Is it possible to make the z4 a proper drivers car?

[itguy]

Ok, so having lived with my 3.0 SE for a while now I've been thinking.

It's not really the kind of car that makes me just want to go for a drive. It's not really a proper sports car in my opinion, more of a GT.

Having recently put proper non run flats on that has helped but I can't stop thinking that all the component parts seem to be there (RWD, decent engine and box, good brakes, wheel at each corner, reasonably light etc) but it doesn't feel exciting in the same way a similar age boxster S or Elise (probably unfair comparison) does. Haven't had an MX5 but I bet if feels more exciting / involving than the Z.

I'm really not looking to have a go at it or change it, but I'm really interested in what options there are to improve what is a good car into a decent sports car.

Initial thoughts -

Geometry - this can play havoc with driving feel and presumably the standard BMW setup is really conservative. Anyone played with any other geo's and if so, what you found / what you got?

Coil overs - ok, I admit that I've not researched this yet but I'm wondering if there is any significant suspension upgrades out there other than just lowering springs (can't see them changing the handling much and I like the clearance the car has as standard - I've had an Elise before with 110F and 120R and it's a right pita)

Steering - I know the M comes with hydraulic pas but I'm not considering going that whole hog. Anything else that can be done? I know it's placebo but was considering getting my spindly old wheel refurbished by Royals to be a M thickness

Engine remap - maybe help with throttle response etc - although sport makes it more twitchy i don't have a huge complaint with it how it is.

Engine / gearbox mounts - any benefit in firming things up? Don't really want loud droning in the cabin though...

All of this thinking has come about because my wife has just ordered a new Fiesta st3 with mountune - which is a sensational car and does make you feel like are just going to nip out the long way to get milk. It has the most incredible ability to steer on the throttle and it feels just electric to drive - even if it doesn't do 4 seconds to 60. A truly epic machine.

 

[Adamski]

I loved my 3.0i - any excuse to take it out, I would go for it

 

[MrPT]

Short throw, weighted gearknob and thicker steering wheel?

The steering feel is a big part of what you're talking about. Not a lot you can do about that.

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[GuidoK]

As I have changed about every aspect about the Z I have a pretty good view on what to do to make the car come 'more alive' and feel more like a sports car.

first of all I don't think the z4 is more of a gt; for that it is not comfortable and well build enough.
To me a sportscar is more about handling and a gt is more about cruising in comfort with (if possible) a lot of power.

If you want to use the z4 as a 'sports car' first of all you have to install a lds.
This will give you more grip on the moments that you need it the most. And some sideways action There's no need for power or handling if you don't have traction. No traction=no foreward motion

I also think that thicker anti rollbars and polybush the complete frame was a nice upgrade. It gives more control and makes the chassis more lively.
If you do this yourself it's a really cheap upgrade. If you're not handy with the spanners... it's pretty expensive as it takes some hours to install.
But I think the rollbars and a complete polybush make a bigger impact on the handling (and preciseness) than for example a (quality) coilover set.
I was amaized on how big an impact that had on the car. The front side polybushing gives more feel in the steering, but polybushing the complete rear axle gives a lot of feedback on what the complete driveline does.
A good coilover set will improve handling, but mostly the handling on bumps. It allows you to tweak the suspension how it copes with bumps&grip. Stiffer springs will reduce bodyroll, but not as effectively as anti rollbars. Good coilovers will have better damping (mine have seperate adjustable bump&rebound so more options of fine tweaking), so it allows you to ride a stiffer spring without getting completely bumped out of the car.

I'm still going to experiment with wheel geometry, especially reducing the casterangle to get more initial bite going into slow sharp corners. I'm still looking in the possibility to do it on the control arm side instead of the more ususal top strut bearing side.

Stiffer engine/gearbox mounts are a nice upgrade as it is cheap and foremost very easy to install (relative to for example polybush your frame or installing a lsd). It will give some more stiffed weight in the car, but I don't think it gives that much of an impact on the physical handling of the car. It's more an upgrade on what you feel (on short sharp corners you can feel the engine wiggle a bit and it solves that).

