Gas suspension

[HS30-H]

I've just picked up my new suspension legs that have been modified with a Bilstein gas "upside down" setup.

The cost of the work was pretty frightening, but they DO conform to F.I.A regulations and they are apparently just about as good as you can get whilst staying within the rules.

I'm going to "recycle" the setup that is currently on the car ( shortened oil-filled LEDA units that I was never happy with ) and hope that these will feel a lot better.

These are what a lot of the Historic Rally guys are running on their cars here in Europe.

Alan T.

[HS30-H]

You can see just how thick the Rods have to be to contain all the valving.

I have driven one of the Historic Rally Z's that runs in the UK series, which was also equipped with one of these setups. It was amazingly nice to drive, and I felt like the suspension was really in control of the car - which I never felt with the LEDA oil-filled setup. After a few laps of hard use, or even just a few miles of bumpy and twisty country roads, the LEDA setup would start to get overheated and cavitate - sending the damping all to pot.

Fingers crossed that this should do the trick........

Alan T.

[onemore240]

Congrats...if you dont mind me asking..how much was the whole thing? They look really nice I hope you enjoy them.

[Mike]

Price and where did you get them?

[HS30-H]

Well, the price I actually paid is kind of hard to break down.

They are not an "off the shelf" item - they are put together as one-offs................

My friend had them made for me by BILSTEIN UK to his specs for Bump, Rebound, overall length of the tubes, Spring length and Spring Rate ( Springs were not in the photos ) as well as the Uniball top mounts and other mounting hardware. Additionally, he supplied the cores to get the work done so that I could recycle my LEDAs ( which should be saleable to someone who wants to use them for a street setup at least ).

He needed some body panels ( including a whole right rear quarter ) to repair his rolled racecar, which I sourced for him along with some high ratio LSD-equipped R200 Diffs and a few other bits. We did a "Contra" so that the minimum of money changed hands, but anyone who wanted to get these done from scratch would have to pay well over $2000 ( USD ) to Bilstein, and that's in the UK - so presumably much more expensive to order the equivalent from your side of the "Pond". You would also have to send some cores over for them to work on, as Bilstein will not supply these.

That might seem a lot of money, but don't forget that Bilstein chop off the whole tube and then add their own tube with all the workings in it. The valving is all specially chosen, as well as the Bump and Rebound rates and other data that is needed to put them together.

Surely there must be companies in the USA that would be able to build a similar setup? I have no idea from who, but wouldn't there be the equivalent available on a special order basis? Having said that, it would probably not be considered necessary for street use by most early Z owners and might not even be thought necessary for circuit race use either.

Having had several different setups on the car ( stock dampers with higher rate springs, then Tokico inserts, then Koni D-adjustables, then the Leda set-up with cut-down tubes ) and never feeling happy with any of them after having driven the gas Bilstein-equipped car, I thought I might as well bite the bullet and go for them.

I thought it might be of interest to some people here who have never seen one of these "upside down" setups before. Its a little bit like the principle used on racing motorcycles.

Alan T.

[onemore240]

Must be pretty special to say you have 1 off bilsteins...congrats again. I was thinking of running Ground Control weld on coilovers with eibach springs and KYB adj. shocks...what spring rates do you have on those?

[HS30-H]

Well, they are not 1-off as in "unique" - more that they are built on a case-by-case basis for each customer / application.

As for Spring Rates, I have a large choice and I'm still undecided. What with all the other setups I've had I now have a pretty large stock of springs in varying lengths and rates - from 180lbs up to 280lbs. However, I would certainly prefer to have a relatively soft spring rate with the dampers doing more work ( my previous setups ended up with the springs so stiff that the dampers were hardly having to do anything ). Colin Chapman - of Lotus fame - used to try to set his cars up with relatively soft springs and stronger damping. That's the theory I am hoping to benefit from.

Anyway, the possibilities are endless when it comes to discussing suspension settings / types. All I can say is that the car I drove with this setup was the my favourite handling / riding Z so far by a long chalk.

Alan T.