CM VS STEEL,Weight savings?
11-12-2004, 12:37 PM
#2
In a Wolfe 6 point roll bar, there is a 20 lb. difference. Chromoly: 60-65 lbs. Mild Steel: 80-85 lbs. If you wanna keep the weight down for best results, spend the money now cause you'll regret it later. Plus, if you plan on purchasing a weld-in, I highly suggest you do it the right way the first time. I spent the extra money and bought the 6 point weld-in chromoly from Wolfe.
11-12-2004, 09:42 PM
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I bought a 6 point weld in mild steel wolfe, and if I had it to do over I'd do the Chromoly one. When I weighed my car this past weekend at the Southern Shootout I almost cried.. 3420lbs with it pretty much stripped down. I weigh about 190lbs with the helmet and fire jacket. I have a "stripper car" and I've taken the back seats out, front bumper support, AC, AIR, front sway bar, all factory seat belts, weighed on draglites, and I have aluminum oval craft front seats. I can loose some more with a tubular K-member, rear bumper support, etc.. but it would have been much more simple to have just bought a chromoly cage. 
11-12-2004, 09:51 PM
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Originally Posted by BlackBeaSSt
In a Wolfe 6 point roll bar, there is a 20 lb. difference. Chromoly: 60-65 lbs. Mild Steel: 80-85 lbs. If you wanna keep the weight down for best results, spend the money now cause you'll regret it later. Plus, if you plan on purchasing a weld-in, I highly suggest you do it the right way the first time. I spent the extra money and bought the 6 point weld-in chromoly from Wolfe.
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11-13-2004, 04:03 PM
#10
...in a nutshell, chromoly has the same density of mild steel (~.283lb/in^3). Among other things, one advantage is it has a higher yield strength. When strengh is an issue, you can run lower wall thickness (of material)vs similar stregth mild i.e. 1020 steel...this is what reduces weight (not because it's 4130). On a negative aspect, it is less ductile which means it can fracture easier.
If weight is a concern...as stated, spending additional money can be worth it in the end....I tell this all the time to the guys purchasing our Bogart rims that may cost a little more...but in the end, you're saving ~50 lbs of converted static weight over prostars/draglites and other similar designs.
Saving 20 here, 50 there etc really adds up in the end...you'll find many of the fastest guys have these similar mods done...and done for a reason. Lowering the overall weight also reduce stresses on the engine drivetrain etc lessoning failures in the end which reduces costs.
Steve
Pres.
If weight is a concern...as stated, spending additional money can be worth it in the end....I tell this all the time to the guys purchasing our Bogart rims that may cost a little more...but in the end, you're saving ~50 lbs of converted static weight over prostars/draglites and other similar designs.
Saving 20 here, 50 there etc really adds up in the end...you'll find many of the fastest guys have these similar mods done...and done for a reason. Lowering the overall weight also reduce stresses on the engine drivetrain etc lessoning failures in the end which reduces costs.
Steve
Pres.
11-14-2004, 12:16 AM
#11
Are u telling me your Bogarts are that much lighter than my Weld Drag lites?
How much weight savings can I get from changing rims?
I'm buying DS2's for the car this week and a Kirkey seat.My buddy is making the brackets for that and I'm removing the cruise control/PS air bag too.I figure I can take out an easy 40lbs with these mods,How much will the rims save me?
I must get my car down to 3400 with me in it (Currently 3620) so I need another 180lbs.I'm commited and I'm going on a diet to try and get healthy,I need to lose 100'lbs and I'm gonna do it.I'll need to find another 80 in the car somewhere
How much weight savings can I get from changing rims?
I'm buying DS2's for the car this week and a Kirkey seat.My buddy is making the brackets for that and I'm removing the cruise control/PS air bag too.I figure I can take out an easy 40lbs with these mods,How much will the rims save me?
