Is it Chromoly that gets tig welded or mild steel get tig too ?
How much roll bar or cage is needed for 10.00 & slower
- Thread starter MOPARMAGA
- Start date
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33IMP
Well-Known Member
You can tig mild steel or mig it, chrome moly has to be tigged. (A race car with a moly cage is more valuable than one with mild steel. Expected to be lighter and stronger)
Actually moly is no lighter than mild steel, size for size. Moly cage is lighter cause nhra allows thinner wall tubing with moly.
Actually moly is no lighter than mild steel, size for size. Moly cage is lighter cause nhra allows thinner wall tubing with moly.
My Daytona maxed out it’s cert at 7.50 because it was mild steel but I never went fast than 8.42@160mph. It had a funny car cage when it was 8.50 cert and needed 7 or 7 bars to get a 7.50 cert. I had the cage taken out of my 82 charger (old pro street car) and had chrome moly put in because it needed some weight loss and the price was more than right (1100.00) but I only ran 10.00 about 100 times in it. The green duster I just sold and my black duster are mild steel and 8.50 cert. My blue duster is full tilt chrome moly 6.50 cert. mild steel cars if built right still bring nice money when selling.
and you don’t have to have the cage cert until that 9.99 threshold. I had a full cage in my Mirada but only ran low 10s for the most part (hit a few 9.9 at sea level). Did it for the safety factor. I’ve had mild steel cages in both cars.
What's the real world weight difference between your mild vs chromoly ?
I’m sure one of the smarter guys on this site can answer that but it would come down to pounds per foot times how many feet. Different cage builders build differently so that’s a hard figure to give.
Meh, just weld you a few random pieces of exhaust pipe together. Done. lol
My son just got home from a race weekend and the shop he works at said the price of chrome moly went up 70% starting in March of this year. It’s a two man shop and my son has been laid off for three weeks because of several cancellations. The owner has also struggled to get tubing this year.
Cage Rage Fabrication LLC, 108 Schar Road, Evans City, PA (2021)
Cage Rage Fabrication LLC, 108 Schar Road, Evans City, PA (2021)
Surely conduit has been used at least
Shoot, yeah I noticed that pricing cages last night, I maybe looking at purchasing a 6pt and adding later.
They do nice work
33IMP
Well-Known Member
I did an eight point, so I could tie the main hoop to the subframe connectors.
And, you will have to tie the seat back to the bar, too.
Oh, and new five or six point belts every two years.
Nathan does some beautiful work and builds some fast cars. He won his class at Drag Week several years ago in a nitrous mustang he built and averaged 7’s at all the tracks. He sold that car and is building a turbo car now. They finished a car a few weeks ago and he let my son dial it in with a small 200 hit. Matt ran several 5.50’s in it.
K.O. SWINGER
Meeting in the alley since 1976
Hey guys how much rigidity will a 6-point add to strength of the chassis?
dirty white boy
50 yr old Juvenal delinquent
seen swing set tubing used in a dirt track u-car before....
A six point sure have frame connectors too at a minimum. Trouble is they usually are plated instead of tie’ing everything together. My sons car is a six point for now but I see major changes down the road. He wanted to keep the rear seat in the car so it is what it is but seems to work well running some high 10.0’s with my old 408@3200 pounds
ScamperTom
Supposed to be working
Chromoly has an advantage because the cage can be built out of thinner (and lighter) tube and be just as strong. Be wary, however, as it is difficult to weld properly. Overheating can make it brittle and liable to crack under stress. I honestly wouldn’t recommend it unless your builder has experience with it. Fabrication mistakes will more than outweigh the material’s advantages. The nhra hasn’t caught on yet, but there’s a type of mild steel being produced now called docol r8 that’s stronger than DOM but much easier to work with than chromoly. Docol® Tube R8 - A.E.D. Motorsport Products
You have to look closely at the regs concerning your class. The nhra has different tube requirements per vehicle weight that in themselves can really add some weight.
1.75” steel at .095 wall thickness weighs 1.68 lbs per ft. It generally takes about 100-150 ft to build a cage depending on the car and how crazy you want to go, which works out to about 150-200 lbs. This is actually less than 1.5” .120 wall tube (1.77 lbs), which a lot of people use. Chromoly tube of similar strength would be 1.75” @.083 which is 1.48 lbs/ft. This is a .2 lb weight savings per foot of tube, which adds up to a 20 lb weight savings for a 100 ft cage. Maybe just skip lunch.
You have to look closely at the regs concerning your class. The nhra has different tube requirements per vehicle weight that in themselves can really add some weight.
1.75” steel at .095 wall thickness weighs 1.68 lbs per ft. It generally takes about 100-150 ft to build a cage depending on the car and how crazy you want to go, which works out to about 150-200 lbs. This is actually less than 1.5” .120 wall tube (1.77 lbs), which a lot of people use. Chromoly tube of similar strength would be 1.75” @.083 which is 1.48 lbs/ft. This is a .2 lb weight savings per foot of tube, which adds up to a 20 lb weight savings for a 100 ft cage. Maybe just skip lunch.
Thanks for that info, so far my heavy diet hasn't amounted to any weight gain yet but that could change I'll be 44 in 4 months lol
Nice, I was thinking of fabbing a set of frame connectors this fall too
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