As Above, any comment s welcome

my only relevant comment would be that if i had used a rivited ally floor, i would've put the seat mounts on bars rather than direct to the floor. in fact, i used steel and still used bars!

JoelP,

Being a rather heavy guy I did plan all along to fit bar for the seats. Want sure that a direct mounting to a steel floor pan would be strong enough let alown an Ali one.

Simon

does a welded steel floor contribute significantly to stiffnes etc? How much of this is offset by weight?

IIRC there was much discussion about this many moons ago (I remember 'cos I was thinking of an alloy floor and transmission tunnel) and the consensus of informed opinion seemed to be that the welded steel floor formed a significant part of the chassis strength and stiffness - I think some of Cymtriks input confirmed this.

Another thought worth thinking about is the 'armour plating' or otherwise of the bottom - if you (or indeed your car) had an ally bottom how would it cope with hitting a rock or suchlike in the road. i.e. would it come through an ally floor?

cheers

phil.

Pioneer,

For what it's worth I know MK used to make the Indy with a welded steel floor. They have since changed to supply an ally floor panel with the kit which is bonded and rivetted to the chassis.

Their reasoning for this was that the underside of the floor gets the brunt of the road cack and suffers with corrosion.
I feel it may be something to do with cost as well though.

My Indy has an ally floor which I bonded on with PU adhesive/sealant and then rivetted. It is not going to come off again that's for sure and it looks good as well.

Photos in my archive if you're interested.

HTH

Nick

Hi

What is that picture of that youve got displayed, it looks a bit like a dax, with some sort of hard roof?

Regardless it looks interesting.

Please tell me more.

I was under the impression that it was a welded transmission tunnel that added strength to the chassis, which is what I have instead of a panelled one.

there was a post recently about the relative weights of alu and steel, so was after some opinions about the weight disadvantage compared to the added strength.

What about going half and half?

I have two really nice ally sheets, which I was going to use for the footwells, then might weld in a steel floor elsewhere?

I know about the recommended welded sheet at the front of the chassis, again which I have included.

Cheers
Mark

9904169,

You're right about Cymtriks mods (trans tunnel etc.) over the original design but the original design incorporated a steel floor in the irst place which he did not sugest removing or replacing to lighten and stiffen.

I originally asked a question about puting diagonal bracing in the trans tunnel and panneling with ali, having worked out that it would give a marginal weight saving and IIRC someone pointed out that the required stiffness would still not be maintained - Cymtriks option being lighter and stiffer. This would also apply to the floor I would have thought as I have also gained the impression (I can't remember where from, and maybe incorrectly) that the welded steel floor was necessary as there is no triangulation whatsoever in that plane in the cockpit.

I can't comment on whether bonded aluminium would serve that purpose adequately - perhaps someone who knows more about these things could comment.

Cheers

Phil

Hi,
Aluminium is probably going to suffer less from the "boing" effect and won't be distorted by heat during welding like steel is but I must say I'm glad I went with steel. I used 16swg (1.6mm) thick steel sheet and seam welded the outside to prevent any cack getting in from the outside. I have stitch welded the inside at a ratio of 1" weld for every 6" and will use seam sealer to seal the rest.

I think if I was going to use ally then I would use some of the special 3M ultra-sticky tape and lots of good quality rivets. I would also want at least 2mm thick sheeting to stop the rocks coming through.

Cheers,
Craig.

So, can anyone comment on the result of panelling the footwells in 2mm ally, then welding in 16swg the rest of the car?

Is this realistic, or should the floor be one discrete unit? (i.e. a single sheet)


mark

Why?
Is it just for the look of the ally finish? If so then just do it in steel as a one piece floor and then skin the footwell with ally. I'd say you want as few joints as possible in the floor.

Cheers,
Craig.

The cymtriks "reccomended configuration" calls for an 18swg steel floor with an optional pair of lateral reinforcing tubes to reduce "boing"

Here's a tip for boing problems...

