I finally bought a Z4 - Ownership thread!

[Usel]

New front discs are on. It looks like I got my money's worth out of the old ones, as they were the worst warped discs my mechanic has ever seen!

Unfortunately, it appears that my heavy braking foot has also taken the Ferodo DS2500s down too. Were I keeping the car (more on that shortly!), I'd probably go to Winmax W5s as I've heard good things in combination with Brembo HC discs. Just to get me back on the road again, the mechanic has fitted OEM-spec pads.

I've had a very kind offer from Usel to go and test out an E89 seat in my car, to see whether it alleviates the sciatic pain I've been suffering on longer drives. Plan is to take him up on that (thank you!) and test out a seat for a couple of weeks when I get back from my annual pilgrimage to a whisky festival on Islay next week.

I plan to leave the Tesla and Discovery as often as possible, and take the Z4 on as many mundane drives as possible to see whether it solves my problem. If so, then we're back in the game, and back on track with the project. aper:

If the E89 seats do help then you can get seats with lumber support. They are harder to find but will help support your lower back on longer journeys.

 

[Usel]

A very kind offer, but I suspect it's not going to solve the problem of legroom and my inability to stretch properly. My knee doesn't fit between the door and steering wheel, so even with cruise on I can't move my right leg sufficiently to stretch it.

Been having a think about your predicament and have you thought about removing the door pull handle and having a pull strap?

To see if this would help before investigating into a custom strap just remove the handle and pop the window down to pull the door closed.

It could just be a case of removing the handle for long drives and pop it back on for normal use.

 

[DaveP]

A very kind offer, but I suspect it's not going to solve the problem of legroom and my inability to stretch properly. My knee doesn't fit between the door and steering wheel, so even with cruise on I can't move my right leg sufficiently to stretch it.

Been having a think about your predicament and have you thought about removing the door pull handle and having a pull strap?

To see if this would help before investigating into a custom strap just remove the handle and pop the window down to pull the door closed.

It could just be a case of removing the handle for long drives and pop it back on for normal use.

In all honesty, a lower seat base would be a huge step forward. My old electric SE seats went lower than my current manual Sport seats, which is what is causing the door/wheel/knee interface. If the E89 seats can solve that (in tandem with a smaller wheel), then we're onto a winner.

 

[Usel]

A very kind offer, but I suspect it's not going to solve the problem of legroom and my inability to stretch properly. My knee doesn't fit between the door and steering wheel, so even with cruise on I can't move my right leg sufficiently to stretch it.

Been having a think about your predicament and have you thought about removing the door pull handle and having a pull strap?

To see if this would help before investigating into a custom strap just remove the handle and pop the window down to pull the door closed.

It could just be a case of removing the handle for long drives and pop it back on for normal use.

In all honesty, a lower seat base would be a huge step forward. My old electric SE seats went lower than my current manual Sport seats, which is what is causing the door/wheel/knee interface. If the E89 seats can solve that (in tandem with a smaller wheel), then we're onto a winner.

Hopefully find out tomorrow

 

[DaveP]

Well, that was an eventful evening. I've written more about it in another thread here, but I'm hugely grateful to Usel for swapping in an E89 Sport seat in the pouring rain (I held an umbrella...) outside his house yesterday evening using his own designed adaptor plate.

Having driven the 35iS a few weeks back, I knew the seat was going to be more comfortable than the E85 Sport seat. And while it took a little bit of fiddling on the drive home (the E89 has such a weird way of adjusting the base angle), I managed to get it to a position that not only gave me more legroom, but also felt a lot less 'pinched' than the E85 Sport seat. I felt like I sat 'in' the seat, rather than 'on' it.



If I was to compare the two, I'd say that the backrest waist bolsters offer a very similar level of support, and I've never really seen the benefit of the upper 'wings' on the E85 seat. The biggest gamechanger is the base bolsters, and I can only describe the E89 seat as the sweet spot between the E85 SE 'park bench' and the discomfort of the E85 Sport seat.