More power is more fun obviously, but I think what a 'sports car' defines is the chassis/handling. There are lots of fast GT's/saloons that are way faster on the highway (m6, c63amg etc), but on a nice mountain pass it's completely the other way round... they don't stand a chance :wink:

 

[Yorkie Z]

I love driving my 3.0 Z4 but it is only a weekend car.

As for fun. I had mine for about a month then stuck an LSD in it as I thought the open diff was sooooooooooo boring after coming from an M3. Now I couldn't be happier. Cheap to run and lots of fun. Would like it a little faster but that's always the way with any car once your used to it.!!!

 

[andya1]

I adore driving my 3.0 I feel totally involved with it and it always feels special driving it, also I just fitted a Stormwerkz v1 gear knob which has transformed the gear change I LOVE driving this car

 

[ZedFourM]

Haven't had an MX5 but I bet if feels more exciting / involving than the Z.

You bet correctly!

Have you tried a Z4M? BMW have always (well, until the latest generation of so-called "M" cars) focussed the M variants at what you call proper drivers, whereas some of the other models are aimed at other sectors of the car-buying public.

 

[Anonymous]

I also think that thicker anti rollbars and polybush the complete frame was a nice upgrade. It gives more control and makes the chassis more lively.
If you do this yourself it's a really cheap upgrade.

I'm looking to sort out my handling, so could you tell me where did you got the thicker anti-roll bars from? Specifically the rear as I think i'm going to stick the front from M3 in.

 

[itguy]

Thanks for the helpful replies.

Regarding the stiffer ARBs and polybushes, what type did you use and did you need a press to extract / install any? I'm happy with spannering but don't have a press currently.

 

[GuidoK]

The old ones you always have to press out. With a press or with a bushing extractor.

Bushings for the arb's are not pressed but all others are. With the right tools the press/extracting alone can be done in less than 15min/bushing. (at least thats what it took me). But you have to get the rear axle off the car etc (although that's not such a big deal as that it sounds)

I have a front m3 arb and a rear h&r arb (adjustable).
Imho the rear is more important because I think the rear on the stock z4 has a tendency to be a bit light (so the rear squats in the corner when cornering&accelerating)
The front can do with a stock m3 arb (26mm) because the front is a lot lighter than the e46m3/z4m because the engine is a lot lighter (aluminium). For the m54 that's 50kg or so, and for the n52 maybe even more.

For the rear h&r arb only 2 settings are tüv approved. There is not much room for the drop links to wiggle/adjust, so the third setting doesn't fit as well (it's a too tight fit maybe?). I use the middle setting.

 

[Anonymous]

The old ones you always have to press out. With a press or with a bushing extractor.

Bushings for the arb's are not pressed but all others are. With the right tools the press/extracting alone can be done in less than 15min/bushing. (at least thats what it took me). But you have to get the rear axle off the car etc (although that's not such a big deal as that it sounds)

I have a front m3 arb and a rear h&r arb (adjustable).
Imho the rear is more important because I think the rear on the stock z4 has a tendency to be a bit light (so the rear squats in the corner when cornering&accelerating)
The front can do with a stock m3 arb (26mm) because the front is a lot lighter than the e46m3/z4m because the engine is a lot lighter (aluminium). For the m54 that's 50kg or so, and for the n52 maybe even more.

Ok having just been out to measure my car has front 25mm and rear 19mm MSport suspension, is it worth upgrading these to 26/21.5? I'm thinking probably not much in it.

 

[Machine monkey]

I have a M rear ARB waiting to go on. But the front made a big difference one of the best things I have done.

