Hi all
is it worth doing an EPAS conversion?
is it worth doing an EPAS conversion?
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EPAS?
- Thread starter Ben1720Cup
- Start date
Fairly sure I prefer the feel of HPAS, though I haven't driven the same car on same tyres/suspension/etc back to back.
EPAS makes the car more reliable (one less thing to go wrong), easier to work on, lighter & more powerful.
Wouldn't bother on a road car, but if it's a pure track/race car I'd consider it a no-brainer for the reliability & extra space alone.
EPAS makes the car more reliable (one less thing to go wrong), easier to work on, lighter & more powerful.
Wouldn't bother on a road car, but if it's a pure track/race car I'd consider it a no-brainer for the reliability & extra space alone.
Martin_172
ClioSport Club Member
I've got EPAS on my van, it doesn't feel as nice as the HPAS but the thing FLYS though the revs, I've never had a 172/182 that revs the way it does, and its a standard engine.
makes getting the engine out easier too which is handy if you enjoy that sort of thing lol
makes getting the engine out easier too which is handy if you enjoy that sort of thing lol
incy-spider
ClioSport Club Member
Just did mine, I feel like I’ll be forever adjusting the assistance knob!
Feels great though and it is also peace of mind as said.. also the added bonus of being able to actually get to my oil filter easily!!
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Feels great though and it is also peace of mind as said.. also the added bonus of being able to actually get to my oil filter easily!!
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What is the rough cost of doing the conversion?
Beauvais Motorsport
ClioSport Club Member
The issue is the non sport electric column is designed specifically for cars with smaller tyres, less mechanical trail and self aligning torque. If you run sticky rubber and increased caster the torsion bar and assistance calibration cant cope and you'll have 'laggy' steering that needs to have the torsion bar twisted a lot (all the way sometimes) to even turn the wheels.
If running a roll centre correction kit, standard or less caster, 15's and even a higher rear (positive rake) then the system can cope fine due to much less MT and SAT. More inline with that of the non sport.
If running a roll centre correction kit, standard or less caster, 15's and even a higher rear (positive rake) then the system can cope fine due to much less MT and SAT. More inline with that of the non sport.
Best answer. Thank you for that.
incy-spider
ClioSport Club Member
I wonder if a Clio 3 197 column could be used in a 182.. obviously a lot different and bulky but could be interesting
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Beauvais Motorsport
ClioSport Club Member
It has been done. I dont have any experience with the mk3s but its clearly much more capable, its mounting brackets compared to the mk2s are way more rigid.
Mr Underhill
ClioSport Club Member
I’m running EPAS on the track car in conjunction with A040/52 tyres, 15” Pro Race wheels, roll centre correction kit, -3.5 degrees of camber. Took a bit of adjustment to get the feel right, but I wouldn’t go back to HPAS for track. Other advantages, as pointed out above, is accessibility to the engine/gearbox/components.
Where is this torsion bar?
Primary function of a column is to transmit torque from hand wheel to pinion. Makes sense & is common to have damping (typically with a rubber isolator) but makes no sense to nerf stiffness (which is what a torsion bar would do).
I have a looped HPAS rack (4x mounting points versus DCI's 2) attached to the subframe via bespoke brackets that raise the rack up in Z to reduce bumpsteer, bolted to a length-adjustable Scenic lower column, welded to a height-adjustable Clio DCI upper EPAS column, mounted directly to the cage. If you're telling me that I did all of that and didn't notice a big springy thing... well...
Can't say I've had any issues with assistance dropping out or being delayed mid corner, but then as above that's influenced by a long list of things. What I have noticed is that assistance takes a good few seconds to ramp up or drop off after you turn the dial on an ebay kit. This is because the adjuster mimics the vehicle speed signal on a DCI, and the EPAS ECU will apply a low pass filter or plausibility check on that signal to stop the steering suddenly going light during instant-unrealistic-acceleration (e.g. wheel spin) or suddenly going heavy in the event of instant-unrealistic-deceleration (e.g. ABS braking or a signal failure).
Primary function of a column is to transmit torque from hand wheel to pinion. Makes sense & is common to have damping (typically with a rubber isolator) but makes no sense to nerf stiffness (which is what a torsion bar would do).
I have a looped HPAS rack (4x mounting points versus DCI's 2) attached to the subframe via bespoke brackets that raise the rack up in Z to reduce bumpsteer, bolted to a length-adjustable Scenic lower column, welded to a height-adjustable Clio DCI upper EPAS column, mounted directly to the cage. If you're telling me that I did all of that and didn't notice a big springy thing... well...
