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6 point Weld in or Bolt in Roll Cage

Posted: Thu Jan 14, 2010 5:22 pm
by Rally_2.6LC
Hey guys in the next couple of months im looking at getting a 6 point roll cage for my LC Lancer which im building into a rally car. The options are a weld in cage or a bolt in cage.....price pretty much exactally the same for the kit.

Weld in advantages are stronger, more body rigidity, more structural.
Weld in disadvantages once its in its in, more expensive for installation, dont really need it for my level of competition.

Bolt in advantages can be removed from car and put into new car if I crash (provided cage is still straight), can remove for rego if the RTA gets pissy with me (even with an engineers cert) cheaper to install
Bolt in disadvantages (opposite of weld in advantages).


Let me know what you think via poll, comments also welcome.



Cheers Matt

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Thu Jan 14, 2010 8:14 pm
by DanTurboLancer
Hey Matt just letting you know there is a problem with the Poll system,
The votes wont go through...


What sort of events will you be entering?
What speeds will you be reaching?
What are your future plans?


Just my thoughts,

In small club events like motorkanas,
(well they did it at the club i raced at, Awaba)
Having a cage puts your car up a class (engine range)
so i took mine out so i could be competetive against the other cars in my Engine Capacity range, rather than racing against cars with bigger engine Cap just because i had a cage...

So a bolt in item can be an advantage for removing for different events also, as long as you dont require the welded in item for your racing...

just a thought mate

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Thu Jan 14, 2010 8:52 pm
by cheaterparts
even if it is bolted in and to CAMS spec it will tighten the body up
remember that you still need to weld plates into the floor to mount the cage to

I prefur weld in cages but it can be an issue REG wise

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Thu Jan 14, 2010 9:58 pm
by davetrees
cheaterparts wrote:remember that you still need to weld plates into the floor to mount the cage to
Not necessarily ...... according to Schedule J of the CAMS Manual :

"Each mounting foot must be attached by at least three bolts on a steel reinforcement plate at least 3mm thick and of at least 12,000mm2 area which is welded to the bodyshell. Examples are shown in drawings 253-18 to 253-24. (For drawings 253-18 and 253-20, the reinforcement plate does not necessarily have to be welded to the bodyshell.)"

These are the FIA specs. For non-international competition, the plates can be smaller in area.

IMHO there is no significant safety advantage in a weld-in cage over a bolt-in (particularly for a base level spec cage) as long as it is well designed & fitted. It also removes the potential danger of dodgy welds in a home-built cage (especially at the top of the A pillar, where it can be hard to get a good full circumference weld).

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Thu Jan 14, 2010 11:05 pm
by amgis_obrut
dont stuff around go for a weld in, 1020 grade mild steel as a minimum or if budget allows go molly

Rod Andrews is the guru, He's helped me out a bit when i made the cage for my Cortina

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 12:13 am
by Rally_2.6LC
Oh well of poll wont go through im sure people can still vote on here by replying to the post.

For motorkhana's having a cage shouldnt put you up a class....in any racing. Motorkhana rules are based on wheel base, Khanacross based on engine capacity and so is circuit racing, rallying depends on a whole bunch of stuff and most people wont let you do a rally without a cage.

Agmis_orbit - Is that your cortina on Rod's website??? I was very impressed with his kit (and he is much more friendly and helpful than Bond) which is why I would choose him over Bond, however he doesnt do bolt in cages :( and im starting to sway more in that direction. Chrome Molly....unfortunatly budget doesnt allow. But yea I would be getting 500mpa (or what ever the pressure fail rating is for steel) steel for the cage either way.

Dave has a point, the plates dont need to be welded so long as there is reinforcing plates on the underside of the body and the cage inside the car bolts through the floor and to the plates on the underside this is fine (same when you reinforce the car for harness bolts to go in). I did get told a trick to weld the full circumfrence of the cage, set it up and tack it in place, then drill holes in the floor and drop the cage down through the floor of the car so you can weld all the way around the bars. These holes in the floor dont matter because you weld a new plate bigger than the holes over the top. ;D




Cheers Matt

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 12:19 am
by Rally_2.6LC
DanTurboLancer wrote: What sort of events will you be entering?
What speeds will you be reaching?
What are your future plans?

just a thought mate

Dan all thoughts welcome....hence why I posted.

Events, mostly motorkhana's and Khanacross with hopefully 2 forrest rallies by the end of the year (new years resolution is to enter a propper rally either drive or nav).
Speeds.....well I hit 175 on the speedo and still had half of 5th gear to go in teh last speed event, but I think the speedo reading was out caus it only felt like around 145-150 (ill have to adjust the gearbox pickup thingy) but max speed of car will only be around 180km/h and in a rally you only really get up to 130-140 if your pushing it fast along long straights (well I would for now anyway).
Future plans are:
more power (quad throttle bodies)
full rally spec car
get it road registered before the year is out.
get into forrest and maybe some touring rallies.
BEST PLAN - do Targa Tasmanina in it one year (if I win lotto)

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 10:01 am
by amgis_obrut
Rally_2.6LC wrote:Oh well of poll wont go through im sure people can still vote on here by replying to the post.

