Liam's Z4C race car project

Wursle · Post by **Wursle** » Thu Mar 04, 2021 5:02 pm

Just out of interest Liam are these the M3 CSL/CS Discs or the regular 325mm E46 M3 discs?

If they are the regular 325mm discs how come you didnt just stay with the OEM Discs as they are 325mm aswell? just thinking from a cheaper consumable perspective is all

Liam22 · Post by **Liam22** » Thu Mar 04, 2021 6:10 pm

These are 325mm discs.

Reasons:
1. The calipers expect 28mm thick discs and OEM is 25mm. While they would work, I don't want to risk pistons falling out with worn pads.
2. I didn't want to buy new 3 sets of rims - these will still fit under 17" rims
3. Weight. OEM is 8.9kg each, 325mm M3 discs are 7.64kg each. So that's a total 2.5kg saving and met my <£100/kg target.

Liam22 · Post by **Liam22** » Sat Mar 06, 2021 8:09 pm

Liam22 wrote: ↑Mon Feb 22, 2021 10:37 pm Currently dealing with a sheared valve cover bolt.

Clingfilmed the engine while I located a stud extractor and a few new bolts.

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Thankfully it came out without a fuss.

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I don't run an engine cover, so sprayed the Valvetronic unit with BBQ paint to smarten it up a little. New seals, new camshaft position sensor and it seems happy (and leak feee).

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Liam22 · Post by **Liam22** » Sat Mar 06, 2021 8:09 pm

[double post delete]

Liam22 · Post by **Liam22** » Sun Mar 07, 2021 12:14 pm

I got gazzzzz's air inlet scoop fitted yesterday
(see viewtopic.php?t=123799&start=30 )

Had it painted!

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Bumper off, and it slots straight in. Beautiful design - fits like a glove and retains the OEM securing hole.

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Nice to see it peeking behind the grill :8

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LittleZ4 · Post by **LittleZ4** » Sun Mar 07, 2021 6:19 pm

Love that scoop!! Love the whole build to be fair

Vanne · Post by **Vanne** » Sat Mar 13, 2021 4:51 am

Love the scoop!

glad the adaptors worked out great, and bet you were happy the valve cover bolt came out nice n easy. exellent work..

Vanne · Post by **Vanne** » Sat Mar 13, 2021 4:57 am

Liam22 wrote: ↑Tue Dec 08, 2020 12:04 pm I had the opposite problem where the DSC was constantly on! My preference is for ABS on and DSC off which I achieved by disconnecting the steering angle sensor. However, prolonged disconnection seems to cause a soft brake pedal so it's occasionally reconnected.

FTR, my Sport button and DSC buttons both operate as they did before I started removing things.

Any idea how it causes a soft pedal? intresting....?

Liam22 · Post by **Liam22** » Mon Mar 15, 2021 10:17 am

Vanne wrote: ↑Sat Mar 13, 2021 4:57 am Any idea how it causes a soft pedal?

No idea, and it's still not 100% confirmed. My hunch is a bug in the ABS unit firmware. I'll be putting a switch on the dash to control power to the steering angle sensor, as I'm getting too old to be upside down in the footwell.

Replaced the side windows with Lexan this week - another 8.75kg saved. Rear screen is out, but before I fit the Lexan I'm looking at using the access to fit bracing between the boot lid and the bodyshell so that the rear wing is solidly mounted.

Liam22 · Post by **Liam22** » Mon Mar 15, 2021 1:24 pm

Have just found out that the replacement rubber trim (between glass and body) for the rear screen is £88+VAT !!!
£46/metre for some rubber trim

Looks like I'll be cleaning and reusing the original. Thankfully I didn't slice through it removing the old sealant, and it came away in one piece.

Vanne · Post by **Vanne** » Mon Mar 15, 2021 8:46 pm

Lucky!

Liam22 · Post by **Liam22** » Sat Mar 20, 2021 10:09 pm

Liam22 wrote: ↑Thu Mar 04, 2021 5:02 pm I'm looking [...] to fit bracing between the boot lid and the bodyshell so that the rear wing is solidly mounted

Look familiar?

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Another example if why it pays not to throw stuff away. This is the slam panel bracing that normally lives behind the kidney grill. I don't need it there as my bonnet doesn't latch there any more.

Needed shortening slightly, with some new holes at the ends to pickup the existing vertical holes in the boot lid. Also needed to make a custom bracket to replace the striker pin.

Surprisgly it also saved 330g over the OEM catch mechanism.

The boot lid is now rock solid, if somewhat more difficult to open than before!

Toppy · Post by **Toppy** » Sun Mar 21, 2021 3:48 pm

Nice re-cycling!

Liam22 · Post by **Liam22** » Sun Mar 28, 2021 8:54 am

When I put the car back together last year I noticed the rubber boot at the propshaft centre bearing was split. Ignored it at the time, but has been nagging me ever since.

Replacing the bearing was interesting. Half the propshaft only just fits in the press.

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Also bought a centring Bush for the gearbox end. Removing that was not straightforward, but I persevered with the Dremel until I could drift it out.

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Finally, the new boot and we're good to go. Note the alignment marks so that the two halves go back together in the same position. Not sure if BMW balance the propshaft but just in case they do...

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Now back on the car, and with a new Guibo at the gearbox end.

Spriteracer · Post by **Spriteracer** » Sun Mar 28, 2021 10:18 am

I did all three of these recently. Re the centering bush - I found a method on Youtube to remove it without having to cut it up and potentially damage the housing.
You pack the inside of the bush with as much wet blue workshop paper as possible and then with a long socket that is a tight fit into the bush also packed with the paper and a short extension on it to close off the hole through, keep hitting it. It takes a while and you need to re-pack quite a few times as the paper compresses, but it did actually work. It seems to be a similar method to the BMW one of using grease and is a bit less messy. Worth noting also that BMW say the bush should project about 4mm from the housing although it is possible to drive it right in flush. I asked my Indy if this was critical and he thought not, however presumably BMW had a reason for it.

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