Can't say I've had any issues with assistance dropping out or being delayed mid corner, but then as above that's influenced by a long list of things. What I have noticed is that assistance takes a good few seconds to ramp up or drop off after you turn the dial on an ebay kit. This is because the adjuster mimics the vehicle speed signal on a DCI, and the EPAS ECU will apply a low pass filter or plausibility check on that signal to stop the steering suddenly going light during instant-unrealistic-acceleration (e.g. wheel spin) or suddenly going heavy in the event of instant-unrealistic-deceleration (e.g. ABS braking or a signal failure).
incy-spider
ClioSport Club Member
Anyone done surgery to it? Taken the torsion bar out and beefed it up?
I run a correction kit on mine, sticky tyres etc.. also a looped standard 182 rack.. feels pretty good, but can feel a sort of disconnected feeling if I’m throwing it hard into turns… it’s not that bad but different to the HPAS.
I am thinking about doing the pure motorsport castor strut top kit but but don’t want to make things harder on the EPAS if it possibly will, i actually thought it could help with more self centre characteristics that more castor gives.?
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Ah I see, so you need to measure some displacement with a known torsional stiffness to calculate torque applied…
So if you beef up the torsion bar without changing the sensor then the torque sensor will under read and presumably give less assistance. Which presumably you can counter by winding the assistance back up.
Presumably more modern EPAS systems have a different sensor type, or just a more precise sensor that can detect small displacements and therefore work with a stiffer torsion bar.
Everyday is a school day etc.
So if you beef up the torsion bar without changing the sensor then the torque sensor will under read and presumably give less assistance. Which presumably you can counter by winding the assistance back up.
Presumably more modern EPAS systems have a different sensor type, or just a more precise sensor that can detect small displacements and therefore work with a stiffer torsion bar.
Everyday is a school day etc.
Beauvais Motorsport
ClioSport Club Member
This is the mk2 column.
This is the hpas from the 182
This is the total amount that can be twisted, although they are disconnected and would obviously take a lot more force to twist. Under parking situations and heavy load it can twist that much.
Also why you should never run a looped hpas rack. A dci rack or manual quick rack conversion are your best bet, but people do weld them together.
You will 100% benefit from the alternatives above, that disconnect feeling is a lot down to the looped rack.
For the cost it would be better to fit a 197 or more modern powerful epas column.
Its a balance when adjusting caster, yes you will gain more self aligning torque (self centering) but mechanical trail also. The way you can offset this is by having the lower ball joint lower to the ground, with a rcck you are already lower and lowering even more could possibly do more harm to the roll centre and the scrub radius (more positive) unless you add more king pin inclination to balance that out. If you lowered the wishbone mounting points also then you could keep your original scrub radius.
Adjust one thing it changes another... Gives me a headache to say the least 😄
This is the hpas from the 182
This is the total amount that can be twisted, although they are disconnected and would obviously take a lot more force to twist. Under parking situations and heavy load it can twist that much.
Also why you should never run a looped hpas rack. A dci rack or manual quick rack conversion are your best bet, but people do weld them together.
You will 100% benefit from the alternatives above, that disconnect feeling is a lot down to the looped rack.
For the cost it would be better to fit a 197 or more modern powerful epas column.
Its a balance when adjusting caster, yes you will gain more self aligning torque (self centering) but mechanical trail also. The way you can offset this is by having the lower ball joint lower to the ground, with a rcck you are already lower and lowering even more could possibly do more harm to the roll centre and the scrub radius (more positive) unless you add more king pin inclination to balance that out. If you lowered the wishbone mounting points also then you could keep your original scrub radius.
Adjust one thing it changes another... Gives me a headache to say the least 😄
Beauvais Motorsport
ClioSport Club Member
If you're interested in making your own
incy-spider
ClioSport Club Member
That’s really interesting, so I could possibly improve the disconnected feeling by fitting a quick rack and pinion like this … http://www.pure-motorsport.co.uk/clio-2-rs-quick-rack-25-reduction.html
It’s a solid pinion
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Beauvais Motorsport
ClioSport Club Member
Exactly that, Brt motorsport also do a manual quick rack.
Adey.
ClioSport Club Member
Is there no way to retro fit the epas from the Twingo RS133, being basically a clio underneath id of thought it would be a near direct fit. The rack itself is shorter/quicker than the non sport version also.
