So begins (continues) the journey to "fix" the EPS

E90angeleyes · 04-21-2021, 02:56 AM

Hello,

My previous BMWs have been an e36, e46, e90, and e39 (not in that order). If the car wasn't an M, it had the sport package. Now, I just can't get used to the electronic power steering (EPS) on my 2016 535i m-sport. It's very soft/ight compared to what I am used to. Too soft/light, especially for a BMW. I have installed KW v2 coilovers and Michelin PS4S tires. I'm still unhappy with the steering feel. Could I make any adjustments to the coilovers to help this issue?

So far I have been advised to either change the thrust arm bushings or change the thrust arms entirely. I'm leaning towards replacing the entire thrust arm because I want maximum change. I have only found Turner motorsports offering replacement thrust arms. Anything else that I can or should change here? Like maybe control arms? Why or why not?

Also, would sway bars (either just front or both) help remediate this issue? What differences would I see in replacing only the front vs. replacing both? I think I have only seen H&R and Eibach offering replacement sways.

Other ideas/thoughts/suggestions? Thanks.

I gotthatzumzum · 05-28-2021, 12:14 PM

Changing bushings won't really change the feel of the steering. The ultra soft/light feeling can be attributed to 2 things. First, it speaks to the capabilities of an electric motor vs. a hydraulic assisted unit. The second is how the systems are designed to be assisted. Hydraulic uses fluid at high pressure to assist, while the latter uses an electric motor connected directly to the steering rack. Long story short, using an electric assisted unit is much more efficient, but has some drawbacks (such as steering that feels too light).

The way I see it, there's only 2 things that you could potentially do to increase the feel. The first may not even be possible, and the second I definitely wouldn't recommend.

Considering the unit is electrically assisted, there should be a module that controls that assistance. It may be possible to code in less assistance from the module for a firmer feel. If possible, I assume this could be done by somehow reducing the current and/or voltage available to the motor itself.

The second option would be to add-in resistance to the steering system, which would need to occur at the tire, the lower ball joints, the upper strut mounts, or in the steering rack/column itself. I honestly don't even know how you'd go about doing that without adding risk to the longevity of components life.

If you land on a fix, definitely post about it. I'm sure there's other's that would be interested in it too.

04-21-2021, 02:56 AM	#1
E90angeleyes Private 7 Rep 90 Posts Drives: 325i Join Date: May 2008 Location: california iTrader: (1)	So begins (continues) the journey to "fix" the EPS Hello, My previous BMWs have been an e36, e46, e90, and e39 (not in that order). If the car wasn't an M, it had the sport package. Now, I just can't get used to the electronic power steering (EPS) on my 2016 535i m-sport. It's very soft/ight compared to what I am used to. Too soft/light, especially for a BMW. I have installed KW v2 coilovers and Michelin PS4S tires. I'm still unhappy with the steering feel. Could I make any adjustments to the coilovers to help this issue? So far I have been advised to either change the thrust arm bushings or change the thrust arms entirely. I'm leaning towards replacing the entire thrust arm because I want maximum change. I have only found Turner motorsports offering replacement thrust arms. Anything else that I can or should change here? Like maybe control arms? Why or why not? Also, would sway bars (either just front or both) help remediate this issue? What differences would I see in replacing only the front vs. replacing both? I think I have only seen H&R and Eibach offering replacement sways. Other ideas/thoughts/suggestions? Thanks. Last edited by E90angeleyes; 04-21-2021 at 04:24 AM..
	Appreciate 0 Tweet Quote

05-28-2021, 12:14 PM	#2
I gotthatzumzum Second Lieutenant 18 Rep 272 Posts Drives: 14 550i - 09 135i - 17 328d Join Date: Dec 2015 Location: Tri-Cities, Washington iTrader: (5)	Changing bushings won't really change the feel of the steering. The ultra soft/light feeling can be attributed to 2 things. First, it speaks to the capabilities of an electric motor vs. a hydraulic assisted unit. The second is how the systems are designed to be assisted. Hydraulic uses fluid at high pressure to assist, while the latter uses an electric motor connected directly to the steering rack. Long story short, using an electric assisted unit is much more efficient, but has some drawbacks (such as steering that feels too light). The way I see it, there's only 2 things that you could potentially do to increase the feel. The first may not even be possible, and the second I definitely wouldn't recommend. Considering the unit is electrically assisted, there should be a module that controls that assistance. It may be possible to code in less assistance from the module for a firmer feel. If possible, I assume this could be done by somehow reducing the current and/or voltage available to the motor itself. The second option would be to add-in resistance to the steering system, which would need to occur at the tire, the lower ball joints, the upper strut mounts, or in the steering rack/column itself. I honestly don't even know how you'd go about doing that without adding risk to the longevity of components life. If you land on a fix, definitely post about it. I'm sure there's other's that would be interested in it too.
	Appreciate 0 Quote