Comprehensive Steering Information Thread

[Bry5on]

I’ll be opening up a CSL/ZCP 924 rack and comparing the guts to a ZHP 712 rack within the next week or so.

David

Not to bother but did you get a chance to get to this one? Thanks!

[dewr]

Hi There David, new member so I can't PM, but very interested in the zhp rack refresh. How can I best reach you? Are you in Socal?

[Bry5on]

Hmm, I haven't had this exact issue with this rack, but I have had it in the past with Z3 racks. Can't really say what caused/fixed it. I run redline D4 ATF. I would recommend flushing the system after some time, which includes replacing the reservior since it has an internal filter.

However, with this LPSR rack, now in both my M3 and my ZHP, I occasionally get a sudden very brief dropout/pulsation in the assist when the front is heavily loaded in a corner and hitting a bump, especially when driving hard for a while (hot PS fluid?). On the ZHP I have an upgraded cooler too. Both cars have tons of tire, so lots of load on the PS system, but this didn't happen with the stock or Z3 racks. It's a bit unnerving and feels like extreme bump steer although I do generally know when to expect it. I do have a bunch of the Volke shims in my M3 pump, although interestingly I never really found those had much effect.

I also found the steering effort to still be too light for my liking with the LPSR black, and it the steering weight doesn't really build up as you turn in. I'm going to remove all the shims out of the pump and start over, as a test. I wonder if I've put too many in at this point or something.

If you are running a front wheel offset below 30-35, this could be an issue with scrub radius that was simply highlighted with the tighter rack.

[Bry5on]

I’ll be opening up a CSL/ZCP 924 rack and comparing the guts to a ZHP 712 rack within the next week or so.

David

Please take some good measurements of the torque shafts if you can!

[davidinnyc]

I’ll be opening up a CSL/ZCP 924 rack and comparing the guts to a ZHP 712 rack within the next week or so.

David

[BBRTuning]

BBRTuning, Did you have any issues with your system after installing the black label rack?

Hmm, I haven't had this exact issue with this rack, but I have had it in the past with Z3 racks. Can't really say what caused/fixed it. I run redline D4 ATF. I would recommend flushing the system after some time, which includes replacing the reservior since it has an internal filter.

However, with this LPSR rack, now in both my M3 and my ZHP, I occasionally get a sudden very brief dropout/pulsation in the assist when the front is heavily loaded in a corner and hitting a bump, especially when driving hard for a while (hot PS fluid?). On the ZHP I have an upgraded cooler too. Both cars have tons of tire, so lots of load on the PS system, but this didn't happen with the stock or Z3 racks. It's a bit unnerving and feels like extreme bump steer although I do generally know when to expect it. I do have a bunch of the Volke shims in my M3 pump, although interestingly I never really found those had much effect.

I also found the steering effort to still be too light for my liking with the LPSR black, and it the steering weight doesn't really build up as you turn in. I'm going to remove all the shims out of the pump and start over, as a test. I wonder if I've put too many in at this point or something.

[Ronan]

What have you tried to do? Did you try those shims in the pump?

When I cold start it doesn't do this pulsing. I also am thinking that the fluid viscosity may have something to do with it. Apparently the fluid spec calls for "pentosin chf-11s" and I've used Redline ATF.

[S54B32]

Hi all,

I've also bought and installed the black tag rack from LPSR in Australia. Its worth it. One of the best mods I've done. My M3 is a 2001 and MK20 DSC. I have read this whole thread and am happy to just drive with the DSC off.

I do however have 1 issue since installing the new rack. The steering is pulsing when turning from left to right when the car is stopped and engine is idling @800rpm, parking maneuvers basically. The steering wheel judders. It seems the pump pressure can't keep up with the rack.

This only started when the new rack was installed. So first thing we did was replace the pump with a brand new Bosch pump. Nil fix.
The pressure hose was replaced during rack install.
The ps fluid reseviour was also replaced.
New Redline D4 ATF fluid.
We have bled the system countless times.
We also reinstalled thw old pressure hose because there is a restrictor built into it and we wanted to eliminate a problem with the new hose. Nil fix.

I've been in contact with Lucas in Australia and he is being very helpful to try to solve this issue.

So from reading this thread I am starting to think about pumping issues.

Can anyone shed any light on it?

BBRTuning, Did you have any issues with your system after installing the black label rack?

Same with Z3 1.9 rack..i had the feeling the pump couldn't keep up with the travel speed at idle.

[Ronan]

Hi all,

I've also bought and installed the black tag rack from LPSR in Australia. Its worth it. One of the best mods I've done. My M3 is a 2001 and MK20 DSC. I have read this whole thread and am happy to just drive with the DSC off.

I do however have 1 issue since installing the new rack. The steering is pulsing when turning from left to right when the car is stopped and engine is idling @800rpm, parking maneuvers basically. The steering wheel judders. It seems the pump pressure can't keep up with the rack.

This only started when the new rack was installed. So first thing we did was replace the pump with a brand new Bosch pump. Nil fix.
The pressure hose was replaced during rack install.
The ps fluid reseviour was also replaced.
New Redline D4 ATF fluid.
We have bled the system countless times.
We also reinstalled thw old pressure hose because there is a restrictor built into it and we wanted to eliminate a problem with the new hose. Nil fix.

I've been in contact with Lucas in Australia and he is being very helpful to try to solve this issue.

So from reading this thread I am starting to think about pumping issues.

Can anyone shed any light on it?

BBRTuning, Did you have any issues with your system after installing the black label rack?

[SQ13]

OD 12.88 mm
ID 10.07 mm
Thickness 0.47 mm

Bumping this in case anyone is searching for shims. I’ve linked shims that are 10mm ID, 13mm OD, and 1.0mm thick. Each shim should get you a 25% reduction. I wasn’t able to find any that were 0.5mm thick, but I also didn’t dig too deeply for them.

I can’t comment on the fitment bc I have the shims Volke was selling, so buy at your own risk.

https://www.depcom.sg/shim-ring-pack-diameter-10-mm/stainless-steel-shim-ring-shim-washer-1.0-x-10-x-13-mm-RS010013100

Edit: Actually…they do have 0.5mm thick shims. If you search “shim 10mm 13mm” on their website, you’ll find other thicknesses too.

https://www.depcom.sg/stainless-steel-shim-ring-shim-washer-0.50-x-10-x-13-mm-RS010013050

Edit 2: Looks like they’re charging $30 for shipping regardless of the quantity. I was gonna buy a pack to compare them to Volke’s, but that’s not happening now lol.

[bigjae46]

is it the LF20 or LF30 you have?

Not sure...whatever WorldPac carries. It was advertised as an E46 M3 pump Bosch rebuild.

[kur715]

I have a Bosch reman...its been fine.

is it the LF20 or LF30 you have?

[bigjae46]

I have a Bosch reman...its been fine.

[kur715]

I know this is an old post now , but can anyone please confirm what pump was used in the original post?

[PSUEng]

Not sure if we are covering pumps in this thread but, I'm curious--for PS pumps, what is suggested for replacement for best longevity: new genuine BMW, reman,...? Big price differences, similar to alternators but the new Valeo is less than reman Bosch/BMW.