Can the curse of modern cars, steering feel, be retrofitted?

[kambites]

SuperchargedVR6 said:

What is it about HPAS that provides feedback?

I think a better question would be what is it about EPAS that removes it.

I don't actually know the answer; I can see no particular theoretical reason that EPAS should damp the steering feel any more than HPAS. I'm not sure there's anything fundamental beyond the fact that manufacturers have had decades to get HPAS right whereas EPAS is relatively new. I wouldn't be surprised if EPAS ends up better than HPAS in the end just because there's less inertia in the steering system.

[k-ink]

EPAS certainly adds another extremely expensive component to fail onto the list. So for that reason alone it is a waste of time, IMHO.

[kambites]

k-ink said:

EPAS certainly adds another extremely expensive component to fail onto the list. So for that reason alone it is a waste of time, IMHO.

It adds one relatievly expensive component with one moving part and removes a significant number of cheaper components and a whole load of bloody awkward plumbing.

Reliability and cost should be one place EPAS beats HPAS hands-down. It doesn't appear to at the moment, but again manufacturers have had a lot less time to iron out the problems than they have with HPAS.

[vrooom]

Soild mount the steering rank to bulkhead/subframe, and soild mount that subframe to body. and run thinner tyress.

[k-ink]

kambites said:

It adds one relatievly expensive component with one moving part and removes a significant number of cheaper components and a whole load of bloody awkward plumbing.

Reliability and cost should be one place EPAS beats HPAS hands-down. It doesn't appear to at the moment, but again manufacturers have had a lot less time to iron out the problems than they have with HPAS.

All very well in theory. But the reality is there was nothing wrong with HPAS. I've never owned a car where the steering failed with HPAS. Yet look at the number of electric racks which failed on the MINI or Z4 (costing thousands of pounds). Just not acceptable to replace a perfectly good part with something which can and does fail. Germans trying to be clever again, but failing.

[kambites]

k-ink said:

But the reality is there was nothing wrong with HPAS.

There is something very wrong with HPAS in the current political climate - it uses more fuel.

[k-ink]

kambites said:

There is something very wrong with HPAS in the current political climate - it uses more fuel.

Meh, big deal. I'll take the extra £1 at fill up over a three grand bill. Plus the carbon footprint to keep manufacturing and shipping replacement parts. The net result is EPAS worse for the planet I suspect. But looking at the whole picture would skew the figures in the brochure wouldn't it

[kambites]

k-ink said:

Meh, big deal. I'll take the extra £1 at fill up over a three grand bill.

Oh I agree entirely, but "the market" doesn't.

I'll stick with an unassisted rack. Best of both worlds.

[Mike_Mac]

SuperchargedVR6 said:

Mike_Mac said:

Personally I'm regarding this as EPAS's fault. I can't think of a car yet that I've been in with it that has felt remotely nice to drive compared to something with a hydraulic rack. Some EPAS systems are better than others, but only within the EPAS frame of reference.

Unless you change the whole rack back to HPAS I can't see what else you can do either! I'm resigned to my next car just having a lot less steering feel.

Progress I suppose - saves a few MPG...

What is it about HPAS that provides feedback?

I'm just thinking EPAS still uses the basics of HPAS, i.e. A rack and pinion directly connected to the hubs with ye old fashioned tie rods, which is rigidly or semi-rigidly bolted to a subframe. The only thing that has changed is the method of assistance.

I know these two aren't the epitome of feedback, but EPAS MK5 Golfs have more feedback than HPAS MK4 Golfs. And conversely, EPAS Type Rs are liked less than HPAS type Rs.

I think there's more to it than the steering method, unless it's a horrible 'steering box' that BMWs used.

Edited by SuperchargedVR6 on Tuesday 28th June 15:11

I am not a steering boffin, so may be well off on this and am keen to learn if so, but new cars I have driven recently (Jag XE, Audi A4, Audi A3 and several others) have, to me, had far less 'feel' than even my old Honda beater that is now well due replacement. I put this down to the new EPAS system and the fact that it is not directly connected to the wheels anymore.

As I understand it, with the new breed of EPAS systems you have no direct linkage between the wheels and the steering wheel - hence it feels very dead, whereas the systems before this where the steering wheel was directly connected to the rack transmit more 'feel' from what the wheels are doing to you as the driver, regardless of how they are assisted.

That was my understanding and, from cars I've driven recently they certainly felt disconnected!

ETA - I'm not saying that overly-assisted hydraulic racks can also feel pretty dead too!!

Edited by Mike_Mac on Tuesday 28th June 16:13

[EricE]

Surely the steering rack alone is just a part of what people think of "steering feel". I doubt a modern day RS3 with hydraulic steering would feel vastly different from one with electric steering. Other factors like weight, weight distribution, tyre dimensions, economic and safe chassis geometry are just as important.
Look at the Alfa 4C, a modern mid engined car with unassisted steering. It still feels all wrong.

