Using an S5 power steering rack on S4 Car?
 

I used to have an S5 vert with power steering. The car got parted out, and I kept the entire power steering system.

Later, I bought an original S4 Turbo II with a manual rack. I would like to put the S5 rack back on my car, but I am not sure it will work properly at high speed after reading a bit about the differences in the power steering electornics, I'm a bit doubtful it will work right.

The thing is, stock, the FC has a power steering computer, but there is only one sensor attached to the S5 unit, an it is not a movable sensor either. My S4 does not have a power steering ECU, but because of the single wire system, is the damn thing even necessary?

Please only respond if you have first hand experience with this, or have done this before, I do not speculation and people saying "it might work" when they are not sure.


Thank you,


Max.

anyone?

If i remember right the s4 ps pump also has 2 lines going on the top while the s5 had one line going to the top. Also the s4 has a sensor with 2 wire while the s5 has only 1 wire. I would check my cars outside but its too cold n i have no light. Seems like more work to make it work with that car.

There were also differences between the power steering systems, I believe it's as follows:

S4 - ALL Models - Vehicle Speed Sensing: (High speed, low power assist)
S5 - All models except for ____ - Engine Speed Sensing: (High RPM, low power assist)
S5 - ??? (Turbo, GXL, GTUs, or Vert... I don't know which one.) - Vehicle Speed Sensing: Same as S4 models

Someone a little more versed than me can fill in what that mystery model is... I'd like to believe it's GXL.

Well, no I have the ENTIRE system, not just the rack..

I got the pump, the rack, all the lines, etc.... so it's all "bolt in"

The problem I'm having is about the "vehicle speed sensing" bit... how exactly does the system limit assist at high RPM exactly? There is only ONE sensor on it, and that sensor doesn't "move" as in it's not an actuator of any sort, and the pump seems like a direct drive system....

Basically, will I be ok if I only hook up the mechanical part of the system and leave the sensors off completely? how can I rig it to only give "high speed assist" and not the full power that it gives at low speed?

well my S5 GTU didn't have variable power steering and I didn't care. I actually prefer it that way cause the feel is more consistent like a manual rack. As long as you pay attention you should be able to handle full-power steering at higher speeds lol.

ok... Honestly I would just depower it and leave it alone.... if I didn't like drifting.

Problem is, I do like drifting, and it sucks donkey nuts to slide with no power steering in these cars. Some guys can do it, but with my driving style I just cant do it, it doesn't feel right.

anyway, I guess I will just chuck it on there and see what happens... if it blows up, fuck it... if not, then great!

That's 90% of the work right there...

I'm downloading the FSMs for bothS4 and S5 so I can study the electrical diagrams and the steering systems. See if I can help you out, because this difference has me curious too.

Besides, a rack can be R&Red in about an hour.

it will work as long as you use the shitty powersteering pump
you can leave that one wire disconnected - it is only for fluid level.

^

That's a PRESSURE switch, not a LEVEL switch.

hm - you ARE right, i stand corrected.
but you can still leave it disconnected! XD

update: power steering works ok... not the best, but a whole lot easier than it was with a manual rack.

People who do the opposite converting TO a manual rack are retarded... I almost broke my thumb driving with one of those.