Chimaera v. Tamora for crash safety
Discussion
Not a subject we may like to think about, and no one buys a TVR for its crash protection, but having had a couple of heavy impacts in my rally car recently whilst protected by a very substantial roll cage it got me thinking about my Chimaera...
Am I right in thinking the windscreen surround is just fibreglass and that there is no metal in the doors either?
Is the Tamora (or any later TVRs) built with better roll over or side impact protection?
Considering selling my much loved Chimaera and swapping for a Tamora but interested in the safety angle (must be getting old
)...
Am I right in thinking the windscreen surround is just fibreglass and that there is no metal in the doors either?
Is the Tamora (or any later TVRs) built with better roll over or side impact protection?
Considering selling my much loved Chimaera and swapping for a Tamora but interested in the safety angle (must be getting old
)... 
The later cars have steel roll hoops built into the windscreen surround and i know the cerbera has steel side impact protection built into the doors as do the wedge cars i don't believe any of the crash protection is an integral part of the chassis so fitting an fia approved full roll cage may be a good idea if your worried about crashing.
Definitely no dedicated roll over protection in a chim or griff although the rear "hoop" will provide some protection if up. The tuscan and tamora do have SIP - again none in the chim/griff although the fibreglass is fairly strong stuff. If you fancy improving the safety in your chim you could fit a TR lane bar which would give protection and looks good as well as well as stiffening the chassis.
From watching GRP cars crash at race events , I thing that the basic spaceframe structure is pretty good in a front or rear impact, but there is no real side impact protection. Looking inside the door of the Tuscan there is a steel structure but it certainly doesn't look like it picks up strong points on the chassis when the door is closed so would almost certainly deflect inwards easily.
I suspect that the roll structure on the T cars is ok, but still not up to FIA standards
I suspect that the roll structure on the T cars is ok, but still not up to FIA standards
Omerta said:
Are you serious? You're talking about the flip-up extruded alumium rag top supports right?
Yes - I've seen a chim rolled down an embankment with the rear section virtually intact. I'm not suggesting it's anywhere near as good as a roll bar but better than nothing. Having said that personally wouldn't like to test it!I have seen several griffs very badly rolled where the driver has got out pretty intact incredibly including one that that went at over 150 leptons with the driver only suffering cuts and bruises . The steel tube supperting the tamora screen does undoubtably offer more protection but is unlikely to be able to take the weight of the car in an accident but might be able to pin you in . The side impact in the leg area is much better though ( in the tamora )
blueg33 said:
From watching GRP cars crash at race events , I thing that the basic spaceframe structure is pretty good in a front or rear impact, but there is no real side impact protection. Looking inside the door of the Tuscan there is a steel structure but it certainly doesn't look like it picks up strong points on the chassis when the door is closed so would almost certainly deflect inwards easily.
I suspect that the roll structure on the T cars is ok, but still not up to FIA standards
About right I think - note that the Tuscan did pass a Type Approval-mandated side impact test (reportedly with the same car that passed the frontal impact test just before) that I think the earlier cars didn't need to be subjected to back in the early '90s.I suspect that the roll structure on the T cars is ok, but still not up to FIA standards
Due to the way it's built, a spaceframed, GRP-clad car has markedly different strengths and weaknesses from your usual steel monocoque jobbie. The tubular frame offers huge structural integrity at high speed 'incidents' where a tin box would fold (especially convertibles) or break in two, and GRP offers very high impact energy absorption (but ultimately, no integrity - that's why I wouldn't want to drive a GRP monocoque car) - OTOH the impact absorbtion characteristics aren't 'programmed' to divert loads from the occupants like modern unitary stuctures, and in a side-to-side view, the occupants are sitting outside the main strength offered by the tubular 'backbone' frame.
The windscreen frame itself could be easily strengthened by injecting structural foam (as is done in the Lotus Evora) but the rollover impact loads have to go somewhere and I would have no idea whether the bulkhead area is strong enough to take them...
