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SVA IVA squabs, backrests and headrests?
rumplitter - 31/10/08 at 08:45 AM

I've got a modified Sylva Mojo chassis, I've already bought the squabs, backrests as the Sylva design. I presume they'll need restraining somehow? Can i just Velcro them in?

Whats the rules on headrests? Rescued attachment 16_04_07 065.jpg
Rescued attachment 16_04_07 065.jpg

coozer - 31/10/08 at 08:48 AM

They need to be secured for SVA so they don't move in a crash.

A bit open to interpretation I suspect for the tester.

Sure some Sylva owner will be along soon to clarify.

Steve

matt_claydon - 31/10/08 at 09:17 AM

Head restraint requirements for IVA:

quote:

6. A system of head restraint must be fitted on every outboard front seat.

7. For outboard front seats the height of the top of the head restraint above the
H point must be at least 800mm.

8. Where optional headrests are fitted to seats other than outboard front seats,
the height of the top of the head restraint above the H point must be at least
750mm taking into account notes 5 and 6.

9. The head restraint must be at least 85 mm wide each side
of the vertical centre line of the seat and at least 100mm high.

10. The head restraint must be securely attached to the seat.

11. The head restraint must not have any roughness or sharp edges likely to
increase the risk of severity of injury.

12. The padding of the head restraint must be sufficient so as to prevent any
contact by a head with any of the internal hard parts of the head restraint.


If you see what happens to a neck in a rear impact without head restraints you won't think twice about the need to fit them!


[Edited on 31/10/08 by matt_claydon]

rumplitter - 31/10/08 at 09:40 AM

What is H?

I've done a quick sketch on sketchUp, would this be acceptable for the support?

Headrest excluded obviously! Rescued attachment head rest.jpg
Rescued attachment head rest.jpg

matt_claydon - 31/10/08 at 09:49 AM

quote:
Originally posted by rumplitter
What is H?


It's the 'hip point'. A notional point that defines where the occupants hip would be. For IVA it's defined by putting a rectangular block of 136mm x 53mm on the seat base. i.e. the H point is 53mm up from the base and 136mm forward of the backrest.

That restraint looks fine. The manual wording strictly requires it to be 'fixed to the seat' but that's probably assuming the seat is adjustable so that the head restraint moves with the seat. In your case the seat is essentially part of the chassis so I would see no problem with the head restraint also being fixed to the chassis.

Dangle_kt - 31/10/08 at 10:19 AM

Is this an end to fibreglass seats?

Head restraints must be suitably padded... well there aint no padding on mine!

Dont tell me we will all need heavy cobra seats! ARG! More cost!

Got to get car done before April!!!

maartenromijn - 31/10/08 at 10:49 AM

I also have GRP seats. If it needs padding, I hope camping mat will do the trick??
The headrest is strong enough I hope??

Seats in car
Seats in car

Mr Whippy - 31/10/08 at 11:30 AM

a pad of 1 inch thick black sticky back foam should be more than enough padding on a glassfiber seat. Probably a good idea anyway as they are quite hard to bang your head off if you don't have a helmet on.

maartenromijn - 31/10/08 at 11:44 AM

I'll make something which is easily removable in case of wearing a helmet on the track.

l0rd - 31/10/08 at 02:15 PM

Stupid Qn

Should I assume that all bucket seats with 4 point harness holes are IVA approved? Would they consider it as haveing headrests?

matt_claydon - 31/10/08 at 02:39 PM

quote:
Originally posted by l0rd
Stupid Qn

Should I assume that all bucket seats with 4 point harness holes are IVA approved? Would they consider it as haveing headrests?


They won't be 'IVA approved', but as long as they comply with the specifications in the manual (which i expect most will) they'll be fine.

Aftermarket seats are very unlikely to have been designed to meet the legislation, but fortunately they usually do. e.g. Some have found that the harness holes only just comply with the height requirements and require the seat padding to be squashed down a bit.