New REDLINE Rollbar for 996s
03-11-2004, 10:29 PM
#1
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New REDLINE Rollbar for 996s
Hey Gents;
Here's a little something I've been working on. Bolt in, only very minor non-visible (with seats reinstalled) mods to the carpet. Does not infringe on seat travel. Comes in and out pretty easily without a trace.
Looking for your considered input and comment!
Home of the Famous SafeGuard 944 Roll Bar.
Here's a little something I've been working on. Bolt in, only very minor non-visible (with seats reinstalled) mods to the carpet. Does not infringe on seat travel. Comes in and out pretty easily without a trace.
Looking for your considered input and comment!
Home of the Famous SafeGuard 944 Roll Bar.
03-12-2004, 12:25 AM
#2
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Nice looking roll bar. I'm curious, why the extra for aft bracing near the floor? With the struts gong rearward from the top is extra fore-aft resistance needed?
Regards,
Regards,
03-12-2004, 07:31 AM
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Hey Bob;
Remember, this is a bolt in bar and requires no other mods than a little carpet trim where it will never show with the seat reinstalled. I use factory reinforced seat belt holes for mounting when possible. The end of the main hoop is merely resting atop the rear body x-member. The "extra bracing" (the horizontal brace running back from the main hoop at the bottom) is the arm that mounts to the rear outer belt hole. It is the bottom mount.
Remember, this is a bolt in bar and requires no other mods than a little carpet trim where it will never show with the seat reinstalled. I use factory reinforced seat belt holes for mounting when possible. The end of the main hoop is merely resting atop the rear body x-member. The "extra bracing" (the horizontal brace running back from the main hoop at the bottom) is the arm that mounts to the rear outer belt hole. It is the bottom mount.
03-12-2004, 10:42 PM
#6
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Now I'm jealous... It's even prettier than your 944 bar in my car.
You may want to consider "guide hoops" for harnesses. Many regions (mine included) are requiring H-straps or some form of guide on the bar to maintain position of harnesses along it's length. Maybe optional?
My 2 cents.
You may want to consider "guide hoops" for harnesses. Many regions (mine included) are requiring H-straps or some form of guide on the bar to maintain position of harnesses along it's length. Maybe optional?
My 2 cents.
03-12-2004, 10:48 PM
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Hey Color, et al;
My design brief is this. I use good old ERW (welded seam) mild steel in .095" wall thickness. Very low tech, but inexpensive and reliable. I know that SCCA has banned it, and everyone who thinks they know something says you need .120 wall DOM. They are full of SCHEISSEN. This bar is not intended for racing. If you race, you get a CAGE in my less than humble opinion.
If it sounds like I have a bit of a boner over this stuff, I do. Too many "experts," not enough people with clear minds, and scarred and dirty hands! I've had a couple pints too!!
I do not see a lot of people getting killed because of tubing failures. The secret to a good design is placement and triangulation, not how heavy the damn thing is. My bar derives strength from triangulation and vertical rigidity. This bar should weigh about 47lbs, by the way.
It is also designed not to infringe on the driver area at all. I HAVE NOT studied the factory or DAS bars closely, but I believe I know where they mount. The rear footwell is extremely tight in a 996, and if you put the seat way back it must hit the main hoop of the bar. My bar is completely behind the b-pillar and does not restrict the driver compartment at all.
Finishes are at the request of the purchaser, with the basic surface being painted. I have not researched powder coat, but I know I could have it done if requested... for a price. Then there is Jet Hot coating and even chrome if you wish. Heck, I'll even go whole hog and build it in stainless if you must!
For a price point, I am thinking somewhere around $750 painted.
More feedback if you please, gents!!!!! This is a prototype, and I'm holding out hope that someone else besides me may have some brilliant ideas to improve it!!
My design brief is this. I use good old ERW (welded seam) mild steel in .095" wall thickness. Very low tech, but inexpensive and reliable. I know that SCCA has banned it, and everyone who thinks they know something says you need .120 wall DOM. They are full of SCHEISSEN. This bar is not intended for racing. If you race, you get a CAGE in my less than humble opinion.
If it sounds like I have a bit of a boner over this stuff, I do. Too many "experts," not enough people with clear minds, and scarred and dirty hands! I've had a couple pints too!!
