2004 BMW Z4 3.0
Discussion
My car has the standard seats, and they are useless. Leather, and quite comfy, but with absolutely no lateral support. Going round corners you had to try to hold yourself upright in the seats.
An easy upgrade is the sports seats from a Z4, but these are very expensive second hand (£1k!). Alternatively, E46 seats are supposed to be a drop in replacement, but I wasn't keen on the look of M3 ones.
I found someone had made up S2000 seats by making adaptor plates up and thought I'd give it a go - but with a twist.
I've always like the Corsa VXR Recaro seats and supposedly (incorrectly, it turns out) they should fit in my Megane if I couldn't fit them here, so I picked up a set. Because they are common they are quite a bit cheaper than you'd expect - I paid £350.
I then picked up another set, because why not. Good job I just finished extending my spare bedroom...
Made adaptor plates up out of 6mm steel. The S2000 seats I'd seen fitted used box section, but I knew that the height of the seat would be an issue so I had to do everything possible to keep them low.
Many grinder discs and drill bits were sacrificed.
I couldn't work out how to use the electric seat runners from the Z4 seats, so decided to use the Corsa runners instead, but they needed quite a bit of modification.
Using the Corsa runners means everything still works, inc the button to fold and slide the seats forward.
I'm aware I'm no pro fabricator...
The channel in the runners was so narrow I even had to grind the nuts down a tad to clear it
Out with the old
In with the new
The good:
The seats are ace.
No less comfy than the standard seats, but so much more supportive.
The car actually feels like it handles better too, probably because you are better connected to what the car is doing.
The bad:
The seats are much bigger than the Z4 ones, which are actually tiny. The Z4 doesn't even have seat airbags - they are in the doors instead.
Because they are bigger, they don't go back as far - but luckily they go just as far back as I need them.
They sit a little higher than the Z4 seats.
However, I think I would've had these problems with any other non-Z4 seats.
An easy upgrade is the sports seats from a Z4, but these are very expensive second hand (£1k!). Alternatively, E46 seats are supposed to be a drop in replacement, but I wasn't keen on the look of M3 ones.
I found someone had made up S2000 seats by making adaptor plates up and thought I'd give it a go - but with a twist.
I've always like the Corsa VXR Recaro seats and supposedly (incorrectly, it turns out) they should fit in my Megane if I couldn't fit them here, so I picked up a set. Because they are common they are quite a bit cheaper than you'd expect - I paid £350.
I then picked up another set, because why not. Good job I just finished extending my spare bedroom...
Made adaptor plates up out of 6mm steel. The S2000 seats I'd seen fitted used box section, but I knew that the height of the seat would be an issue so I had to do everything possible to keep them low.
Many grinder discs and drill bits were sacrificed.
I couldn't work out how to use the electric seat runners from the Z4 seats, so decided to use the Corsa runners instead, but they needed quite a bit of modification.
Using the Corsa runners means everything still works, inc the button to fold and slide the seats forward.
I'm aware I'm no pro fabricator...
The channel in the runners was so narrow I even had to grind the nuts down a tad to clear it
Out with the old
In with the new
The good:
The seats are ace.
No less comfy than the standard seats, but so much more supportive.
The car actually feels like it handles better too, probably because you are better connected to what the car is doing.
The bad:
The seats are much bigger than the Z4 ones, which are actually tiny. The Z4 doesn't even have seat airbags - they are in the doors instead.
Because they are bigger, they don't go back as far - but luckily they go just as far back as I need them.
They sit a little higher than the Z4 seats.
However, I think I would've had these problems with any other non-Z4 seats.
Edited by Jakg on Wednesday 24th August 10:06
First MOT in my ownership - failed on corroded brake pipes, which was an advisory before so not too bad.
Garage replaced them and at the same time got them to replace all the fluid with ATE Type 200, and all the bleed nipples with some new stainless HEL ones as the existing ones were starting to round.
An advisory on worn ball joints so did those, too.
Annoyingly on my Megane a front balljoint is £15 and can be pressed in and out of the arm in situ. On the Z4 you need a whole new arm (£64) - although I went for Meyle HD arms where the balljoints are replaceable in the future (but they are still £30).
Access to the middle bolts on the arm was quite tricky, from the bottom you've got 1/8th a turn max using a spanner, and from above you need to use a bunch of extensions & UJs
The other side access was even worse, which was annoying as rust had made the bolt mega-tight - you can just about make out the nut next to the engine mount.
Even went to Halfords to get some wobble extensions, but just couldn't line it up, so spanner it was - the force of undoing it has literally made my hand swell!
Got them out in the end though
When I changed the wishbone bushes, I was a bit lazy and didn't bother lining the carrier up over the collets on the chassis properly, just started doing the bolts up and thought it'd bring the carrier home on it's own. Nope, it just damaged the threads as it wasn't lined up right...
