Fast road / Track build

[Hamalmac]

Hello everyone.
I've owned my 3.0si 2006 roadster for almost 3 years now, and I admit to kind of falling out of love with it recently just using it for my daily short commute. To cut a long and meandering story short, I put the car up for sale recently and received almost no interest, so I decided to do a couple of little jobs in preparation for the impending miserable Scottish winter. Tyres first, No big deal, and next a job I'd been putting off for the entire time of ownership, the Vanos solenoid , well blow me did it not just transform the behaviour of the car!!!! Pulling a lot stronger from low down till peak torque ( which im sure has increased).
The upshot of this is that my love has been rekindled and I have decided to embark on a raft of modifications aimed at increasing its potential as weekend summer blaster and trackday car, this is where you lot come in, because despite a reasonable automototive knowledge I am looking for advice based on experience on a number of issues.
Issue 1:- I've decided to run a set of BC Racing coilovers, but am unsure of Spring rates.
Issue 2:- Brake pads. No matter where I look I find a host of vehement and oftern contradictory advice/opinions on a fast road / track pad.
Issue 3:- poly bushing front rear bush and rear trailing arm bushes. ( worth the bother?)

Starting with these 3 topics, I'd appreciate any advice. The car as it stands is pretty standard bar 19" CSL's , Mtec grooved and drilled discs. Also I intend to remove the weighty heated memory seats, fit custom built exhaust system and a thorough going over of entire car and replacing worn parts etc as necessary.

Many thanks

 

[Ed Doe]

1. I really rate the Bilstein B12 kit as an alternative to coilovers. Personally I haven't run them on the zed, but with other cars I have run them, I wouldn't choose them again unless spending some serious cash - they usually don't have the operational range of a set of dampers, so you generally end up with a very firm ride which reduces grip on bumpier tracks, and on the road. Just have a think about it before plumping straight for coilovers.
2. I've had mintex 1144 pads on a previous car and thought they were ace. However, again, I'd personally get out on track with the OEM brakes - you'll be surprised (as I was only a month ago on track at Goodwood) with the performance. My plan is to get some Mintex 1144s eventually, but I don't think I'll bother before the next couple of trackdays to be honest...
3. I've polybushed the front and rear arbs, the Wishbone 'Lollipop' bushes, and the Rear Trailing Arm Bushes (RTABs). The difference is night and day against the sloppy old OE stuff I had on the car when I bought it. There is a slight increase in NVH, but to me the compromise is totally worth it for the additional precision you get. Well worth it in my opinion!

Aside from that, I'd do the following;
1. Get some 18" alloys on it, it'll improve the ride, make it better on track, and you'll find tyres slightly cheaper!
2. Get some decent tyres - Michelin Pilot Sport 4, or Pilot Supersports are cracking, and will make a big difference to how the car feels o track
3. Get out and enjoy the car BEFORE spending any money. Honestly, change the brake fluid, then book a track day. You'll spend a fortune on bits you think you'll need before getting out on track, and come away with another even longer shopping list. Just get out for a day or two, and after that you can make a good judgement on what you NEED to do to the car to improve it to your tastes

I can't stress enough, the last one is the best bit of advice I was given prior to getting out on track. Admittedly I'd already done the tyres and the Bilstein B12 kit, and the Polybushes, but I'd have ended up spending a fortune on brakes only to not need them.... Just go enjoy it, you'll have a blast!!!

 

[Hamalmac]

Thanks Ed.
That's exactly the sort off feedback I'm looking for. My shopping list may well change now.
Cheers

 

[bazpro88]

just put yellow stuff pads, new standard discs , braided hoses and new fluid in my 3.0 and it stops brilliant now. even better when the brakes get a bit heat in them.
am kind of in the same boat as you, got bored of the car and put it up for sale but keep spending money on bits trying to like it again lol

 

[JimBob78]

Hi
Did you do both solenoids? Ive done the bottom one, can't remember if it's the intake or exhaust..
You may also want to seek out stiffer anti roll bars.

 

[Hamalmac]

Hi.
I decided to change both after the success of the first one (exhaust side). Haven't driven it since, because the my steering wheel is off at Royal for a vacation.

 

[goldbcfc]

Ive tracked a few times im my 3.0i Z4 this year was really good fun. Had 3 now the first had lowering springs was ok on track quite a lotof roll still. The 2nd had KW coilovers with pollybushes much better very stable. The 3rd i have now just has standard sport suspension. I had pagid pads / brembo disc on first but 2nd had those EBC disc and pads. Ive heard many good things over the years about EBC but never tried their products. They were great stoppers best ive had on a car will buy again for sure. You should think about having a remap done that will make things even more responsive. Every little helps i know (some who have most likely never remaped before) will say you only gain 10bhp etc blah blah but i always remap my petrol bmw's. There's always a noticable gain well worth the £100-300 you pay. BW chiptune highly recomended. AP tuning is their approved dealer they sells BW chiptune maps im sure they have branch over your way.

 

[Hamalmac]

Thanks for the info. I know a lot of N/A owners poopoo a remap due to lack of big numbers but I'd be willing to give it a try. I've just ordered my BC Coilovers , so hopefully these will be an improvement over my current standard Sport set up. Saw these on Amazon just after my order was confirmed. https://www.amazon.co.uk/gp/aw/d/B002OEXRSM/ref=mp_s_a_1_3?ie=UTF8&qid=1480638116&sr=8-3&pi=SY200_QL40&keywords=bmw+z4+coilovers&dpPl=1&dpID=519KnZmJRIL&ref=plSrch. A full set of H&R coilovers gor £525

 

[Machine monkey]

Yellow stuff pads I have heard good things about.

Yes polly bush what you can. I also updated my front ARB to one off an M3. Also look into a limiting kit for the rear trailing arm bushes (if you don't polly bush them)

The other thing if you want to have a predictable usable rear end look into fitting a LSD. It's not cheap but I can't recommend the M factory (nothing to do with BMW M cars) enogth. That polly bushing the m3 ARB and coilovers transformed the handaling of my car. It corners flat and and you can get all the power down quicker.

 

[Ed Doe]

^^ You mean you CAN recommned the Mfactory one right? :lol:

Also there is currently an offer going on supply & fit of Quaife diffs at Birds Auto in Iver: http://www.z4-forum.com/forum/viewtopic.php?f=2&t=91595

 

[Hamalmac]

I would dearly love to get my hands on an LSD and run lower final drive, unfortunately it's prohibitively expensive. I'd happily forego my next holiday to pay for it, but I'd end up completely single .