nick205
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| posted on 22/3/24 at 08:58 AM |
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EPB (Electric Parking Brakes) for kit cars
Remembering this recent thread on locating the parking brake under the steering wheel...
https://www.locostbuilders.co.uk/forum/29/viewthread.php?tid=220539
It got me thinking about EPB's (Electric Parking Brakes), which many modern tin tops have these days. My last 2 VW Passats (both 2007 model year)
had an EPB. I have to say I got used to it very quickly and appreciated the removal of a bulky handrake lever between the front seats.
What IVA rules would apply to transfer a system like this to a kit car?
I'm assuming you'd have to transfer the complete system. Would ABS rules come into play and would they stop you doing this safely / cost
effectively?
I'm not about to do this BTW, just thinking aloud.
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pigeondave
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| posted on 22/3/24 at 01:13 PM |
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I think the guy at Simtek uk have done this on their YouTube channel.
Could be worth looking into their body logic modules as I think they can do it.
No, it was this video
https://youtu.be/8wApSyx_flo?si=yTBceiW0lwpy2Lqf
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adithorp
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| posted on 22/3/24 at 07:56 PM |
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The calipers are quite bulky so room might be an issue.
Although you could bodge with just power on/off, you'd need the control softwear to set/adjust. Without that I think you'd have a variable
bite point.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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SteveWalker
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| posted on 22/3/24 at 08:23 PM |
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There are probably tin-tips with systems that just use a motor to pull a conventional brake cable, which would mean standard calipers or drums, but no
need to find a good location for the handbrake lever.
I can't see IVA having any interest in whether the handbrake has a lever or a switch and motor, as long as it works properly.
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adithorp
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| posted on 22/3/24 at 09:24 PM |
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quote:
Originally posted by SteveWalker
There are probably tin-tips with systems that just use a motor to pull a conventional brake cable, which would mean standard calipers or drums, but no
need to find a good location for the handbrake lever.
I can't see IVA having any interest in whether the handbrake has a lever or a switch and motor, as long as it works properly.
A few had remote motors though mostly gone from current production. Megan Scenic for one. Also of course, LR Dicos/RangeRovers BMW X5, but that motor
weighs half what your kit does and still has an ecu running it.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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JAG
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| posted on 25/3/24 at 08:47 AM |
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So there were a few cars with a 'motor-cable-puller' system and an integrated ECU between 2008-2015'ish. Jaguar cars had such a system.
The unit is heavy and prone to problems because of cable stretch and automatic cable adjustment.
Later systems used a motor-on-caliper design with a remote and dedicated ECU. The software is 'tuned' to suit the weight and other
attributes of the car. THe drive-away-release function is the most problematic and depends upon the friction material/pads.
Most modern systems use the same motor-on-caliper design but the software is now integrated into the ABS Modulator unit (which has it's own ECU).
This saves cash and reduces packaging problems but has similar software tuning to the previous system with a dedicated ECU.
I have seen one company that offer a 'special' ECU that can provide the basic parkbrake functions when connected to a pair of
motor-on-calipers. I don't recall the company name and I don't know if they are still operating.
FYI - each caliper draws approx' 15 amps when holding a large tin-top on a 25% incline.
[Edited on 25/3/24 by JAG]
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
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Slimy38
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| posted on 25/3/24 at 09:06 AM |
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quote:
Originally posted by JAG
FYI - each caliper draws approx' 15 amps when holding a large tin-top on a 25% incline.
That's interesting, I'd have thought that once the caliper has been wound on to the disc the power requirements would drop to zero? I think
even in the IVA manual it says that there shouldn't be a loss of braking force if power is removed?
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Mr Whippy
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| posted on 25/3/24 at 09:30 AM |
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quote:
Originally posted by Slimy38
quote:
Originally posted by JAG
FYI - each caliper draws approx' 15 amps when holding a large tin-top on a 25% incline.
That's interesting, I'd have thought that once the caliper has been wound on to the disc the power requirements would drop to zero? I think
even in the IVA manual it says that there shouldn't be a loss of braking force if power is removed?
Why do you think it would require power to hold?? as far as I can tell it's just a motor turning a screw thread. As above the MOT and IVA would
require the handbrake to hold fully regardless if there is any power or not. Think about it, if you left your car with the handbrake on, on a 25%
slope drawing 15amps, you'd come back in the morning with you car at the bottom of the hill 
Fame is when your old car is plastered all over the internet
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gremlin1234
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| posted on 25/3/24 at 09:43 AM |
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after a quick search I found
wilwood make a kit ~£1000 !
https://www.rallydesign.co.uk/product_info.php?products_id=25532
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Mr Whippy
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| posted on 25/3/24 at 10:07 AM |
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quote:
Originally posted by gremlin1234
after a quick search I found
wilwood make a kit ~£1000 !
https://www.rallydesign.co.uk/product_info.php?products_id=25532
Alternatively go to the scrap yard and get pair. Must be all of £300 worth of parts in that kit.
