For as much time as I have researched cage design (and have watched others duke it out on this forum over different designs), there is still one major question that remains: why is there such a drastic design difference between road racing cages and drag racing cages? I guess I understand the different needs for door bar design, but beyond that I don't see how the design would change so drastically. When I see a rollover on the 1/4 strip, the forces appear to be much the same as a rollover on the road course. The goal is still to preserve the integrity of the chassis to maintain a pocket of relative safety for the driver. No?

So why does an SCCA/NASA cage look like this:






And a drag racing cage looks (so I'm told) like this?:






Is a head on collision into a tire wall that much different if the tire wall is on the strip rather than the track? Do drag cars roll differently? I understand that the rules for cage design are different for SCCA vs. NHRA, but that's not the point. Physics don't change, so why not similar designs (with the obvious exception of driver's door bars for W2W racers)?

I suppose this could be posted in either drag or RR forums, so I figured I'd just post it here.

 

this is just from my own thinking, but the major difference between the needs of a drag cage and a road racing cage is to protect from a direct side impact. thats why you have horizontal door bars required on road racing cages, and not on solo1 cages, and also drag cages. passenger side doorbars werent even required until recently. the main hoop is good enough in a rollover IMO, the front hoop is to anchor the doorbars, while it does provide extra rollover structure.

btw, i dont think your comparison of this other drag cage is really suitable. that doesnt make for a typical cage. the designer already noted he made the rear bars bend to clear the back seat and plans on padding all the tubing around the driver, which is no different than padding the halo on a typical road race cage i suppose.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">
btw, i dont think your comparison of this other drag cage is really suitable.</TD></TR></TABLE>

Well, I was doing a little research on the SFI rules 25-1a and it appears that this is not an uncommon design (although other examples of 25-1a cages seem to be more size appropriate for the car and offer an easier exit for the driver in case of emergency). I use this cage as an example because it's a Civic and therefor has similar requirements in terms of mass and size.

Also, I don't really put the curved rear supports in the "different" cagegory since Kirk racing, until recently, offered the same design.

 

Also don't forget that a drag-car driver doesn't really need to look anywhere but straight ahead - I think there would be a few visibility concerns on a road course with that drag cage, no?

It certainly doesn't look very easy to get out of the car with that bigass bar there, either.

 

I have a hard time seeing the front of the drag cage, but it looks like it was designed mainly with frontal impacts in mind. Side impact is definitely weaker than the SCCA cage. I don't like curved hoop stays in either type of cage, especially since you could get away with straight tube very easily...

The SCCA cages are not the only way to do things either, however the SCCA is very, very rigid in their specifications to discourage innovation (good for broke racers, I guess but no fun for us engineers )

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Targa250R &raquo;</TD></TR><TR><TD CLASS="quote">Also don't forget that a drag-car driver doesn't really need to look anywhere but straight ahead - I think there would be a few visibility concerns on a road course with that drag cage, no?</TD></TR></TABLE>

So you're saying that road race cages sacrafice some safety for visability?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by travis &raquo;</TD></TR><TR><TD CLASS="quote">

So you're saying that road race cages sacrafice some safety for visability?</TD></TR></TABLE>
That's not the context in which I said it (I was thinking more along the lines of "how could you see your mirrors with those bars in the way?"), but you may have brought up a good point there.

 

somethign else to keep in mind that may possibly play a role-the main purpose of a drag cage is safety-protect the driver while adding as little weight as possible.
many roadrace cages also incorporate chassis-stiffening as a bigger factor into the design.on an FF drag car,obviously you're not as worreid about chassis twist and specifically stiffening the rear section of the car.
chris

 

neither of those cages are good choices for debate , they are both desgined improperly.

RR cage needs to protect the driver and stiffen the entire car.

Drag cage needs to fight weight transfer and prevent frame twist.

think of the forces each is subjected to , one turns and the other goes straight , seems pretty self explanatory.