MadaboutKitcars

Yep, I think that approach will work a treat. I'll be interested to see what moulding you come up with - I really like the idea of an upholstered 'eyebrow' type dash top with a painted 'metal' panel to take the instruments and switches. If you don't make one Chris I sure will.

The dash on my Spyder sets it apart from most of its kind -



It was a moulding taken from a Porsche 550 Spyder that Gary Janes just happened to have laying around in his workshop. I was going to make something myself, but Gary sold me the 550 dash and I adapted it to fit the Sammio body.

To me, the dash is one of the most important aspects of a replica/kit car/Tribute, as together with the steering wheel, seats and gear-lever it's one of the primary interfaces you have with the car. After all, when you're driving a car you spend more time looking at the dash than anything else.

Not sure if you can tell, but I'm really excited about this project.

Just read back through the Kobra thread and found this image -



I take it you took a moulding from that prototype dash? Bit of work to give it the slightly raised 'pod' to take the Z3 gauges and that'd do nicely.

Also came across this picture -



Anyone know if the fillet panel that runs from the back of the transmission tunnel to half way up the rear bulkhead is structural? (the triangular bit with an oblong hole that looks like a holder for an i-phone on its front face).

I'd be tempted to take the angle grinder to it if it isn't.

I don't know for certain but when i stripped my interior out it didn't seem to be for anything other than bolting the plastic trim to.

Having said that, in your picture it looks quite substantial for a trim holder so perhaps it also braces the rear bulk head in some way

Make a panel to cover it in alloy with swagged holes

Something along these lines if you get my drift

Yep, I'd box it in if it's structural, but if it isn't I'd rather cut it out and leave a flat bulkhead. It's funny how details like that matter, but to me they just do...

It looks structural to me. I think it would be classed as stiffening. I think you have to be very carful taking an angle grinder to anything on these shells. Else you may find the car requiring an IVA with all the nit picking and expense that involves.

I don't know if these base units are classed as a chassis, a floor pan or a body shell, VOSA/DVLA have some pretty strict guidelines/rules regarding what you can and can't do without the need for an IVA.

ACE have a page which covers this and contains some guidance, but interpretation is key, our interpretation may differ from that of VOSA/DVLA. There are cases where non structural parts have to remain, especially with body shells, sometimes even drilling a panel or re-shaping it can be classed as a modification, in some cases it can call into question it's integrity. In VOSA/DVLA's eyes altering a panel destroys it's originality and therefore it is modified. A bugger I know but those appear to be the rules. Here is a link to an ACE guidance page of their website. I suspect the BMW Z3 is likely viewed as a body shell or floorpan structure and almost every panel has to remain as it came out of the factory. There are other pages on the ACE website which are helpful in this regard.

http://www.the-ace.org.uk/chassis-and-monocoque-modification/

Don't get me wrong, I am NOT anti modification but as one who has been bitten hard by the system I am very cautious, I try to help anybody avoid the disaster of spending a great deal of time and money building a car which is then deemed to need re-registering and therefor needing an IVA. That is the whole point of using the Z3 as a base, so one needs to be very carful not to bastardise it. To get the ultimate result it can become a bit of a tightrope walk, just don't fall off.

These things suffer from broken spot welds and iffy diff mounting as standard so do you really want to chopping out a strengthening panel?

Thanks for the feedback guys, you're absolutely right about not messing with anything structural - it just looks like a carrier for the plastic trim to me though and I'd love to get rid of it.

Guess I'll have to wander into my local Beemer dealer and ask the man in the oily overalls with a hand-rolled fag hanging out the corner of his mouth for a definitive answer...

I know they were built Stateside, but are they really that bad?

Anyone know if the diff issue is linked to the power output of the engine - are the bigger motors overpowered? If so, all the more reason to stick with a 1.9.

OK, found my own answer regarding the diff here -

http://www.bimmerforums.com/forum/showthread.php?1979601-Subframe-trunk-floor-differential-mount-failure

Looks like the monocoque was only ever meant to take a lightweight 140hp motor and anything bigger can stress the structure to the point of catastrophic failure.

But hey, at least you can boast to the other patients in A&E that your car was going 150mph when the back wheels came off...

From what I have read on the forums it was only really the Z3Ms that ripped their own arses off

The other, even the 2.8, are more about firm but gentle acceleration rather than screaming, neck snapping thrust

I read that only z3ms are affected too. The extra 100 odd horse power and traditional LSD will do that! (The Torsen diff in the 2.8 seems less harsh in action to me compared with the clutch type used in M cars)

Anyone with a Z3 should change the diff oil occasionally. BMW called it lifetime oil but it isn't. I changed mine in about 15 minutes and it came out like drinking chocolate. A lot smoother and quieter since the new oil went in.

Instructions
The diff has 2 plugs at the back. Remove the spare of you have one to see them more easily.
Loosen the top one slightly to make sure you can. You don't want to drain the diff and find you can't undo the fill plug.
Remove the lower plug and let the oil drain fully.
Put the bottom plug back in and remove the top plug.
With the car level, fill the diff until it just starts to dribble out.
Refit the top plug and drive away happy

That's good advice. As much as I like drinking chocolate it isn't a good lubricant

As much as I like 75W/90 oil it isn't a good bedtime drink.

The world is better when everything's in the right place

I put 75W/140 in to replace it. each to their own

Build Progress

Inner support panels bonded to inside of front end body section



Channels for front lights wiring boned in





GRP latch plate with steel inserts and captive nuts to accept standard BMW Z3 bonnet latches



Rollcage brackets bolted to Z3 softtop fixing points in windscreen head rail





GRP insert bonded top of windscreen head rail to join to new rear body section



New alloy insert bonded into Z3 petrol tank neck....




.... before new flexible pipe was installed



Headlights, front indicators and side marker installed and wired. I really like Bob's chioce for side markers

Rollcage drops into existing Z3 roll hop uprghts...





...and bolts down at rear to inner wings above Z3 rear lights



Rear inner mounting panel test fitted

Looking great, a spectacular effort, well worth the wait.

That's looking soooo good.

Few questions though:

Will the bonnets for diy customers come fully built up with inner panels, hinge points and wiring guides?

Could you take some pics inside the car so I can see the relationship 'twixt roof and roll hoop please (want to plan for a headliner).

Is that fan in the boot part of the active 'ground effect' aerodynamics package?

It is looking bloody good though, did I mention that already?

Great work, looks like you've done everything you can to make the builders life easier

Wow, it gets better every time I see it and looks like a top quality kit with some well thought out details. Well done guys!

I have spotted a few things that are making me rethink my quick and simple build plans though. Thats not necessarily a bad thing, just requires a different picture in my head.

Tell us Gaz.

Tell us of these things you have spotted of which you speak, and of the picture you have in your head.

Don't keep ideas to yourself, we're all ears.