Securing / Bolting Seats in a Tornado

[Joe T]

Originally Posted by Russ Noble

Simple. The seatbelts restrain your body so it can't move. Therefore the seat can't move. The loads go into the frame not the seat. If that's not the case then you need to look at your seatbelt design.

Edit. Steve C you have got it right.

If a car ever gets airbourne and hits the deck the force of your bodyweight is transmitted downwards through the floor, most seat belts only restrain you towards the back and down.
No belts actually take your weight and suspend you!
So your seat does do some work!
You cant truly beleive you can remove the floor section place a jack under the car where your seat was bolted in, rest your seat shell on it, get in and strap your harness on, get somenone to let the jack down and your good to go?

Cheers

Joe T

[Russ Noble]

Haha Joe,

You got me on that one!

Guess I better butt out of the discussion I'll just agree to disagree.

Cheers,

[Gregg]

Originally Posted by Russ Noble

Simple. The seatbelts restrain your body so it can't move. Therefore the seat can't move. The loads go into the frame not the seat. If that's not the case then you need to look at your seatbelt design.

Edit. Steve C you have got it right.

Would tend to agree with Steve based upon construction of vehicle. The originals and if the SPF is true to form, have the seat base and back as an integral part of the mono chassis. From my understanding, that is not the case in a tube frame car. You have a seat shell covered with foam, which is then bolted to the floor/chassis.

Russ, "The seatbelts restrain your body so it can't move". I guess you are uncomfortable when you drive. Your belts must be as tight as an astronauts'.

Sorry Russ, but you haven't convinced me. If the seat is only bolted to a sheet of 1/8 in aluminum, I would be willing to bet that over time and mileage, the floor, at the seat mounting points would suffer some type of fatigue. We can agree to disagree, however my car will not rely upon the floor alone for a seat mounting point.

[Jac Mac]

Originally Posted by Russ Noble

Haha Joe,

You got me on that one!

Guess I better butt out of the discussion I'll just agree to disagree.

Cheers,

Knowing Russ reasonably well & being aware of his stature etc I can understand why he might wish to remove the floor panel area immediately beneath his seat. Could lead to a 'NEW' innovation for GT40's to be discreetly known as the'''Noble BUMP IT'''-- sort of an inverse Gurney Bump.

Jac Mac

[Paul W]

Ahem, with my flame-proof suit on I and every Tornado builder I know of have fitted either the metal straps or in my case - a short length of 1 inch box section welded into the chassis to bolt the seats through. Here's a pic - not sure if it was posted or obvious in my build pics.

[Gregg]

Paul, thanks for your reply and pictures. However, if you review this thread and the build thread you will note that neither Scott or Andy have actually stated how the seats are mounted or that there is steel strap/box tubing supplied/installed with the kit. Looking at Scott's build thread, I do not see either strap or box tubing welded to his chassis for seat support. Hence the safety issue questions, originally raised by a Tornado owner, Andy Green. I didn't think the question was out of the ordinary or difficult in being answered. Sorry, but safety is paramount with me.

I expect to get flamed now.

Where is Falli when you need him??

[SteveB]

There is another aspect to this apart from the crash/ restraint issue.
If the seat is not integral a'la SPF or hard up against the bulkhead, the seat provides the support to hold the driver in a fixed location. When cornering forces, braking or clutch depression takes place, the effort is transmitted into the seat, tending to tilt the seat back and lift the front mountings... that are resisted by the floor mounts.
If there is space behind the seat it will move and tip back if the front mount fails..suddenly and could cause a momentry loss of control as the only way to stop falling back is to pull on the steering wheel.
Then you will rely the harness.

Steve

[Ian Anderson]

I have a question to Andy Green

As you say you are with Lotus cars, I believe the Elise is made with an Aluminium chassis etc.
Please could you show / explain how the seats are mounted in these? Also are the belt mounting points on the elise on the seat / subframe or chassis.

I too have a Dax and like Dave my seat is bolted to the floor only and this thread raises some concerns - yes your steel bracket needs to be fitted as a minimum -

Thanks for the idea / advice

Ian

[Pat Buckley]

FYI - the seats In many racing cars, in my case I recall that a Lola Formula Atlantic car, the seat is nothing more than a quarter shell of fiberglas that was placed into the tub to provide some comfort for your ass and hips - no fasteners of any kind. It was the seat belts that held it all in.