 

[paulgs1000]

I loved my 3.0i - any excuse to take it out, I would go for it

+1

'The Z4 a proper drivers car?' :? Well we've got to respond to that haven't we . . . :fuelfire:

On the road exploiting my 3.0si offers me lots of driver involvement. Yes steering feel could be improved and a LSD would be great to have but in all honesty for on the road use, it is a sensational car (for the money). Having come from an MX5 then a 2.0i sport to the 3.0si the capabilities of the 3 litre caused me some concern as to the driving experience before I took one out and decided to go for the larger engine - now the extra performance adds to the experience but I understand what you're looking for and I wonder if it's possible to change the nature of the Zed or perhaps easier to just head for the Lotus ( a totally different route?)

My MX5 was a great fun car - the Zed feels more planted on the road and more settled (bar the steering). My MX had a brilliant gearbox, wonderfully involving handling, felt lighter and more fun (performance ok). But the Zed feels a more seriously able sports car and to be honest quite enough for the road - using all it's performance on the road would lead to a ban and perhaps becoming a danger to other road users so exploiting it's performance calls for care, attention and the right road and traffic conditions whereas the MX could be used full on for more of a typical drive. Perhaps that made it fun and that was one of my concerns before changing to the 3 litre. Taking the Zed out is a differently challenging experience and often road and traffic conditions dictate how much fun can be had but there is a real sense of occasion in taking it out and serious intention needed to make the most of it - in that respect it is a very challenging and serious driver's car.

So would you be able to convert the 3 litre into a sports car with the lively responses of an MX5 - I don't know but from what I've gleaned from the Forum and members, the idea of trying an Z4M might address quite a few of your concerns and be a more straightforward way to get to where you want to be. There's also a great deal of fun to be had keeping the 2.0 litre on the boil so as a different approach (and cheaper option) why not try the sport version with a four pot. I loved mine!

The Z4 not a proper driver's car

Good luck I do hope you find your 'right' sports car.

:driving:

 

[GuidoK]

I thought the difference was huge, I was coming from stock suspension. So 24 front, 18mm rear.
But the 2.0i is a lighter engine, so the front may benefit less. But the rear is imho still the weak link. I did some video analasys and the rear definately hangs down in one corner when turning+accelerating. Having more power and more traction (lsd) may increase that too.
So I think it's still worth upgrading. These mods are relative cheap (300-400gbp for both arb's) compared to quality coilovers (over 1500gbp).
Just like bushings; the whole car can be done for about 400gbp I think. And bushings wear out (shocks obviously too)
Also most other performance upgrades are much more expensive (without the install costs): supercharger (4000gbp+), cams(1000gbp), bbk's front+rear (min. 1200gbp/axle) etc etc.

 

[Smartbear]

Ok, so having lived with my 3.0 SE for a while now I've been thinking.

It's not really the kind of car that makes me just want to go for a drive. It's not really a proper sports car in my opinion, more of a GT.

Having recently put proper non run flats on that has helped but I can't stop thinking that all the component parts seem to be there (RWD, decent engine and box, good brakes, wheel at each corner, reasonably light etc) but it doesn't feel exciting in the same way a similar age boxster S or Elise (probably unfair comparison) does. Haven't had an MX5 but I bet if feels more exciting / involving than the Z.

I'm really not looking to have a go at it or change it, but I'm really interested in what options there are to improve what is a good car into a decent sports car.

Initial thoughts -

I came from an Elise prior to the zed & while the 3litre has much more engine it's the extra weight that blunts it's edge (series 2 Elise-860kg Z4-1300+kg) however, it's a more suitable day to day car that still retains some fun & that's why I made the change.
Trust me, unless you are a masochist you would not enjoy an Elise as your daily driver!
Regards

 

[GuidoK]

I have a M rear ARB waiting to go on. But the front made a big difference one of the best things I have done.

That will only fit if you use the m3 rear axle (with the really short ratio diff) (I presume you mean a m3 (or z4m) rear arb). Also use spacers or rims with different ET because the m3/z4m rear axle has a narrower track width as the standard rear axle.