It's rare that BMW get ergonomic design badly wrong (the E39 and E46 in Sport trim are pretty much perfect for me), but as a bigger guy (6ft3, 110kg+) the E85 Sport seats are bloody awful. With these E89 seats, I not only seem to have more legroom, but I also sit low enough to fit a helmet with the roof up too.

I'll report back again in a few days, but rumours of the demise of my Z4 project might be a bit premature...

 

[Usel]

Your description of the E89 M-Sport as being a halfway point between the two E85 seat's is quite accurate imo

So far it's seems positive, further testing will hopefully identify if you need the lower back inflating support which can be found on some E89 seats.

Hopefully you can start to enjoy the car now

 

[Mr Tidy]

Let's hope E89 seats are the answer to your problem then Dave.

 

[DaveP]

Let's hope E89 seats are the answer to your problem then Dave.

I never should have bloody bought those Sport seats after I sat in yours and declared them uncomfortable.

 

[joelvdrZ4C]

Oh that’s interesting! I’m in standard seats now, tried the M seats for a week and removed them cause my knees are against the dash. How’s that in these? Are they lower?

 

[Usel]

Oh that’s interesting! I’m in standard seats now, tried the M seats for a week and removed them cause my knees are against the dash. How’s that in these? Are they lower?

It's hard to tell the exact reason why there is more room, maybe the seat base goes a little lower at the back, the front does go lower but not by much.

I am 6ft 1" and around 15st and I have more room than the E85 M-Sports. E89 m-sports seem to suit people who are wider.

I need to update this thread as it has changed a little bit for the best way to install them but here is a guide:

https://z4-forum.com/forum/viewtopic.php?t=140545

I also installed the seats in this person's car who also found there was more room:

https://z4-forum.com/forum/viewtopic.php?t=142189

 

[DaveP]

Oh that’s interesting! I’m in standard seats now, tried the M seats for a week and removed them cause my knees are against the dash. How’s that in these? Are they lower?

First impressions are that you can move them further back than the Sport seats, due to the backrest shape. Oddly enough these seem to fit even better into the recess than the Sport seats, which squeaked against the plastics when fully back. My legs are definitely lower, if not loads straighter, than in the Sport seats.

The biggest change for me (and my hefty backside) is that the bolsters on the base of the Sport seats are so aggressive and wide that you're artificially raised. Even with the base in its lowest position, I still didn't have loads of clearance under the wheel and my upper legs felt 'pinched'. The more relaxed bolsters of the E89 seats mean that my legs rest more naturally (no 'pinching'), with the added bonus that sitting more 'in' the seat (rather than 'on' the bolsters) gives more clearance under the wheel.

Having nearly been ejected from my SE seats during a tankslapper on an airfield tuition day, I knew I needed something with more lateral support. It just turns out that Sport seats aren't ideal, and definitely aren't comfortable for me. These feel like the happy medium.

 

[DaveP]

It's easy to see where BMW might have got it wrong when you look at the E85/6 Sport seat next to something comparable.

Z4


S2000


The base bolsters on the Z4 are so much 'fatter' than those on the S2000, which means they reduce the base cushion space by quite a lot more for those of us with more generous posteriors.

When you compare the two against the E89 Sport seats, it's clear to see that the E89's base is much closer to the S2000's in terms of shape and design.

 

[DaveP]

It almost looks like BMW took the base bolster design from the much wider E46 M3 seat and transferred it over (with a few tweaks) to the narrower Z4 seat.

 

[DaveP]

We're back in the game!

I've decided to go ahead and gratefully accept Usel's offer of selling me his E89 seats and adapter plates. He even offered to completely repaint the leather for me, which I declined as his standards are quite a long way higher than mine!

To celebrate keeping the Z4, I've obviously gone and done a bit of spending.

Ordered this beauty of a steering wheel (in 320mm flavour) and the E46 Momo boss. This should really help with leg clearance under the wheel, making getting in and stretching on longer drives a doddle.