I think there was a much better chance that car would end up upside down than a GT40 - could be wrong. Many were involved in some quite spectacular incidents - and I can't recall any drivers leaving the scene.

I don't recall the thickness of the aluminum tub in that car but I am betting it wasn't much more than .060".

[Dave Lindemann]

Interesting thread. I own a 1977 Lotus Esprit and and a 1973 Lotus Europa TCS and the seats in both are bolted only to the fiberglass floor. While these are admittedly "old technology", it is my understanding that even the later Esprits have the seats bolted to the fiberglass. The bodies have no structural steel elements and the chassis is a backbone type so there is nothing else to bolt the seats to but the fiberglass floor.

Dave L

[Gregg]

Originally Posted by 2124

FYI - the seats In many racing cars, in my case I recall that a Lola Formula Atlantic car, the seat is nothing more than a quarter shell of fiberglas that was placed into the tub to provide some comfort for your ass and hips - no fasteners of any kind. It was the seat belts that held it all in.

I think there was a much better chance that car would end up upside down than a GT40 - could be wrong. Many were involved in some quite spectacular incidents - and I can't recall any drivers leaving the scene.

I don't recall the thickness of the aluminum tub in that car but I am betting it wasn't much more than .060".

Pat how big is the cockpit on the Formula Atlantic?? How about the quality of drivers racing versus that litlle old lady who should have stopped driving years earlier? Just a thought or two.

[Tim Kay]

......let's not forget the gas tanks!!.........I often ponder with myself whether to use seat belts at all

[Andy Green]

On the Elise there is a bonded & riveted cross-member that the front of the seat bolts and a similar one by the bulkhead. For the type approval test to allow us to sell the car worldwide, we have to meet a static pull test on the seat (which tests the mounts and the seat frame) and the seat-belt mounts. On the Esprit, the seats are bolted to the fibre-glass, but these are locally reinforced and the body is structural, which contributes to more than 50% of the overall torsional stiffness of the car.


With the occupant in place and correctly adjusted seat belts in an accident, the belts are doing all the work, as others have rightly pointed out. However the point I originally raised was that my 2001 build chassis does meet the wording of the SVA document (Seats are required to be secured firmly to the chassis or other obvious load bearing parts of the vehicle structure) and from what I understand even new chassis from Tornado is not compliant in this area - Andy Sheldon please correct me if this incorrect.

Regards
Andy

[Pat Buckley]

Originally Posted by Gregg

Pat how big is the cockpit on the Formula Atlantic?? How about the quality of drivers racing versus that litlle old lady who should have stopped driving years earlier? Just a thought or two.

How big? About as big as a well done GT40 seat.

As for the little old lady, I would rather face her at 55 in my 3000 pound sedan then some testosterone laden Villenueve wanna be going into a corner at 140 in an open wheel race car!

LOL....

[Russ Noble]

Haha Pat,

Back in the day when every NZ single seater driver was a testosterone laden Amon, McLaren or Hulme wannabe, banging wheels like crazy, I had a Formula B 1.6 Brabham BT21. I am a very tall guy and the only way I could get in it was to take the seat out. I actually raced that car without a seat, lying on the fibreglass clip-on undertray which used to scrape on the ground on the bumps going up over the hill at Pukekohe!

Worst thing was when the petrol tank sprung a leak and my overalls were acting as a wick for the fuel that seeped onto the tray, I had my fingers crossed that contact with the track surface was not causing sparks in the wrong places.

Hence, I guess, my conviction that the seat did nothing other than protect my fundamental orifice from potentially intruding objects, and leaking fluids.

Fortunately, maybe, the ultimate strength of that thin fibreglass tray was never tested

Cheers

[Jac Mac]

Originally Posted by Russ Noble

Haha Pat,



Worst thing was when the petrol tank sprung a leak and my overalls were acting as a wick for the fuel that seeped onto the tray, I had my fingers crossed that contact with the track surface was not causing sparks in the wrong places.

Hence, I guess, my conviction that the seat did nothing other than protect my fundamental orifice from potentially intruding objects, and leaking fluids.

Cheers

I guess that finally puts to rest any speculation that you are a tin-assed tight ass then.

[Ian Anderson]

Andy

Many thanks for your reply re the Elise.
Is there loas spreaders / washers used to spread the load any more than the bonded in parts?

Would large (say 3 inch) washers above and below the skin reduce the risk until I can get the