[HotRodSaint]

I need to replace my power steering pump soon.

Before the need arose, I was thinking about changing the FW steering box to an SS box.

If I use an SS box, should I also use an SS steering pump?

Whats involved in changing to an SS pump? Is it just a pump swap? Will it work with the FW box? Will an FW pump work with an SS box?

What exactly does this variable assist do for me? It doesn't seem to be speed related, as in the faster you go the firmer it feels.

Any ideas?

 

[toomanytoyz]

I need to replace my power steering pump soon.

Before the need arose, I was thinking about changing the FW steering box to an SS box.

If I use an SS box, should I also use an SS steering pump?

Whats involved in changing to an SS pump? Is it just a pump swap? Will it work with the FW box? Will an FW pump work with an SS box?

What exactly does this variable assist do for me? It doesn't seem to be speed related, as in the faster you go the firmer it feels.

Any ideas?

Well, AFAIK, the variable assist is in the pump. At least that's what my parts guy told me. So if you want to lose that, then I'd go with the impala pump. I am unsure if the lines are different for that application though... And, the VA is speed sensitive. Notice how easy it is to turn the wheel in the parking lot, but how firm it is on the highway? At least that's how mine is. Maybe you don't have the variable assist, or it's not functioning properly if you notice otherwise...

Oh, on a side note, I have a steering box out of a 35k mile Impala that I was going to install in my car if you'd like to buy it. I've had it for a year and have not had time to install it, and I could use the cash for it now anyways. It's actually still in the sealed box it was sent in!

 

[HotRodSaint]

And, the VA is speed sensitive. Notice how easy it is to turn the wheel in the parking lot, but how firm it is on the highway?

How does it the VA FW compare to the SS at highway speed? Any experience?

I'll get back to you on the box. I need to work out the options on the pump first.

 

[toomanytoyz]

How does it the VA FW compare to the SS at highway speed? Any experience?

I'll get back to you on the box. I need to work out the options on the pump first.

Well, for one, the ss doesn't have variable assist.

And make me an offer if you're interested.
[email protected]

 

[toomanytoyz]

How does it the VA FW compare to the SS at highway speed? Any experience?

I'll get back to you on the box. I need to work out the options on the pump first.

OK...actually, after having re-read what you asked, I don't think I answered your question in my last response. The SS has a firmer feel all the time than the FW has even at it's firmest. I actually prefer the feel of the SS/9C1 steering over the FW, but I just don't have the time to do the swap. I'm not sure how much of the "feel" is due to the box though. I know the SS box is a quicker ratio (12.9:1 or close) and the FW box is closer to 15.0:1, but that number doesn't say anything about the box feel...

*shrug*

I think most of the feel is due to the pump.

 

[Katshot]

The Variable Assist is just applied via a variable oriface valve on the back of the pump that takes the place of the standard fixed oriface valve on the rest of the cars. I have no first-hand experience with these swaps but have talked to guys that swear by the "F" body box.
The Variable Assist system defaults to full boost so if there's no appearent difference between low and high speeds, your system may have a fault and be in the default mode.

 

[HotRodSaint]

The Variable Assist is just applied via a variable oriface valve on the back of the pump that takes the place of the standard fixed oriface valve on the rest of the cars. I have no first-hand experience with these swaps but have talked to guys that swear by the "F" body box.
The Variable Assist system defaults to full boost so if there's no appearent difference between low and high speeds, your system may have a fault and be in the default mode.

Thanks Kat. It might not be in default. I might not have noticed the difference between ultra light and light.

I was looking at the FSM and it appears that the VA pump plugs into the PCM which sends a signal as to how much boost to give. Do you think I could cause other issues if I installed a pump that didn't connect to the PCM? Thats assuming an SS or F-body pump doesn't have the same type of connection. (Time to buy 2 more FSMs.)

It seems logical that an Fbody pump would give a better feel, since it was 'sportier' than a SS. The conversions were on a Bbody?

 

[Katshot]

The pump doesn't matter. It's the gear that controls the "feel".
The connection you're talking about is on the variable valve which screws into the pump in place of the normal fixed valve. The two valves are interchangable as far as how they mount, one replaces the other. Just unscrew one and screw the other in. You will be left with a wire hanging but it will not cause any problem anywhere else.

 

[HotRodSaint]

The pump doesn't matter. It's the gear that controls the "feel".

I confess to know nothing about power steering. I don't even check the fluid as often as I should.

But since it has a valve, then the valve must be there to control flow. So logic tells me it's the flow that 'powers' the steering.

So couldn't the Cadillac VA over power it ever so slightly making it feel lighter, while another pump with a different valve could make it feel harder?

 

[Katshot]

If all you're talking about is "overall" ease of steering wheel rotation, you're right about the valve, just remember that the pumps are the same. As for the boxes, they are not designed for just a flat linear feel. Some have more on-center feel, shorter ratio, etc. The box controls the character of the steering and the boost level from the pump controls how hard or soft the steering wheel turns. The fixed oriface valve that comes on all non-variable assist steering systems is designed to allow a fairly moderate amount of hydraulic boost but generally it can feel over-boosted on the highway if you set it for easy turning in the parking lot, or UNDER-boosted in the parking lot if you set it to feel more stable on the highway. That's where the variable assist system earns it's pay. Women and older folks tend to like a steering that's easy in low speed manuevers so GM installed the systems on big cars that tend to be driven by those people. I think it's only on the full-size Buicks and Cadillacs and they just happen to be driven mostly by older folks.
What would be nice is if GM used a driver-adjustable P/S system like Lincoln has.

 

[HotRodSaint]

In your best judgement, does the VA and fixed SS feel the same at speed?

I might leave it alone and go for a box instead.

 

[Katshot]

The "feel" you're talking about is probably the box. There's definately a better "feel" from the Chevy boxes. I would suggest changing the box and then disconnecting the VES This would very closely (if not exactly) replicate the SS system. You might want to experiment with using the Chevy box AND the VES to give you basically the best of both worlds. If I ever do mine, I intend to just swap a "F" body box in and retain the VES. It's really going to be a subjective thing though.
The point being, if you were to install a Chevy pump you wouldn't notice any difference since the two cars use the same pump. The VES valve just takes the place of the fixed valve on non-VES applications.