350Matt said:
the cerb is the safest of the lot
every car has a full cage thats hard mounted into the chassis and the side impact bars in the doors are tied into the cage
Cerbs dont tend to have the drivers seat fully fitted to the chassis (they're generally mounted at the front only, with the rear mounted to the fibreglass?! - the passenger seat is only mounted to fibreglass too) and the rear 'cage' is connected to fibreglass rather than chassis again. Better than the Chim/Griff by miles, and better in roll than a Tam/Tusc in my opinion, maybe the Tuscan is about on a par with the rear targa section bar?every car has a full cage thats hard mounted into the chassis and the side impact bars in the doors are tied into the cage
T350/Sag are safest, they connect at both ends (although the furthest part of the rear 'cage' only goes into fibreglass) and the seats are connected to chassis, rather than fibreglass floor.
I know that seats bolted directly to the chassis are an MSA requirement, though I don't see it making much difference to roadgoing applications unless the seats weigh 100 lbs each (say a 30 lbs seat suffering a max deceleration of 30g for a halfway survivable crash - I'm making the numbers up as we go 
- that's a 900 kg load divided over four bolts into the 'glass, not the sort of load I'd subject the floor of the body shell to permanently but not too bad either?) - the driver is being anchored to the chassis by the seat belts...
- that's a 900 kg load divided over four bolts into the 'glass, not the sort of load I'd subject the floor of the body shell to permanently but not too bad either?) - the driver is being anchored to the chassis by the seat belts...Edited by 900T-R on Tuesday 7th June 13:23
At work, so cant see which picture is which .....
impacted 3 sides of the car into armco @ c30-40mph by the time i'd spun abit.
Glass fibre is good for disipating crash energy, (and is used in some crash structures as a result)
the chassis is very strong .. altho i wouldnt like a side impact with anything pointy!
http://www.pistonheads.co.uk/gassing/topic.asp?h=0...
Custard
impacted 3 sides of the car into armco @ c30-40mph by the time i'd spun abit.
Glass fibre is good for disipating crash energy, (and is used in some crash structures as a result)
the chassis is very strong .. altho i wouldnt like a side impact with anything pointy!
http://www.pistonheads.co.uk/gassing/topic.asp?h=0...
Custard
blueg33 said:
From watching GRP cars crash at race events , I thing that the basic spaceframe structure is pretty good in a front or rear impact, but there is no real side impact protection. Looking inside the door of the Tuscan there is a steel structure but it certainly doesn't look like it picks up strong points on the chassis when the door is closed so would almost certainly deflect inwards easily.
I suspect that the roll structure on the T cars is ok, but still not up to FIA standards
Having had the door card off on my Tuscan, the diagonal brace picks up the hinge (bottom IIRC) which is integral with the w'screen roll hoop and then runs to the door lock which is connected to the rear/targa roll hoop. Appreciate this was never impact tested as part of type appro' - as mainstream cars will be.I suspect that the roll structure on the T cars is ok, but still not up to FIA standards
As an aside, I can remember reading that when a Tuscan was submitted to the 30mph offset front impact test at MIRA they just changed the front wishbones and the car was driveable. IIRC this comment was from TVRCC Sprint magazine - so I guess there is some vested interest.
Nick
nawarne said:
As an aside, I can remember reading that when a Tuscan was submitted to the 30mph offset front impact test at MIRA they just changed the front wishbones and the car was driveable.
And after that, they used the same car for the side impact tests - or so TVR said at he time...Thanks for all the replies so far It seems the newer cars are safer which is reassuring (or at least will be once I've bought one!) Glad to have it confirmed that the newer cars have a metal hoop in the windscreen surround, does the Tamora have door bars too as the Tuscan appears to?
It seems the newer cars are safer which is reassuring (or at least will be once I've bought one!) Glad to have it confirmed that the newer cars have a metal hoop in the windscreen surround, does the Tamora have door bars too as the Tuscan appears to? tvrdavid said:
Yes - I've seen a chim rolled down an embankment with the rear section virtually intact. I'm not suggesting it's anywhere near as good as a roll bar but better than nothing. Having said that personally wouldn't like to test it!
Yes, I saw a Chimaera roll down an embankment after failing to take a motorway roundabout. The chap walked away, but I can't imagine how. I had a roll bar put in the Griff about a week after. Gassing Station | General TVR Stuff & Gossip | Top of Page | What's New | My Stuff