Liam's Z4C race car project

[srhutch]

I noticed that only the offside rear fog lamp was working despite having a good bulb in the nearside lamp. Did some searching to find this is normal!

MSA rules require either a central rain light or a symmetrical pair. So I found the offside wire and bridged the two lamp connectors to prove that the nearside will light up. It's the yellow wire with black stripe.

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Cut both wires of the same colour and used the nearside one as live for both sides. This worked but triggered the bulb warning light on the dash as I had cut the unused feed for the nearside lamp!

My slightly dodgy solution was to splice all 4 ends together. So the lamp check works, but I also have both fog lamps working. Used a heat shrink solder tube for the splicing.

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The near side fog works when the brakes are applied with force and act as extra breaks lights, might not function as a fog from factory though. Can't remember and not great my car.

 

[Liam22]

Yeah, I need to code that out and not have the brake force thing. Then I realised I could probably code the fog lamp operation... doh!

 

[ted494]

Cut both wires of the same colour and used the nearside one as live for both sides. This worked but triggered the bulb warning light on the dash as I had cut the unused feed for the nearside lamp!

My slightly dodgy solution was to splice all 4 ends together. So the lamp check works, but I also have both fog lamps working. Used a heat shrink solder tube for the splicing.

Hi Liam, do you know if it would be possible to just have the passenger side fog lamp on instead of the drivers side? I only need the need the passenger side in my RHD Z4M to work so it can pass the German TÜV. Thanks for your help
Andrew

 

[Liam22]

Hi Liam, do you know if it would be possible to just have the passenger side fog lamp on instead of the drivers side? I only need the need the passenger side in my RHD Z4M to work so it can pass the German TÜV. Thanks for your help

Hi Andrew, it should be as easy as swapping the wires over. Find both black/yellow wires, cut and swap. Perhaps fit connectors on the cut wires so that it is easily reversible.

 

[ted494]

Hi Andrew, it should be as easy as swapping the wires over. Find both black/yellow wires, cut and swap. Perhaps fit connectors on the cut wires so that it is easily reversible

Thanks Liam! Did exactly that and it worked perfectly. Currently at the TÜV waiting to see if it will now pass.

 

[ted494]

Passed with no problems! Thanks again for the help

 

[Liam22]

Passed with no problems! Thanks again for the help

Yay!

 

[AlpinaZ4]

Liam... any ideas what wheels you will be running?
Are you allowed aftermarket?

 

[Liam22]

Liam... any ideas what wheels you will be running?
Are you allowed aftermarket?

Aftermarket are allowed. I'll be using:

Style 194 for dry (17x8J, 17x8.5J)
Style 294 for wet (17x8J square)

 

[AlpinaZ4]

- Carbon roof panel

Possibly useful:
http://www.carbon-factory.de/en/automotive/bmw/bmw-zseries/e85-e86/103/bmwvz4-roof?c=162&number=SW10005

According to realoem the roof panel is 7,9kg so not much weight saving.

I chased this up with a different German supplier btw
Price is around 1500 euro...

 

[Liam22]

After removing the heater I needed to loop the heater hoses to close up the coolant circuit. Conveniently, they both run from the expansion tank, so the heater bypass loop can be very short. But I couldn't find a way of using the old inlet/outlet hoses to loop together. So after a little research (looking at photos on eBay) I took a punt on the 2.0i heater hose having a suitable length of hose attached.

Some careful cutting with a Dremel and use of a hose joiner I have a not-very-pretty solution... but it has saved another kilo:

 

[Liam22]

Next up, bonnet catches.

For racing to MSA regulations the OEM bonnet release mechanism must be removed and replaced with externally operable bonnet pins. After removing the bonnet release and central catch mechanisms I realised that the diagonal bracing in front of the radiator is just to protect the slam panel from distortion - so I removed that too! Another 1.3kg.

I replaced the catches with a pair of Aerocatch flush fasteners. As usual I spent a very long time agonising about where to fit them. In the end I went for as close to the OEM positions as possible. And to optimize for weight saving I decided to replace the nearest bolt with the bonnet pin.

The bonnet pins (M10) replace M8 bolts, so I first needed to drill and retap the thread.



Then with the bonnet pin fixed in position, mark the approximate area on the underside of the bonnet. Of course, because I was working in the same area as the original bonnet catch, there was the added complexity of removing the steel reinforcement. Dremel to the rescue.



The white-tac shows a witness mark where the top of the bonnet pin meets the bonnet. Now we have a centre point for a pilot hole.



Draw around the template with a Sharpie and cut it out...




And if everything goes to plan the Aerocatch unit will meet perfectly with the bonnet pin.



While I had the front bumper off (to remove the slam panel bracing) I fitted a pair of the new style wire rope towing eyes and cut holes in the bumper to suit! Tested by winching onto the trailer.

 

[Kev]

Do you need two?

You're adding weight now

 

[Liam22]

Why 2 towing eyes? The MSA strongly recommend having a pair front and rear. So seems sensible to follow that advice on a new build, especially as it might become mandatory in the future.

But yeah, 650g for all 4... that hurts. Although the bonnet pins saved 1.6kg so I'm still winning.

 

[Mr Tidy]

Future-proofing - sounds like a good plan!

And at least you've had a net saving taking the bonnet pins into account - result.

 

[Joycey]

Enjoyed reading that, really capable cars these coupes. The handling really surprises a lot of bigger cars on track. Did near on 15 track days in my coupe with nothing to fault other than eating pads.

 

[adam1985]

Why 2 towing eyes? The MSA strongly recommend having a pair front and rear. So seems sensible to follow that advice on a new build, especially as it might become mandatory in the future.

But yeah, 650g for all 4... that hurts. Although the bonnet pins saved 1.6kg so I'm still winning.

Plus by the look of it weight saving from removing the headlight washers

 

[Liam22]

Did near on 15 track days in my coupe with nothing to fault other than eating pads.

It does seem heavy on rear pads. Chewed through a set of Ferodo DS2500 in a couple of hundred miles. About to switch to Pagid RS29 in the hope they will last a season.

Plus by the look of it weight saving from removing the headlight washers

Headlamp washers: 675g (the covers will get glued back on)
Front number plate: 480g
Fog lamps: 1.5kg

The list goes on...

 

[JamieZ4C]

Love seeing the progress of this project.

If I did something like this, I think I'd become absolutely obsessed with finding ways of losing weight! Stay away from the drill and angle grinder, Jamie :lol:

 

[Liam22]

Stay away from the drill and angle grinder, Jamie :lol:

Funny you should say that...



Boom! 13kg