Inconsistent EPS

[Adg]

Hi there

Wonder if anyone is able to share some wisdom. The following issue ive experienced in other cars with electric power steering but to a lesser degree, and have never got to the bottom of it. 
I currently have a Mk8 Civic Type S (the one that looks like a Type R) 

I have found even from day one that the steering is very inconsistent. I dont know if im just sensitive to it but some days it feels a fair bit heavier then lighter. On the days it feels heavier i find i have much more confidence driving the car normally (i dont thrash my cars). 
In particular the steering weight is inconsistent from left to right, even stationary. I have had this on other front wheel drive cars with Eps but on this its definitely more noticeable, is it a fairly normal characteristic? Right turns are much tighter than left turns, that actually feel quite loose in comparison . I know a Civic isnt going to be a benchmark in steering feel but i just want to have a more comfortable experience day to day. 
 

Ive had steering and suspension components checked quite a few times aswell as a geometry setup with camber bolts to try and fix this but no joy,now im trying not to aimlessly throw money at it now. Tyres are Avon ZV7s 17’ which from what ive heard are good robust tyres. 
 

The car does appear slightly higher on its tyres on the left side with a larger wheel arch gap but have been told this is normal, other than that only thing i can think if is worn springs or rear shocks. All quite old i think?
 

Maybe i just dont get along with electric power steering? Ive always found them less confidence inspiring after hydraulic rack cars but more or less every car has eps now! 

[Tony]

Question..... Does the pull/ drift left or right?

[Adg]

It does pull to the left slightly yes, when you relax the grip on the steering wheel. And when driving normally and stationary ive noticed it doesn't self centre as much as the other side. I know on most cars a small amount is noticeable but I find it quite noticeable.

[Tony]

I assume the geometry hasn't been checked yet?

I need you to test something?...... In a safe area can you drive at around 10mph, let go of the steering and watch if it moves in increments... This will tell me where the problem is or is not. What i would like to see is the steering moving in increments per revolution of the tyres.

[Adg]

Thanks Tony. Yes geometry has been done but with a company more local, they fitted camber bolts (can provide readout too if it helps) 

I managed to try that in a flat car park and it actually didnt move at all. Im assuming this is testing it in a straight line with hands off wheel.

i reduced psi in tyres today a few notches below Hondas recommendation (30psi) i am feeling an improvement- theres still the unevenness in steering weight but the car does feel more planted. 

[Tony]

I would like to see the printout. Our ethos is we don't have problems, we have solutions. The way to get the solution is the narrow down the reasons and then focus on the reason and solution.

As said the printout is a method to focus on or move on.

[Adg]

Certainly. Here is the print out. This was done quite recently after fitting camber bolts. 
One thought i have had is whether the tyres just arent suited to this car (Avon ZV7 R17)

 Im doubtful tyres would cause uneven steering effort when stationary though.
 

[liner33]

A mate is having a similar problem with his daughters Mitsubishi Colt , the fault has been traced to a faulty steering rack but the price is too high to make financial sense think its ITRO £1700 on a car worth £900 

Any chance that the car had received a knock ? 

 

[Tony]

On 14/10/2020 at 13:51, Adg said:

Certainly. Here is the print out. This was done quite recently after fitting camber bolts. 
One thought i have had is whether the tyres just arent suited to this car (Avon ZV7 R17)

 Im doubtful tyres would cause uneven steering effort when stationary though.
 

Once again they haven't measured the caster angle! I see this every day, seems companies think if it's not adjustable they won't measure it.

One of the casters duties is directional stability but also...

Toe-out on turns

Steering return

Included angle

Steering weight

SAI ( steering axis inclination )

Roll force leaver

Annoying thing is all those angles are acquired by turning the steering 20 degrees left, 20 degrees left. Another point about the measurement is "CLOSE THE DOOR!"

When training most operators turn the steering with the door open? You don't drive the car with the door open, do you? A door is very heavy so when open it will pull the sprung chassis to one side.

[Adg]

Yes Tony well spotted! Im with you there, wherever I go they never measure castor on cars that are non adjustable, and I have witnessed a few places adjusting while the door is open. 
Small details but Id imagine it makes a fair difference with how the car feels. 

Funnily enough I did notice recently that the front left wheel sits slightly further in the arch than the right. It might just be me...however I do think it sits slightly higher on the left than the right. Hopefully I haven't put on weight to cause it!!!! 
Still odd the steering weight feels different sometimes.

Out of interest what would cause uneven castor to investigate. That is what it feels like driving...Like there's more castor on the off side than near side.