Rebody Oh no. It's not another 507 Rebody. Oh yes it is!

ruan

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British Zeds
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3
Are all the pepper pot wheels 15 inch? What tyres should be fixed to them?
 

Pond

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British Zeds
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Spaldingski, Lincs
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Z3 project and E89 Z4
Are all the pepper pot wheels 15 inch? What tyres should be fixed to them?
That will depend on the width of the rims.
My new wires are 15" x 6" so will just about take 205mm widths. With 65 profiles they will be very slightly larger diameter than the staggered 17" on the car now. 195mm x 65 profiles would be a better fit for the rims and the diameter but they just look a little 'weedy'.

It's worth noting that cars with DSC (not sure about ASC) do not like a rolling circumference change of more than around 3%. It can play havoc with the DSC operation.
 

Duncodin

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Pontrhydyrun
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Z3 M44
That will depend on the width of the rims.
My new wires are 15" x 6" so will just about take 205mm widths. With 65 profiles they will be very slightly larger diameter than the staggered 17" on the car now. 195mm x 65 profiles would be a better fit for the rims and the diameter but they just look a little 'weedy'.

It's worth noting that cars with DSC (not sure about ASC) do not like a rolling circumference change of more than around 3%. It can play havoc with the DSC operation.
How does the dsc/asc know that the rolling radius has changed? It can't know that the car travels a little bit further each rotation of the wheels.

I'm willing to give it a try with too tall tyres. The arches are so big they need filling.
 

Pond

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Z3 project and E89 Z4
How does the dsc/asc know that the rolling radius has changed? It can't know that the car travels a little bit further each rotation of the wheels.

I'm willing to give it a try with too tall tyres. The arches are so big they need filling.
It measures the rotational distance against speed. If there is a certain difference in speed of the rear wheels it applies the brakes to the faster wheel. I have seen this discussed on another BMW forum (so it's third party info), but apparently the 'data' for any given model is programmed into the DSC brain (I can't remember the module TBH). If the programmed parameters change by too much, it doesn't know whether it is on foot-or-horseback as it can't compute anything other than approx +-3%. Chances are it just won't work as well as it did, but it is generally a system that isn't intrusive anyway.

You can't notice it at all on the E89, only that the rear wheels get much more brake dust on them than the fronts!
 

Duncodin

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It calculates the speed based off of the rotation of the output shaft. It uses what it 'thinks' is the rolling radius of the wheel to calculate speed.

How would it know if fhe rolling radius is different. It has no other way to calculate/know speed. It'll simply calculate the speed wrong.

Er. I think.

I'm gonna do it anyway and I'll be sure to come back and tell you how it went.
 

Pond

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Spaldingski, Lincs
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Z3 project and E89 Z4
C
It calculates the speed based off of the rotation of the output shaft. It uses what it 'thinks' is the rolling radius of the wheel to calculate speed.

How would it know if fhe rolling radius is different. It has no other way to calculate/know speed. It'll simply calculate the speed wrong.

Er. I think.
Cos the speed of the wheel for a given rolling radius is pre-set in the DSC module by programming. Yes, the speedo will read wrong, but that is not where the 'speed' or 'distance travelled over time' is calculated for the DSC.
TBH I don't know the maths or science behind it, but when I read a discussion about how it works, it made sense.

And it's all very interesting. More interesting than sanding GRP, anyway. :)
 

Duncodin

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Although I do still intend to get 15" style 36 wheels I'm aware that my MOT date is fast approaching and I've spent way too long fiddling with stuff that didn't need doing. So I need to spend time and money doing stuff that is necessary for MOT.

So, in the meantime, I'll keep my existing 16" style 35's but want to make them a little less prominent. Painted one of them in body colour and took a photo and photo edited it onto the car to see what it'll look like.

Style35.jpg


not to scale but I think it'll look OK for now. I think when I get the style36 I'll paint those body colour too.
 

Duncodin

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Wheel arch liners. Don't fit exactly but near enough and quite neat.

20240817_101806.jpg


Screenshot_20240817-102055_Gallery.jpg


Screenshot_20240817-103343_Gallery.jpg


Edit.
Forgot to mention. The plastic sheet is one of those black plastic builder's tubs you get in B&Q. I tried 4mm rubber sheet but too wobbly. This B&Q tub is real easy to cut, very flexi but quite rigid once screwed in place.
 
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GZed

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t-tony

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E89 Z4 23i Auto
We used to make mudguards for grass track car trailers out of the same type of thing many years ago.

Tony.
 

Duncodin

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About to go in 🤔
Screenshot 2024-09-13 at 13.25.17.jpg


But Yay! 🥳

Screenshot 2024-09-13 at 13.27.57.jpg


Never had fewer advisories. Actually the car failed on headlight alignment but he adjusted them and retested straight away.

Emissions are pretty good. Hear lots of horror stories about M44 emissions.
Screenshot 2024-09-13 at 13.27.01.jpg


So. Last few years not done anywhere near enough miles in it.

Oh. There's more. While waiting for the MOT I got talking to this guy. He liked my car. He races this beemer at castle coombe. Few awards on his shelf - in his body wrap shop. Seriously thinking of giving my car to him for a wrap.

Screenshot 2024-09-13 at 13.33.35.jpg
 

Pond

Zorg Guru (III)
British Zeds
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Location
Spaldingski, Lincs
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Z3 project and E89 Z4
Did your MOT tester not ask any questions why it doesn't look like a Z3 anymore?
Or did he/she/they/it just treat it as per the DVLA info, as you have a standard interior and airbags, etc?
I understood, from previous dealings on Cobra forums, that it can be tricky if the car is registered as one thing (a Z3), but presented as something else.
Just interested.
 

DaveP

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Reading
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Z3 2.2 Kobra rebody (see pic)
Did your MOT tester not ask any questions why it doesn't look like a Z3 anymore?
Or did he/she/they/it just treat it as per the DVLA info, as you have a standard interior and airbags, etc?
I understood, from previous dealings on Cobra forums, that it can be tricky if the car is registered as one thing (a Z3), but presented as something else.
Just interested.
I can answer that from my Kobra experience at least. I have been taking mine for MOTs for 4 years plus and only last year did I have a discussion about what the car was. I have a Kobra dash and replacement steering wheel so it becomes very relevant.

My V5 states that it is a BMW Tribute Kobra so it is tested as a different car. Ie no airbags or warning light for such. I went to a new tester last year who saw on the MOT database that it was a Z3 and wanted therefore to see airbags etc. we chatted it through and it passed after discussion. I wish I had asked him to change the description on the MOT database in readiness for.this year.

Essentially it depends where you go and how to the letter the tester is. If you don't rename it and change the MOT database in could be a difficult process.

Just my point of view in a bit of a minefield.

Dave
 
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