Jesus-Ninja
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| posted on 5/8/08 at 11:17 AM |
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driver position for sva
I'm stil in the design phase, or rather returning to it after laying out some components and having a re-assesment.
I'm building a mid engined car with a transversely mid mounted saab 2.3 lump, using the S14 suspension geometry.
How far forward can the driver go? Is there any requirement, for example, for the driver to be within the axles? Ideally I'd like te driver, who
will be centrally positioned, to have their feet slightly in front of the front axle line.
I'd look it up myself, but I'm currently braving the rain in a tent in the new forest, with nothing but a pda with roaming internet and a
copy of PPC!
Oh, the wife's here too, but I suspect her response will be "that sounds nice, dear...."
Suspension geometry tool here >>> http://www.locostbuilders.co.uk/viewthread.php?tid=81376
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speedyxjs
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| posted on 5/8/08 at 11:35 AM |
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quote:
Originally posted by Jesus-Ninja
How far forward can the driver go?
Check out whippys earlier post
How long can i resist the temptation to drop a V8 in?
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speedyxjs
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| posted on 5/8/08 at 11:36 AM |
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Linky
How long can i resist the temptation to drop a V8 in?
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Jesus-Ninja
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| posted on 5/8/08 at 11:49 AM |
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quote:
Originally posted by speedyxjs
Linky
Top man. Thanks! 
Couldn't see any reference to sva issues with the driver position, but then I'm reading all this on a 3" screen!
Are we saying that it's acceptable? I currently have the a-pillars (in my mind) above the front axle line, and it's looking good (again,
in my mind.....)
Suspension geometry tool here >>> http://www.locostbuilders.co.uk/viewthread.php?tid=81376
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iank
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| posted on 5/8/08 at 11:58 AM |
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I've never noticed anything in the SVA manual that explicitly requires/prohibits any layout.
However there is a general 'in the view of the examiner is unsafe to driver/passenger/other road users' clause that could potentially be
dragged into play.
I'd give the SVA station a call and have a chat about your intentions. Legs in front of the front axle is a bit dodgy unless there is plenty of
crash absorption structure in front. IMO.
The forward control vans that did that don't seem to be about any more - where they banned?
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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ReMan
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| posted on 5/8/08 at 12:32 PM |
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I thought that "racing cars" prohibited feet first any longer?
Unless that's a personal fact as opposed to a fact-fact
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mr henderson
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| posted on 5/8/08 at 12:38 PM |
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quote:
Originally posted by Jesus-Ninja
Ideally I'd like te driver, who will be centrally positioned, to have their feet slightly in front of the front axle line.
Why?
If there's some doubt as the the SVA rules it may be that there is a safety consideration, and perhaps one ought to consider it.
Personally I think it's a terrible idea, and would be most reluctant to drive a car that put me so much closer to the scene of the accident.
John
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02GF74
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| posted on 5/8/08 at 12:47 PM |
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quote:
Originally posted by mr henderson
Personally I think it's a terrible idea, and would be most reluctant to drive a car that put me so much closer to the scene of the accident.
John
but further away from the accident if shunted up the rear!
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Jesus-Ninja
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| posted on 5/8/08 at 12:47 PM |
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quote:
Originally posted by mr henderson
Why?
If there's some doubt as the the SVA rules it may be that there is a safety consideration, and perhaps one ought to consider it.
Personally I think it's a terrible idea, and would be most reluctant to drive a car that put me so much closer to the scene of the accident.
John
Why? Because it all sits together well like that, and helps to balance that weight, being mid engined.
I agree, that a phone call or visit to my local SVA tester will answer a lot of questions, but I'm in the midle of nowhere when the grey cells
started working....
Of course, safety is a concern, which is why the vehicle wil include a full roll cage encompassng the driver down to the pedal box (more than most
coffin dodgems... )
[Edited on 5/8/08 by Jesus-Ninja]
Suspension geometry tool here >>> http://www.locostbuilders.co.uk/viewthread.php?tid=81376
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mr henderson
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| posted on 5/8/08 at 01:02 PM |
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quote:
Originally posted by Jesus-Ninja
Why? Because it all sits together well like that, and helps to balance that weight, being mid engined.
What I am not following here is why the car needs to be so short. Unless the engine is very long, and you are accommodating an extremely tall driver,
then what's the problem?
I agree that for me to fit in a Lotus Europa I would need a hole in the bonnet for me to stick my feet through but then Colin Chapman was a midget and
designed cars for midgets (a Lotus tradition which continues to this day), but you are starting from scratch.
Why not just put some extra length in the wheelbase and not have the worry?