[kambites]

EricE said:

Look at the Alfa 4C, a modern mid engined car with unassisted steering. It still feels all wrong.

It feels wrong, but at least it feels something. You may not be able to have good steering with no feel, but you can certainly have bad steering with lots of it.

I think part of the problem is that EPAS allows pretty much complete control over steering weight which in turn allows the manufacturers to run more extreme geometry to increase grip levels. Couple that with stability control systems which mean he fundamental breakaway characteristics of a chassis no longer have to be designed to be "safe" and you end up with a setup which simply wouldn't have been possible twenty years ago. Modern tyres getting grippier don't help either.

Or to put it another way, increasing steering feel would necessitate reducing grip (and in FWD cars traction, hence reducing headline performance figures) and for 99% of buyers grip and 0-60 times are far more important. I suspect many people driving now wont even really know what steering feel is because they will never have experienced it.

Edited by kambites on Tuesday 28th June 16:18

[k-ink]

kambites said:

Oh I agree entirely, but "the market" doesn't.

I'll stick with an unassisted rack. Best of both worlds.

Yep, pretty much problem solved!

[Gary29]

Mike_Mac said:

As I understand it, with the new breed of EPAS systems you have no direct linkage between the wheels and the steering wheel

Edited by Mike_Mac on Tuesday 28th June 16:13

I'd be very surprised if there was no direct linkage between the steering wheel and steering rack?!

[kambites]

Gary29 said:

I'd be very surprised if there was no direct linkage between the steering wheel and steering rack?!

Infinity have removed it under normal driving conditions, although there's a "failsafe" clutch which engages a physical link if the EPAS system loses power.

[Bullett]

I thought this was just me.
My wife has a new A3 and it has no feel at all in the steering.

[SuperchargedVR6]

Mike_Mac said:

SuperchargedVR6 said:

Mike_Mac said:

Personally I'm regarding this as EPAS's fault. I can't think of a car yet that I've been in with it that has felt remotely nice to drive compared to something with a hydraulic rack. Some EPAS systems are better than others, but only within the EPAS frame of reference.

Unless you change the whole rack back to HPAS I can't see what else you can do either! I'm resigned to my next car just having a lot less steering feel.

Progress I suppose - saves a few MPG...

What is it about HPAS that provides feedback?

I'm just thinking EPAS still uses the basics of HPAS, i.e. A rack and pinion directly connected to the hubs with ye old fashioned tie rods, which is rigidly or semi-rigidly bolted to a subframe. The only thing that has changed is the method of assistance.

I know these two aren't the epitome of feedback, but EPAS MK5 Golfs have more feedback than HPAS MK4 Golfs. And conversely, EPAS Type Rs are liked less than HPAS type Rs.

I think there's more to it than the steering method, unless it's a horrible 'steering box' that BMWs used.

Edited by SuperchargedVR6 on Tuesday 28th June 15:11

I am not a steering boffin, so may be well off on this and am keen to learn if so, but new cars I have driven recently (Jag XE, Audi A4, Audi A3 and several others) have, to me, had far less 'feel' than even my old Honda beater that is now well due replacement. I put this down to the new EPAS system and the fact that it is not directly connected to the wheels anymore.

As I understand it, with the new breed of EPAS systems you have no direct linkage between the wheels and the steering wheel - hence it feels very dead, whereas the systems before this where the steering wheel was directly connected to the rack transmit more 'feel' from what the wheels are doing to you as the driver, regardless of how they are assisted.

That was my understanding and, from cars I've driven recently they certainly felt disconnected!

ETA - I'm not saying that overly-assisted hydraulic racks can also feel pretty dead too!!

Edited by Mike_Mac on Tuesday 28th June 16:13

Me neither but there has to be a direct link to the wheels for failsafe reasons. As Kambites said, without the assistance in the rack - be it motors or pressurised fluid - the steering is extremely heavy, but it is still there none the less for you to limp home with.

That's what I don't understand. If there is still a direct link between rack/pinion and the wheels, why is the helm so numb?

I've tried: EPAS with a motor in the rack, EPAS with a motor in the steering column, old fashioned hydraulic, unassisted, rack & onion and steering boxes.

Of all of those, the Motor in the rack method and Hydraulic were the best for feel / weight imo.

I think it's partly down to the way the assistance varies. It can feel a bit synthetic with EPAS.

[DottyMR2]

kambites said:

EricE said:

Look at the Alfa 4C, a modern mid engined car with unassisted steering. It still feels all wrong.

It feels wrong, but at least it feels something. You may not be able to have good steering with no feel, but you can certainly have bad steering with lots of it.

