New TVR still under wraps!
Discussion
TA14 said:
If you have a rectangle formed o/o steel tubes and try to deform it to a parallelogram then the c/f panel diagonal will be in tension one way. The c/f is stiffer than steel so should stress first (although the base resin will alter this property) so that the bracing will be of use before the tubes collapse, as long as the steel to c/f glue is strong enough and stiff enough. I guess that GM and his team will have considered this a lot.
The parallelogram argument makes sense, and saves some diagonal bracing tubes. It must work otherwise they wouldn't be using it. Maybe one day they could use webbing or wires to achieve a similar effect (carbon nanotubes anyone?)Plus if it's a sandwich and sits between the tubes like this o===o rather than the sheet I was envisaging ( o---o ) that mitigates some of the problems too.
The iStream chassis is really a game of compromise.
What you really want, is a mass optimised monocoque tub, made out of carbon fibre, because it has the highest practical strength to mass ratio.
But that means a lot of design, and lot of manufacturing tooling, and complex (hence slow and expensive) production processes.
At the other end of the spectrum is the simple metalic tube space frame. Easy to design, capable of accepting changes to it's design without being entirely re-tooled, simple to build, but it cannot deliver the mass to strength ratio of the carbon tub.
So, Istream is the "half way house" (well, really it's the quarter way house) being reasonably stiff, reasonably cheap, reasonably easy to make. It's the Goldilocks of chassis and enables low volume platforms to be viable. It takes the advantages of a tube frame, and some of the advantages of a monocoque, and brings them together, whilst keeping costs, and tooling overheads controllable. It's nothing new really, because it's be around for at least 30 years (take a look at an F40 for example).
Companies that have slightly higher volumes/budgets, for example Lotus and AML take the next step up the ladder and use an aluminium monocage, but make it from simple extrusions to allow one basic design to the tailored to multiple applications (the eponymous "VH" platform, where VH stands for Vertical Horizontal, and refers to the ability to scale the design in those planes without major retooling)
What you really want, is a mass optimised monocoque tub, made out of carbon fibre, because it has the highest practical strength to mass ratio.
But that means a lot of design, and lot of manufacturing tooling, and complex (hence slow and expensive) production processes.
At the other end of the spectrum is the simple metalic tube space frame. Easy to design, capable of accepting changes to it's design without being entirely re-tooled, simple to build, but it cannot deliver the mass to strength ratio of the carbon tub.
So, Istream is the "half way house" (well, really it's the quarter way house) being reasonably stiff, reasonably cheap, reasonably easy to make. It's the Goldilocks of chassis and enables low volume platforms to be viable. It takes the advantages of a tube frame, and some of the advantages of a monocoque, and brings them together, whilst keeping costs, and tooling overheads controllable. It's nothing new really, because it's be around for at least 30 years (take a look at an F40 for example).
Companies that have slightly higher volumes/budgets, for example Lotus and AML take the next step up the ladder and use an aluminium monocage, but make it from simple extrusions to allow one basic design to the tailored to multiple applications (the eponymous "VH" platform, where VH stands for Vertical Horizontal, and refers to the ability to scale the design in those planes without major retooling)
Max_Torque said:
So, Istream is the "half way house" (well, really it's the quarter way house) being reasonably stiff, reasonably cheap, reasonably easy to make. It's the Goldilocks of chassis and enables low volume platforms to be viable. It takes the advantages of a tube frame, and some of the advantages of a monocoque, and brings them together, whilst keeping costs, and tooling overheads controllable. It's nothing new really, because it's be around for at least 30 years (take a look at an F40 for example).
Or an early Vixen.CHIMV8 500 said:
Hi All
There was obviously talk of 2017 being the year!
Realistically when do they think, as the factory isn't even refurbished from an old shed for want of a better word??
I thought i heard that the one that was discussed here (the purple roof conspiracy) was not chosen ? There are no news regarding the reveal, are there ? I hope that will happen sometime soon as i need to make travel arrangements.There was obviously talk of 2017 being the year!
Realistically when do they think, as the factory isn't even refurbished from an old shed for want of a better word??
HarryW said:
Has anyone been allocated a date/time slot for the reveal yet?
Nope. All I know is the weekend of the 18th of March or the 25th March. I haven't heard any more of the photographic archive either. I sent my images in but not heard anything since. I guess they have more important things to deal with!bullittmcqueen said:
CHIMV8 500 said:
Hi All
There was obviously talk of 2017 being the year!
Realistically when do they think, as the factory isn't even refurbished from an old shed for want of a better word??
I thought i heard that the one that was discussed here (the purple roof conspiracy) was not chosen ? There are no news regarding the reveal, are there ? I hope that will happen sometime soon as i need to make travel arrangements.There was obviously talk of 2017 being the year!
Realistically when do they think, as the factory isn't even refurbished from an old shed for want of a better word??
Bluebottle said:
I'm pretty sure L.E. siad that the first LE cars would be produced by GM at his facility.
Now that you´re saying it, i think i remember something like that, too. But cannot remember the source anymore. Did anyone receive anything concerning the reveal in the last weeks ? 
Snakes said:
It's really happening! Just received my "Reveal Update" email asking me to provide my preferred attendance dates and times. Can't wait! Plus the image of my T350C was used on the inside cover of Sprint by TVR regarding their photographic archive. Maybe I have a chance?
Please, Please don't undersell yourself Clive ...... The Pic of your car is on the August page of the TVRCC Tees Valley region calendar ....... unless I'm totally wrong.
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