Contacted Ian @ Carbotech to ask him to make up a set of XP8 pads in Z4 300mm fitment. I hope to god they squeal a bit less in normal use than they did on my Mini, because they are borderline impossible to fade on track. Going to team them up with a set of Brembo High Carbon discs and keep my newly-fitted OEM pads in my trackday toolboox as emergency spares. Might look into a bit of brake cooling too.

Booked a trackday in July with my usual group of mates at Bedford on the GT layout. For me this is the best track in the UK to properly explore the limits of your car. It's flat and well-sighted, and it has a real mix of slow and fast corners with loads of runoff. It's also the very first place I ever did a trackday, in the Peugeot 206 GTi that I shared with one of my trackday group 7+ years ago.


Finally, I gave the poor thing a wash - its first since I got back from the Ring in April. I still need to do the embarrassingly dirty boot and door shuts, but it at least looks broadly presentable now.


Everyone likes a happy ending (and not the type you normally tip a small Thai lady for either).

Outstanding items on the To Do list before the trackday in September are:
1. Fitting a shorter diff. Current fave is the 3.46 so the engine isn't screaming on the motorway.
2. Getting a gauge fitted to show oil pressure and temp. I'm a bit concerned in general about oil temps, so might even go the whole hog and fit a thermostatic oil cooler somewhere.

 

[Mr Tidy]

I'm glad you've solved your seat problem, now you can just focus on the other mods.

 

[DaveP]

Oh god, it's just so beautiful. And, on the plus side, being about 40mm smaller than the stock rim, in conjunction with the new seats I get a lot more space to stretch my right leg.

 

[DaveP]

Again, I owe a debt of gratitude to Usel for his support and help with all of this, but the E89 seats are finally in and I'm very happy!



We managed to strike a deal whereby he would take my (non-working) powerfold mirrors in part payment for the seats, so we set about dismantling the door cards on the pavement outside his house. Of course, some moron had clearly been in there before, and they'd made an absolute shambles of the vapour barriers. Without new parts to hand, and not wishing to have the door cards off again too soon, I cued the A-team music and went to town in the only way I knew how - bodging.



Still, if it's stupid and it works, maybe it's not stupid after all?

We also spotted that my early (2003) car was pre-wired for the 10-speaker system door speakers, so I might have a look into what level of faff is required to drop those in for a bit more volume.

New pads are being made up as I type this, and Brembo HC discs have arrived. Next steps are to get them fitted with some high-temp grease/paste, and get the car over to enuff_zed to see whether he can work his coding magic on my airbag light. The steering wheel continues to delight, and I can't believe it took me so long.

Then it's a case of one or two more jobs (and probably a quick service) before September's Ring trackday:
1. What to do about oil temps? Flying blind doesn't fill me with hope, and the faff of fitting a thermostatic cooler bothers me similarly. Might just plumb in a temperature gauge on the Vanos banjo and be done with it.
2. Diff time. Current fave is a 3.46, but I need to do some maths and figure out what the impact to cruising speed/revs would be if I went all the way up to a 3.64 (as fitted to the 3.0si auto and 2.5i auto).

 

[DaveP]

If anyone cares (and is still reading), I did the maths on the gear ratios thing.

For a cruising speed of 75mph, I'd be at roughly these revs with the following ratios (25" tyre and 0.85 ratio 6th gear):
1. My 3.07 OEM diff: 2650rpm
2. A 3.46 diff from the 3.0si: 3000rpm
3. A 3.64 diff from a 2.5i auto: 3100rpm

Given how small the difference is between the latter two, I think I'm just going to jump straight to the 3.64 and see how it goes. The standard diff is WAY too long, and even though it's got plenty of torque it just makes the car feel so sluggish. YOLO, I guess.

 

[Micke]

Nice to see a fellow MT member around here I remember following the topic about your 53 a while ago.

 

[DaveP]

Nice to see a fellow MT member around here I remember following the topic about your 53 a while ago.

Ah, the Mini I basically ruined. Great days. At least it kept me busy during COVID lockdowns.


Trying my hardest not to go down the same road with the Z4, as it's still pretty usable despite the changes.