jeremymilo

86.5 5-speed 928

My steering pump was dead, so I replaced it. After that was done, steering at low speeds/RPMs was better but still quite heavy, so I replaced the rack.

That didn't address the heavy steering, so I'm wondering if this is just normal, or if there are other things I should try. (I'm definitely getting some power assist at low speeds, but less than I thought I'd get.)

I don't want to upgrade to the high-output pump and all the associated rack changes to handle the higher pressures.

Is there a softer steering torsion bar option that would help the existing system generate more power assist at lower torques?

James Bailey

do you have stock wheels ? small steering wheel ? and is it only "heavy" at idle speed when parking ??

FredR

Is your steering heavy or is it your perception of the steering that is heavy? If you are used to driving Amercian cars with typical US power steering then the 928 will naturally feel heavy to you because it has a relatively heavy steering action- one reason why you can actually feel what is going on with the front tyres when you are driving on the limits.

The steering will also feel a little heavier if by any chance you have more toe-in than is needed and conversely setting minimum toe will ease the steering a little but you may not like the feeling of "twitchiness". If you can, suggest you let someone with a similar model and plenty of 928 experience give you their comparative assessment before thinking about throwing more money at the problem.

Regards

Fred

karl ruiter

I think you are on the right track, although popular opinion here is likely to disagree. My '79 and my GTS have the same wheels and tires on them, but my '79 steers much easier. The difference, I think, is lighter sway bars on the '79. Which might also point you towards you solution. I don't know how the bars changed over the years, but I would start with PET and look to see what part numbers were used for different years.

Vilhuer

'78-79 use 26mm front bar and '80-95 use 28mm. There are two different versions of 28mm, early and "S4" style.

dr bob

The 'softer steering torsion bar' the OP asks about is the one in the spool valve that's part of the pinion. Not the anti-roll bar.

Would be interesting to find a lighter-effort pinion option, perhaps from a heavier more luxe ZF-equipped car. Maybe a big BMW or Merc sedan, for instance. Swap that into a 928 rack to lessen the wheel effort.

James Bailey

928s were made to be driven with TWO HANDS on the steering wheel plus remember the early 911s NEVER had power steering !! Most " Drivers " actually want to KNOW what the front tires are doing.....
But yes if you are eating a doughnut and drinking coffee while backing out from the front of the bakery, the steering might seem a bit heavy...

GregBBRD

Wow. Someone that finally understands what makes the power steering actually work!

The later "increased power assist" steering racks had a torsion bar that twisted easier. Yes, they added a higher output pump, but that was only to "cover" the occasional increased demand for fluid, because the spool valve ports were further opened.

The "rebuilders" never realized that there was a difference in these torsion bars, thus they are "shuffled" around so much in different racks that it is almost impossible to get one of the increased effort racks, on an exchange basis. Lots of horror stories about people swapping out racks and ending up with reduced power steering.

One of the pieces I'm working on is replacement torsion bars in various configurations, so people that have wider tires can get steering better suited to their individual needs.

These are not ready for "prime time"....still figuring out twist percentages required and machining up prototypes....but they are coming!

Taipo

Greg, how would you see the reduced steering effort torsion bars being made available? As a component or would you be expecting to supply a complete spool valve or a complete rack? It looks to me as though the torsion bars are drilled and pinned in the spool valve individually and that it would be hard to just fit a replacement torsion bar?

'90 S4