Lighter Steering ?????
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Burning Brakes
Joined: Jun 2001
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From: Miami, FL
Lighter Steering ?????
Is there a way to get lighter steering?? The steering on the 928 is VERY HEAVY. The car would be so much nicer if the steering were lighter. I know the newer ones(90+) got lighter steering (via revaled pump). I drove a 1992 today, the steering was incredible. The car even feels lighter!! Is there a way to revale our pumps??? Or, is it possible to upgrade to the newer 90+ pump.
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Joined: May 2001
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From: Spokane, WA
The upgrade should just mean a new pump and lines, probably $$$ though.
Before you go too far have you tried flushing ths system and replacing the resovior ??
This improved mine.
Chris
Before you go too far have you tried flushing ths system and replacing the resovior ??
This improved mine.
Chris
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Joined: Jul 2001
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From: Midland, Texas
Weissach,
Different strokes I guess...
When the shARKANSAS Frenzy and Traveling Circus got on the road I really apprecited the heavier feel.
There were two instances going into left camber, decreasing radius, curves into a quick dogleg with left to right camber into a diving flat left HARD turn where the front end UNLOADED with no warning <img src="graemlins/oops.gif" border="0" alt="[oops]" /> My impression was that I had zero front end tire contact with the road while the rear wheels just kept loading - due to right foot torque commands.
Imagination, I can assure you, is much faster than reaction time. Momentum and torque coupled with centrifical (fugal?) force had big plans for us... frisbee or the triple Lutz? In any case I developed an appreciation for the 'heavy' feel and a greater respect when the the feel gets 'light'. Besides, I think that heavy feel is part of the reason our sharks will roll straight at speed with both hands off the wheel while we are constructing Dagwood sandwiches out of the cooler in the back seat.
John S.
Different strokes I guess...
When the shARKANSAS Frenzy and Traveling Circus got on the road I really apprecited the heavier feel.
There were two instances going into left camber, decreasing radius, curves into a quick dogleg with left to right camber into a diving flat left HARD turn where the front end UNLOADED with no warning <img src="graemlins/oops.gif" border="0" alt="[oops]" /> My impression was that I had zero front end tire contact with the road while the rear wheels just kept loading - due to right foot torque commands.
Imagination, I can assure you, is much faster than reaction time. Momentum and torque coupled with centrifical (fugal?) force had big plans for us... frisbee or the triple Lutz? In any case I developed an appreciation for the 'heavy' feel and a greater respect when the the feel gets 'light'. Besides, I think that heavy feel is part of the reason our sharks will roll straight at speed with both hands off the wheel while we are constructing Dagwood sandwiches out of the cooler in the back seat.
John S.
Thread Starter
Burning Brakes
Joined: Jun 2001
Posts: 1,152
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From: Miami, FL
If all you have to do is turn the wheel to drive (on automatics), then it's okay. But add to it the heavy clutch and shifter, it becomes a handfull. There must be a way of revalving the pump.
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Joined: Feb 2002
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From: Ft. Lauderdale FLORIDA
I test drove an '88 S4 a while back-
It felt much heavier than my '85 S2 5 Speed. The steering was "oily", meaning that it felt a bit more damped than mine. And it made me wonder about the alignment of my '85- my car feels "manic" compared to this car, though I've had my car aligned correctly and to specs via a shop here in town. I have to drive my car 100% of the time, while the '88 felt very relaxed, far more stable, and less maneuverable. I didn't push it through a set of curves, unfortunately, so this might just be subjective observation.
Normy!
'85 S2 5 Speed
It felt much heavier than my '85 S2 5 Speed. The steering was "oily", meaning that it felt a bit more damped than mine. And it made me wonder about the alignment of my '85- my car feels "manic" compared to this car, though I've had my car aligned correctly and to specs via a shop here in town. I have to drive my car 100% of the time, while the '88 felt very relaxed, far more stable, and less maneuverable. I didn't push it through a set of curves, unfortunately, so this might just be subjective observation.
Normy!
