A few bits and pieces and a trip to Spa - New Windscreen

[Mikey_Boy]

Hi folks,

Just thought I'd share my journey with the Z4M now that I've bonded with the car for a little bit. A lot of credit has to go to Exdos on here as he's been a bit of an inspiration for my mods so a public thanks for him, even if my bank manager doesn't think the same way... :evil:

I've had my coupe for nearly 2 years now - here's my newbie thread:

http://www.z4-forum.com/forum/viewtopic.php?f=11&t=52796&p=779114#p779114

The only mod I'd managed up until recently was a stubby!!

Having used this forum for a good bit of advice, I took the plunge and started on a raft of mods - first up, ZHP gear knob - my only rationale for fitting it was because my original knob was looking a bit tired and I'd seen other threads on here and elsewhere saying they were good!

Here's the knob as bought from the dealer:



After stripping down the old knob and having a bit of trim here and there - I ended up with this:



Like most others, I've ended up with a bit too much material here and there, but overall, it's FAB compared to the old knob...

Next up - strut brace:

Again, having read the threads on here, I decided on a Strongstrut kit:



The company is real pleasure to deal with and got the parts out to me very quickly - it's also a doddle to fit and it makes a LOT of difference - stability under braking and lift under acceleration is MUCH improved.. Now of course, I have a taste for the mods!!!

So.... onto suspension. Having driven the car for a while and read Exdos excellent thread on the topic, I had to agree that the OEM set up is basically pants - big frilly ones at that. Given the car is primarily for road use with the odd track day thrown in, I took the plunge and bought a Bilstein PSS10 kit with new OEM bushes for the rear trailing arms, bush limiter kit, new OEM front bushes and new anti roll bar drop links at the front and rear:





The eagle eyed amongst you will have seen I have also converted to studs and put 8mm spacers on as well - another worthwhile mod - the car looks nicer with the spacers AND it feels more 'planted'

Bush limiter:



Whilst the wheels were off, I thought it would be rude not to refresh them!!

New tyres, (Michelin super sports, OEM sizes), new centre caps and new 'M' badges courtesy of ebay:



(I won't bore you with all 4!!!)

Finally, I also fitted a new throttle pedal so that I could heel and toe easier:



And last but by no means least, I've always thought that the grills on the car are a bit exposed:



So I made up some mesh grills for inside to stop the stones - I figured it might protect my air con condenser on track days with lots of debris flying about:



And a 'yes, I've just been washed' shot after all the mods were fitted:



And so, off to Spa we go - Javelin trackdays did a CRACKING deal for 2 days at Spa in March - it could have snowed but it was worth the risk as the weather was SUPERB - I've driven there before and it's awesome...

Here she is in the garage:



Badge trophies:



And out on track in case you don't believe me...
Eau Rouge:



La Source:



What can I say - the car is TRANSFORMED!! A much better ride, more compliant and better in pitch and roll - the grip from the Michelins both wet and dry is superb.

However, I did have issues with brakes - I detailed that in a separate thread here:

http://www.z4-forum.com/forum/viewtopic.php?f=9&t=75517&p=1114394#p1114394

So I've now got an AP BBK on order - like I said, me and the bank manager aren't speaking much these days!! More to come soon....

 

[Mikey_Boy]

Ooooo - and I forgot - vibra technics engine mounts are fitted too - also super....! The car just keeps getting better....

 

[exdos]

Mikey_Boy,

I'm glad you've found my ramblings useful and enjoying the car now it's sorted! Until owners transform their cars from OEM condition to where you now are, they simply fail to see the difference that can be achieved for relatively small outlay.

You could've saved yourself some money by doing my brake cooling ducts mod: http://www.z4-forum.com/forum/viewtopic.php?f=24&t=38775&hilit=brake+cooling+ducts+exdos

 

[mattwaltersz4m]

Nice little history there. Car looks great and Spa is an amazing circuit, I could only manage one lap as a passenger before being

 

[jimmybell]

Looks great - another +1 vote for Exdos' mods and advice. I'm inching closer to the suspension/mounts/bush limiter setup.

I wonder if anyone has ever done alcantara steering wheel, i'd love that.

 

[Mikey_Boy]

Thanks guys!!

I'm a bit unhappy with the interior on mine (I love the layout and the quirkiness, but it's a bit tired after some use) so I can see some updates happening there too... Alcantara wheel?? Hmmmmm.... :evil:

I'll post again once the brakes have arrived and fitted with more pics!

Has anyone fitted Recaro SPG race seats by the way? If so, does anyone have pics and the name of a good retrimmer??

I *knew* this would happen once I started modding.... :?

 

[Mikey_Boy]

Some lovely boxes turned up the other day:



Big front calipers:



BIG front disks:



Big rear calipers:



Can't wait to get these fitted............!! :evil:

 

[TomK]

Ooooooh lurvely! I really really want a set of these, can't justify getting rid of my brembos yet but soon.... Fantastic brakes. Are they the 5575 caliper fronts? Where did you get them from, good price?

 

[TomK]

Has anyone fitted Recaro SPG race seats by the way? If so, does anyone have pics and the name of a good retrimmer??