Beauvais Motorsport
ClioSport Club Member
Ive heard the racks fit but the columns are slightly different.
Edited.
182 trackcar, XC60t6
Or…..no PAS at all for a track only car. I haven’t missed mine and I binned it years ago.
Martin_172
ClioSport Club Member
is it not a handful when it gets out of shape? maybe I need my Weetabix but I think id struggle to catch it if it got out of shape without PAS
incy-spider
ClioSport Club Member
They may vary but the HPAS rack on mine looped is the worst thing in the world to drive.. soooo heavy and I do eat my weetabix.
I have the PMS short rack kit coming for mine so I’m going to make sure I don’t have any overly tight/seizing rose joints or something whilst I re build the rack! (Do have EPAS)
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incy-spider
ClioSport Club Member
Okay so some info.. converting a HPAS rack with the looped method is s**t. Mainly down to the pinion as talked about above, not many people even know it’s a two piece design which causes some horrible feeling steering.
also the right amount of fluid that is acceptable in the rack is an unknown, in my case when I pulled it apart yesterday had quite a lot still in there which could have caused a few stiff issues..
anyway now the best bit, I’ve converted to a short rack from pure 25% reduction, the steering now feels sharp and precise as it used too but… BUT!!!! now I have problems with my ESP because the the steering angle sensor is saying say 5 degrees and the actual amount the wheels turn is a lot more so then that messes with the YAW sensor!! 😔 for now I have disconnected the YAW sensor so I can use it without the ESP cutting in at 10mph when turning, but that obviously has left me with the SERV and ESP lights on which I’m hoping to sort by re flashing the ABS computer with non ESP software but don’t even know if it possible yet..
anyone have a work around?
also the right amount of fluid that is acceptable in the rack is an unknown, in my case when I pulled it apart yesterday had quite a lot still in there which could have caused a few stiff issues..
anyway now the best bit, I’ve converted to a short rack from pure 25% reduction, the steering now feels sharp and precise as it used too but… BUT!!!! now I have problems with my ESP because the the steering angle sensor is saying say 5 degrees and the actual amount the wheels turn is a lot more so then that messes with the YAW sensor!! 😔 for now I have disconnected the YAW sensor so I can use it without the ESP cutting in at 10mph when turning, but that obviously has left me with the SERV and ESP lights on which I’m hoping to sort by re flashing the ABS computer with non ESP software but don’t even know if it possible yet..
anyone have a work around?
incy-spider
ClioSport Club Member
Here’s a vid of the HPAS pinion
Beauvais Motorsport
ClioSport Club Member
@incy-spider Is the steering wheel in the same position with the new rack as it was with the original hpas rack? Or did you have to clock the epas coupler?
incy-spider
ClioSport Club Member
Yep exactly the same place, and even re zero’d the angle sensor. It’s down to the yaw at what the computer thinks is low steering input
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Beauvais Motorsport
ClioSport Club Member
You may need renault clip software to reset it. Are you sure you didnt spin the wheel when the rack was out?
incy-spider
ClioSport Club Member
I work at Renault mate so yep used Clip, I’ll definitely 100% check the sensor is central tomorrow but definitely sure it didn’t move
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Martin_172
ClioSport Club Member
What happens if you clear the code, and then switch ESP off every time before you drive? im not clued up on the inner workings of the system.
incy-spider
ClioSport Club Member
Even with the ESP turned off on the switch there’s still an element of some kind of ABS cutting in on the pedal. No actual faults pop up but ESP cuts in. Very annoying
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Martin_172
ClioSport Club Member
ah ok, yeah it must detect the different from expected wheel speeds due to more lock being dialled in, frustrating but there will be a solution I'm sure!
incy-spider
ClioSport Club Member
I’m not sure if it’s wheel speed or the degrees of yaw it’s sensing at what it thinks is a small amount of steering input
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Martin_172
ClioSport Club Member
Id have thought if it was activating the ABS that's going to be due to it sensing a slower than expected speed so thinking you are starting to get lockup. Does it only do it at slow speeds? Id check the live data and make sure the sensors are all reading correctly in a straight line.
Beauvais Motorsport
ClioSport Club Member
Is there a way you can configure a lock to lock reset in clip?
incy-spider
ClioSport Club Member
incy-spider
ClioSport Club Member
It was all fine before I did the short rack mate, I’ll take a look at all suggestions though [emoji106][emoji106]
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