reduced chassis stiffness with lowered floor

[V7 SLR]

Doesn't it depend on the weight of the driver? Myles weighs about as much as an empty egg carton so he'll never frighten his floor by getting it close to the tarmac.

 

V7, on the other hand, already bears witness marks where its floor has worn thinner because of some fat bast... erm... driver has forced it downwards. And that happens under normal conditions, not only when the floor rivets snap.

 

Another thing, I've noticed V7 grounds out when it lands in the centre of a sharp-cambered road after flying off a hump backed bridge. 😳

[Alex Wong1697456877]

V7 - you are a waif compared to me!! I'll wait and see someone else's car with the mod - although I'm not tall, I like to sit quite upright and a lowered seat sounds appealing to me.

[tiddy1]

The thickness of teh aluminium will make absolutly no difference to the stiffness. as you have basically cut a big hole in the middle. I cant see why you should slope the floor up at the front, it does not give any more clearance but it removes the flat pannel from in front of the cross brace. If you left that in than at least you would retain half the stiffening effect. the tub part under your arse will add little or no torsional rigidity .

[Tony C]

Cut a big hole in the middle - in the middle of what?

 

If the floor at the front didn't slope, I think your feet/pedal position would be out of alignment.

 

Those that have fitted a lowered floor - did you use the old floor as a template for the rivet holes in the lowered floor?

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[sjmmarsh]

Alex

 

Yes - it is possible to ground the floor - I've done it going over a crest at 50. When the car sank on its suspension on landing there was a loud bang as the rear bolts holding the seat in hit the road.

 

On inspecting the car later there was only a slight grazing to the surface of the bolts - no damage. There is about 1cm of thread protruding beyond the nut so I'll have to trim them back.

 

I think it was so loud because the floor of the car rang like a bell.....

 

Steve

[bat flattery]

Tony,

 

To answer your question:

yes, you use the old floor as a template for positioning the holes for the tunnel side and front chassis members and the internal side panel holes for positioning the holes for the outside and rear chassis members.

I fitted a lowered floor to my SV last summer - well worth the effort and ££'s - a real improvement as I no longer look through the top inch of the windscreen and as I am lower in the car, wind buffeting is reduced.

 

 

Peter

 

Red Roadsport SV

FP53FHB

[Tony C]

Thanks for that - from my understanding of what you've written, the lowered floor hangs from different holes/rivets on its outer edge. I seem to remember my existing floor as being secured with vertical rivets all the way round.

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[bat flattery]

Tony,

 

That's correct - the existing floors are flat and so all rivets are in tension, with their axes vertical.

On the lowered floor, the inboard side and front edge are as per the existing floor, but the outboard and rear edges are vertical (and slide up behind the interior trim panels) so the rivets are in shear with their axes horizontal.

 

 

 

Peter

 

Red Roadsport SV

FP53FHB

[Tony C]

Thanks Peter; I can now visualise how to transfer all the chassis hole positions - something that was giving me concern. Did you use "Ordinary" pop rivet pliers or "Lazy Tong" or even pneumatic. I would imagine that that ordinary pop pliers would be a pain in the wrist 😬

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[bat flattery]

Tony,

 

I used a basic Stanley hand riveter for about half the rivets but struggled with holding the rivet hard into the hole 😳 whilst trying to close the handles to pop the rivet. I found I was sometimes setting the rivet behind the floor panel only and so the rivet wasn't actually holding the floor to the chassis member.

I then upgraded to a Stanley hand riveter where the head can swivel thro' 90° which made things very much easier. Although after about 120 rivets (all steel), you do end up with forearms like Popeye 😬.

 

Are you contemplating this mod?

 

Peter

 

Red Roadsport SV

FP53FHB

[Tony C]

Thanks for the info Peter - good ol' L7C 😬

 

It's next on my list. I have Brooklands so don't suffer screen visibility problems, but would like my bulk to stick into the airflow less AND lower the CG a tad.

 

The problem you describe, of closing the rivet with the lowered floor panel a distance from the chassis member, can be overcome by using "Cleko" or "Avdel" clips - temporary fixing devices for use when riveting - luckily, some of which I have 😬

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[Bricol]

So I take it you fill in the old holes with blind rivets or similar on the underside of the side and rear?

 

Bri

[bat flattery]

Bricol,

 

The side holes must have rivets replaced in them as they hold the side skin in place. As far as I can recall, the rear holes just needed a rivet in to block the hole up to keep the Dinitrol that I squirted in.

 

Peter

 

Red Roadsport SV

FP53FHB