Comprehensive Steering Information Thread

[old///MFanatic]

correct, this is the link to the product.

https://burkhart-engineering.com/en/shop/Steering-angle-sensor-adapter-suitable-for-BMW-E46-M3/

My car now works as it did with the OE rack.

Oh my that’s not at all what came up on Google for me. What came up was a metal adapter for the column. This is a wired coding converter.
Helpful solution for some early cars. Thanks for sharing.

[maupineda]

Wait, so to clarify. You personally fixed the DSC issue with this steering angle adapter by Burkhart?
Or you were told somewhere that it would fix it?

Reason I ask is the adapter online doesn’t look like it’s made to fix the DSC issue (unless I’m looking at wrong part)?

correct, this is the link to the product.

https://burkhart-engineering.com/en/shop/Steering-angle-sensor-adapter-suitable-for-BMW-E46-M3/

My car now works as it did with the OE rack.

edit:

this photo shows the SZL reading. 0 when the wheel is straight.



next is the SZL reading when the wheel is turned 90 degrees, SZL reads 90, so far, so normal.



however, when querying the MK60 module, at 90, it reads 105, so you can see the compensation the adapter does.

[old///MFanatic]

Some updates to close the loop on this and update you on the 2 main drawback of the black tag

• A modifiy hose does solve the pulsation issue.
• The DSC issue can be fixed with the steering angle adapter sold by Burkhart

Wait, so to clarify. You personally fixed the DSC issue with this steering angle adapter by Burkhart?
Or you were told somewhere that it would fix it?

Reason I ask is the adapter online doesn’t look like it’s made to fix the DSC issue (unless I’m looking at wrong part)?

[maupineda]

Some updates to close the loop on this and update you on the 2 main drawback of the black tag

• A modifiy hose does solve the pulsation issue.
• The DSC issue can be fixed with the steering angle adapter sold by Burkhart

So I am calling it a success, and the drive with it is very nice, there is a bit more feedback through the wheel, driving on the canyons is just a blast!

[heinzboehmer]

Car is now aligned and everything is bottomed up. overall it is a nice upgrade, however, I had spoken to soon and there are some pulsations when you are close to 70% of the track travel to either side.

In the M3cutters forum there are some details about the fix LPSR came up with, it explains why 02'topaz is having heating issues. They are adding a secondary restrictor within the high pressure line, not sure where, but this would limit oil flow which will create extra heat and slow down cool down in heavy duty such as track or auto-x.

The pulsations are not bad, but are noticeable to any enthusiast, that said, the feel of it is so nice, that right now it is not enough of an issue to put me off. I still have my OE rack and can go back to it at anytime.

Maybe in my case the modified line is ok as I don't track the car, and the fix maybe ok for street and even canyon road usage (question mark on that one), however, I am not convinced the pulsations are a problem perse.

From what it was stated on the other forum, the pulsations come from swealing and contracting of the hose, I would need to look into this from a fluid dynamics point of view, and rather than a restrictor, a slight different diameter, or even a braided line design may also solve the issue, even a different length and routing can be alternatives to explore.

Since the pulsation does not happen during normal driving, I don't think this is an issue, however, I can see this being a problem if you auto-x the car as the rapid wheel movement will result in flow disturbance.

LPSR is in Australia, right?

I wonder if LHD vs RHD has anything to do with this. Length of the hydraulic lines is different between the two, so the resonant frequencies should be different as well. Maybe not as noticeable in the RHD cars?

Besides tuning the resonant frequency of the hydraulic lines, changing the diameter of the pump pulley could drive the frequency into a range that's unreachable during normal driving. Unsure if you could keep the pulley a reasonable size though, some math needed here for sure before continuing with the speculation.

[Bry5on]

If the pulsation were associated with the hose expanding and contracting:
1) I’d expect it to be such a high frequency that it would be hard to notice and
2) you could mitigate it by putting the restrictor closer to the pump/hard line

Given that you can feel it, my guess is that you’re feeling the pressure regulator open/close. It’s a bit of a gamble, but you could try the reverse of shimming the pump regulator to force it to operate at a bit higher pressure, though you’d change the assist level.

[maupineda]

Car is now aligned and everything is bottomed up. overall it is a nice upgrade, however, I had spoken to soon and there are some pulsations when you are close to 70% of the track travel to either side.

In the M3cutters forum there are some details about the fix LPSR came up with, it explains why 02'topaz is having heating issues. They are adding a secondary restrictor within the high pressure line, not sure where, but this would limit oil flow which will create extra heat and slow down cool down in heavy duty such as track or auto-x.

The pulsations are not bad, but are noticeable to any enthusiast, that said, the feel of it is so nice, that right now it is not enough of an issue to put me off. I still have my OE rack and can go back to it at anytime.

Maybe in my case the modified line is ok as I don't track the car, and the fix maybe ok for street and even canyon road usage (question mark on that one), however, I am not convinced the pulsations are a problem perse.