'85 S2 5 Speed
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Just a reminder that tires and tire pressure both make a world of difference in steering feel.
"effort" in the wheel is a function of pump pressure, and also affected by the little torsion spring in the spool valve in the steering gear. This little spring is what feeds fluid into the rack cylinder when you need it. I don't know how servicable this part of the rack is on the 928 though-- One of the guru's might want to say something. In the meanwhile, many US cars have 'speed sensitive' power steering, where a tiny bypass port adds a little negative pressure bias to the spool valve. Actually adds pressure boost while the pump pressure is low, more like 'engine speed sensitive' but drivers don't know the difference.
ZF makes racks for plenty of cars that steer with less wheel effort. Might be worth a look at spool assemblies from them next time you do a rebuild.
"effort" in the wheel is a function of pump pressure, and also affected by the little torsion spring in the spool valve in the steering gear. This little spring is what feeds fluid into the rack cylinder when you need it. I don't know how servicable this part of the rack is on the 928 though-- One of the guru's might want to say something. In the meanwhile, many US cars have 'speed sensitive' power steering, where a tiny bypass port adds a little negative pressure bias to the spool valve. Actually adds pressure boost while the pump pressure is low, more like 'engine speed sensitive' but drivers don't know the difference.
ZF makes racks for plenty of cars that steer with less wheel effort. Might be worth a look at spool assemblies from them next time you do a rebuild.
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From: Grosse Pointe, MI
This is the same problem I just noticed on my 87. Big Dave came over and I got to drive his 85. His was a nice moderate feel. My 87 has done wonders for my biceps but what a pain in the ! My rack is leaking a little bit and all I've done is top off the fluid. Can someone explain how to FLUSH the power steering system? Thanks 
Three Wheelin'
Joined: May 2001
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From: Hudson Valley NY
weissach,
The pump delivers more oil at higher speeds. Change the pulley to increase the pumps turning speed.
Or the pump has a flow-limiting valve which controls flow rate and a pressure-limiting valve, which limits the maximum pressure in the system. Changing the spring tension in the valve will increase the pressure. The pressure-limiting valve opens at 100 bars.
If there is enough interest maybe one of the billet aluminum pulley makers will make 928 pulleys, air pump, alt, power steering, etc. Just like Speedhut did the illuminating dash.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
The pump delivers more oil at higher speeds. Change the pulley to increase the pumps turning speed.
Or the pump has a flow-limiting valve which controls flow rate and a pressure-limiting valve, which limits the maximum pressure in the system. Changing the spring tension in the valve will increase the pressure. The pressure-limiting valve opens at 100 bars.
If there is enough interest maybe one of the billet aluminum pulley makers will make 928 pulleys, air pump, alt, power steering, etc. Just like Speedhut did the illuminating dash.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Thread Starter
Burning Brakes
Joined: Jun 2001
Posts: 1,152
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From: Miami, FL
First things first: The steering on my car is perfect. I currently have four other 928s, they are all the same. So, there is nothing wrong with my actual pump. But, it's still driving me crazy. I noticed that it does not bother me as much on the automatics. I know that I am not the only one because Porsche "fixed" this problem on their later cars. All one needs to do is drive a 91+ to feel the difference. The feel alot lighter and responsive.
I don't think that a pulley could change much. Because steering effort is the same at 1000rpm and 5000rpm. But doing some mods to the actual pump might be the way to go. I think I will go to a local steering rack rebuild shop and ask about the "torsion spring in the spool valve".
I don't think that a pulley could change much. Because steering effort is the same at 1000rpm and 5000rpm. But doing some mods to the actual pump might be the way to go. I think I will go to a local steering rack rebuild shop and ask about the "torsion spring in the spool valve".
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The 91+ models not only have a lighter weight pump which delivers more pressure, they also have a different steering rack.
Maybe you should call the "Big Three" to find out if these newer pumps and racks are compatible with the older model cars.
Let us know what you find out!
Maybe you should call the "Big Three" to find out if these newer pumps and racks are compatible with the older model cars.
Let us know what you find out!