I do not see a lot of people getting killed because of tubing failures. The secret to a good design is placement and triangulation, not how heavy the damn thing is. My bar derives strength from triangulation and vertical rigidity. This bar should weigh about 47lbs, by the way.
It is also designed not to infringe on the driver area at all. I HAVE NOT studied the factory or DAS bars closely, but I believe I know where they mount. The rear footwell is extremely tight in a 996, and if you put the seat way back it must hit the main hoop of the bar. My bar is completely behind the b-pillar and does not restrict the driver compartment at all.
Finishes are at the request of the purchaser, with the basic surface being painted. I have not researched powder coat, but I know I could have it done if requested... for a price. Then there is Jet Hot coating and even chrome if you wish. Heck, I'll even go whole hog and build it in stainless if you must!
For a price point, I am thinking somewhere around $750 painted.
More feedback if you please, gents!!!!! This is a prototype, and I'm holding out hope that someone else besides me may have some brilliant ideas to improve it!!
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03-12-2004, 10:56 PM
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Originally posted by RedlineMan
Hey Color, et al;
My design brief is this. I use good old ERW (welded seam) mild steel in .095" wall thickness. Very low tech, but inexpensive and reliable.
Hey Color, et al;
My design brief is this. I use good old ERW (welded seam) mild steel in .095" wall thickness. Very low tech, but inexpensive and reliable.
). Unless things have changed from the manufacturing standpoint, it's not as strong. DOM tubing is so cheap anyway, why wouldn't you use it? Saving a few bucks on raw materials for a cage doesn't make much sense to me, especially when someone's life is at stake.Cheers, James
03-12-2004, 11:56 PM
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Hey Dave, good to hear from you Old Bean!!;
Yeh... Chicago Region is on my Boner List. Here goes a right-religious rant, but an educational one!!!
I've got a real hard-on for these groups going their own little way, trying to legislate equipment. I don't fault their intent, but I DO their knowledge. Here's the questions I have for them:
- Do belts REALLY slide?
- Do guide hoops really solve the Bigger Problem, which is keeping the driver IN the belts?
- Does one "guide hoop" position work for EVERY belt path?
Answers:
- Maybe... Maybe yes. Maybe no.
- NO!!!!
- NOOOOOOO!!!!!!!!!!!
The last two hit the target of unintended, unforseen, un-thought-of consequences that really get me riled up. The last one is the BIG ballistic for me.
Keeping the belts in one spot at their mount assures NOTHING where driver retention is concerned. A stock seat will still peal the belts off the drivers shoulders, and then only in "certain circumstances." A race seat COMPLETELY OBVIATES the need for these "guide hoops" because the retention of the belt is DIRECTLY PROXIMATE to the driver, not 6-12-20 inches behind them WHERE IT DOES NO GOOD. A sternum strap will keep the driver belted UNDER ANY CIRCUMSTANCE no matter what seat is used. Even if the driver's freaking head flies off!!!
And hold on... the point that REALLY gets me animated is something NO ONE ever thinks about. Let me ask the #1 Pertinent Question:
How wide is the belt path for the seat everyone will use?
Answer:
How the HE!! do I know?????
A stock seat will have the shoulder belts, say, 16"s apart. One race seat might have belt pass-throughs at 6". Another 4". Another 3".
Racing harnesses should ABSOLUTELY ALWAYS run in clear straight paths with no bends, folds, or other infringements if possible. This allows stress to be absorbed most effectively by the material, spreading the load EVENLY throughout its length.
If it absolutely must be, some longitudinal bends of a slight nature are tolerable, such as laying the belt over a guide bar or the side of a seat base. This will STILL allow the load to be absorbed in a LINEAR fashion, EVENLY, over the ENTIRE length of the belt. The MOST DANGEROUS and potentially DEADLY situation is any setup that necessitates LATERAL BENDS in a belt.
If some impediment causes a lateral change in a belt's path, this creates a fulcrum or stress point. Now, the load cannot be absorbed EVENLY by the entire length of the belt. MORE STRESS will be focussed at the point the belt changes lateral direction. This is what happens when you stuff belts fixed at 16" apart at their mount through a seat with holes 4" on center! More stress equals higher likelihood of failure. Ask Dale Earnhardt Sr. why his belt ripped. Oh... heck, that's right... you can't ... He's DEAD!
