Suspension setup for trackday only Z3 2.8

[Stormy_be]

Hello,

My Z3 2.8 is only used for trackdays. I even trailer it to the track.
For the moment I'm still doing starting on the improvements.
I have upgrade the brakes to brembo supersports and rebuild to front calipers.
Have got ride of 80% of the interieur.
I have done 4 trackdays with it since I bought it in februari.
I didn't do costly mod's yet as I first wanted to make sure that the basic mecanics of the car were good.

I know I will need to fit a roll cage (don't know yet by whom).
I will need strut braces.
Racing seats and seatbelts.

Was looking at the suspension packages possible.
As it is a trackday only car...no need for much comfort.
I hear a lot about the Bilstein B12's, but that's for people still driving it on the road.

I only use the car for 4-5 trackdays a year (for the moment no real racing YET), so I don't wont to spend a fortune on a modification that will only save me 0.2 seconds.

Any ideas?
Any known bargains?

Thanks,
Koen

 

[hard top]

Welcome Koen, there are a few on here that should be able to answer your questions. Witch tracks are you running on?

 

[Stormy_be]

Mostly driving at Zolder (Belgium)

 

[swamper]

i can only say the ones i have tried but me and a lot of the other guys swear by Bilstein B8s
you also want the H&R ARB's as well

 

[Stormy_be]

The thing that holds me back is the adjustability of the bilsteins. Or the lack of.

On the subject of the ARB's: heard something about not putting them on the harderst setting without enforcing the rear shocks or shock mounting plates?

Also heard some issues people had with the front strutbrace and the "extra nut"...

 

[GazHyde]

Also heard some issues people had with the front strutbrace and the "extra nut"...

Do you mean the earth connector on the suspension tower? Most strut braces come with a cut out for those, or at least the one I had did. Tends to be the cheap ones which don't. If it doesn't have one most people use a grinder to make a cut out.

 

[Stormy_be]

Is there a real difference in the strut bars? Or is it just looks?
I tend to say that a steal one would even be better is doing it's task then a aluminium one (as aluminium bents easier).

 

[GazHyde]

Probably more down to looks than anything tangible, and I've not heard of a Z3 strut brace bend as yet. Only time I heard of a failure it was a particularly cheap one being sold on eBay.

As like anything, you get what you pay for!

 

[Stormy_be]

Does anyone know if it would be possible to mount an M suspension under a 2.8?
I suppose the M is a lot stiffer.
Don't know if the M also used the E30 rear or already the E36.
And if the front mounting points remained the same?

Thanks, Koen

 

[Brian H]

Does anyone know if it would be possible to mount an M suspension under a 2.8?
I suppose the M is a lot stiffer.
Don't know if the M also used the E30 rear or already the E36.
And if the front mounting points remained the same?

Thanks, Koen

I see no reason why you cannot use ///M suspension however if you are buying new ///M parts you will pay far more than if you use an aftermarket kit like Blisteins, FYI the ///M uses the E30 rear and also has a narrow rear beam similar in dimentions to the 1.9.
I belive with suspension you get what you pay for so I am afraid I do not think you will get a top end track day setup for bargain prices unless you find a second hand setup being sold.

KW suspension is deemed to be very good and they offer 3 vairiants from option 1 being standard to option 3 being totall adjustable, these are not cheap though.

 

[Stormy_be]

I know KW is the top end.
But the V3's or the clubmans are at 1700€... for a car I'm using 4-5 trackdays a year...

Thinking between the bolstein B12's and the KW V1's, vogtland, AP's top-end (as they are damper-adjustable), ... all in the range of 700-800€

Other things on "the list"
Also H&R ARB (think that will be a very good price/performance) --> 350€
Don't know yet about bushings...as play in the running gear will cause as much issues (or loss in "performance"/lap times).--> 300-350€?
Steelflex brakelines.--> 150€
Some brake vent/ducting (and the air intake as mentioned here) --> 150€
Racing seats and seatbelts (less ungent for the moment) --> seats 400€ each, seatbelts 150€ each
almost forgotten the front strutbar --> 150€
last but not least : roll cage - which is also really pricy. --> 1000-1500€

Makes a large sum for a car I bought for 2000€...

But won't be doing it all at once....the misses wouldn't agree

Lucky I can do the Polyester body panels myself.

 

[zedonist]

The Z3M suspension benefits from the ability to adjust the front castor angle, other than being lowered to start with, offers no further benefits, plus you can buy aftermarket castor adjustment plates. IMHO i would for your limited track days just go with the Bilstein B12 kit, lowered and uprated dampers on eibach springs, the only benefit of the coil overs will be further reduced height and the ability to adjust the corner weighting of the car, for which you will need access to corner scales. Which ever way you go look at performance tuning sites in Germany i have had some great bargains delivered £600 on the B12Kit, H&R ARB full kit £246 @ Orange-tuning.de, they have some good deals on coil overs also.

The best modification by far for the handling is the H&R ARB kit, just remember that the front setting is the one that affects the rear and vice versa, so putting the front on hardest setting will give you the least roll at the rear, i would argue that the two reasons why some people see failure at the ARB points is due to incorrect tightening and the fact that the car is always performing in the extreme of its suspension movement, add that to an aged car and joints that have not been race prepared and you will see failure, so it is probably best to weld in reinforcement gussets where required and pre-empt the failure.

For strut and body bracing look at the Strong Strut range, the front tower strut does work, but i doubt many road users push their car to the limit where they would see a difference, so in essence they look nice and do nothing, but in a track car you will be producing the forces that the brace will deflect.

One thing you don't seem to have covered is differential choice, this can make a huge difference on acceleration times, and having a choice could benefit on tight twisting tracks where top line speed cannot be achieved.

I think other than suspension, brakes and other safety items, i would be investing my money in some race tuition, easily worth 5 - 10 seconds a lap and cost far less than performance modifications, and knowing how to drive the car correctly around a track can also save on the wear and tear of the vehicle and prevent any failures.

One other thing, you have got to have is a really cool air brushed helmet, add some horns etc......please post a pic

 

[Stormy_be]

Well, I agree on the tuition part.
I have to say I am very fortunate on that part.
I am mostly driving at Zolder (Belgium).
I've got a friend who has driven more laps there then anyone can imagine...for example, he's raced there in 5x 24h races, 3x 10h races...so he knows the track...every cm of it.
We've had sort of trackday with him (it was to drive around with children). As it was raining, he didn't want to drive in his westfield, but he took his Opel Zafira DIESEL (standard company car).
He was outbraking porsches !!!....crazy to see what track knowledge can do.

I've also checked the people from orange-tuning.
But they don't have (or I can't find it) the B12's on their site.
And about the H&R ARB's. Some have kit's with the link bars, some don't...hard to know what is exacly included :-s

 

[zedonist]

Hi, my bad i meant the H&R kit was from Orange Tuning you want the "H&R BMW Z3 Stabilizer-Set FA + RA" £255. the kit contains the two ARB bars front and rear and the uprated bushings, drop links you will need to supply your self.

The Bilstein kit i also got from Germany from a company called aze-tuning.de and having checked the invoice it was €650 delivered (£550):

http://www.aze-tuning.de/index.php/cat/c24815_Z3.html

 

[Stormy_be]

I'll spread the work, the amount spent...otherwise, nothing to look forward to next month