RPM sensitive PS to speed sensitive PS?

mbtoloczko · #1 10-11-2004, 05:20 PM

Does anyone know if its possible or difficult to convert from the rpm-sensitive power steering system to the speed-sensitive power steering system?

SVXer95 · #2 10-11-2004, 05:40 PM

Don't know anything about the conversion, but why would you want to do such a thing? I have driven both kinds and I really prefer the feel of the rpm sensitive power steering. It is heavier and you get more road feel. Maybe its just me, but those qualities are important for highway and spirited driving.

mbtoloczko · #3 10-11-2004, 05:53 PM

Ah, I haven't driven a car with the speed-sensitive PS, but it seems like a more logical way to control the PS behavior. However, if the speed-sensitive PS provides less road feel than the rpm sensitive, then I wouldn't bother.

immortal_suby · #4 10-11-2004, 06:02 PM

My wifes svx had the speed sensitive rack replaced with the rpm sensitive one by the PO. It is much heavier than mine.

I think I like the speed sensitive better but I have different rims/tires on mine so it might just feel better from that.

oab_au · #5 10-11-2004, 06:02 PM

Quote:

Originally posted by mbtoloczko
Ah, I haven't driven a car with the speed-sensitive PS, but it seems like a more logical way to control the PS behavior. However, if the speed-sensitive PS provides less road feel than the rpm sensitive, then I wouldn't bother.

Hi Mate, I drive both, the SVX is speed and the liberty is rpm. I prefer the speed sensitive as it is more stable as the box changes gear and the rpm drops, the assist goes up.

The speed sensitive unit just remains constant during the changes, and has less assist as the road speed incresess. Feels solid at high speed, through the 3rd to 4th change.

You would have to compair the racks and control units.

Harvey.

mbtoloczko · #6 10-11-2004, 06:56 PM

Hi Harvey. Yeah, I was thinking it might work more like that. Mostly the rpm-sensitive seems to feel ok, but I have found that during auto-x, it can mess a bit with the steering feel. In one instance where I come into a cone with the engine WFO and then push in the clutch, the rpm-sensitive rack does not respond quickly enough, and for a second, the PS offers very little assist and its nearly impossible to turn the wheel. First time it happened, I almost didn't make the cone.

#7 10-12-2004, 05:42 AM

My girlfriends SVX has speed sensitive steering, my SVX has RPM sensitive. I prefer the feel of the RPM sensitive steering system. Her steering feels too light at low speeds, where as mine has a nice solid feel at all times. Call my crazy but I think the "cheaper" steering system feels better.

Dave

majeskyb · #8 10-12-2004, 01:59 PM

I have "speed sensitive" steering in my RX-7. No power steering at all!

The faster the car moves, the easier it is to turn. I don't mind it at all, except when I have to turn the wheel at a dead stop. Besides then, I really don't mind no power steering though

Chiketkd · #9 10-12-2004, 02:11 PM

Mychailo,

I think swapping to speed sensitive steering should be relatively straight forward, but you'll probably need the complete steering rack from an LS-L or LSi parts car.

I love the 'heavier' rpm sensitive steering in my 96 L, and I've driven Tom's 92 LS-L and his son Nick's '96 LSi with speed sensitive steering, and the assist is definitely greater which gives the wheel a light or floaty feeling a times.

Either way, when you're racing, surprises are never good, and you should definitely go with something you feel most comfortable with...

-Chike

Mr. Pockets · #10 10-12-2004, 04:10 PM

Quote:

Originally posted by mbtoloczko
Hi Harvey. Yeah, I was thinking it might work more like that. Mostly the rpm-sensitive seems to feel ok, but I have found that during auto-x, it can mess a bit with the steering feel. In one instance where I come into a cone with the engine WFO and then push in the clutch, the rpm-sensitive rack does not respond quickly enough, and for a second, the PS offers very little assist and its nearly impossible to turn the wheel. First time it happened, I almost didn't make the cone.

That sounds like a good reason to change, if you ask me. Anything the car does that is surprising or unsettling should be dealt with.

Is there any way to disable the steering's RPM sensitivity? Maybe you could find a simple electronic way to make sure the steering didn't change its assist with RPM. It might end up too heavy or over assisted, but at least it'd be consistent and that'd be an improvement over what you're dealing with right now.

I imagine that such a distraction, and preparing and compensating for it, is distracting you from what you should be doing and not helping your times one bit.

FlagstaffSVX · #11 10-14-2004, 02:23 AM

How can I tell which version I have?

Oh, and would it matter which one I had if I was swapping out the PS pump?

gl1674 · #12 10-14-2004, 10:59 AM

Quote:

Is there any way to disable the steering's RPM sensitivity

The sensitivity is controlled by a single solenoid & valve on the steering rack. You either have to disconnect it completely or wire it to a power source. Sorry I can't tell which way it is, but it's easy to figure out by trying. Be careful - at minimal assist the steering is very heavy, almost impossible to turn at low speeds.

Chiketkd · #13 10-14-2004, 11:07 AM

Quote:

Originally posted by FlagstaffSVX
How can I tell which version I have?

You have a '92 LS-L. LS-L and LSi models came with the speed sensitive steering. L and LS models came with the rpm sensitive rack.

-Chike

FlagstaffSVX · #14 10-14-2004, 06:02 PM

Hmm... new problem, (thread hijack)

I ordered a new PS pump from Checker and while my PS pump has some wires coming out of it, the one Checker gave me does not. I take it they gave me the wrong pump even though I specified LS-L?

I guess I might as well just take it back now even though I'd like to hear from you guys first.

gl1674 · #15 10-15-2004, 12:53 AM

The assist control valve and solenoid are on the steering rack, not the pump. The switch on the pump is some kind of pressure switch, I don't know what it does, on my car it seems to do nothing at all. Most likely it just warns ECU about high load from PS pump and used to increase engine RPMs when steering wheel is turned with the car stationary.

The engine RPM sensing and speed sensing pumps have different internal passages and different pressure control valve shapes.
You can't tell by just looking at it which one is it and you can't just swap the valve - well, you can, but you will not get the right pressure curve.