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Balroks

Cage builders..

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kbrew8991
Whats your opinions/experience with the Moly vs Steel? (besides the obvious weight/cost)

 

I'm pretty sure you can't get a logbook now with the thinner wall moly, so the weight savings is gone leaving you with a PITA material to work with thats more brittle and the like to boot...

 

easy decision to me

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racecarbuilders

rules are allways changing ..i dont have a current rule book infront of me ....but it used to be if the weight of your car required you to use 1 3/4 120 wall dom... you could used 1 3/4 .095 wall 4130 due to its higher tensel strength ..if that is still true there would be a weight savings of about 30 % ....check the rule book the tubing requirements go by the final weight of your car ..if you are or think you may be on the edge use the bigger stuff better to be safe than sorry ....

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kbrew8991

pretty sure you'd have to use the same required wall thickness between both materials, erasing the weight savings

 

the CCRs are available at http://www.nasaproracing.com" onclick="window.open(this.href);return false; - might be useful for a cage builder to have a copy

 

page 63:

Up to 1500 lbs.

1.375” x 0.095” Chrome-moly / Seamless mild steel (DOM)

 

1501 - 2500 lbs.

1.500” x 0.095” Chrome-moly / Seamless mild steel (DOM)

1.500” x 0.120” ERW* (No issuance of log books for cars with ERW cages 04/30/03)

*Note- Specifications listed for reference for inspection of grandfathered vehicles.

 

2501 - 3000 lbs.

1.500” x 0.120” Chrome-moly / Seamless mild steel (DOM)

1.750” x 0.095” Chrome-moly / Seamless mild steel (DOM)

1.750” x 0.120” ERW* (No issuance of log books for cars with ERW cages 04/30/03)

*Note- Specifications listed for reference for inspection of grandfathered vehicles.

 

page 64:

3001 - 4000 lbs.

1.750” x .120” Chrome-moly / Seamless mild steel (DOM)

No ERW allowed.

 

Over 4000 lbs.

2.000” x 0.120” Chrome-moly/Seamless mild steel (DOM)

No ERW allowed.

 

(I did have to go look it up to remember for sure fwiw )

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racecarbuilders

i have it at the shop but not here but found it on the board ...so i just took a refresher course on the NASA rules .... yes they did take away the weight savings for molly ...and dash bars are optional ??? humm... we all learn things....they are required in scca and grand am cup ..no offense to anyone but ... do you know how many i have snaked through because they didnt want to admit it was a race car and give up the AC from now on i can leave it out we can add it when they want to save the 100 lbs of ac stuff...cool hopefully gator will post the pics i sent him of his evo just need to add the door bars and window net and call it done

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kbrew8991

I think your shop did the SRT4 that I was in for One Lap of America 2007

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racecarbuilders

i did one ..it was black ...i cant remember his mame off the top of my head he was from orlando i think

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kbrew8991

yup - that guy sold it to the guy who owns it now (Doug Wind out of SC - 1lapSRT on this board) and is kicking some ass with it mostly Time Trials and Time Attack stuff though

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Balroks
i have it at the shop but not here but found it on the board ...so i just took a refresher course on the NASA rules .... yes they did take away the weight savings for molly ...and dash bars are optional ??? humm... we all learn things....they are required in scca and grand am cup ..no offense to anyone but ... do you know how many i have snaked through because they didnt want to admit it was a race car and give up the AC from now on i can leave it out we can add it when they want to save the 100 lbs of ac stuff...cool hopefully gator will post the pics i sent him of his evo just need to add the door bars and window net and call it done

 

Can't wait to see those pics

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Gators2001
Can't wait to see those pics

 

 

As you requested:

 

100_2932.jpg

 

 

 

100_2933.jpg

 

 

 

100_2934.jpg

 

 

 

100_2935.jpg

 

 

 

100_2936.jpg

 

 

 

100_2937.jpg

 

 

 

100_2938.jpg

 

 

 

100_2939.jpg

 

 

 

100_2940.jpg

 

 

 

100_2941.jpg

 

 

 

100_2942.jpg

 

 

I cant wait to see her in person!!!

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Balroks

F*ing nice dude, he doing the door bars and the front halo next?

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Gators2001

yup.

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racecarbuilders

front is there look close all it needs is door bars

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Rob O

Now that is a nice tight fit! Thanks for the pics.

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Balroks
front is there look close all it needs is door bars

 

Ah, Gator and i were discussing the cross on the top much like you did in the back, some people like to use it. Personally with my alum roof i'd want a double cross, in case i land head first on a stump or post like that video posted earlier could have - i'd like to have something there besides the surrounding bars. Interesting points on the 4130, the guy i'm looking to use, or rather the guy who's looking to sponsor due to the new shop opening (he's no newbie, just a bigger shop and splitting the names), does only Tig welds in 99% of the fabing he has done already. But from the sounds of it - from a direct safety standpoint - either is satisfactory. It'll come down to measuring each tube and getting the exact weights of both types which i think i can do, and post it up. However if he falls through the cracks, expect a phone call from me

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Gators2001

Yea, I opted not to put in the Halo Diagonal.

 

I felt like it would come to close to my head. Many have it, and its probably just me.

