As the title states at what point is CM worth putting in? I have the ability to tig or mig, so that is not an issue. Looking at doing 25.5, probably going to start fresh, so the old jegster cage is getting cut out.

Also looking for any pointers since I'm just gonna chop the old 6x6 plates out and go with 8x8 to cover the previous hole, or do I have other options?

Waiting on my 25.5C literature to come snail mail.... Jesus! Cant SFI get with the times and make a downloadable manual????

When you want a cage thats about 50% lighter and
better resale.. if you do sell it

There is a E.T. limit on using mild steel tubing for SFI cages, I believe it is 7.50 or slower in the 1/4 mile If your planning on keeping the car and making it goes faster and faster then go for the good stuff to start with
As Mike has pointed out it is stronger and lighter as well as returning to its original position in race cars during the runs instead of bending and staying bent after the stress

IMO put a moly 8.50 cert in it and you're good to go. Especially around here!

simple answer is always! too much upside to ignore!

It wont meet 25.5 with steel.

Good to know. I'm sure it states this in the book along with plenty of other things.

I guess I know my answer. 4130 it is!

Yup, it's a no Brainer if your rebuilding

I wouldn't bother with Mild Steel personally. I have a few of the cage regs scanned, can't remember which ones I ended up with.

Since when??

It doesn't matter, does it?

No cage with a mild steel hoop will cert quicker than 8.50. A 25.5 cert is good to 7.50

SFI Spec 25.5C Full Bodied Car Stock or Modified/OEM Floorpan and Firewall with OEM Frame or Uni-Body Construction – 7.50 to 8.49 Seconds; 3,600 lbs. Maximum

I love mine. I can't believe how much lighter it is than with M/S. The only down side is the expense, so try to minimize mistakes.
FYI, I'm building mine to 25.4B specs. Mild steel is definitely acceptable with full specs under Section II Basic Construction Practices, SFI 25.4B Material List, and SFI 25.4B Tube Size Color Chart.

If your going bracket racing, why spend the extra $ on a CM cage? The weight savings of CM will not win you any races. Nascar uses mild steel, so it can be built strong and safe. Now if you're racing heads up, then the weight savings of CM makes it a necessity.

A roll bar just to go 11s or mid-high 10s? MIG and MS, maybe the right choice for some. But it would get cut out and CM used for any upgrades were it up to me. Anything that will need a tag of any kind, CM.

I've been setting it up more for grudge and heads up racing. I mean bracket racing isn't out of the question at a track 100s of miles away.

But I've already exceeded my 10 point cage, luckily my home track is pretty lenient and hasn't sent me home yet. So an update is needed. Especially if I want to go to other tracks that may follow the book to the T.

You never know what you may do. You can't hardly give a car away with a mild steel 8.50 cert cage these days. The moly cage will always help resale.

Now a lot of guys do the moly 25.5 deal and don't put the FC cage in, but it can always be added later. Usually if I do that for guys, I put the back and side bars in and just leave the FC hoop out. Have also made all the FC cage stuff, just didn't put it in the car right then. Why you may ask? Some guys swear they can't see in a car with a FC cage. I have never had a problem, but they claim they can't see. But, they know the car will sell better with the FC cage, so they have me make it in case they need to put it in. Sounds weird but done it several times

was this a rule change over the last couple years, I thought 25.5 (7.50) could be mild, moly, or a mix.
My car is a mix, the main hoop being mild steel, it certed a few years ago 25.5.

You are correct, it can be a mix at 25.5. There are so many specs now, hard to keep them straight