John
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mr henderson
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| posted on 5/8/08 at 01:03 PM |
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quote:
Originally posted by 02GF74
quote:
Originally posted by mr henderson
Personally I think it's a terrible idea, and would be most reluctant to drive a car that put me so much closer to the scene of the accident.
John
but further away from the accident if shunted up the rear!
Not really, as it's my understanding that this is going to be a short car, otherwise the problem wouldn't arise
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Jesus-Ninja
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| posted on 5/8/08 at 01:14 PM |
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not quite from scratch. the suspension geometry is pretty much defined, and I don't want to screw up akerman.
The driver will be as far within the front axle line as possible, which may well be all the way. I suppose the question is more of a "what
if", but it's starting to look like the feet will be just beyone the rack although well in front of the front edge of the wheels.
I want to be able to accommodate two passengers slight to each side and behind the driver (a la McClaren F1)
Suspension geometry tool here >>> http://www.locostbuilders.co.uk/viewthread.php?tid=81376
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Mr Whippy
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| posted on 5/8/08 at 01:49 PM |
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Anyone who thinks a front axle is protection in a crash should watch a bit of F1 racing. 20kg wheels & tube wishbones simply shear off especially
since they are held on by little brackets that you made in the vice. They is no reason why you can not build a crush zone infront of your feet that
will do a lot more to protect you. Forward control vans and trucks were inherently dangerous because the was nothing but the front panel between your
legs and an object, hence they were dangerous.
Fame is when your old car is plastered all over the internet
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Jesus-Ninja
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| posted on 5/8/08 at 02:11 PM |
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quote:
Originally posted by Mr Whippy
Anyone who thinks a front axle is protection in a crash should watch a bit of F1 racing. 20kg wheels & tube wishbones simply shear off especially
since they are held on by little brackets that you made in the vice. They is no reason why you can not build a crush zone infront of your feet that
will do a lot more to protect you. Forward control vans and trucks were inherently dangerous because the was nothing but the front panel between your
legs and an object, hence they were dangerous.
Thanks everyone. I'll have a chat with an SVA place. Are there any SVA testers registered as forum users on here?
Suspension geometry tool here >>> http://www.locostbuilders.co.uk/viewthread.php?tid=81376
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Mr Whippy
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| posted on 5/8/08 at 02:30 PM |
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I suspect there are but they will never say, they'd just be flooded with questions
Fame is when your old car is plastered all over the internet
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matt_claydon
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| posted on 5/8/08 at 04:40 PM |
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I don't think the SVA manual has anything to say on the matter, but in the Protective Steering section the new IVA manual has the following:
quote:
The vehicle structure ahead of the steering rack or box.
Of primary concern is the position of the steering rack or box. If the rack or box is ahead of the axle centreline, there will clearly be less of the
vehicle structure available to deform and absorb energy than if the rack is behind the axle. Check for some energy absorbing device such as:
1. an energy absorbing bumper, or bumper mounting (eg mounted on hydraulic dampers or telescopic tubes);
2. a crushable section of chassis comprising one or more deliberate weaknesses;
3. in the case of a tubular chassis, deliberately un-triangulated bay or arrangement of tubes likely to deform progressively;
4. in the case of a composite monocoque an area of bodywork which the presenter can demonstrate has been designed to crush progressively and dissipate
energy;
5. in the case of any vehicle, a non-structural nose cone of any material which the presenter can demonstrate has been designed to absorb energy.
Note 1: The first area of the vehicle to make contact with a barrier in a crash test may not be the chassis. The front wheels may do this. If this is
the case, the load path from the hub carrier to its mountings on the chassis should be examined. The initial deformation might take place to the sides
rather than the front of the chassis.
Note 2: If the steering rack or box is mounted behind the axle centreline, then there is far more room for the chassis to deform before moving the
steering column backwards. A well designed vehicle will minimise further deformation once the impact has reached the steering rack or box.
Note 3: In cases where the steering rack or box is mounted behind the axle centreline, it may well be behind part of the engine or gearbox. In this
case, check that no rigid part of the powerplant is likely to bear directly against the end of the steering shaft as it enters the rack or box and in
so doing, transmit a force up the column towards the driver.
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Jesus-Ninja
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| posted on 5/8/08 at 05:36 PM |
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Cheers, Matt. That's really useful. Definitely there needs to be something between driver and impact, whether it's the axle or a
specifically designed and considered crumple zone. The latter being far preferable to sinple distance and plenty of engine and wheels!
Suspension geometry tool here >>> http://www.locostbuilders.co.uk/viewthread.php?tid=81376
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minitici
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| posted on 5/8/08 at 06:16 PM |
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My feet are right on the front panel of the TiCi.
Steering column is near vertical between the legs
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