For motorkhana's having a cage shouldnt put you up a class....in any racing. Motorkhana rules are based on wheel base, Khanacross based on engine capacity and so is circuit racing, rallying depends on a whole bunch of stuff and most people wont let you do a rally without a cage.

Agmis_orbit - Is that your cortina on Rod's website??? I was very impressed with his kit (and he is much more friendly and helpful than Bond) which is why I would choose him over Bond, however he doesnt do bolt in cages :( and im starting to sway more in that direction. Chrome Molly....unfortunatly budget doesnt allow. But yea I would be getting 500mpa (or what ever the pressure fail rating is for steel) steel for the cage either way.

Dave has a point, the plates dont need to be welded so long as there is reinforcing plates on the underside of the body and the cage inside the car bolts through the floor and to the plates on the underside this is fine (same when you reinforce the car for harness bolts to go in). I did get told a trick to weld the full circumfrence of the cage, set it up and tack it in place, then drill holes in the floor and drop the cage down through the floor of the car so you can weld all the way around the bars. These holes in the floor dont matter because you weld a new plate bigger than the holes over the top. ;D




Cheers Matt
Nah not my corty , he hasnt actually done any work on my car only given me some great advice

It all been made here in my shed, pretty easy really

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 4:21 pm
by DanTurboLancer
Sorry mate yes you are right Khanacross is what i was thinking of.

Rally_2.6LC wrote: Future plans are:
more power (quad throttle bodies)
full rally spec car
get it road registered before the year is out.
get into forrest and maybe some touring rallies.
BEST PLAN - do Targa Tasmanina in it one year (if I win lotto)

I go on the theory, do it right the first time., and you spend less....
Not that always works out for me lol

It seems the money is around the same.
But i would be looking at it for in the future,
the events you wish to enter, what requirements to they have for Cage?

Speak to a couple of Engineers,
Will they be happy to pass the car with either option cage in?


If the higher level events you want to enter later, require a welded cage, you may as well look at that option...

But if they dont, and your Engineer is not keen on the idea of a cage for rego, then you know you can bolt one in the night before...

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 9:01 pm
by cheaterparts
Rally_2.6LC wrote: I did get told a trick to weld the full circumfrence of the cage, set it up and tack it in place, then drill holes in the floor and drop the cage down through the floor of the car so you can weld all the way around the bars. These holes in the floor dont matter because you weld a new plate bigger than the holes over the top. ;D

Cheers Matt
or if you cant do that - I have in the past had to use a stick welder to get around to top
when ether a tig or mig gun cant get in the space

with a stick welder you just bend the rod to get it to the correct welding angle and it only about the top 25 mm that cant easy be reached

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 9:18 pm
by Rally_2.6LC
Interesting cheater, i would have thought the rod would snap......

The engineer is happy to pass either cage so long as it doesnt block line of sight.
They cost the same to buy in kit form, but I then need to pay someone to weld the cage in for me.
The levels I can enter in this car require a 6 point cage, either weld or bolt in.



Cheers Matt

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Fri Jan 15, 2010 9:39 pm
by cheaterparts
Rally_2.6LC wrote:Interesting cheater, i would have thought the rod would snap......

Cheers Matt
no you can tie most mild steel rods in knots - the flux falls off at the bend though

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Mon Jan 18, 2010 9:01 am
by MATNES
go a weld in cage. you can get a basic 6 point cage for around $1500 and all you have to do is paint it.
there is a guy who spent the same money then spent hours trying to fit it.

as for mr trees post about poor welding have a pic of a home made cage and the poor weld job done on it
a pillar
Image

main hoop

Image

and the bottom of the driver side main hoop had no penatration where it was attached to the floor and it just fell out with little effort.

as for the easyness of swapping a bolt in cage if it is a big shunt best to replace it anyway

MATT

Re: 6 point Weld in or Bolt in Roll Cage

Posted: Tue Jan 19, 2010 1:15 pm
by panda
My preference is a fully welded in cage. My rally Sigma had a full 6 point cage, fully welded in.
Couldn't believe the difference it makes to the cornering & handling. It just shows just how much flex a standard body shell must have.
If the unthinkable happens & you should write off the shell, then simply cut the car shell off the cage & refit the cage. But, from personal experience, I've found that the cage from a wrecked car will most likely have stress fractures, & will need a thorough inspection before re-using.

cheers, panda