Want a full cage. Any tips?
 

Entry price is around $4-5k, they tend to top out around $7-8k depending on how many bars are going into it, what type of roof bar it's using (single piece A pillar bars tend to be more expensive than a halo hoop setup), if it's though the firewall, what kind of door bars it has, if it's got seat mounts, does it have a single or double roof diagonal, how many diagonals in the main hoop as well as your rear drop bars, where it's gusseted to and how many there are etc.

There really isn't anywhere you can save in regards to doing work yourself unless you know who's doing the cage.

The only two metals cages are made of are DOM steel or chromoly. Chromoly is a fair bit more expensive and the only advantage it has is that it's lighter but the downside is if it's not welded properly you risk the chance of the weld or heat affected zone will shatter instead of the tube bending in a crash. So if you choose to go chromoly make sure they have experience welding it already.

The other big consideration is tube size. Cages are either 1.5" or 1.75" tube. My preference is 1.75" tube because it's stronger and lighter (has a thinner wall thickness than the 1.5" which makes it lighter most of the time and strength is mostly dependent on outer diameter). The only downside is it takes up more space. Depending on what sanctioning body you're racing with determines how thin you can go with the wall thickness here's a pretty good guideline on cage construction: https://www.nasarallysport.com/rules...xkZJeFmXS9FHvI

All spot on points. The Nasa CCR has some of the same info but not as many pics. The material depends on your car weight. Not the weight with you, cool suit, fuel, etc as raced. Only the things that are "part of the car". Several tips.

1. If you're under 3k lbs dry, Use 1.5x120. The added viability makes a world of difference and makes crawling through it to work on it MUCH easier. A handyman style gutted evo should weight around 2750. Assume the cage will weigh ~250lbs.
2. MAKE SURE the guy is uber experienced. The main hoop should be about 7-18 inches back from the B pillar if you want to fit the seat and harness with room to spare.
3. Assuming you have a race seat already. If not get it first because it's height will determine where the horizontal bar goes behind the seat as there are tolerances on belt mount angles.
4. Have the guy do nascar door bars, not X's. This will require you to gut the doors (good thing).
5. Have the guy weld "handles" for entry/exit. This is a simple bar between the A pillar and the top horizontal bar. Think of it as where the top corner of the windshield is where you'd pull up and out.
6. Take advantage and have him throw bars in the trunk area (tie in the strut towers with a "removable" bar as some bodies make it illegal when you go to resell it) for the purpose of mounting the wing directly to the chassis. Plus it stiffens up that whole area.
7. Don't let him sell you on this whole design that puts the A-pillar bars 4 inches away from the frackin a-pillar and then go welding extra material to tie them together. Wasted weight, ruins visibility. Bend the bar right and weld that b*tch directly to the a-pillar without anything between.
8. Go in on the removable steering wheel, Electrical cut off switch (or at least the mount), Lexan windows, and the fire system at this time. You can keep the windshields glass if you want, I still do.
9. He'll love you if it's in running condition so he doesn't have to try pushing that thing around the shop.
10. Be prepared to replace the windshield because they're almost guaranteed to crack it. And be VERY careful on the first car wash, there will be metal all over your paint.

And so on.

Prep:

1. Gut all 4 doors.
2. Take out all the insulation/sound stuff
3. Pop the roof off if you can or if not they will in order to weld around the upper joints, but he'll need the roof. Good test question for them.
4. As it sits, mark where you want the seat to be. Try for bolt in position, no adjustable junk.
5. Take out as MUCH of the interior as you can. The more you remove that's less he has to remove. Especially when it comes to wires. Because we have OMG wires.

1. take a looong read of the rules of the series you are competing in. That will dictate your cage.
2. Personally I prefer the FIA type cage with X door bars as it is stiffer and lighter than NASCAR type door bars. Nascar ones are there for side impact protection.Choice will depend on the rule book.
3. Make sure you connect all suspension pick up points into the cage. No point having it just for safety. Use it for chasis stifness
4. Personally, I would use this opportunity to seam weld the shell... this will make the whole process more expensive though. Might as well cut out the trunk floor then.

Agreed! Experience will play a huge factor in how well the cage hugs the inside of the car which makes a huge impact on visibility and getting in and out of the car. It's really funny, my cage has a nascar bar for the driver's side and x bar for the passenger side. I love watching passengers struggle to get over it whenever I take someone for a ride :)

Doing the interior prep work will definitely save money. But the one thing I'd probably not recommend doing is taking the roof off without talking to the cage fabricator first. My cage was done without removing the roof, er at least there's no signs the roof was removed. As long as your side roof bars aren't super tight to the roof you can get enough space to squeeze a welder in there. The shop I used to work at doesn't remove the roof for every cage either. And on a similar note, most racing bodies will require the main hoop to be one continuous piece so keep that in mind.

Also, floor mounting with boxes vs plates allows the cage to be tucked closer to the car better. Usually there's some seam sealant in the area where these boxes will go (as Balrok said, the main hoop on an evo usually needs to be pretty far back, mine is right in front of where the rear seat shelf is) so grinding away any sealant where the box or plate is going will save a load of time for the fabricator. Subaru is notorious for their heavy use of seam sealer, can't tell you how much of that stuff I've been covered in lol.

The lexan windows are really easy to make if you have access to a sheet brake to make cuts. I made mine from polypropylene because lexan was in my car which has less give to it and is more likely to crack. Both sides ended up cracking or pieces breaking off at some point. Zero issues with the polypropylene so far. If you're racing NASA keep in mind that the fronts need to be removable unless you're racing in TTU.

One of my favorite things about my cage is it replaces the factory dash bar with it's own that ties the A pillar bars together. Whoever made it took most of the factory bracketry off the stock dash bar and threw it on the cage's dash bar so the steering column, fuse box and dash panel all bolt straight onto the cage. Saves some weight and neatens things up and being able to remove the dash with just 3 easily accessible bolts makes a world of different on saving time for working underneath there.

One thing about installing a cage I wasn't aware of before hand was that it becomes extremely dangerous to drive around without a helmet. You get in an accident and your head hits one of those bars and its lights out. I'm not saying people don't do it all the time, just something to consider.

Half the fun is when you get your motor running again and sprinting down country roads, at night, in a caged car, with no helmet, or headlights, on cold tires ;)

Put the bars in the right place and you'll be fine. My neck would have to snap before my head hits a bar in my car so I don't worry about that too much. I also don't do tons of street driving.

Another important point is that you need to decide on is a seating position and a seat. That way the cage builder can tailor your position and the seat so you can reach all the pedals and turn the steering wheel.

It stands to reason that if a roll cage is being built for the car it should be designed in a way that increases the structural rigidity of the chassis. Some cage builders don't do that and then it becomes a waste of time and money.

one HUGE misnomer is that chromoloy weights less than DOM - they weight the same!

Some organizations allow a thinner wall moly which is where the notion that it weights less came from - but more rules these days don't differentiate between the two.

We used some moly parts on our car but did it sparingly due to the cost/benefit.

1.75x.095" chromoly would be the ticket for cage material for the weight of an Evo. Stronger and lighter than 1.5x.120" tubing.

1.75.0951.679 1.5.1201.769

its .09lbs/ft less. IIRC we used 140' on our cage (its super extensive) so that would be 12lbs.

really rough estimates the cost difference would be $2,100 more for a moly cage.

is 12lbs worth $2100???

also keep in mind you could do 1.75 x .095 DOM for $2,100 less and weight the same.

DOM mild steel and chromoly weight the same. I just prefer to use chromoly for things that might save my life.