I think part of the problem is that EPAS allows pretty much complete control over steering weight which in turn allows the manufacturers to run more extreme geometry to increase grip levels. Couple that with stability control systems which mean he fundamental breakaway characteristics of a chassis no longer have to be designed to be "safe" and you end up with a setup which simply wouldn't have been possible twenty years ago. Modern tyres getting grippier don't help either.

Or to put it another way, increasing steering feel would necessitate reducing grip (and in FWD cars traction, hence reducing headline performance figures) and for 99% of buyers grip and 0-60 times are far more important. I suspect many people driving now wont even really know what steering feel is because they will never have experienced it.

Edited by kambites on Tuesday 28th June 16:18

Agreed, manufacturers are moving to EPAS I think as it can tie in with their TC/SM systems to make it a full package. Many many sensors all checking what is going on and where, variable steering feel to work round heavy steering in town which was always a downside to heavier steering to give feel at higher speeds, they can control how they want the steering to feel in any given situation regardless of setup and easier packaging by having EPAS instead of HPAS.
Plus, given how heavy cars are, could you imagine how hard some of these monstrosities would be to drive if they couldn't lighten the steering right up in town and then weight it up out of town to stop it being twitchy. Loads of big 4x4s are now pushing close to 3 tonnes, try piloting that around in town without seriously lightened steering.

There is now one more layer between you and the rack which is going to remove a bit of feel. They can introduce weight artificially now but it doesn't increase feel, just tricks you into thinking the steering is nice and weighty.

I do think HPAS is the better system though all round, certainly at the moment. There is surely a reason that many "skunkworks" divisions take EPAS systems, launch them in the bin and fit HPAS instead (AMG Black I'm looking at you)

Edited by DottyMR2 on Tuesday 28th June 17:24

Edited by DottyMR2 on Tuesday 28th June 17:25

[Mr2Mike]

kambites said:

I think a better question would be what is it about EPAS that removes it.

I don't actually know the answer; I can see no particular theoretical reason that EPAS should damp the steering feel any more than HPAS. I'm not sure there's anything fundamental beyond the fact that manufacturers have had decades to get HPAS right whereas EPAS is relatively new. I wouldn't be surprised if EPAS ends up better than HPAS in the end just because there's less inertia in the steering system.

It's very fundamental. The motor has to be geared down to provide sufficient torque for the assistance required, often by a worm and wheel gear system. The motor armature is a heavy lump of iron with significant inertia by itself, but when viewed from the road wheel side of the rack, this inertia is magnified significantly by the gearing. This effectively provides a mass damper i.e. a mechanical low pass filter which greatly attenuates any vibration being passed up from the road wheels.

Additionally a worm and wheel driven backwards tends to present quite a high level of frictional loss, and this further removes the steering feel.

The only difference in the steering between the original and facelift versions of the much maligned Civic EP3 rack is that the 'worm' in the facelift was modified to include a rubber "buffer" at either end that permitted the worm to move a few mm up and down (the worm being driven by a splined coupling on the end of the motor that permits this movement). This helps to isolate the mass of the motor armature from the rack, so vibrations don't get as heavily attenuated.

An HPAS rack simply doesn't have this rather effective mass damper built into its design. It does have some hydraulic damping however, which is why they aren't quite as good as a decent manual rack. And by decent I don't mean a hydraulic rack with the pipes disconnected- which gives you the worst of everything, despite what certain (usually Honda owning) ignorami might believe.

Edited by Mr2Mike on Tuesday 28th June 20:12

[Flooble]

Is there also an element of over-assistance in more modern cars? I find that each generation of cars seems to have even lighter steering than before. My first car had no power assistance at all and weighed about a tonne, which I just checked is about the same as a modern Mk 7 Fiesta.

Maybe kids today are just weaker than we were and need all that extra support, which naturally isolates you from the road?

[405dogvan]

Whenever I see people complain of 'steering feel being lost in modern cars' I sorta laugh - this isn't the first time...

The difference between pre-electric power steering cars and the last of the non-PAS cars of the 90s is enormous - the lack of feel was noticeable then BUT those cars also tended to have absolutely dead on-centre feel too (non-PAS didn't have this - modern cars lack it too)

I'd say we lost 'proper steering feel' when we started fitting PAS for the most part - the changes on the better (read enthusiast focussed) cars may transmit a bit less 'information' but they are WAY better devices for providing inputs,especially given the extra performance available!?!?

Back in my EVO forum days, someone had an Integra Type-R and when his PAS failed he realised it was still driveable and so had the PAS removed to 'save weight' - said it felt a lot better (to him) - tho I believe parking was 'challenging' ;0

Electric steer is mainly a packaging issue I believe? Electric racks take up less space/have less clutter attached to them??

Maybe expect 'artificial steering feel' as an option soon - like the 'artificial engine noise' is already here?

I'd settle for getting rid of that fking awful whine (my biggest moan about electric cars also - it's a HORRID noise)

Edited by 405dogvan on Tuesday 28th June 21:00