Fame is when your old car is plastered all over the internet
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JAG
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| posted on 25/3/24 at 11:19 AM |
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quote:
each caliper draws approx' 15 amps when holding a large tin-top on a 25% incline
Hmm I worded that badly. Each caliper draws 15 amps to produce the clamp load necessary to hold a large tin-top on a 25% incline. Once holding, the
current draw drops to zero as the caliper gearbox can maintain the clamp force without any current - as required by
ECE Reg 13h
[Edited on 25/3/24 by JAG]
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
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nick205
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| posted on 25/3/24 at 11:50 AM |
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quote:
Originally posted by JAG
So there were a few cars with a 'motor-cable-puller' system and an integrated ECU between 2008-2015'ish. Jaguar cars had such a system.
The unit is heavy and prone to problems because of cable stretch and automatic cable adjustment.
Later systems used a motor-on-caliper design with a remote and dedicated ECU. The software is 'tuned' to suit the weight and other
attributes of the car. THe drive-away-release function is the most problematic and depends upon the friction material/pads.
Most modern systems use the same motor-on-caliper design but the software is now integrated into the ABS Modulator unit (which has it's own ECU).
This saves cash and reduces packaging problems but has similar software tuning to the previous system with a dedicated ECU.
I have seen one company that offer a 'special' ECU that can provide the basic parkbrake functions when connected to a pair of
motor-on-calipers. I don't recall the company name and I don't know if they are still operating.
FYI - each caliper draws approx' 15 amps when holding a large tin-top on a 25% incline.
[Edited on 25/3/24 by JAG]
The 2x 2007 VW Passat estates I had both had EPB's. When "activated" you could hear an electric motor sound from beneath the car. The
parking brake came on.
Even with then car full of people and luggage the parking brake had no problem on steep slopes. It also had "Hill Hold" to stop you rolling
back on a hill (junction/traffic lights).
No idea on weight penalty of the system over a lever type parking brake. It worked well and was a pleasure to use though!
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Mr Whippy
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| posted on 25/3/24 at 12:48 PM |
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My sister has it on her Golf, I'm not a fan tbh but it does have hill hold and without that I think releasing an ebrake smoothly on a slope would
be difficult. Call me old fashioned (whatever gave you that idea ) but there was nothing wrong with the mechanical handbrake. They way things are
going with their fly by wire everything BS if you loose your power you might as well just bale out the car  that is if the doors will even open
This is why my next daily driver is to be a 1940's pick up the most complex thing in that will be my phone...
Fame is when your old car is plastered all over the internet
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nick205
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| posted on 25/3/24 at 01:06 PM |
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quote:
Originally posted by Mr Whippy
My sister has it on her Golf, I'm not a fan tbh but it does have hill hold and without that I think releasing an ebrake smoothly on a slope would
be difficult. Call me old fashioned (whatever gave you that idea) but there was nothing wrong with the mechanical handbrake. They way things are
going with their fly by wire everything BS if you loose your power you might as well just bale out the car that is if the doors will even open
This is why my next daily driver is to be a 1940's pick up the most complex thing in that will be my phone...
Understand your concern with the "fly by wire" approach and losing power.
However, I suspect to pass all the safety standards these systems have to have "fail safe" modes.
i.e. if all power is lost then no (or least possible) risk is caused to
1. Vehicle occupants
2. Pedestrians
3. Other road users
4. No doubt the list goes on...
[Edited on 25-3-24 by nick205]
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Mr Whippy
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| posted on 25/3/24 at 01:45 PM |
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Tbh I don't have your faith, I see "innovations" moving quicker than regulations or common sense. The handbrake for the last 100 years
has been the final failsafe when everything else is gone, normally so simple in operation that it should always work (if maintained correctly). Now
it's working though a computer and we all know how unreliable those stupid things are. The fly by wire steering as used in the cybertruck has no
mechanical link at all to the rack, personally something I think should be illegal and has no place on the road as does so called self driving cars.
Fame is when your old car is plastered all over the internet
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SteveWalker
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| posted on 25/3/24 at 02:17 PM |
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I've not problem with a steer by wire system - if it is properly implemented. Three independent systems, with any two able to override the third
- as was used for decades in aircraft.
It would have a great advantage that it should be possible to make steering wheel, instruments and pedals swappable to the other side, simply by
unclipping and re-clipping, in minutes, for driving abroad.
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Mr Whippy
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| posted on 25/3/24 at 02:38 PM |
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I have no problems with fly by wire on aircraft but there are some difference when you compare the two -
1) Aircraft are highly regulated.
2) Aircraft have huge mandatory inspection requirements (have a look at what happens to an airliner).
3) Aircraft are maintained by extremely qualified people.
4) Aircraft parts are certified and very controlled.
1) Cars are not regulated even slightly close to aircraft.
2) Cars have a very basic 1 yearly look over with a rubber mallet.
3) Cars are maintained by anyone including DIY mechanics who watched some youtube hack.
4) Car parts are often cheap budget knock offs or secondhand scrap parts from ebay.
So just because aircraft have been using fly wire means nothing using it on cars, unless your happy having the same kind of standards applied.
Fame is when your old car is plastered all over the internet
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