What have you done to your E89 today

So some bank holiday fun.
1. Touch in some paint chips.
2. Hopefully replacing a fuse gets the wing mirror adjusters and heaters working both sides..
3. See if minute application of super glue using cocktail sticks on some very small wind shield chips, hides them.
4. Try to track down why my iDrive screen is random whether it shuts down at shutdown. Says obd some mech. problem. Might bad connector.
5. eBrake on light flickers or not at all. Tidying some wiring under dash resulted in it not coming on at all, seems like loose connector pin somewhere.
 
RobbiZ4 said:
The Z4 will drive much faster due to the reduced weight. 🏎️
Click to expand...
Hi Claude..if I had a carbon fibre boot lid on my Z4 E89 35is how much faster would it accelerate to 60mph and 100 mph ?

1:15 PM
Claude responded: Short answer: barely measurable.

Calculated marginal acceleration gains from weight reduction physics
Calculated marginal acceleration gains from weight reduction physics
Short answer: barely measurable. The honest numbers below.

Mass saving assumption

OEM E89 steel boot lid: ~15–17 kg (estimate — worth weighing yours for the book if you want to be precise, since the E89's lid carries the hardtop latch hardware so it's heavier than a softtop's). CF replacement: ~5–7 kg. Realistic saving: ~10 kg, or 0.66% of a 1,505 kg kerb weight.

Physics

0–60 on a 500 BHP RWD is traction-limited through 1st and most of 2nd, so mass reduction barely helps in that phase. 0–100 spends more time in the power-and-drag-limited regime, where every kg counts proportionally. Add the rear-axle complication: removing weight from over the driven wheels actually trims launch grip very slightly, partially offsetting the gain.

Rule of thumb that fits real-world testing: time reduction ≈ 0.3–0.5× mass reduction percentage for 0–60, and ≈ 0.5–0.7× for 0–100.

Estimated gains

Baseline With 10 kg out Gain
Stock 35is 0–60 4.7 s ~4.68 s –0.02 s
Stock 35is 0–100 ~10.8 s ~10.74 s –0.05 s
Your TTE500 0–60 ~3.8 s ~3.79 s –0.01 s
Your TTE500 0–100~8.5 s~8.46 s–0.04 s
 
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1. Paint chips done..for now.
2. Applying some logic, mirror adjust and heaters on separate fuses, but neither working.
Contact cleaned the plugs to the main computer right side, hoping to cure parking brake light and mirrors.
Sure enough the crappy connector to door switches again behind the door card was the problem.
Removed, contact cleaner, replace, working.
3. That was pointless exercise.
4. Never had time to look at iDrive.. Spent at least 2 hours again trying to align the bonnet gap where it meets right wheel arch.
Finally black plastic thing broke. Struggling to get it to align, removed black thing, cable tied. Cable ties did the trick, almost set the gap and
flush.
 
Summer is here so time to change from the winter 5W-30 Mobil 1 ESP which has done about 3k miles over the winter/spring for the Fuchs Pro Race 5W-40 which is better for those TTE500 turbos on a hot summers day. But not so good for long life use so 5k-6k before the winter oil goes in.

Fresh Mahle filter comes with o rings and a new drain crush washer.

All went well apart from muppet here putting the fresh filter housing o ring on the top groove as opposed to the middle groove..result light weep from said housing with engine running!..Good job I checked.

Previously there was some oil in the inside valley of the cam cover...most armchair pundits proffered it was a gasket / cam box leak. I doubted it simply because it look clean and I theorised that it was misdirected oil from an earlier fill / top up.

Anyway paranoid as I am., took of the cosmetic cover to revisit..maybe just maybe the vaguest of oil / dust near the turbos but no obvious leaks.

Ran the engine for quite a while with cosmetic cover off and no sign of leakage.

Ready for a couple of runs this month then Iberia for June!IMG_0347.jpegIMG_0347.jpegIMG_0348.jpegIMG_0349.jpegIMG_0352.jpegIMG_0350.jpegIMG_0340.jpegIMG_0344.jpeg
 
Forgot while door card off fitted some noise insulation foam to inside of doors. Has it made a difference, not sure, ears feel bunged up last few days.
All the clips were broke so ordered 20 for £1.98.
 
