Roll Cage Photos
#16
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George.."impossible to get a bar
under the dash, though I think the 928 has one there already." The stock dash bar is thin sheet metal very thin sheet metal . It helps hold the steering column and little more. I personally prefer to see the front windshield bar not have a bend in the middle(that is where it will bend more) ,that the cross brace behind the seats not have bends at both ends ,that the diagonal be in a single plane, and the floor pan sheet metal is not very structural and the cage tie into the rocker panels. A diagonal or X between the rear down tubes would greatly increase the integrity of the roll bar/cage. But I assume for the rules of open road racing it is a cage. The bolt in door bar adds very little strength or safety since the bolts become pivot points and the projecting flat tabs would fold rather easily but must count for the rules. The best safety feature would be racing seats , getting lower in the car since the roll bar hoop is rather low. Plus stock seats have far too much compliance cushion and padding and no matter how tight the restraint system you bounce up and down banging your head on the roof. The shoulder harness mounting points need some metal rings 1/2 circles welded to the bar on each side of the point where the belts mount so they can not slide side to side. It would be best to use a sternum protector strap as well. The anti submarine strap to be effective must pass through the seat bottom. Also pad the windshield bar because the NASCAR guys say anything you can touch with your hand your helmet can hit ! Pad the front down tube so your lower leg does not hit a metal tube. Not to be too critical (Yea right) but based on some of the comments I think perhaps many people have not looked carefully at very many roll cages. Some gusseting of the joints would greatly increase the strength of the welds even small triangles of flat stock helps assure that where one tube Ts into another that it stays together. Squares are bad triangles are good the more points you attach the cage to the chassis the better and six points is the MINIMUM ! A real cross brace near the dash ties together both front down tubes and to displace one ,rip it from the welds you must displace BOTH .
under the dash, though I think the 928 has one there already." The stock dash bar is thin sheet metal very thin sheet metal . It helps hold the steering column and little more. I personally prefer to see the front windshield bar not have a bend in the middle(that is where it will bend more) ,that the cross brace behind the seats not have bends at both ends ,that the diagonal be in a single plane, and the floor pan sheet metal is not very structural and the cage tie into the rocker panels. A diagonal or X between the rear down tubes would greatly increase the integrity of the roll bar/cage. But I assume for the rules of open road racing it is a cage. The bolt in door bar adds very little strength or safety since the bolts become pivot points and the projecting flat tabs would fold rather easily but must count for the rules. The best safety feature would be racing seats , getting lower in the car since the roll bar hoop is rather low. Plus stock seats have far too much compliance cushion and padding and no matter how tight the restraint system you bounce up and down banging your head on the roof. The shoulder harness mounting points need some metal rings 1/2 circles welded to the bar on each side of the point where the belts mount so they can not slide side to side. It would be best to use a sternum protector strap as well. The anti submarine strap to be effective must pass through the seat bottom. Also pad the windshield bar because the NASCAR guys say anything you can touch with your hand your helmet can hit ! Pad the front down tube so your lower leg does not hit a metal tube. Not to be too critical (Yea right) but based on some of the comments I think perhaps many people have not looked carefully at very many roll cages. Some gusseting of the joints would greatly increase the strength of the welds even small triangles of flat stock helps assure that where one tube Ts into another that it stays together. Squares are bad triangles are good the more points you attach the cage to the chassis the better and six points is the MINIMUM ! A real cross brace near the dash ties together both front down tubes and to displace one ,rip it from the welds you must displace BOTH .
#18
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So Jim,
How much for this roll cage your describing? Will I get the how much is your life worth answer?
Will I still be able to keep the car reasonably stock? Street Legal? How much weight will it add?
I did put padding on the front bar, and plan on adding some more.
![](http://sis125.berkeley.edu/928/wk-rollcage/IMG_8438.jpg)
I already know your opinions on ORR and most things related to DEVEK so I guess I should have
expect this...
Anyway, as Rich said earlier, I also hope I never have to find out how well it works.
How much for this roll cage your describing? Will I get the how much is your life worth answer?
Will I still be able to keep the car reasonably stock? Street Legal? How much weight will it add?
I did put padding on the front bar, and plan on adding some more.
![](http://sis125.berkeley.edu/928/wk-rollcage/IMG_8438.jpg)
I already know your opinions on ORR and most things related to DEVEK so I guess I should have
expect this...
Anyway, as Rich said earlier, I also hope I never have to find out how well it works.
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bc,
I've had the car up to 176 mph on the gps (I use 2), and it could have gone faster. The
car is rpm limited right now, ~186 mph at 6400 rpm, which is also the limit on the Y rated
tires. I plan on putting in a 88 S4 transmission next year, then I figure it'll be drag limited
at around 200 mph. This is theoretical based on some spread sheets I use, though they've
worked well so far. I'll have to use (Y) rated tires or racing tires to pass tech at those speeds.
I've had the car up to 176 mph on the gps (I use 2), and it could have gone faster. The
car is rpm limited right now, ~186 mph at 6400 rpm, which is also the limit on the Y rated
tires. I plan on putting in a 88 S4 transmission next year, then I figure it'll be drag limited
at around 200 mph. This is theoretical based on some spread sheets I use, though they've
worked well so far. I'll have to use (Y) rated tires or racing tires to pass tech at those speeds.
#20
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Very sexy doors John ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
[QUOTE=John Veninger]A picture of my cage and the "stock" bar Jim mentioned that is located behind the dash (for those who have one!)
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
[QUOTE=John Veninger]A picture of my cage and the "stock" bar Jim mentioned that is located behind the dash (for those who have one!)
#21
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George,
Use the high density roll bar padding where ever your head may hit. Looks like the area you missed with padding was the diagonal bar and the two down bars on each side of the door. The "hard" padding is much better in saving your head if you bounce off of it. The soft padding is nice for when you crawl in and out of the car, but becomes as thin a piece of paper during a crash. I have some soft stuff on my side bars and by my legs. The other "problem" with the soft padding is that it melts and drips very easily during a fire!
Here is a picture:
http://www.pegasusautoracing.com/Pro....asp?RecId=636
Use the high density roll bar padding where ever your head may hit. Looks like the area you missed with padding was the diagonal bar and the two down bars on each side of the door. The "hard" padding is much better in saving your head if you bounce off of it. The soft padding is nice for when you crawl in and out of the car, but becomes as thin a piece of paper during a crash. I have some soft stuff on my side bars and by my legs. The other "problem" with the soft padding is that it melts and drips very easily during a fire!
Here is a picture:
http://www.pegasusautoracing.com/Pro....asp?RecId=636