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Donor cars with ABS?
Slimy38 - 8/2/13 at 07:24 PM

If a donor car has ABS, what would I do with it? Bearing in mind I want to be reusing the uprights, hubs, brakes etc. Would I have to replace any of the braking system with non ABS components?

I'm guessing trying to move the ABS system to the kit car would be a bad thing?


mookaloid - 8/2/13 at 07:35 PM

I have been wondering if we shouldn't be putting ABS systems in our cars but it probably would need a standalone ECU.

I have never seen one advertised. Do they exist?

you shouldn't need to worry too much about the ABS parts - you just leave them off.


Not Anumber - 8/2/13 at 07:51 PM

When i was planning to build a Haynes Roadster from an MX5 donor I looked into it and had intended to fit ABS.
As the same sorts of ABS kit appear to be fitted to cars of quite different weights then I'd say the weight of the car probably isnt a factor, after all ABS only reacts when it senses a wheel locking under heavy braking: the wheel would lock whether it was on a light or a heavy car and the ABS would solve it the same way. It's not an inteligent system like traction control for instance that monitors several factors, it just momentarilly takes the anchors off when you over do it.


snapper - 8/2/13 at 08:02 PM

Be careful
Be very careful
Don't surmise

I asked the very same question of a neighbour and good friend who is a senior drive train engineer for Fords
Weight is a factor as are many other dynamic issues
In essence the ABS is both mechanically and electronically designed for that chassis
There are adter market traction controls that have an ABS expansion but its not that easy to retro fit

I would like ABS but just fitting the donor stuff is more hope than sense


Slimy38 - 8/2/13 at 08:26 PM

quote:
Originally posted by mookaloidyou shouldn't need to worry too much about the ABS parts - you just leave them off.


That sounds good to me! Will I need to do anything with calipers, hydraulics etc or are they all the same whether ABS or not?

[Edited on 8/2/13 by Slimy38]


hootsno1 - 8/2/13 at 08:37 PM

Just disconnect the sensor, if you are you going to use the donor ECU with the dash clocks you can take the bulb out the back of the abs light, or if you are going to change the clock there will be no asb light


mookaloid - 8/2/13 at 08:40 PM

No change to the calipers

The actual plumbing of the brake pipes will obviously be different.

If you are using Sierra stuff then you can use the master cylinder with a pipe to each front caliper and one pipe to the rear.


matt_gsxr - 8/2/13 at 11:16 PM

ABS is a great idea on my 2 tonne day-to-day car.

The brakes and tyres on my little Phoenix are just so much more powerful.
So, if I do go out in the rain and drive too fast and need ABS, then I deserve to crash.

So (for me) it is all about risk mitigation.
The risk of crashing due to me accidentally failing to accurately reverse engineer the ABS system is large.
The risk of me crashing due to not having ABS is small.

Implement it if you want (its your car) but I think that you don't need it and you are probably making your car more dangerous.

Matt


skodaman - 9/2/13 at 03:01 AM

I didn't think you were actually allowed abs on kit cars. I was a bit worried it would be made compulsory because by all accounts it's not cost effective/save to do for the reasons outlined above. I can't stand abs anyway.


v8kid - 9/2/13 at 07:20 AM

I think Bosch do an aftermarket abs ecu - always meant to investigate it


Slimy38 - 9/2/13 at 09:01 AM

quote:
Originally posted by matt_gsxr

Implement it if you want (its your car) but I think that you don't need it and you are probably making your car more dangerous.

Matt


I think my original post was poorly worded, I wanted to know how to get rid of it from a donor that may have it, rather than trying to implement it on my car.

If it was going to be significant hard work to convert to non-ABS I'd have just looked for a non-ABS MX5, but at least if it can just be ignored then that keeps my donor options open as much as possible.


britishtrident - 9/2/13 at 09:28 AM

Biggest pit fall is doing away with the servo, fitting a smaller bore master cylinder will reduce the required foot pedal pressure back to reasonable levels without the pressure being so low it will bring about unintended locking.wheel


PeterV - 9/2/13 at 10:08 AM

quote:
Originally posted by skodaman
I didn't think you were actually allowed abs on kit cars.


I'm sure your right, don't think its allowed on kit cars. If memory serves, when I was researching cruise control rules, there are words in the IVA documentation that say "NO" to ABS but never mention cruise.

I replumbed the ABS system to standard master cylinders and used the hub timing rings for my speed sensor. Very handy in fact

[Edited on 9/2/13 by PeterV]


Slimy38 - 9/2/13 at 10:35 AM

quote:
Originally posted by PeterV
and used the hub timing rings for my speed sensor. Very handy in fact




I might have to steal that idea!


rdodger - 9/2/13 at 06:26 PM

Complete Kitcar built a Marlin 5EXI and used the donor (MGF I think) ABS system. I think they may have done on their Murtaya too.

The Bosch system I spoke to the Bosch guy who was on the Hawk stand at a show a couple of years ago. He was happy at the time for kit car owners to use it. Since then I believe a few Ultima builders have enquired and been told it's for racing only. I guess thats more to do with them not wanting to end up in court rather than suitability.


atomic - 27/2/13 at 02:37 PM

The Bosch Motorsport ABS M4 system is technically for off-road use only for legal reasons, however it is in use by some low volume manufacturers like Pagani with the Huayra. It is an infinitely configurable system with on the fly adjustment. That would stop most people using it is it's base price of £9000


You could use the Ate (Continental Teves) MK60 from a 2003-2006 BMW E46 M3 / MK60E5 from a E60 M5. There are standalone harnesses available from several manufactures. It's a four-channel system but it's not programmable.

When deploying ABS many things need to be taken into account. Brake disc diameter/surface area, rolling radius, sprung and unsprung weight, modulation, piston pressures/modulation and master cylinder volumes etc are only a few of the things that need to be accounted for.

[Edited on 27/2/13 by atomic]


mookaloid - 27/2/13 at 02:50 PM

quote:
Originally posted by atomic
The Bosch Motorsport ABS M4 system is technically for off-road use only system for legal reasons, however it is in use by some low volume manufacturers like Pagani with the Huayra. It is an infinitely configurable system with on the fly adjustment. That would stop most people using it is it's base price of £9000


You could use the Ate MK60 from a 2003-2006 BMW E46 M3. There are standalone harnesses available from several manufactures. It's a four-channel system which applies ABS to each wheel but it's not programmable. When deploying ABS many things need to be taken into account. Brake disc size/surface area, rolling radius, sprung and unsprung weight, modulation, piston pressures are only a few of the things that need to be accounted for.


On that basis if I upgrade the brakes on my Tintop for something bigger and better, would that upset the ABS which is already installed? or is it not that critical?


chubby - 5/3/13 at 06:33 PM

does anyone know what the difference is between the abs and non abs calipers? are they the same mounting?
Cheers
Chubby


atomic - 8/3/13 at 03:16 PM

quote:
Originally posted by mookaloid
On that basis if I upgrade the brakes on my Tintop for something bigger and better, would that upset the ABS which is already installed? or is it not that critical?


That really depends. If the kit has been well developed then it should be okay as they will have taken things into account regarding disc circumference, pad/disc area, modulation, calliper piston sizing and master cylinder displacement etc. Some BBK's work well some do not. When it comes to brakes there is some truth in you get what you pay for.