Re-working 1" box section under seats?

[lambostylus]

Putting the seats in - and becoming increasingly annoyed with the lopsided chassis bar (1" box section) that runs across the passenger side under the seats.

Has anyone tried to cut this out and put it under the floorpan, same as the driver side? I assume this wouldn't affect the structural rigidity much, and would give an extra inch or so play for the seat depth - unless I want a stupidly high roll bar for a road car, I need to look at these options!

Any thoughts out there?

[Pete&Matt]

our chassis is one of the last and both the box sections are underneith giving a flat floor pan in the cockpit.....

[spegru]

I am thinking of cutting this cross section out and refitting it underneath in order to lower the seats.
Anyone got tips on doing it?

thanks

[stylussprinter]

Why do you need to cut it out to lower the seats My seat sits directly on the floor then to support your thighs the front needs to slant upwards anyway . The seat has threaded inserts in it's base at the rear corners and front . Rear is fixed tight onto the floorpan then the front is supported by ally tubes between seat and floor with long bolts going through to the threaded inserts

[spegru]

I'm 5' 11".
I have some fairly low Lotus Elise seats (a tight squeeze but they are great), without their runners.
Even so, I'm conscious that my head is higher than I'd really like it, compared to the rollover bar.
I reckon there could be quite a bit of additional headroom availble by lowering the floor pan a bit.
As you say, the seat base needs to tip back, so this may need only be to done to the steel bit at the back rather than the alloy. Even simply removing the bar itself might gain an inch, and more would be available if the back of the seat pan was recessed.
I seem to remember that a GTM Coupe that I used to have, had a similar style dropped floor pan - from the factory

So, like I asked - anyone done that - or have any tips/ideas? (or recommended people to do the work?)

steve

[stylussprinter]

I'm 5' 11".
I have some fairly low Lotus Elise seats (a tight squeeze but they are great), without their runners.
Even so, I'm conscious that my head is higher than I'd really like it, compared to the rollover bar.
I reckon there could be quite a bit of additional headroom availble by lowering the floor pan a bit.
As you say, the seat base needs to tip back, so this may need only be to done to the steel bit at the back rather than the alloy. Even simply removing the bar itself might gain an inch, and more would be available if the back of the seat pan was recessed.
I seem to remember that a GTM Coupe that I used to have, had a similar style dropped floor pan - from the factory

So, like I asked - anyone done that - or have any tips/ideas? (or recommended people to do the work?)

steve

Floors have been lowered by Neville Powell (babybertha on this forum) a previous chassis builder of Stylus's but to accomodate very tall drivers . Factory supplied rollover bars are non functional other than for a ' midget ' and simply there for adornment . Rollover bar should be 2 inches above your helmeted head with you in the lowest seated position --- obviously this varies from person to person . In my case the bar is 23ins from memory from the ledge behind the seat top to top of bar.

[CMA]

Does anyone have any pictures of the lowered floor?

[stylussprinter]

Does anyone have any pictures of the lowered floor?

MattD may have because it's his uncle's Purple V8 that was dropped under the seatpan by Neville Powell for it's previous owner/builder John Rocky.
It's a doddle to do if you're determined to do it though ---- just angle grind out the sides and back sections(not too close to the chassis tubes though) --- then bend downwards to form the forward section into a gentle slant for around 6 or 7 inches ---- then allowing for the floor drop of say 2 inches , bend the rest back up parallel with the seatpan .
Cut and shut the sides/rear with some 1.5mm sheet.
You could of course simply cut the above area described totally out then cut/shut with sheet BUT remember if you do it that way to have a nice gentle slant at the front edge --- if you don't and then hit some thing while driving it could do loads of damage
I wouldn't do it on a track or competition car because at a later stage in ownership you may fancy lowering the car THEN find you have 1 inch clearance

[MattD]

Its the forward floor that's modified on the V8.
Its been dropped on the drivers side as part of the tunnel widening to create new space for the pedal box.
This is all fully welded in steel rather than alloy & includes a single 1" box tube right across driver & passenger side.
As a result it has flat floors on both sides (which is what you are after). The original steel rear seat section is as original, not lowered.

A few more pics show it in the V8 build thread in "General Stylus", but you'll have to look past all the tools

What I did on my own car was to cut 1" sq out of the GRP seat base to go over the internal tube (fixed seat).
As the wife found this seat "too hard" I also picked up two seats recently from a Fury that had Caterham seats fitted.
These both have the underside of the seat runner cut 1" step half way through in the appropriate place & spacers under the front seat edge,
(rear bolts direct through the steel floor). In this way the seat sliders still work, are structurally strong enough, & floor is unmodified.

[spegru]

I've still been thinking about this - for a few years in fact!
Anyway with my original 1997 stylus with the bar under the seat and Lotus Elise seats I was never sure whether the seats actually sat on the bar or on the floor behind the bar. Since the base of the seat slopes up towards the front it could have been either.
So how to measure the under seat clearance at various points? (obviously you cant actually see).
I heard of people using blu tack or plasiticine but I just dont have any. So I was thinking about something squashy that would keep its shape, when Bingo! I know - garden Soil !

So after trowelling a layer of soil in behind the floor bar, putting the seat back in and sitting on it, and then removing the seat again in order to measure the thickness of the compacted layer, I have established that although the seat sits on the bar and then goes downward to the floor, it never actually touches. There was a layer of soil 1cm thick there. Therefore there is at least 1cm to be gained by removing the bar. It's not the whole bar thickness but is at least half - and even 1cm of lowering would be welcome

As well as removing the bar and replacing it with another under the floor, I suppose I could also dish the floor under the back of the seat by 1cm to get the seat lower by the whole 2cm of the above floor, bar thickness
Not sure how wide to make such a dish but I expect the soil idea could be used again to find that out!

Who'd have thought of an automotive use for mud?

PS I tried to add illustrative pictures from my phone but nothing happened