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TurboShortBus

Mild steel tubing - TIG or MIG, either one (the roll bar in my 1994 GT is TIG welded mild steel)

 

Chromemoly tubing - TIG only, plus heat treating

 

Mark

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TurboShortBus
...the guy i'm looking to use, or rather the guy who's looking to sponsor due to the new shop opening (he's no newbie, just a bigger shop and splitting the names)...However if he falls through the cracks, expect a phone call from me

Is this an Orlando-area shop? I pretty much already know exactly how I want my cage layout to be; I just need a good local installer. If that's not possible, then it looks like I'm off to Stuart.

 

Mark

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racecarbuilders

balrock... i know this will sound bias... because i am a cage builder... but i caution you on the mufler shop that says they only tig weld.... muffler shops mig weld exhaust systems together.. they just dont use the tig welding process...tig welding is much to slow to be profitable.....so it would be very unusual to see a tig welder in a muffler shop... just remember once the cage is in it is sort of perminant and it can be the worst thing you ever did to your car if it is done poorly.. this is a quick 101 on welders so you know the difference ...mig welders the wire comes out of the center of the gun and burns back when it makes contact ...the weld will be about 1/2 inch wide and look like a bead of smoothed calking ...tig the torch is only heat and the rod is added separately kind of like soder and sodering iron ... giving you much more controle the process takes about 4 to 5 times as long as a mig weld of the same length.. the finished weld is only about 1/8 inch wide therfore the 2 pieces of tubing must fit together perfectly which also takes much more time especially if you dont have an end mill knotcher...there is more than enough work out there... i havent missed a day in 6 years ...i just dont want to see anyone get burned even if it is free... it still my not be a deal

Edited by Guest

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Balroks

Indeed, thanks for the tips. I wouldn't take my car near a muffler shop generally, especially if i didn't know already the people, practice, and craftsmanship. I've been around tig and mig, well racing in general for years with my father so i'm not totally n00b . But the biggest debate for me right now is cost verses weight because i'm still in the designing phase (Net Engineer by trade, nerd i know ) Shortbus made mention that, even with the new rules (which could change again for 09 but unlikely?) the difference, as he heard, is moot. So if we take Gator's cage for example...if you were to make the same one, given unlimited time and money of course, out of CM, what would be the real world savings? And would the 1.5x.120 or the 1.75x.095 weigh less?

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TurboShortBus
So if we take Gator's cage for example...if you were to make the same one, given unlimited time and money of course, out of CM, what would be the real world savings?

Huh? Check this previous post:

 

For what we do, there is no weight difference, because we are required to use 0.120" thick (or whatever it is) wall tubing for both mild steel and CM; only NHRA allows thinner wall thickness for CM compared to mild steel, so that's why it's "lighter." I believe that CM is a tad heavier than mild steel when comparing identical volumes.

And this previous post:

 

page 63:

2501 - 3000 lbs.

1.500” x 0.120” Chrome-moly / Seamless mild steel (DOM)

1.750” x 0.095” Chrome-moly / Seamless mild steel (DOM)

1.750” x 0.120” ERW* (No issuance of log books for cars with ERW cages 04/30/03)

*Note- Specifications listed for reference for inspection of grandfathered vehicles.

 

page 64:

3001 - 4000 lbs.

1.750” x .120” Chrome-moly / Seamless mild steel (DOM)

No ERW allowed.

You won't be saving anything, if you're looking to go lighter. You'll be spending more money for the same result.

 

Mark

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Balroks

Oy, google is my friend lol, granted. I can't just get it from one source you understand. So considering carbon content, same sizes, brittle verses not-as-brittle, etc etc etc. It sounds like it would be moot and a pain in the arse to do moly and not really get anything. Ok so enough about that. Back to the second question - which size would be lighter given an entire cage structure?

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racecarbuilders

i am not sure which would be lighter???? i guess i could cut a 10 ft sec of each and try and stand them on my scales ....most that have the option of 1 1/2 go that way 1/4 inch doesnt sound like much but when it is next to your head it is... let me know what you find out onthe weight thing just F.Y.I. the average cage has 80 to 100 ft in it

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Balroks

Cool, ya even a 1 foot section on a scale would be invaluable. Thanks!

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Balroks

Got some info searching after lunch today. Mild steel tubing:

 

1'x1.5x0.120 = 1.768 lbs

1'x1.75x0.095 = 1.679 lbs

 

Take a typical car as Builder said earlier

 

1.50 = 141.44 lbs to 176lbs

1.75 = 134.32 lbs to 167 lbs

 

So we can see, it's only a bloody 10 lbs difference.... wow. Time for me to go on a quick diet

Edited by Guest

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TurboShortBus
So we can see, it's only a bloody 10 lbs difference.... wow. Time for me to go on a quick diet

And, you will only "realize" that 10 lb difference if you have the option between the 1.5" x 0.120" and 1.75" x 0.095" tubing sizes, which only happens if your car is in the 2501-3000 lb range. But, if your car weighs 3001 or more (presumably fully loaded), then you don't have a choice, as the 1.75" x 0.120" is mandatory. I'm not sure what gutted Evos weigh these days, though.

 

Personally, I would rather not be at the upper limit of required tubing sizes. If my car was to weigh 2999 lbs with cage, driver, gas, cool suit, etc., then I'd rather go with the 1.75" OD than cut out 10 lbs with the 1.50" OD.

 

Mark

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