Careful with putting buckets in these cars, the cabin is very narrow and you'll find the door card very close to the 'shoulder' of a bucket. My sparco corsa, just fits, so worth thinking about checking if you can.

 

[Mikey_Boy]

Thanks Tom for the advice!

I'm lucky enough to have a pair of SPGs in stock after I sold another car - I use them in my track car (another BMW and the door clearance is tight on that too!) and I absolutely love them as seats so would love to get these fitted if at all possible, trimmed in proper BMW leather. The standard seats are nice for distance driving but pretty rubbish for anything (ahem) spirited!

I got the brakes from Amber Performance in the end - the thick end of 3k but given that the car is now a keeper and I want to use it as much as possible hence why I am chucking some cash at it to get it right for me to just get out there and enjoy it. A garage queen she is not going to be!

Does anyone know a good seat trimmer??

 

[MrPT]

Love this post.

What's the theory behind strut brace = less lift under acceleration?

 

[Mikey_Boy]

I'll give you my spin on it and let others shoot me down in flames...

The strongest shape in engineering is the triangle. From the factory, the Z4 has just 2/3rds of the triangle at the front with the braces that they put in for the front turrets so the strut brace addresses that, effectively 'joining' the two front turrets together and helping the general rigidity at the front end. This helps with stability under braking and lift under acceleration as the front end is less floppy. That said, I'm sure a lot of the lift under acceleration is made a lot worse by the standard springs being way too soft and the back being too firm... I'd refer you to Exdos' thread for further details!

What's also significant (in my mind at least) is the distance between the engine bay firewall and the strut towers - this is massive on the Z4 so the bodyshell is already on the back foot with any kind of front loading when cornering where the turrets could deflect under significant loading. Putting the strut brace on sharpens up the turn in quite a bit in my view with the extra rigidity it offers - on the flip side, it makes the car more understeery, but that is addressed by turning the front dampers down a little bit and letting the suspension work better.

 

[Mikey_Boy]

And another lovely box landed today:



Fitting for these and the brakes will be done by my local Indy soon!

@Exdos - if you see this, you have PM regarding the shims required for the front Anti Roll bars if you can help there please - by JINGO they are beefy!!

 

[exdos]

@Exdos - if you see this, you have PM regarding the shims required for the front Anti Roll bars if you can help there please - by JINGO they are beefy!!

Been away and just replied to your PM.

 

[Mikey_Boy]

Thank you sir!! I have replied...

 

[Mikey_Boy]

Some big brake loveliness now fitted:



Pretty tight in there!!!



And rear calipers on the standard OEM disks:



I've also had the BMW E46 Anti roll bars fitted (you have to take my word for it as I couldn't get any pictures) and thanks again to Exdos for the recommendation - this modification is SUPERB!!

So, back out on track (with M Track Mode sorted as well) - this time at Donington (and apologies for the BookaTrack plug - I'm not associated with them in any way, just too tight to buy their pics):



Just wanted to show how little roll the car now has and the brakes....?? Oh... My... Goodness......!!

This car is now a serious weapon on track - I think I need better seats!!! :evil:

 

[Beedub]

Awesome stuff....

how about a detailed review on the brakes ??????

 

[Argenta]

Great stuff!
Re the seats, ever tried the CG Lock for the belt..? A great help I think for sitting firmly in place. Used it both in my Fiat/Recaros and Z4MC.

http://www.cg-lock.com

 

[Mikey_Boy]

I have indeed tried a CG lock - in fact, one is currently fitted to my car... 8)

Trouble is, I have been little spoilt using race seats in my my track car and nothing comes close for that extra 'feel' of the car underneath you. I've got a pair of Recaro SPG seats in stock so just hunting down a good retrimmer to get them looking factory before exploring installation options. I'm even toying with the idea of heating pads to keep the seats heated... :roll:

As for the brakes - let me try and sum up how good they are. Pedal feel is the same as factory - i.e. can be a bit mushy at the top of the pedal, but firms up nicely as the pedal travel increases. This should be the case as I have increased piston area at both the front and the rear of the car, so the mastercylinder sizing should be correct if AP have done their sums.

After 12 hard laps of Donington, there was no fade whatsoever or change in pedal feel. They did however start to grumble a bit which I would put down to heat build up - I will look at some cooling ducts as I am sure this will help and is a problem on Z4s regardless of braking system used.

Always pays to be smooth in a Z4 because of the 'auto-prime' system - lift off the accelerator too quickly and the brake system primes itself so when you stand on the pedal (as it thinks you need an emergency stop), all the braking happens pretty much instantly!! Quite a shock when it happens, but easily managed just by being smoother with your inputs.

Bottom line? An expensive mod for sure but you always feel like there's braking capacity to spare which increases my confidence no end. With all the chassis mods done, I am delighted with the result!

 

[jpeeters]

Thanks for the review of the brakes! My OEM discs cracked on the Nurburgring last weekend, so I'm looking at my options to replace or upgrade the OEM setup. Your feedback will definitively help in my decision process.

Any reason you didn't choose for Stoptech or Brembo (or other BBK manufacturers)?