From what it was stated on the other forum, the pulsations come from swealing and contracting of the hose, I would need to look into this from a fluid dynamics point of view, and rather than a restrictor, a slight different diameter, or even a braided line design may also solve the issue, even a different length and routing can be alternatives to explore.

Since the pulsation does not happen during normal driving, I don't think this is an issue, however, I can see this being a problem if you auto-x the car as the rapid wheel movement will result in flow disturbance.

[maupineda]

Yes, I am aware of that and I can see it on drift cars where you jam the system lock to lock, but I am sure street or even track car won’t be an issue.

[moproblems]

I have added the SLR limiters, they are plastic and although I thought about aluminum limiters, I don’t want a metal part rubbing on the rack’s shaft as it may scratch it over time. Ideally you would want a slight press fit so they stay at the end of the shaft next to the tie rods, but for street application plastic will do, plus I never force the steering on lock. With the limiters I have 1.1 turns to either side which give the perception of a much quicker system, but I still have the OE turn radius as I keep the system same as OE with a total of 138-140mm of rack travel.

Just know the SLR limiters are generally a maintenance item for some. My buddy has had to replace them every season on his drift car as they come apart.

Unrelated, but does anyone still have shims on hand?

[maupineda]

I have added the SLR limiters, they are plastic and although I thought about aluminum limiters, I don’t want a metal part rubbing on the rack’s shaft as it may scratch it over time. Ideally you would want a slight press fit so they stay at the end of the shaft next to the tie rods, but for street application plastic will do, plus I never force the steering on lock. With the limiters I have 1.1 turns to either side which give the perception of a much quicker system, but I still have the OE turn radius as I keep the system same as OE with a total of 138-140mm of rack travel.

[maupineda]

Received the replacement rack and finished the install. I took her out for a spin and impressions are good!

the steering feel is slightly clearer with some extra road texture coming through the wheel. The lack of spacers make the Z to have a much tighter turn circle (obviously) and I did not see any contact at full lock, but will still add the limiters when I get them next Monday.

out on the road it does take some time to adjust as at highway speeds very minor input on the wheel steers the car; on highway 17 to Santa Cruz she felt really alive and the whole car is very alert. I am liking it, the quick steering and the shorter drive ratio have transformed the car.

[maupineda]

I measured the distance from the outer most edge of the rack housing to the inner face at which the inner tie rod bottoms out, the black tag measures 24mm and the OE rack 19. Is tough to say the exact measurements as is impossible to line up the caliper perfectly every time, so let’s say is 5-6mm more on the BT, which means the limiters on the Z4M rack are between 5 to 6mm

i suppose the BT rack is the same as any other E46 as the Z4M’s 2.8 turns lock to lock must come from these built in limiters.

the rack displacement per turn is 50mm, the value below is 70 and change when centered. So, the Z4M rack itself is not faster than the CSL



The below image shows the depth to the surface that stops the inner tie rod



The same measurement on the Z4M rack is 19mm

[maupineda]

You can see the OE rack and the BT rack together, on the outside they look very similar, the casting quality is rather good with some areas showing more rugged surfaces.

i am glad to report that I will get a warranty replacement rack, which should fix the issue with the splines on mine



this is when I installed it before I had to take it off.



the Z4M rack does have limiters built into it, I need to measure how thick they are as I will need limiters on the BT or the tire will hit the inside of the wheel well, this is in part why the Z has less lock to lock turns (~2.8), basically it just does not use the full 150mm of total displacement. Some basic math.

1.5 turns or 75mm of track travel equals to 540degrees or 37.24 degrees at the wheels assuming a 14.5 steering ratio

According to BMW, the ratio of the Z4M coupe is 12.8:1, so at 1.5 turns the wheels are at 42.2 degrees, which is a lot more. Plus the Z has less space as it uses the smaller control arms from the 330 ZHP.

[maupineda]

Thanks for sharing! Interesting what you describe.

[02'topaz]

I’ve been running the LSPR black tag rack since last season and initially had no major issues other than the pulsation described by other users at full lock. This honestly didn’t affect the function of the car for me, but given the fix was a custom PS line from Lucas, I went ahead and installed it.

Attended my first track day since the new line went in, and had major issues with presumably boiling the fluid. After 1.5 laps on a track with short straights and lots of corners, began losing power steering. As the car cooled, things returned back to normal. Tried to push another lap just in case the system had not been bled properly, but same issue, with whining from the PS pump and near total loss of power steering.

Street driving is absolutely normal and the pulsation of course is gone. But I have traded a problem that didn’t bother me for a car that is no longer usable on track. Running D3 atf per Lucas’ recommendation and not Chf-11s.

Naturally one would think it’s time for a cooler, but why was this issue not present before with the same rack/OEM line at the same track on two occasions and only now with the new custom line?

PS reservoir was replaced when lines were refreshed so a clogged filter cannot be the issue.

Anyone else having this issue and have any insight on how to rectify other than potentially going back to the OEM line and just dealing with the pulsation (as long as it longterm doesn’t fry my pump).

Shitty way to start the season today but thankfully didn’t bin the car when losing PS completely into a hot corner…