If I weld guide hoops on Dave's bar that hold the belts at stock seat width (16"), and he uses them on a race seat with pass-throughs 4" on center, he now has belts that are not running longitudinally straight to the latch, cannot therefore absorb stress evenly over their entire length, may fail at any point along the outward edge of the belt (because it is stretched tighter than the inside edge), or may suffer a stress riser at the point of lateral deflection (the seat pass-through), and may therefore contribute to a fat lip, a rung bell... or his UNTIMELY DEMISE!!!!!
---------------------------------------------------------------
I quitealmostsortof apologize for this bellicose blowout, but to quote Catherine Hepburn in "Rooster Cogburn", "Blessed be thy Message, if thy INTENT be Pure!" I REALLY CARE that folks get the straight scoop. I don't claim to know it all, but I THINK!!!!! If nothing else... and even if I'm full of scheissen, y'all might get to thinkin too! Maybe I SHOULD have accepted that invitation to be PCA National Safety Chairman?
All the best to my Track Brothers!
Yeh... Chicago Region is on my Boner List. Here goes a right-religious rant, but an educational one!!!
I've got a real hard-on for these groups going their own little way, trying to legislate equipment. I don't fault their intent, but I DO their knowledge. Here's the questions I have for them:
- Do belts REALLY slide?
- Do guide hoops really solve the Bigger Problem, which is keeping the driver IN the belts?
- Does one "guide hoop" position work for EVERY belt path?
Answers:
- Maybe... Maybe yes. Maybe no.
- NO!!!!
- NOOOOOOO!!!!!!!!!!!
The last two hit the target of unintended, unforseen, un-thought-of consequences that really get me riled up. The last one is the BIG ballistic for me.
Keeping the belts in one spot at their mount assures NOTHING where driver retention is concerned. A stock seat will still peal the belts off the drivers shoulders, and then only in "certain circumstances." A race seat COMPLETELY OBVIATES the need for these "guide hoops" because the retention of the belt is DIRECTLY PROXIMATE to the driver, not 6-12-20 inches behind them WHERE IT DOES NO GOOD. A sternum strap will keep the driver belted UNDER ANY CIRCUMSTANCE no matter what seat is used. Even if the driver's freaking head flies off!!!
And hold on... the point that REALLY gets me animated is something NO ONE ever thinks about. Let me ask the #1 Pertinent Question:
How wide is the belt path for the seat everyone will use?
Answer:
How the HE!! do I know?????
A stock seat will have the shoulder belts, say, 16"s apart. One race seat might have belt pass-throughs at 6". Another 4". Another 3".
Racing harnesses should ABSOLUTELY ALWAYS run in clear straight paths with no bends, folds, or other infringements if possible. This allows stress to be absorbed most effectively by the material, spreading the load EVENLY throughout its length.
If it absolutely must be, some longitudinal bends of a slight nature are tolerable, such as laying the belt over a guide bar or the side of a seat base. This will STILL allow the load to be absorbed in a LINEAR fashion, EVENLY, over the ENTIRE length of the belt. The MOST DANGEROUS and potentially DEADLY situation is any setup that necessitates LATERAL BENDS in a belt.
If some impediment causes a lateral change in a belt's path, this creates a fulcrum or stress point. Now, the load cannot be absorbed EVENLY by the entire length of the belt. MORE STRESS will be focussed at the point the belt changes lateral direction. This is what happens when you stuff belts fixed at 16" apart at their mount through a seat with holes 4" on center! More stress equals higher likelihood of failure. Ask Dale Earnhardt Sr. why his belt ripped. Oh... heck, that's right... you can't ... He's DEAD!
If I weld guide hoops on Dave's bar that hold the belts at stock seat width (16"), and he uses them on a race seat with pass-throughs 4" on center, he now has belts that are not running longitudinally straight to the latch, cannot therefore absorb stress evenly over their entire length, may fail at any point along the outward edge of the belt (because it is stretched tighter than the inside edge), or may suffer a stress riser at the point of lateral deflection (the seat pass-through), and may therefore contribute to a fat lip, a rung bell... or his UNTIMELY DEMISE!!!!!
---------------------------------------------------------------
I quitealmostsortof apologize for this bellicose blowout, but to quote Catherine Hepburn in "Rooster Cogburn", "Blessed be thy Message, if thy INTENT be Pure!" I REALLY CARE that folks get the straight scoop. I don't claim to know it all, but I THINK!!!!! If nothing else... and even if I'm full of scheissen, y'all might get to thinkin too! Maybe I SHOULD have accepted that invitation to be PCA National Safety Chairman?