B21 said:
Hi Claude..if I had a carbon fibre boot lid on my Z4 E89 35is how much faster would it accelerate to 60mph and 100 mph ?

1:15 PM
Claude responded: Short answer: barely measurable.

Calculated marginal acceleration gains from weight reduction physics
Calculated marginal acceleration gains from weight reduction physics
Short answer: barely measurable. The honest numbers below.

Mass saving assumption

OEM E89 steel boot lid: ~15–17 kg (estimate — worth weighing yours for the book if you want to be precise, since the E89's lid carries the hardtop latch hardware so it's heavier than a softtop's). CF replacement: ~5–7 kg. Realistic saving: ~10 kg, or 0.66% of a 1,505 kg kerb weight.

Physics

0–60 on a 500 BHP RWD is traction-limited through 1st and most of 2nd, so mass reduction barely helps in that phase. 0–100 spends more time in the power-and-drag-limited regime, where every kg counts proportionally. Add the rear-axle complication: removing weight from over the driven wheels actually trims launch grip very slightly, partially offsetting the gain.

Rule of thumb that fits real-world testing: time reduction ≈ 0.3–0.5× mass reduction percentage for 0–60, and ≈ 0.5–0.7× for 0–100.

Estimated gains

Baseline With 10 kg out Gain
Stock 35is 0–60 4.7 s ~4.68 s –0.02 s
Stock 35is 0–100 ~10.8 s ~10.74 s –0.05 s
Your TTE500 0–60 ~3.8 s ~3.79 s –0.01 s
Your TTE500 0–100~8.5 s~8.46 s–0.04 s
Click to expand...
Or a subscription to weight watchers?
 
Remember at school the boring physics experiments rolling a trolley down a slope with a paper tape and a pencil marking dots...
 
Recently helped a 'client' assess and but a 2009 35i.

The interesting aspect was that despite having 12 keepers in the time there was a very comprehensive paper trail.

The post warranty costs of over £5,300 included injectors, gearbox leaks, ignition coils, cracked camboxes, coolant pumps and thermostats.

I've written it up as a case for my book.

An extract here.. https://www.dropbox.com/scl/fi/mgns...hase.pdf?rlkey=thevkgklf3u2bvnl0tlkuzkw2&dl=0
 
So..adjustable camber front and rear on E89s.

By default its very limited, especially on the front.

Geometry wise the rear has a disproportionate camber compared to 'classical' settings to ensure a very tame understeer effect when a muppet boots it on a slippy surface.

In my case with over a dozen significant chassis modifications (M3 control arms, Ohlins dampers, uprated springs, H&R ARBs, Hardrace RTABs and rear bushes, Powerflex rear camber arms, wider wheels, wider tyres, Meyle HD tie rods, adjustable drop links, Quaife LSD etc) the stock GEO settings are not suitable.

What it needs now is much more front camber to stop it understeering and about a degree more rear camber than front....probably around 1.5-2.0 degrees on the front.

I did use some traditional adjustable camber / castor top hats..but..they are fabricated entirely in metal and result in significant medium frequency vibration transmitted into the cabin..as seen on the dashcam video where you can see the camera resonating with the NVH injected by them.

I went back to a set of Meyle HD top hats..but there's barely any adjustment..about 0.5 camber max on the front.

However I did find these babies.. https://k-mac-camber-kits.com/produ...-m-front-cambercaster-strut-tops-192416-1j-3/

These are fully adjustable..and..use an elastomer mount to help isolate NVH as per originals..I'll probably fit them over the winter as the seasonIMG_1329(1).JPGIMG_1328(1).JPGIMG_1326(1).JPG
 
Managed to sort out the main key and now have 2 operational keys again, luckily it was just a new case and a new rechargeable battery and new blade cut. All for £50. A lot cheaper than BMW wanted.
 
Replaced the aerial with a stubby, swapped the gear knob for an M Performance one, and got new tyres fitted at the front. Up a profile and ditched the runflats- a lot more comfortable now!

Sitting perfectly now- no other plans!

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