I must get my car down to 3400 with me in it (Currently 3620) so I need another 180lbs.I'm commited and I'm going on a diet to try and get healthy,I need to lose 100'lbs and I'm gonna do it.I'll need to find another 80 in the car somewhere
11-14-2004, 10:09 AM
#12
JS,
The actual weight savings is 8-10 lbs (depending if your using spacers or not currently). Rotational unsprung weight is not the same as static weight. Depending on the rim manufacture specs, 1 lb of rotational weight is equivalent to 6-8 lbs of static weight. This means that our rim that saves you ~8 lbs will net 48-64 lbs in static weight savings (meaning it would like removing ~50 lbs off your car)
I'd say if you want to loose quite a bit of weight, an easy way would be to change over to drag brakes and calipers...you'd be able to go over to a P2 rim easier which are even lighter, not to mention more mass is directed towards the center of rotation.
Between the upgraded brakes and wheels, your going to loose a very good amount of unsprung weight. The Ds2's are a great choice...much lighter then 1573's or the VW's tires (which I suggest no one use!!). You'll stop a bit better and have less frictional losses with the DS2's).
Your in the right direction, changing your seats, and the air bag is a great start for easy inexpensive weight loss. Don't forget to remove the entire air bag brace..the brace alone is ~8-10 lbs. There's a list in here for all the part weight losses...you can add them up to see where you'll end up...I'm not sure what you've removed...but there are many areas you can remove quite a bit of free weight.
I'd imagine changing out all the parts you mentioned and I've added, you should easily see 125-150 lbs off your car. Just keep in mind, unsprung weight is actually worth quite a bit more so don't overlook those areas.
Those mods will bring you down into the "10 sec" club.
It's all how fast you want to go and how much you want to spend. You need to find your happy median.
Good luck!
Steve
Pres.
The actual weight savings is 8-10 lbs (depending if your using spacers or not currently). Rotational unsprung weight is not the same as static weight. Depending on the rim manufacture specs, 1 lb of rotational weight is equivalent to 6-8 lbs of static weight. This means that our rim that saves you ~8 lbs will net 48-64 lbs in static weight savings (meaning it would like removing ~50 lbs off your car)
I'd say if you want to loose quite a bit of weight, an easy way would be to change over to drag brakes and calipers...you'd be able to go over to a P2 rim easier which are even lighter, not to mention more mass is directed towards the center of rotation.
Between the upgraded brakes and wheels, your going to loose a very good amount of unsprung weight. The Ds2's are a great choice...much lighter then 1573's or the VW's tires (which I suggest no one use!!). You'll stop a bit better and have less frictional losses with the DS2's).
Your in the right direction, changing your seats, and the air bag is a great start for easy inexpensive weight loss. Don't forget to remove the entire air bag brace..the brace alone is ~8-10 lbs. There's a list in here for all the part weight losses...you can add them up to see where you'll end up...I'm not sure what you've removed...but there are many areas you can remove quite a bit of free weight.
I'd imagine changing out all the parts you mentioned and I've added, you should easily see 125-150 lbs off your car. Just keep in mind, unsprung weight is actually worth quite a bit more so don't overlook those areas.
Those mods will bring you down into the "10 sec" club.
It's all how fast you want to go and how much you want to spend. You need to find your happy median.
Good luck!
Steve
Pres.
11-15-2004, 12:21 AM
#13
Originally Posted by critter
I bought mild steel because I don't have a TIG. You are supposed to TIG moly. OTOH, if all that matters is that it looks like a cage I suppose that doesn't matter.
11-15-2004, 11:56 AM
#14
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Originally Posted by DietCoke
You have to tig all the important things to be NHRA legal, so if thats your reason for not getting CM, why bother?
11-17-2004, 01:30 PM
#15
Originally Posted by critter
Really? Not that tigging everything is a bad idea, but the rule book said MIG or TIG for mild steel, but only TIG moly. Have they changed that?
11-17-2004, 02:06 PM
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Originally Posted by DietCoke
The bar can me MIGed but everything that touches chassis HAS to be TIG welded to be legal. Technically.
FWIW, I saw the moly bar TIGed to the mild steel plates but the plates were then then MIGed to the floor pan. Are you saying that is illegal?