An interesting read: http://www.racetechmag.com/articles/article.php?id=64 I'd spotted the roll cage going through the B-pillars earlier in the year, with neat packaging of clearanced door cards as you'd expect: For comparison, this prototype pic doing the rounds on the 'net is just normal, tubes inwards of the B-pillar: Then again, a quick look at the Kamei Golf and you'd wonder how long it's going to be, before they actually catch up with the USA, whose take on door bars has been visually streets ahead for years Also evident, and seen in the Fiesta WRC aswell, is that the maximum height of the tube structure is not at roof level, being down from the roof, the Mini using very straight tubes. Fiesta shown: Overall weight => centre of gravity, surely?
Interesting reading,is the roof/cage seperation reason; That it makes an impact/crumple absorbing zone before hitting the cage? if the two are touching then they would act as one,no? i suppose shorter tubes are stronger too but it can't be by much as its only little bit shorter. Just guessing mind. Been thinking about A to B pillar strength of late,the door bars look quite low too,wonder if they are the same hight on both sides as the seats are not .
Yeah, those door bars do look low. If anyone saw the Mini Challenge accident at Snetterton..... [YOUTUBE]zZakcQkTXVo[/YOUTUBE] You would want the highest (and lowest) door bars you could get! One of them lost control on the grass and ended up aimed towards the apex of the hairpin... 80+mph collision onto the passenger side door/corner. The Kerb launched the car straight into the door bars of the other (missing the sill). Snapped the tubes and went deep into the car. Lucky to be in the passenger side! Those WRC door bars are too low surely??? Although it doesnt look like they will snap! they should regulate that door bars are made from one piece, and not welded/joined in the middle. I moved my race seat as far to the centre as possible without it being weird or uncomfortable... The Mini's are ridiculously strong cars, and these two where bent like you wouldn't believe. Both drivers survived (HANS anyone?), one with broken collar bone. Scan to four-fifths of the way through these pictures to see one of the cars: http://jalbum.net/en/browse/user/album/1063838/
I don't think you can really compare the WRC cage to a circuit racer, the IMSA style cage is all about protecting from side impacts from another car. the WRC cage is to protect the occupant while its tumbling and rolling end over end. The cage isn't really there to directly protect the driver as such anyway, its there to maintain the integrity of the shell and absorb some of the energy so that the secondary safety components like the seats, helmets etc. can do their thing. In a side impact the door bars are where they are to channel the impact via the hard seat into the hard parts of body like the pelvis. You don't want softer parts like the ribs or legs taking the loads so it makes sense to actually keep the bars away from those bits although its a bit counter intuitive. I would imagine the main issue is intrusion from things like fence posts, that's the thing that will really do the damage like in Kubica's incident. A bar wont stop that and its difficult to do anything about it unless you do drive a tank! looks like a nice cage but would look better in a mk2 golf
- surely that is directly protecting the driver? ...and both circuit and rally would share the same attitude towards distancing the seat from the bars and crash structure? I reckon the two must be comparable by design attitude - although I would want a crazy cage if I was rallying through a forest. Yeah, a rally car never gets T-boned, but there are plenty of other parts of the scenery that can smash into the side in a totally unpredictable manor.
absolutely keeping the bars away from the driver is a good thing. What I mean is that we should maybe look at the cage slightly differently in terms of its purpose. The door bars are there as a structural member linking the front cage legs to the main hoop. They're there to bear roll over loads primarily, they're not necessarily there to protect the driver from intrusion. If they do 'shield' the driver that's a bonus but main the main function. No amount of bars will protect against a fence post etc. my main point was about the comments of the bars looking too low, IMO they're exactly where you want them. If an impact were to move them at all, the first thing they would hit is the 'hard' seat rather than a 'soft' leg/ribcage/substitute your body part here
I was rallycrossing before door bars became mandatory. I was certainly glad they did, as the thought of a crushed pelvis from being T boned was a very real danger
agreed door bars are good the comments were talking about the above door bars being too low which assumes that they were designed to protect arms/legs/upper body, I'm just saying they probably weren't designed with that in mind. Prodrive know their stuff and there's a reason its done like that, just trying to understand the reasoning. Perhaps they're low to aid the recovery of a driver in a crash, not easy to remove someone with possible spinal injury from a climbing frame? I think there's definitely area for improvement in most motor-sport cages and this seems to go some way towards that. things have improved a lot in road cars but I think crash protection is still pretty crude in motor sport, as always I guess it comes down to money. Would interesting to see how a typical cage manufacturer design and test their cages, assuming they do actually test at all.
