Speedtoys

Ditto

FredR

The very reason that Louie developed his adjustable rear links was to reduce the [chronic?] understeer on models with stock rubber. The idea was to have something that one could adjust on the car at the track side and then reset to stock for the trip home. They are also adjustable length wise to ensure there is no pre-load. Still have mine on the rear at the softer setting.

Not sure I see any point in having the Devek bar on stock rubber. As I am aware its range is something like 40% stiffer to 100% stiffer than stock. The stock roll bar brackets do need reinforcement and that is an easy but essential mod.

What seems to happen is that when one upgrades the wheels and fits wider rims/rubber the front end grip seems to increase disproportionately [a good thing] thus inducing some tendency towards oversteer and this is when the Devek bar seems to pay big time. I used to run with 265s on the front and 295s on the rear with the bar set somewhere in the half to three quarters range. These days just tootling around town I run with 255s on the front and 285s on the rear with the bar at about the half way setting- an excellent combo for street use.

As Dr Bob says, with stiffer springs it is a system package that different users will invariably set up differently. The only problem is that as with anything that is infinitely variable, there is one correct setting and an infinite number minus one wrong ones! To test mine I used to use a newly constructed roundabout near my home that had a big run off area around the periphery- just kept going faster and faster until I could feel whether the front or rear was slipping. With Michelin Cup tires I was pulling up to something like 1.2G lateral acceleration- had to stop as I was going dizzy. Happy days!

Speedtoys

Well, to go another level, may people oversize the rear rubber, which...is going to push the front on LSD cars a bit.
Wider isnt always better..its a system..

FredR

Indeed- a system is only as good as its weakest link. If one has a substantial power adder then for the traffic light derby there is a case for wider rear rubber but not for increased cornering as it simply exaggerates the natural understeer- BTDT!

atb

Is this correct? Fairly certain the red sway bars were offered by 928 Specialists and actually had a matching rear bar offered as a set. I have these in my S4.

FredR

Blue is for the S4/GTS. They also did a lighter bar for the earlier models as I recall but no idea idea what colour it was. 928 specialists had a red coloured sway bar design as I recall

NoVector

FredR

Thanks for sharing that- I used to have an original copy somewhere.

Now the interesting question- i have always worked on the premise that the Devek bar went from stiffer than stock to much stiffer- my memory being a bit hazy as to the actual numbers. Now I am left wondering what they meant by "67% stiffer" did they mean to imply something that was not as stiff as the stock bar or did they mean it started at 67% stiffer and onwards and upwards from that point? The English syntax implies the latter.

belgiumbarry

in rally ( partly of road ) we don't even use a front sway bar.. sure not in wet conditions.

I am interested at what may be the Weissach axle pin kit.... as we use indeed wider tires. Seems a cheap change , drill and bigger bolt ?

FredR

I very much doubt you will need a Devek bar but you will need windscreen wipers on the door windows!

As I recall the Devek pin kit was no more than a simple nut and bolt that requires some drilling to push it through. If you want lift off over steer then probably a good idea to pin the thing. In terms of the original concept, pinning the Weissach bush had a very mixed reception in the 928 community.

dr bob

The pin kit language is a bit deceptive. The amount of rear toe change expected is much more related to total effective wheel offset than the tire width stated in Devek literature and popular lore. Meanwhile, Porsche had no trouble fitting progressively greater effective offset with rear spacers, all the way to the GTS cars with 350 Prussian Ponies. No changes in the bushings or mounts for that. For loose-surface rally driving, you would never notice the rear toe steering difference, and straight-line rear toe change makes no difference in handling or feel regardless.

I suspect that Devek was marketing a solution looking for a theoretical problem that might have affected their open road race top speed number, and that only minimally. For us mere mortals, the rear toe steering makes the cars a lot more predictable especially in off-throttle corners.

Speedtoys

This is a specific use case. In road racing a 1G RX7, we would disconnect the rear bar, and do everything we could to remove the front bar, without removing it if it was wet, including shedding lot of tire pressure.

Just depends how you want the weight of the car to work for you.

GregBBRD

Talk to Mark Anderson at 928 International about pinning the rear arms, before you do it. He can also tell you how.

Speedtoys

928 Rear Swaybar ‘Steroid’ links, NIB. $100

https://www.flickr.com/gp/28804666@N08/Z2L6U2
6.6.0

Bigfoot928

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