Thinking Of Doing An Anti Roll Bar Kit

[Robert Linton]

This would include adjustable titanium and aluminum drop links and 4-position zinc passivate coated adjustable 4130 chrome-moly tube front and rear anti-roll bars with machined 4130 ends, Orkot® bushings, titanium bushing stops, titanium mounting brackets and titanium fasteners.

[macfly]

I think that would be a stunning alternative to the heavily built solid Dinan swaybar set. I've fitted the Dinan to both my Z8's and find it to be one of the very best upgrades in terms of the handling payback, but I'd love a lightweight set with Cartridge quality!

I know you saw GM's comments over on Roadfly, but worth repeating here too I feel;

Bob, may I make one suggestion? Since I believe most people will want to increase the anti-roll rate of their Z8, could you adjust the length of the bars to provide optimum geometry when they are set to one of the stiffer settings?

Currently, with the Dinan bars, which are the same overall length as the stock bars, when you position the drop links in one of the stiffer (shorter) holes, the relationship of the drop link to its mounting points at the bar and the suspension is no longer vertical.

What I would like to see is a one increment stiffer front position at the same length as the OE front bar and a two increment stiffer position at the same length as the OE rear bar.

This would require your tubular bar to be somewhat stiffer than the OE bar, but I assume this can be done to most any spec. If you make it longer overall than the OE bar, you can still retain the OE stiffness setting with a longer mounting point, albeit with less than ideal drop link geometry.

Again, I don't think most people will want to retain the stock settings so I don't see this as a problem. In any case, what you propose will certainly save weight, increase adjustability, improve coupling response and look like a million bucks! Please put me on the list for a set!
Grease Monkey

[Robert Linton]

I am finally getting to the production of anti roll bar kits with new hollow tube 4-way adjustable anti roll bars, titanium/aluminum adjustable drop links, substantially upgraded bushings and titanium brackets and fasteners. Is anyone interested?

[macfly]

so long as we get a serious fix from BMW.

I have been really happy with the upgraded swaybars I've had in the past, and consider it about the best single upgrade I've ever done to a Z8, so have such a set would certainly be a plus.

[Norcal]

But, after "the fix", and at what cost? If I may be so rude.

[Robert Linton]

I do not yet know. My guess would me that, given a maximum of ten complete sets wherein one does not achieve economies of scale and given the cost of labor, materials and machining (much of it quite intricate) and for:

1 4-way 4130 tubular adjustable front anti-roll bar with machined and welded ends -- all with appropriate coatings
1 4-way 4130 tubular adjustable rear anti-roll bar with machined and welded ends -- all with appropriate coatings
2 machined Orkot front bushings
2 machined Orkot rear bushings
2 machined titanium front brackets with approppriate coating
2 machined titanium rear brackets with approppriate coating
4 machined titanium front fasteners
2 machined titanium rear fasteners
2 machined titanium/aluminum adjustable front drop links with approppriate coatings
2 machined titanium/aluminim rear drop links with approppriate coatings

the cost could be approximately $5000+ dollars.

[Norcal]

I'd rather put the money into coilovers, wheels, or brakes perhaps. Maybe eventualy.

Thanks

[macfly]

I was about to put them up for sale, as I won't be puting them on my 'keeper', I bought them for the long departed 'beater'.

[Norcal]

So I should put them on my beater? LOL! Seriously, I am very intrested, but only if they have the abiliity to be adjusted between fiirmer than the ACS, and softer. Any idea if this is the case?

[macfly]

as I haven't had them on the car, and it is so long since I had the ACS kit I don't remember their specs either! Incase you want to read more here is the KW tech sheet.

[Norcal]

I can't relly tell from this doc. what the ride height adjustment range is, or the relative springrates/firmness. Perhaps Dieter can clarify. Isn't this what he has?

[Norcal]

Looks like this kit can lower ride height from 25mm-45mm (nearly 2 inches!!??) The ACS is fixed at 25mm (.9")

My concern is that the ACS can be very abrupt, and skips around on the less than billiard table smooth roads that I often frequent. I'm still not sure if setting the KWs to the same 25mm height, yet with better bound/rebound control could yeild a more pleasing ride (less abrupt).

As for the required wheel spacers, could this also be accomplished by changing the offset in a custom wheel, such as the HREs? (I think yes).

[Robert Linton]

A model drop link.

[Bend]

Bob,
Sounds great.
If it helps you any, put me down as a maybe. I have some car issues right now.
Let me know when it is time to pull the trigger.
Thanks.
Ted

[Robert Linton]

The almost final specs are:

1 5-way 4130 tubular adjustable front anti-roll bar with machined and welded ends -- all with appropriate coatings
1 3-way 4130 tubular adjustable rear anti-roll bar with machined and welded ends -- all with appropriate coatings
2 machined Orkot front bushings
2 machined Orkot rear bushings
2 machined aluminum front brackets with approppriate coating
2 machined aluminum rear brackets with approppriate coating
4 titanium front fasteners
2 titanium rear fasteners
2 machined titanium/aluminum double adjustable front drop links with approppriate coatings and titanium nuts
2 machined titanium/aluminum double adjustable rear drop links with approppriate coatings and titanium nuts

That's the good news -- although a year late (other matters took higher priority).

The bad news is that there will only be five sets and three are already spoken for.

[macfly]

until I know the outcome of the events we discussed. I am mindful of what you said about your Mother, and the museum, but I just have to get everything sorted out in my mind. If you can give me a couple fo months to figure it all out that would great.

[Robert Linton]

4130 anti roll bars waiting for shot peening and electroless nickel coating.

P.S. As these are made from tube, the ends are welded on. Take a look -- that is what welding should look like!

[macfly]

and looking very forward to gently 'Cartridging' my Z8.

[Robert Linton]

Attached are three pictures of anti roll bars, albeit not for a Z8, coated with electroless nickel. One was shot peened before coating and the other was shot peened and beed blasted giving the more dull finish. Which do you prefer for the Z8?

[Robert Linton]

Here is a picture of the new rear anti roll bar mounting point welded to my Z8. This piece allows a proper anti roll bar mounting block with two fasteners rather than merely a fastener and a tab that could break.

[Robert Linton]

Here is a picture of the rough machined (it will be cleaned up a bit and then annodized black) rear anti roll bar mounting block next to the old mounting tab. With this approach, not only is the entire assembly more secure, but the bushing that will be encased in the middle is able to do a better job.

[Robert Linton]

And here is a picture of the new front mounting block and the old mounting piece. Again, the new mounting block will be finished and annodized black. Of course, the front and rear anti roll bar mounting block fasteners are titanium.

BTW: It is this type of detail that costs!

[Robert Linton]

Although not yet anodized, here are pictures of the anti roll bar mounting blocks attached with titanium fasteners.

[Robert Linton]

Machined ti-nitrided titanium components of the drop links.

[macfly]

Wow, those are pretty, they almost look like Christmas lights!!

[Robert Linton]

Now the anti roll bars are plated with electroless nickel.

[thegunguy]

Wow, those are pretty, they almost look like Christmas lights!!

I wish I could afford to hang them on our tree. :D

Beautiful work, Bob.

[Robert Linton]

Thank you.

At long last, in a few weeks, the anti roll bars kits will be completed.

[Robert Linton]

First shot of front drop links. One change that will be made is that the nuts at either end of the black rods will be ti-nitrided titanium instead of the steel pictured.