All the best to my Track Brothers!
Last edited by RedlineMan; 03-13-2004 at 01:31 AM.
03-13-2004, 12:14 AM
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Hey James;
You find that paper, eh? I'd love to read it.
Note that nowhere did I say that I was not aware that DOM was not stronger. Note also that in many cases, any "lack of material strength" can be more than compensated for by good placement and triangulation. Witness the Maserati Tipo 60/61 "Birdcage."
Please know that I am not dissing your assertions in any way. I am merely trying to point out that just because DOM may be stronger does not make a well designed piece made of ERW less safe than a marginally designed piece made of Hercules Alloy.
Local pricing is running $1.31/ft for 1.75x.095 ERW, and $2.75/ft for like-sized DOM. Local stock choices STINK! Cheap is a relative term, eh?
Thanks for your input. I would of course bend to the will of the market as long as they are willing to pay for the difference. I could do them in SS, CR, or Iconel even!!
You find that paper, eh? I'd love to read it.
Note that nowhere did I say that I was not aware that DOM was not stronger. Note also that in many cases, any "lack of material strength" can be more than compensated for by good placement and triangulation. Witness the Maserati Tipo 60/61 "Birdcage."
Please know that I am not dissing your assertions in any way. I am merely trying to point out that just because DOM may be stronger does not make a well designed piece made of ERW less safe than a marginally designed piece made of Hercules Alloy.
Local pricing is running $1.31/ft for 1.75x.095 ERW, and $2.75/ft for like-sized DOM. Local stock choices STINK! Cheap is a relative term, eh?
Thanks for your input. I would of course bend to the will of the market as long as they are willing to pay for the difference. I could do them in SS, CR, or Iconel even!!
03-13-2004, 08:47 PM
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Originally posted by RedlineMan
Hey James;
You find that paper, eh? I'd love to read it.
Local pricing is running $1.31/ft for 1.75x.095 ERW, and $2.75/ft for like-sized DOM. Local stock choices STINK! Cheap is a relative term, eh?
Thanks for your input. I would of course bend to the will of the market as long as they are willing to pay for the difference. I could do them in SS, CR, or Iconel even!!
Hey James;
You find that paper, eh? I'd love to read it.
Local pricing is running $1.31/ft for 1.75x.095 ERW, and $2.75/ft for like-sized DOM. Local stock choices STINK! Cheap is a relative term, eh?
Thanks for your input. I would of course bend to the will of the market as long as they are willing to pay for the difference. I could do them in SS, CR, or Iconel even!!
Cheers, James
03-14-2004, 11:39 AM
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Hi John:
Pretty cool concept - I especially like the way it doesn't impinge on the driver compartment at all (an important thing when you are 6'7"). Hopefully this would also make it a safe distance from my head which is obviously important if used on the street when not wearing a helmet.
Looks like it'd be fairly easy to get in and out since the main hoop is shorter. Now...as long as all those pluses don't come at the cost of safety It'll be great
Pretty cool concept - I especially like the way it doesn't impinge on the driver compartment at all (an important thing when you are 6'7"). Hopefully this would also make it a safe distance from my head which is obviously important if used on the street when not wearing a helmet.
Looks like it'd be fairly easy to get in and out since the main hoop is shorter. Now...as long as all those pluses don't come at the cost of safety It'll be great
03-14-2004, 12:05 PM
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Please forgive a dumb question from a rollbar novice here, but reading that it weighs 47lbs my first question is would titanium not work as well, and be a lot lighter? I see it used in many bicycles round here, so it is strong and light.
Also what are the carpet cut ups for folks like me with a GT3, no rear seats?
Also what are the carpet cut ups for folks like me with a GT3, no rear seats?
03-14-2004, 02:58 PM
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Titanium could be used but it presents it's own design problems. First, it's about 45.00/ft. vs. steel which is 2.60+/-. So for a rollbar which might use 30/ft+/- you are looking at 1400.00 in raw materials alone. Titanium is fairly easy to work with given the right tools but it is very time consuming which is where the money goes when one fabricates with it.
Cheers, James
Cheers, James