Luego steel floor stitch welded (I think thats the term, never welded so not massively up on my terminology - basically its 4-5 inches weld followed by 4-5 inch gap all the way around) on the inside (probably seamed round the outside, cant remember), significant boing.

sikaflexed round all the edges on the inside, boing all but gone, now more of a dull rubbery noise.

But does anyone know what the car in the photo is that user PioneerX is showing?

Pretty sure it's by a by a Dutch company called Donkervoort.

James

Check out http://www.donkervoort.nl/

Expensive, but very very nice I believe.

Cheers

Nick

Right, I think it's a Donkervoort too. I didnt get the picture from there, just found it of a wander through the net at one point.

schuin-voren

[Edited on 5/2/04 by PioneerX]

Do they normally come with tyres that sticky?


James

at €40000 for the basic model I should hope so

for that money i,d want number plates and some rent in the window

and 5 yrs warranty... hyundai style.

The reason for wanting to do the footwell in ally is two fold:-

I have two very nice pieces of ally the perfect size for the footwell, which would mean it wouldnt rust.

Also, as there are now no local steel merchants (my local one moved to Wishaw), getting an 8x4 sheet of steel could prove tricky. Smaller ones however...

But locosts always are tricky, right?

Mark

A welded in steel floor is probably best for our purposes. It is cheaper, stronger, easy to weld in if stich welded to avoid distortion, and less likely to fall out.

I have heard of riveted floors falling out on some kits. Could be nasty. I've never heard of this happening to a Caterhm7 but this could well be due to the fact that their chassis is very stiff, more than twice the book chassis, and so does not flex enough to wear out the rivets.

If you scroll back through my posts on chassis analysis I do suggest 18 gauge (1.2 mm) for all welded on panels instead of the book 16 gauge (1.6 mm). The thicker book panels don't add much to stiffness but do add a fair bit of extra weight. Any "boing" problems can be improved by adding an extra pair of B2 tubes inline with the front of the seat, from the bottom of the V made by TR5/K1 and TR6/K2 to the tunnel base.

A mate from work dropped his bike the other day doing around 30mph, the road chewed through the ali flywheel cover with surprising ease, leaving a gapping whole. I would have thought that after a couple of grounding's on sleeping policemen (a couple in yeovil require a tractor to drive over without scraping the floor) you would find yourself with a new air conditioning unit, which I'm sure is a mot failure. I've gone for steel, mainly as it was already fitted to the chassis when I brought it.

but you could un-rivet a riveted chassis easier than you could un-weld a welded one?

Steel it is methinks

Mark

What some Australian builders have done (abd I will do too) is to use a steel floor with a few stiffening ribs folded into it which both stop the "boing" and give you somewhere to bolt your seat rails to. I've had a quick serach for a photo with no success so I'll try an illustration - hope this turns out OK.

__ __
____/ ______/ ____



Dominic

quote:

---

Originally posted by 9904169
but you could un-rivet a riveted chassis easier than you could un-weld a welded one?

---

By using the removed panels as templates

Mick

You could always make a support tray for the seat using carbon/kevlar composite. It's very easy to do and I can supply details etc. A company called CFS (on web) supply materials at reasonable cost.
cheers
Rob

For seat supports, what is wrong with a couple of bits of steel square section across the floor in the appropriate place with a couple of brackets welded directly to these and drilled to accept the bolts? That's what I've done and it was quick and painless.
Cheers,
Craig.

quote:

---

Originally posted by Mix
By using the removed panels as templates

---

to stop the panel panting, a couple of right angle stiffner's would do the trick. A bit of 16 swg ali strip bent through 90^ and riveted to the inside of the footwell would provide plenty of support, plus you could hide it under the floor paneling (if your putting some in). Works on aircraft panels.

I'm going for an ally floor, but have put in some extra chassis bars to strengthen the floor area and triangulate to the dif mounting points for strength aswell.

Not quite finished as the welder packed in, but heres a pic:


Ned.

I dont think triangulation adds much there ned.

what it does do is put obstructions on the floor where your feet should go, unless you have a false floor on top.

Also, if you hadnt used triagluars and had just used two bars across where your seat would go, you would have two nice bars to 4 point bolt your seat to.

atb

steve