Andrzejsr
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| posted on 16/3/21 at 11:01 PM |
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Foam race seat - any tips before start ?
Hello!
I am planning to make a foam racing seat for MNR Vortx. Was looking and rading at some tutorials on internet. Those are mostly relations from one
time job.
Would like to ask here maybe some of You has experience with making such seat and could share some tips etc : which density foam is best (have seen
from 30-200 grade which is from 30kg/m3 to 200kg / m3, the latter is described as stiff and has less expandability (the low density foam has huge
expandability obot 20-30x , the high-density much less , something 1:5 .
Also - shoud the seat be with a plate on the bottom , so not directly sitting on the aluminium floor and steel bands to which original are the
fiberglass normal seats mounted ? Was thinking to add some aluminum maybe 3-4mm plate bolted to those steel bands
Its is someone else picture but wanted to illustrate which steel bands I mean, its from Westfield but in MNR it is similar :
https://forum.wscc.co.uk/forum/uploads/monthly_2017_09/1.jpg.3b5b970605410b4b4ca0e3a19ba1ba1b.jpg
I am not sure that fitted with rivets floor panels have enough strenght to hold +/- 100kg driver in shaking car :-/
I will appreciate sharing any help, thoughts and tips in this subject !
https://aswestfield.wordpress.com/
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djtom
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| posted on 17/3/21 at 12:08 PM |
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There's a good writeup in this thread that I've had bookmarked for years - still haven't got around to making one for myself though
so I can't say how well it works in real life! Looks like they use a ply base to spread the load.
Foam Seats
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MikeR
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| posted on 17/3/21 at 10:18 PM |
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Don't forget, the seat isn't holding you in, the seat belts hold you in. The seat stops you moving about. I think the foam seats will
spread your weight over it's base, so you don't need the steel, just done velcro to hold it on place.
NB I made one 10 years ago and still haven't finished the car so I'm perhaps not the best person to advise
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Andrzejsr
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| posted on 18/3/21 at 11:28 PM |
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Thank You djtom and MikeR.
The first link is very helpful , great tutorial !
The foam they use seems to be this one:
http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=362496020434&t=1579766422000&category=133209&seller=jjcraceandrally&a
mp;excSoj=1&excTrk=1&lsite=3&ittenable=false&domain=ebay.co.uk&descgauge=1&cspheader=1&oneClk=2&secureDesc=0
Yes, I am aware that the belts are wht is holding me in place, but my concern is about the "bottom" . Maybe I will add two steel flat bars
bolted perpendicular to the flat bars originaly made to bolt the sesat to. Those new bars will add surface and allow for proper positioning of the
crotch straps to mount.
Well, still open to all ideas and tips !
As for the foam I have found two types which are described as to make race seat , one is 32kg/m3 , and second 43kg/m3 , expansibility in order 30 and
20x
https://www.ebay.co.uk/itm/2-Part-PU-Expanding-Foam-Seat-Kit-For-Motorsport-Racing-/362496020434
https://www.merlinmotorsport.co.uk/p/2-part-foam-seat-making-kit-ss-foam
So I need something in this range, maybe closer to this stiffer as Merlinmotorsport sells.
https://aswestfield.wordpress.com/
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Mr Whippy
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| posted on 19/3/21 at 06:57 AM |
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Are the foams fire resistant? That would be my first question.
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Mr Whippy
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| posted on 19/3/21 at 07:01 AM |
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quote:
Originally posted by MikeR
Don't forget, the seat isn't holding you in, the seat belts hold you in. The seat stops you moving about. I think the foam seats will
spread your weight over it's base, so you don't need the steel, just done velcro to hold it on place.
NB I made one 10 years ago and still haven't finished the car so I'm perhaps not the best person to advise
The seats normally pushing back on the harness otherwise you'd be against the rear bulkhead. You definitely want the seat securely fixed to the
car.
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JimSpencer
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| posted on 19/3/21 at 10:57 AM |
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quote:
Originally posted by Mr Whippy
quote:
Originally posted by MikeR
Don't forget, the seat isn't holding you in, the seat belts hold you in. The seat stops you moving about. I think the foam seats will
spread your weight over it's base, so you don't need the steel, just done velcro to hold it on place.
NB I made one 10 years ago and still haven't finished the car so I'm perhaps not the best person to advise
The seats normally pushing back on the harness otherwise you'd be against the rear bulkhead. You definitely want the seat securely fixed to the
car.
Hi
Erm.. No..
That's not how a foam seat works, it completely fills the gap between your backside/back and the floor/bulkhead - Mike has it correct -
it's standard practice to not fasten the foam seat in.
When swapping drivers you simply jump out, lift the seat out after you, drop your co-driver seat in, they hop in and do up their belts.
HTH
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Andrzejsr
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| posted on 19/3/21 at 12:24 PM |
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As I understand it is not (fire resistant) , but that is also I think regular seats with soft foam or pads in everyday cars that goes on trackdays .
All I can do is wear all in nomex and have instaleled Fire Extinguisher System. It is not easy flammable I think on the other hand.
I know there are FIA approved materials and it looks like expanded polyestrene small balls "glued" togeder in shape with special resin ?
hardener ? . It behaves inf fire similar like regular polyestrene (I think, or maybe this is special one?)
https://www.youtube.com/watch?v=-1owY9cHT9o
As for the safety - above is good explanation how it improves safety in the case of impact.
As for the supporting I know it supports on the wall behind and on the floor. My only concern is the floor aluminium panel is riveted to the
chasis.And I dont trust rivets a lot  . Normal seat is sitting on the flat steel bars which are _welded_ to the chasis. So I would like the new foam
seat supports also on those bars, not on the thin aluminium and alu rivets.
[Edited on 19/3/21 by Andrzejsr]
https://aswestfield.wordpress.com/
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pigeondave
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| posted on 19/3/21 at 04:59 PM |
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I know its not foam but it shows how the seat is lifted out
https://youtu.be/yBjY5eH8rGo
and the fact that as stated above, the belts hold you in.
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Andrzejsr
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| posted on 3/5/21 at 01:36 PM |
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Update - seat finished!
https://aswestfield.files.wordpress.com/2021/05/img_20210503_013505265.jpg?w=1024
https://aswestfield.wordpress.com/majsterkowanie/
All process was longer than I thought it will be. Used mostly 35kg/m3 density foam, with some 200kg/m3 at the bottom, total volume approx 10l of foam,
100m of duck tape, approx 0,5l resin and some fiberglass.
Fitting is great , cant wait to try it on the track , but it will take some time as I am still waiting some parts from MNR ordered last year... :-/
Thanks for all useful info and links!
https://aswestfield.wordpress.com/
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