villagehoppa
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| posted on 23/7/15 at 12:00 PM |
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Brakes!! Can I use abs, is it ok and ok for iva?
Hi All, I'm working on a project which basically re-bodies a Ford Focus Mk2 on to a spaceframe chassis, my question is, when it comes to the
brakes, can I carry over the whole brake assembly including the abs? I didn't know where the IVA stood on such things? As the vehicle will be
substantially lighter than the donor would there be any problems too? I'm guessing that the brakes would lock up easier so would there be any
way of adjusting them or better just going with an aftermarket set up? I want to use as much of the donor to keep costs down so would ideally like to
go with the donor set up. Any inputs would be most appreciated. Thanks in advance..
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Daf
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| posted on 23/7/15 at 12:33 PM |
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I can't see a problem with using it, the ABS senses when a wheel locks up (stops rotating) so weight shouldnt make any difference. The Focus ABS
would work equally well with 5 fat people in it or one skinny person. I'd be tempted to stick with a braking system a manufacturer will have
spent millions on developing as aposed to anything else. This is just my opinion though - I'm sure someone will be along to prove me wrong!
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loggyboy
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| posted on 23/7/15 at 12:53 PM |
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Depends on the original system, for example the ABS on my clio also dicates brake balance, so weight changes may have a negative effect.
Do you really want it?
Mistral Motorsport
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coyoteboy
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| posted on 23/7/15 at 12:56 PM |
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Depends how advanced the system is in the donor. Even as far back as the early 90s cars were using inertial sensors to identify acceleration rates and
adapt their output based on that - the wheel speed sensing is only part of it. It's hard to know what the effect would be without knowing the
details of the system of course and it might simply be the case that the parameters of the control are slightly different for a lighter car as the
correction happens faster etc. Certainly plenty of ABS/stabilty systems detect weight levels in the car and set brake biasing and change triggers
based on things like rate of decel with rate of wheel speed change etc. That said, none of that affects whether the IVA allows it etc, which I think
it does off the top of my head.
[Edited on 23/7/15 by coyoteboy]
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prawnabie
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| posted on 23/7/15 at 01:40 PM |
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quote:
Originally posted by loggyboy
Depends on the original system, for example the ABS on my clio also dicates brake balance, so weight changes may have a negative effect.
Do you really want it?
That would be EBD, best to avoid cars using that if you are puting the system into something else.
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Kdempsie
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| posted on 23/7/15 at 05:59 PM |
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I'd need to double check but I think ABS is specifically forbidden in the IVA manual.
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robertst
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| posted on 23/7/15 at 06:15 PM |
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quote:
Originally posted by Kdempsie
I'd need to double check but I think ABS is specifically forbidden in the IVA manual.
Nope, its allowed:
 
Description
But i guess more testing will be necessary, so one more thing for them to fail
Tom
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turbodisplay
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| posted on 23/7/15 at 07:37 PM |
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Main issue with ABS is unintentional Ice mode activation, where the lower mass makes the ABS think the car is on Ice so gives massively reduced
braking.
Darren
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Kdempsie
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| posted on 23/7/15 at 08:05 PM |
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Oops, my bad. Must have been thinking about something else.
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Bluemoon
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| posted on 23/7/15 at 08:44 PM |
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other snag may be at mot time i.e. are you allowed to remove the abs system if it has one at iva, not sure what they cary-over to the v5. you might be
locked into keeping abs?
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talkingcars
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| posted on 23/7/15 at 09:34 PM |
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quote:
Originally posted by Bluemoon
other snag may be at mot time i.e. are you allowed to remove the abs system if it has one at iva, not sure what they cary-over to the v5. you might be
locked into keeping abs?
It is possible to remove it from a regular car but you have to remove all trace, even the light on the dash.
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talkingcars
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| posted on 23/7/15 at 09:35 PM |
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quote:
Originally posted by coyoteboy
Depends how advanced the system is in the donor. Even as far back as the early 90s cars were using inertial sensors to identify acceleration rates and
adapt their output based on that - the wheel speed sensing is only part of it.
And these sensors are normally hidden in the ABS ECU.
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villagehoppa
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| posted on 24/7/15 at 06:41 AM |
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Thanks all , great info as always... Brakes are usually vehicles specific I would have thought, it is going to need a bit more research but thanks
you for all of you reply's, there is some great stuff there to think about. I don'y suppose anyone knows any 'Ford Brake
Specialists' who would know the inner beatings of a 'brake system' heart!!?? Thanks again... J
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snapper
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| posted on 24/7/15 at 08:22 AM |
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I do but in all honesty it's like asking a Professor of Quantum mechanics to explain it in simple terms.
The little I do understand is that today's systems are integral with the ECU in that wheel rotation is just a single part of the complex vehicle
dynamics, things like lateral G, friction sheer, yaw etc all come in to play, at this stage in the conversation I said "well put it in simple
terms" he said "I have" "God how much more simple do you need?"
Gulp
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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DW100
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| posted on 24/7/15 at 09:57 AM |
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The MkII focus uses at least 4 different types of Teves abs pump, most of which have Traction Control System and Electronic Stability Control. This
will have been tuned to the exact dynamics of a Focus. It will use info from multiple sensors from multiple control units with info conveyed across
the CAN network. Mounting of things like Yaw sensors and G sensors need to be precise in order to give the correct info and the likely vibration from
a kit built car could well confuse the system leading to very unpredictable behaviour.
Not saying it can't be done but....... probably beyond the scope of an amateur designer.
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villagehoppa
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| posted on 24/7/15 at 12:41 PM |
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Ah I see, very well put. I might have to think of a much simpler way then if that is the case. I don't want anything fancy, just something
good and reliable to stop me using as much carryover parts as possible. Maybe I can scrub the abs part and stick to a servo from an earlier models
maybe? I'll have a think, thanks again... J Does anyone do a servo assist kit?...
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SteveWalker
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| posted on 24/7/15 at 01:28 PM |
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All the fancy bits (traction controls, stability control, etc.) are optional extras aren't they? That should mean that a Ford dealer should be
able to disable them. I don't know whether the basic ABS would still be okay for a much lighter car or not, but it's more likely with
everything else disabled.
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gremlin1234
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| posted on 24/7/15 at 04:50 PM |
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quote:
Originally posted by villagehoppa
Maybe I can scrub the abs part and stick to a servo from an earlier models maybe? I'll have a think, thanks again... J Does anyone do a servo
assist kit?...
would the lighter car need a servo?
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villagehoppa
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| posted on 27/7/15 at 07:16 AM |
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I was thinking of it weighing something in the region of 7 to 800 kgs, would that need a servo or just use a master cylinder?
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Slimy38
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| posted on 27/7/15 at 10:55 AM |
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quote:
Originally posted by villagehoppa
I was thinking of it weighing something in the region of 7 to 800 kgs, would that need a servo or just use a master cylinder?
Plenty of older production cars weigh more than that with no servo assistance.... how strong is your right leg? 
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