 

[itguy]

I thought this thread might evoke some emotion :lol:

I've owned a S1 Elise and an S2 Exige S before, then a 996 Turbo, an S2000 and 2 high power westfields before that lot, so I know that trying to get the Z to be something it isn't designed for is a challenge and it will never be 800kg in road going trim!

Don't get me wrong, I love driving the Z and it always feels like an occasion and quite special.

But - I bought the Z because it's a compromise because we love to do euro roadtrips down to the alps and the joy of cruise, aircon, xenons and c.40mpg on a long motorway slog is very handy. Thing is though, I then want it to turn into a lotus when I get there :evil:

It sounds like simple initial changes like front and rear ARBs (fitted with new polybushes) and a geo (to make sure it's where it should be, have never had one done on my car) is the initial way to go - then possibly look at polybushing all the suspension.

Ref the ARB prices you suggest - are these aftermarket/used or dealer? I presume they are both bolt straight on? (ie M front - E46 M3 right?) and H&R rear?

 

[Anonymous]

I've just been having a look around and the prices look about right. Theres a H&R adjustable front/rear kit for about 366 delivered but its not clear if it comes with new bushings. http://www.motorsportworld.co.uk/frame-manranges.asp?code=84
Whiteline also do them for front/rear but the front is not adjustable for ~£400, again it isn't clear if these come with new bushes either.

I'm not sure if adjustability is one of those specs they just use for competitive advertisement or not because I've read a few posts on other forums where people say they've tried all the settings and settled on the hardest as best for them.

 

[GuidoK]

Prices are new/aftermarket:
h&r rear only:
http://www.ebay.de/itm/H-R-Stabilisator-HA-BMW-Z4-Roadster-Coupe-Z85-33276HA-/110713598509?pt=DE_Autoteile&fits=Make%3ABMW|Platform%3AE85&hash=item19c70b722d

H&R front+rear:
http://www.ebay.de/itm/H-R-Stabilisatoren-Set-BMW-Z4-Roadster-Coupe-Z85-ab-03-33276-1-/190779351604?pt=DE_Autoteile&fits=Make%3ABMW|Platform%3AE85&hash=item2c6b55e234

ST suspensions front+rear:
http://www.ebay.de/itm/ST-Stabilisator-VA-HA-Set-BMW-Z4-Coupe-E85-Z85-52020019-/370987152848?pt=DE_Autoteile&hash=item56608eb5d0

Both complete kits have a 27mm front arb.
A used m3 arb can be found for €50 or so, some in good nick, some completely rusted.

They all bolt straigt on, but the rear arb is a bit of a hassle.
PU bushings you can partly get from powerflex and partly from strongflex. A combination of both allows you to completely polybush the chassis.
Superflex, whiteline and some other brands also have some bushings.

The z4 will never be something like a lotus/westfield/caterham because the weight difference is huge, and weight is something that completely transforms a car. But the chassis comes alive when you go 300hp+ and stiffen up some of the suspension parts and install a lsd. The chassis is clearly designed to handle a lot of torque, but that is also something like an achillis heel.
A lot of power means e.g. a very strong trailing arm is required. That is made of cast iron, and weighs 13kg or so..... (the rest is light; profile steel or cast aluminium)
If you look at how elegant the suspension arms of a lotus are designed.. very straight foreward and very light.
If you want a real sportscar, there's no place for cast iron on the suspension parts except for the brake discs
But a real sportscar also won't have aircon, satnav, an elaborate sound system, a motorized roof, electric leather seats etc etc.
All dead weight that serves no purpose on performance. So the z4 is a car designed with compromises. But it allows you to still have long trips in relative comfort.

 

[jaxZ4]

Liking this thread and share some of the views (at both ends) & having booked another euro trip including autobahn & alpine passes I'm considering some more upgrades like more poly bushes & a lower end BBK ( k-sport maybe) so keen to see other thoughts re geo check etc.

Healthy debate too . . . .


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