pm
by spamwell
Image

mine is mounted on the rear like that but i do not have the bar going through to the chassis but as far as i can tell this section is very strong anyway i rolled my previous sierra with this exact same setup all the way over and the corners did not even budge

Image
after roll heaps of stuff straightened rollbar already removed, rear corners where still perfect, the rollbar actually kept the bpillar straight

Posted: Fri Nov 07, 2008 9:03 pm
by Dee
I've just finished buiding my cage, I did a whole lot of measuring & some cad drawings, trying to figure out how i could get max space, part exo/part roll over protection etc. I can post up pics of the dwg if anyone wants? Its pretty simpleton though (5 min jobby)

We thought about "tieing" braces into the panels through the voids at the b & c pillars (just as the thread shows on pirate with the C pillar). Where as the B would go inside the panels under where the targa bar is, to a plate where under the sill (or just straight through it) & tie to the chassis or a slider support.
I wanted to run a "double" b pillar with both slightly angled toward each other to resemble the targa bar of the soft top. I even hunted around for a secondhand (damaged) targa bar so I could lop the bottom half of the spot welded mounting plates off them, weld a flat piece on the top, to use as a b pillar mount...


The main problems i had was I want to be able to throw full doors on if i needed (ive since been running half doors and have realised i probably never will put them back on). Also getting tube inside the panels & welded off to plate at either end seemed a bit of a task for me & would be difficult to remove if i ever had to. that and i was hoping to enter an entry level comp or two in the future, & I thought a conventional style 6-point cage would get past scrutineering much easier than someting built through/off panels etc...
Headspace was a big problem though, theres no way youd get a 2" chop to a 'cage' b pillar & have enough head room, the b pillare would have to be way back, & by the time you did that youd have enough space for the targa bar.
Also i would have struggled to make the whole cage look 'hidden'. IE it would stand out like dog balls (i didnt wanna sheet in the twin b pillar). with my normal style 6 point cage now i can throw the targa bar on with 4 screws/bolts (cosmetic only) to support my bikini top. Putting both those on takes a couple of minutes (seatbelts are mounted to cage) and they hide the cage extremely well.

In the end it seemed like too much work and i just wanted to get a cage in so i went the conventional 6-point method.
I also tacked it up with the dip down in the front. I found it difficult to acheive enough head room with the spreader bars in the roof going to the low point in the centre, i ended up pulling it all apart & flipping the top windscreen bar around to follow the line of the windscreen.

Greg i have a photo somewhere of a cage with a pillars mounting to where you mentioned i'll try and find it...
Either way I still reckon its an awesome idea, it was just in the too hard basket for me. would love to see someone with the time/skillz to try it! (do it greg) :D

Posted: Sat Nov 08, 2008 9:13 am
by grimbo
sounds like nother well researched plan by greg (newbies take note). Is this a cage setup for the black Sierra or is there another secret squirrel buildup in progress?

Posted: Sat Nov 08, 2008 1:38 pm
by lay80n
Post the .DWG if you can Dee.

Layto....

Posted: Sun Nov 09, 2008 9:00 pm
by sierrajim
Even as a "sports" cage i'd be making sure that the mounting points were more than just bolted through the body. The rear mount on the pirate one would be neat, strong enough for a "sports"cage but removable enough for the visits to Vicroads.

Why not look at getting a cage put on your engineers report? Everything else has been done to the required level, why not go that little extra and be able to tell Mr Plod that you're road legal?

Posted: Mon Nov 10, 2008 7:43 am
by Highway-Star
sierrajim wrote:Why not look at getting a cage put on your engineers report? Everything else has been done to the required level, why not go that little extra and be able to tell Mr Plod that you're road legal?
Especially if your seat belts will be fixed to the cage. Will They?

In general, it sounds great :cool: .

Posted: Mon Nov 10, 2008 8:37 am
by Gwagensteve
The pirate bar though the rear 3/4 looks pretty good to me.

I think it will also need a cross brace behind the front seats. I was playing with my lwb tub yesterday and they really are stupidly flexy around the door latch area.

Steve.

Posted: Mon Nov 10, 2008 12:58 pm
by greg
sierrajim wrote: Why not look at getting a cage put on your engineers report? Everything else has been done to the required level, why not go that little extra and be able to tell Mr Plod that you're road legal?
I've never investigated the requirements for re-locating seat belt mounts. I would imagine it could go two ways:
1. really easy
2. absolutely horribly hard / near impossible

Could be worth checking out though. If the cage was built without the limitations of the B-pillar, it might be feasible to have it done with sufficient head clearlance to meet the requirements.

Posted: Mon Nov 10, 2008 1:00 pm
by greg
Dee wrote:I can post up pics of the dwg if anyone wants? Its pretty simpleton though (5 min jobby)
Yep - happy to have a look.
Dee wrote: would love to see someone with the time/skillz to try it! (do it greg) :D
Sadly this is only half correct. I'm a little bit time poor :D

Posted: Mon Nov 10, 2008 1:04 pm
by greg
grimbo wrote:sounds like nother well researched plan by greg (newbies take note). Is this a cage setup for the black Sierra or is there another secret squirrel buildup in progress?
There's always something else being built grimbo.

I still have a lwb tray back at my place waiting to be chopped down to a swb ute (think mightyboy at 2:1 scale). :cool:

Scary to have my plans referred to as "well researched" though.

Posted: Mon Nov 10, 2008 1:13 pm
by grimbo
what happened to the green one?

well by researched, I mean there was no sms talk or any mention of 6" mufflers :D

Posted: Mon Nov 10, 2008 1:26 pm
by greg
just thinking out loud here, but has anyone ever seen a sierra with a vertical a pillar? i.e. scorpion style?

http://scorpion4x4.com/coppermine/displ ... t=0&pos=14

i've always been fond of this very wide sort of look, which is not dissimmilar to what my car is now, but i'm just not sure if it would look any good - still not flat and wide enough to pull it off.

Posted: Mon Nov 10, 2008 1:27 pm
by greg
grimbo wrote:what happened to the green one?
That car went straight to the pool room ;)

Then it became a source for spare parts (most of which are worn out and / or broken). :?

Posted: Mon Nov 10, 2008 1:35 pm
by Gwagensteve
greg wrote:just thinking out loud here, but has anyone ever seen a sierra with a vertical a pillar? i.e. scorpion style?

http://scorpion4x4.com/coppermine/displ ... t=0&pos=14

i've always been fond of this very wide sort of look, which is not dissimmilar to what my car is now, but i'm just not sure if it would look any good - still not flat and wide enough to pull it off.
Don't try and make it look like a good idea by posting photos of the coolest car ever built (even though that's probably the rudest version of it've seen)

Vertical A pillars look wrong on anyhting that wasn't supposed to have vertical a pillars.

IE the scorpion was designed to look military from the outset, and as HMMWV's, 6X6's etc all have flat screens, the look was appropriate for the scorpion.

Running a flat screen on something designed to have a 60deg screen will make the car look like it's going even slower, designed by rednecks and made out of PVC pipe.

Steve.

Posted: Thu Nov 13, 2008 10:43 am
by Dee
Dee wrote: Greg i have a photo somewhere of a cage with a pillars mounting to where you mentioned i'll try and find it...
finally found that pic...

Image



unfortuantely i opened my dwg & realised i'd modified the tube thru the panelwork to just a normal-style internal cage & didnt save a copy of the orig :(

May do another one if I get time though... Incase I ever build another one & wanna do it that way. I probably will leave the windscreen though & go down beside the dash with the A pillar though as the windscreen is only 2 screws to remove when goin wheelin...