The top bolt did start to tighten but it then it started to get looser again and that's when I knew I'd done it. Left it at the time but I knew I had to fix it.
Borrowed a Helicoil kit and although I was a bit terrified it turned out ok in the end.
My suggestion is to loosely insert the ball joints first, put the nut on but don't tighten at all. Then get the bush lined up properly over the collets, and put the bolts in tight enough to keep it on them, but loose enough it can move. All the guides say to do the bushes last - but then you end up with very little play so it's a real pain to line up (which was why I rushed it last time).
Note I said the *top* one was worn out. I forgot that and drilled out the perfectly good bottom one first, oops.
Torqued up fine though the second time round so alls well.
My assistant wasn't much help either.
Some of the "vagueness" in the steering has gone and the tramlining has reduced a little too which is good. Now need to work out if I want to get it aligned again (would be the third time in less than a year...)
Garage replaced them and at the same time got them to replace all the fluid with ATE Type 200, and all the bleed nipples with some new stainless HEL ones as the existing ones were starting to round.
An advisory on worn ball joints so did those, too.
Annoyingly on my Megane a front balljoint is £15 and can be pressed in and out of the arm in situ. On the Z4 you need a whole new arm (£64) - although I went for Meyle HD arms where the balljoints are replaceable in the future (but they are still £30).
Access to the middle bolts on the arm was quite tricky, from the bottom you've got 1/8th a turn max using a spanner, and from above you need to use a bunch of extensions & UJs
The other side access was even worse, which was annoying as rust had made the bolt mega-tight - you can just about make out the nut next to the engine mount.
Even went to Halfords to get some wobble extensions, but just couldn't line it up, so spanner it was - the force of undoing it has literally made my hand swell!
Got them out in the end though
When I changed the wishbone bushes, I was a bit lazy and didn't bother lining the carrier up over the collets on the chassis properly, just started doing the bolts up and thought it'd bring the carrier home on it's own. Nope, it just damaged the threads as it wasn't lined up right...
The top bolt did start to tighten but it then it started to get looser again and that's when I knew I'd done it. Left it at the time but I knew I had to fix it.
Borrowed a Helicoil kit and although I was a bit terrified it turned out ok in the end.
My suggestion is to loosely insert the ball joints first, put the nut on but don't tighten at all. Then get the bush lined up properly over the collets, and put the bolts in tight enough to keep it on them, but loose enough it can move. All the guides say to do the bushes last - but then you end up with very little play so it's a real pain to line up (which was why I rushed it last time).
Note I said the *top* one was worn out. I forgot that and drilled out the perfectly good bottom one first, oops.
Torqued up fine though the second time round so alls well.
My assistant wasn't much help either.
Some of the "vagueness" in the steering has gone and the tramlining has reduced a little too which is good. Now need to work out if I want to get it aligned again (would be the third time in less than a year...)
Good work mate, enjoyed reading this stuff. Im the dubiously proud owner of an e93 with the N53 3.0 engine, so it's kinda related to yours in that it's a convertible, a BMW and can break in very expensive ways at any time for no reason
It looks lovely though and is great to drive, same as yours. The e93 doesn't tramline at all though, doesn't that do your nut in?
It looks lovely though and is great to drive, same as yours. The e93 doesn't tramline at all though, doesn't that do your nut in?
dave_s13 said:
The e93 doesn't tramline at all though, doesn't that do your nut in?
Yes! Not my daily driver, and not something I'd choose for a long motorway journey so I'll tolerate it.I've got a new pair of (non-runflat) tyres in the shed but I feel silly putting them on as the runflats on the front still have >4mm.
Hopefully that should cure it.
On the topic of tram-lining I've had 4 BMWs with run-flats, and 2 that had non run-flats.
Neither of the E46s without run-flats ever did it.
Both Z4s on Bridgestone RFTs did it a lot!
My E87 and E91 on Pirelli RFTs did it a bit, but nothing like as bad as the Z4s.
When my current Z4 needs tyres I'll have to decide whether I want to stay on RFTs - but even if I do they won't be Bridgestone!
Neither of the E46s without run-flats ever did it.
Both Z4s on Bridgestone RFTs did it a lot!
My E87 and E91 on Pirelli RFTs did it a bit, but nothing like as bad as the Z4s.
When my current Z4 needs tyres I'll have to decide whether I want to stay on RFTs - but even if I do they won't be Bridgestone!
Had some of the same tramlining issues on my old E85 and funnily enough, similar issues with a garage's alignment settings for sport and normal suspension.
Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.
I also had the alignment done properly by a local Lotus specialist after the Hunter machines had messed the rear alignment up to the point that going over a wet man hole cover would cause the rear to drastically throw out sideways. I'd recommend finding someone that will road test what they've done and apply some experience to it rather than just making the lights go green then hoping for the best.
Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.
I also had the alignment done properly by a local Lotus specialist after the Hunter machines had messed the rear alignment up to the point that going over a wet man hole cover would cause the rear to drastically throw out sideways. I'd recommend finding someone that will road test what they've done and apply some experience to it rather than just making the lights go green then hoping for the best.
SamJB said:
Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.
It looks like only the front fits, not the rear - I'm wary of stiffening up the front at the expense of increasing understeer. Not that I have a problem with that at the moment.Edited by Jakg on Tuesday 5th March 17:26
Jakg said:
SamJB said:
Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.
It looks like only the front fits, not the rear - I'm way of stiffening up the front at the expense of increasing understeer. Not that I have a problem with that at the moment.I feel you'd need far more than an anti roll bar on the front of these to stiffen it enough to promote understeer.
Great progress. Can't help but think you are still missing a trick though.
Fitting a new set of good tyres is the most cost effective improvement you can make, especially if you are junking runflats.
It's all a bit of a crapshoot until you do that. A new set of F1 Assym 3s transformed my Z4 3.2. Steering, ride, traction, tramlining....
Not expensive either!
Fitting a new set of good tyres is the most cost effective improvement you can make, especially if you are junking runflats.
It's all a bit of a crapshoot until you do that. A new set of F1 Assym 3s transformed my Z4 3.2. Steering, ride, traction, tramlining....
Not expensive either!
Jakg said:
I've just got to remember that this is supposed to be a cheap entry into the world of convertibles and resist the urge to start modifying it...
I’ve always been contemplating a brake upgrade.As standard it has 300mm discs and single-piston calipers at the front
Looked a bit weedy for a 155MPH car. My diesel Megane has Brembo 4-piston calipers from the factory!
There were a couple of routes available:
1 - E46 330i / Z4 3.0si 325mm
Straight fit, easily available, but because of their popularity the carriers + calipers sell for about £100
I’ve done this upgrade on my old MG ZT (it uses E46 brakes) in the past as was impressed.
But they are still single-piston and I thought maybe I could try something different.
2 - E82 135i 6-pot
I liked this idea, but simply couldn’t find any. They were only ever fitted to the E82 135i, which isn’t that commonly broken.
3 - Porsche Brembo Calipers + Brackets
Much more like it, but the brackets aren’t cheap and the popularity means the calipers aren’t either.
4 - F30 M-performance Brembo Calipers
Came across someone fitting them to an E46 - https://forum.e46fanatics.com/showthread.php?t=107... and piqued my interest - bolt on and eaily available.
Picked these up for a little over £200 because they’d been painted red absolutely terribly.
After some wire wheel action it turns out they are supposed to be silver.
Because they are only a few years old they were in very good condition.
I also got a spare set of rear calipers to refurb.
This was harder than it sounds, because there are a handful of calipers or carriers used on E46/Z4s, but in various configurations. I think it ended up being something daft like an 02-04 325i/328i but nothing else fitted!
Being about 15 years old they were in way worse condition, rust etc. I tried a wire wheel and my ultrasonic cleaner but it wasn’t making much difference.
Ended up trying electrolysis - https://www.the75andztclub.co.uk/forum/showthread....
The layer of scum and slime that formed on top was absolutely disgusting.
They didn’t come out perfect, but most of the rust was easily removed after.
The car had red calipers fitted which I’ve never thought was a great look on a dark-red car.
I’ve spray painted calipers in the past but never really been happy with the finish, so I tried a different kind of kit this time, from BCS Autotmotive - https://www.bcs-automotive.co.uk/shop/brake-calipe...
Went for gunmetal, this is the ad picture…
Primed
First coat
Second coat
Thought they looked a bit weird plain so went for some stickers. I know this will be divisive!
From the factory they can come as part of the “M Performance Brakes” pack with the //M sticker so I don’t feel *too* bad about it.
They are supposed to be upside down (or at least, thats how BMW do it) on one of the calipers.
Lacquer over the top and then baked
Unfortunately - disaster
I think some brake fluid leaked out while in the oven and ate off the paint. Luckily as it’s brush-on, localised repairs were very easy.
I overhauled the rear calipers (seals, dust boots, sliders, slide bushes), but left the fronts as they were so new.
Overall the kit wasn’t cheap, especially not when I had to buy primer and lacquer on top. And being a brush-on kit, you get brush marks. That works ok for a metallic gunmetal finish, but for a flatter colour I doubt it would. Not sure what I’d do next time!
Then it was fitting time.
Straight off the bat I had problems, the disc retaining screws both rounded off despite doing everything properly.
Ended up using a chisel to tap them out.
I’m using 345mm Z4M / E46 M3 CSL front discs. I got a second hand set in case they didn’t fit as they are quite pricey. I’ll try to get a new set later on.
