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Z4 3.0 Track car build

2003 - 2009, roadster, coupe, facelift
oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Fri Jul 14, 2017 8:20 am

Disaster! (Well, a little bit..)

New 17" lightweight 8.5 wide 4 square wheels (That look awesome) and RSR Tyres too wide at the front and catching on strut - Needs 5mm so looking for some 10mm spacers and longer studs. Should I fit spacers all-round or would just the fronts be ok? I'm getting the geo done as soon as the wheels are on and sorted.

Cheers for the advice all :)

o

[IMG]http://img.photobucket.com/albums/v705/ ... 02A071.jpg[/IMG]

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Steve84N
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Z4 3.0 Track car build

Post by Steve84N » Fri Jul 14, 2017 12:11 pm

Front increase in track only is good to reduce understeer.

What offset are the wheels? If it would be better visually I'd space the rear too but I wouldn't say it was necessary unless you find it has too much oversteer after doing just the front.

I think you're going to need some aggressive camber to avoid the front catching the arch liner by the reflector.
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mjennings23
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Z4 3.0 Track car build

Post by mjennings23 » Fri Jul 14, 2017 12:31 pm

Surely a track car should always be function over form, no need to add spacers (and therefore extra unsprung weight) to the rear axle unless absolutely required. Looks should have no bearing.

Regards to front camber, I'd expect a track dedicated car to be running a heavy front camber anyway, around -3 degrees or so, so that wouldn't be an issue.

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Z4 3.0 Track car build

Post by Artful-Bodger » Fri Jul 14, 2017 6:42 pm

If Oalloyd is using the Z4M lollipops with increased castor, this has already added more camber under steering, so adding in a load of camber without checking tyre temp spread is a seriously bad idea.

Secondly spacers are another bad idea , especially on the front, the King Pin Inclination (KPI) of the front geometry is designed to put the steering centre point of the tyre as close to the middle of the tyre as is practical, a race car with custom built uprights will be designed so the KPI intersects the centre of the tyre contact patch for the size and diameter of the tyre used, road cars tend to have a scrub radius allowance as it's quite difficult to achieve with road going geometries, so adding spacer will increase the scrub radius with negative effect.

If your going to modify suspension it's a good idea to do a lot of research first , just buying bits and bolting them on is a bad idea and can lead to dodgy handling and odd handling quirks.

For a total novice a good starting point is Alan Staniforths Race Car Suspension book.
Rules are for the guidance of wise men and the blind obedience of fools - Colin Chapman

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Fri Jul 14, 2017 11:40 pm

Hey all, and here she is!

I think the black 17's suit it well and it will look better still with the front grill inners painted.

[IMG]http://img.photobucket.com/albums/v705/ ... 7A5041.jpg[/IMG]

Front spacers on and rear ones on order for balance - Agreed they are not strictly needed i'd like them on none-the-less as wider track means a bit more grip and it will look more balanced. Bodger I take your point ref set-up but this is the only way we could find to get arch clearance, lower it, get camber and package the 255 tyres. Its now with a well known BMW specialist to get the full geo set-up completed as well as a second-opinion spanner check on all the areas that have been enhanced for extra piece of mind. Corner weighting would also be a good shout.

Cheers all and next up is interior removal, new seats, fitting of induction aspects and the HID kit - Can't wait!

o :)

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Wed Jul 19, 2017 3:57 pm

Just about to go and pick her up from the BMW specialist having had a spanner check and suspension set-up / alignment - Looking forward to a fun drive home but also keen to get it on the track asap to give it a proper shake-down.

Wish me luck!

o :)

kin quick
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Z4 3.0 Track car build

Post by kin quick » Mon Jul 24, 2017 10:27 pm

Following with interest, how's it all going??

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Tue Aug 08, 2017 3:49 pm

Hi all,

Its been a busy few weeks with the car to say the least.

I got some 12mm Eibach spacers and extended studs for the front to help clearance and all is now well, even in extreme cornering. The sticky 255's also have the added benefit of looking just slightly awesome :D :thumbsup:
[IMG]http://img.photobucket.com/albums/v705/ ... F11B0B.jpg[/IMG]

Its been back in the workshop to get the interior stripped and a few other mods done.

Here it is getting its CDV deleted - This has ade changes feel much better already and should help preserve the clutch on track
[IMG]http://img.photobucket.com/albums/v705/ ... C30FEB.jpg[/IMG]

Front grills painted black and M badges removed - far cleaner now :thumbsup:
[IMG]http://img.photobucket.com/albums/v705/ ... F50FDC.jpg[/IMG]

Remap in and has made throttle response sweeter and the new panel filter has added some extra rasp. The intake duct is going in this week as are the harnesses and race seat.

Its virtually all done now, all there is to do is drive it - 'Ring departure is in 2 weeks time, can't wait!

o

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Thu Aug 10, 2017 8:41 am

Just ordered some soft white LED bulbs for the interior and planning on throwing out the reverse alarm module - It's huge!!!

o :)

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Seal3.0
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Z4 3.0 Track car build

Post by Seal3.0 » Thu Aug 10, 2017 11:48 pm

I hate this thread. I track mine, and now realise how many more mods I need to make. Can someone give Westminster a call and ask them to shake the magic tree in my direction please! Ta. :thumbsup:


Seriously though, great thread!
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bradz
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Z4 3.0 Track car build

Post by bradz » Fri Aug 11, 2017 2:31 pm

A very interesting read, I also track mine.

I'm going to give the offset bushes a go first as I'm struggling with under steer mid corner!

Adam
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Fri Aug 11, 2017 3:04 pm

Cheers guys,

Off-set bushes feel free, car feels so much more planted in corners and with the wider tyres I doubt i'll ever find out what understeer is like in a Z4....

o :)

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Fri Aug 11, 2017 3:36 pm

Hey all,

Interior now coming out - So many pieces, its like a massive jigsaw!
[IMG]http://img.photobucket.com/albums/v705/ ... G_4844.jpg[/IMG]

Looking good now stripped - i'm putting back in a race seat (obvs) as well as black door cards and a black centre console to house switches etc. Will post up more pics soon!

[IMG]http://img.photobucket.com/albums/v705/ ... G_4845.jpg[/IMG]

o :)

oalloyd1
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Z4 3.0 Track car build

Post by oalloyd1 » Tue Aug 15, 2017 5:03 pm

Hey all,

Wheels have been sold so I have a couple of pennies to get the now-bare floor painted in Raptor for a non-slip and high wear resistance finish - Will send you pictures once it's in. In other news, today the Pagid discs and DS25000 pads went on along with some 12mm Eibach rear spacers to get it looking nice and even stance-wise - Will post up pics also.

Cheers and comments welcome,

o

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philbo909
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Z4 3.0 Track car build

Post by philbo909 » Tue Aug 15, 2017 5:15 pm

oalloyd1 wrote: Fri Aug 11, 2017 3:36 pm Hey all,

Interior now coming out - So many pieces, its like a massive jigsaw!
[IMG]http://img.photobucket.com/albums/v705/ ... G_4844.jpg[/IMG]

Looking good now stripped - i'm putting back in a race seat (obvs) as well as black door cards and a black centre console to house switches etc. Will post up more pics soon!

[IMG]http://img.photobucket.com/albums/v705/ ... G_4845.jpg[/IMG]

o :)
Surely you don't need door cards in a track car?
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