The pad retaining pins I’d bought didn’t fit so I had to use the original ones - note how the (new) top pin hasn’t gone across anywhere near as far as the (old) bottom one
It didn’t have a chamfer on the end so it didn’t lock in place, either.
I initially used F30 brake hoses as per the guide but the length was too long and the grommets weren’t right so I get a set made up by HEL.
I couldn’t get the rear hoses fitted properly as the unions on both sides were totally seized and just rounded off.
Ended up replacing the whole lot with braided hoses at the back, too.
When reassembling I accidentally torqued the rear carriers up to 110nm (as per the fronts), not 65nm, so needed new bolts, too. Luckily they came out without too much hassle.
When trying to bleed the brakes my Eezibleed started leaking again (this is my second, and has already had new o-rings to combat the last leak!).
I splashed out on a a Sealey bleeder - half the reviews said it was fantastic, half said it leaked. Mine turned up and leaked - until I found a tip online to put silicone grease around the cap and it was fine. Way easier than trying to deflate a spare tyre to the right pressure.
Flushed another litre of ATE Type 200 brake fluid through and bleed the clutch as well in case I had any contaminated fluid.
I had to fit larger spacers than I’d like to clear the calipers
I had a horrible moment when I put the wheels back on as they stuck out miles!
Luckily when back on the wheels it turned out ok, but I will look into ways to bring them in a bit
Only fitted them the other day so rubbish pictures. A little too early to give lots of feedback - but they do at least work!
Edited by Jakg on Wednesday 24th August 10:07
Jakg said:
I've just got to remember that this is supposed to be a cheap entry into the world of convertibles and resist the urge to start modifying it...
This really isn't going well!It's got standard M-sport suspension, but is 15 years old. It could do with a refresh, but a Bilstein B8 kit is about £600, and OE parts even more so.
I found this on eBay and knew I had to get it.
KW V1 coilovers, about 4 years old - £1,200 RRP! I got them for a fifth of that.
First off, big shout out to my latest toy - a big battery impact gun.
I've tried some cheap Lidl ones and they were... ok. I use a Bosch impact driver a lot but it doesn't have the power to crack stuff off. This thing claims 1600nm of torque so I shouldn't have that problem...
The shock bolt looks looked like it might be a problem, but came out with no effort at all.
In fact getting all the old suspension out was very very easy - way easier than my Megane. Only annoyance was having to remove the rear "parcel shelf" to get to the rear shocks which is very awkward from inside the boot.
Out with all the old stuff.
With the suspension out I also had a look at the rear arm mountings - the thing the socket is on in this picture
They didn't seem to have any play on the car but I changed them anyway.
Officially you need to remove the arm but if you bend back the dust shield (and remove the disc obviously) you can get to them.
I've done this in the past on my MG ZT and really struggled - the threaded rod + washers did nothing and I had to use my hydraulic puller.
This time there wasn't enough access for the puller so I had to settle for my ball joint press - basically a big C clamp. 32mm 12-point socket as a pusher and a bit of tube on the arm itself.
It was a bit of a struggle, ended up using the impact gun to get them in / out and i'm not sure the press would do it again but got them all out.
The upper mountings are ball joints (on the left in the picture).
The lower ones are just rubber bushes (on the right).
The M3 / Z4M uses the ball joints on the lower, too - but the rest of the Z4 / E46 range don't, apparently for cost reasons.
Off the car it was clear the ball joints had a little play and the bushes looked past their best.
I fitted ball joints in both the upper and lower parts, and fitted them using the press in reverse.
Don't look exciting fitted though.
I also fitted rear strut reinforcement plates, although I'm not sure if they are any good
My assistant has a lot to learn
All back fitted
I replaced most of the nuts and bolts I touched, too, as well as the top mounts.
I also had a go at adjusting the handbrake as I had to wind the shoes back when I took the disc off and didn't count how far I'd done it - it's a little better now but it's still rubbish. I think the mechanism on one side might need an overhaul.
Had it aligned and everythings back to where it should be, except the rear camber that won't adjust on one side - I had a go (to try at least put it back to what it was before) when I was putting it together and couldn't do it, either. So I'll get a new eccentric bolt / nut etc and try it again.
I also managed to get into an argument at the garage as apparently the rubber bushes at the back keep moving when they tried to free off the camber bolt.
I explained they are ball joints, but apparently they aren't - they are rubber bushes. They helpfully pointed out ball joints have a ball in them and move around.
What would I know, I only fitted the things...
Ride height wise my aim is basically stock - I've had a go but need to let it settle before finishing it off.
Early days but it drives better - I was expecting horrible stiffness but it rides better than my Megane on stock (refreshed) suspension.
Edited by Jakg on Tuesday 29th October 22:19
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