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Retrofitting ABS
jeffw - 14/11/13 at 08:30 AM

In an idle moment I was wondering if anyone had fitted ABS to a kit and what parts where used. It would be interesting to see how effective it is on a lightweight car.

theprisioner - 14/11/13 at 08:41 AM

I have never seen an autonomous after market system for sale. These things appear to be part of the factory ecu development. They can, and in my case, be a separate ECU linked via a CAN bus to the main ECU for fault reporting via the DLC connector. My Puma had one (I think must look and see) and in theory I could have retained it. It was never developed for a rear engine car so I never gave it a thought. It might be dangerous in my case. Interesting thought!

loggyboy - 14/11/13 at 08:45 AM

Dont do it! ABS is great for safety, rubbish for going fast.

britishtrident - 14/11/13 at 09:01 AM

ABS systems require extensive development for individual models not to be messed with.

Bosch do make a competition only system that can be set-up by linking it to a Laptop, but they do not sell it anybody that wants it only to approved customers.

britishtrident - 14/11/13 at 09:02 AM

quote:
Originally posted by loggyboy
Dont do it! ABS is great for safety, rubbish for going fast.


That must be why it was banned from F1 then

jeffw - 14/11/13 at 09:39 AM

quote:
Originally posted by loggyboy
Dont do it! ABS is great for safety, rubbish for going fast.


I think you'll find this isn't correct anymore. ABS is used extensively in race cars now and it is there to make them go faster....

[Edited on 14/11/13 by jeffw]

PSpirine - 14/11/13 at 10:27 AM

In my experience, modern (i.e. current model year cars) ABS and even traction control systems are pretty damn impressive.

Yes, there may be some odd situations when ABS gets confused, but if anything, on a race track, conditions are pretty easy (to predict/program/process by the ECU), and I struggle to believe that a human can modulate better than a 4-channel system which can pulse individual wheels.

If anything, these systems allow you to apply more brake force (using PWM) to the wheels with more grip in a bend.
Without ABS, you'd be effectively braking both the inside and outside front wheel with equal force, which in my mind can't be as efficient - you'd either end up with a locked inside wheel, or your outside tyre not making use of all the available grip.

Pavel

loggyboy - 14/11/13 at 10:28 AM

quote:
Originally posted by jeffw
quote:
Originally posted by loggyboy
Dont do it! ABS is great for safety, rubbish for going fast.


I think you'll find this isn't correct anymore. ABS is used extensively in race cars now and it is there to make them go faster....

[Edited on 14/11/13 by jeffw]


As mentioned above - it can, when it designed well and specfically designed for going fast, and not as safety feature. Any retrofit system based on a road going system (DIY or otherwise) would not make you go faster or allow brake harder.

britishtrident - 14/11/13 at 12:58 PM

Ignoring the strange Girling belt toothed driven mechanical fitted to some small Fords and Fiats about 25 years back I have yet to drive a bad ABS system and all modern Bosch systems are streets ahead of the ones fitted in the 1980s/early 1990s

Bosch motorsport ABS

ashg - 14/11/13 at 03:31 PM

i have done a retrofit abs system in the past. the hardest part will be working out where to mount the pump, abs rings and sensors.

loggyboy - 14/11/13 at 03:36 PM

The Clio setup is pretty rubbish, not sure if its age rather than design. But the 172 Cups that were designed for track homologation, and were sans ABS. So Renault must have had their reasons - beside weight loss.

loggyboy - 14/11/13 at 03:43 PM

quote:
Originally posted by britishtrident
Ignoring the strange Girling belt toothed driven mechanical fitted to some small Fords and Fiats about 25 years back I have yet to drive a bad ABS system and all modern Bosch systems are streets ahead of the ones fitted in the 1980s/early 1990s

Bosch motorsport ABS


From what ive read thats over £5000s worth - I suspect that could be spent in better places to go faster on most cars. - so unless yor competing at a very high level, very very not locost!

jeffw - 14/11/13 at 03:56 PM

Might have to try and get bigger front tyres on the car instead then...

MikeRJ - 14/11/13 at 09:02 PM

quote:
Originally posted by britishtrident
Ignoring the strange Girling belt toothed driven mechanical fitted to some small Fords and Fiats about 25 years back I have yet to drive a bad ABS system and all modern Bosch systems are streets ahead of the ones fitted in the 1980s/early 1990s

Bosch motorsport ABS


The system on my 53 plate ZS180 was pretty awful. If the ABS was activated by e.g. braking whilst passing over an expansion strip, it would continue to modulate the brakes irrespective of the grip available, providing negligible stopping effort. The first time I found this I was braking fairly lightly approaching traffic lights on on a downhill section of road and hit a metal expansion strip, which sent me sailing down the road and almost into the back of another car. Once I learned to immediately release and re-apply if it activated then it was ok, but it's the exact opposite of what you should normally do with ABS.

[Edited on 14/11/13 by MikeRJ]

britishtrident - 17/11/13 at 03:12 PM

quote:
Originally posted by MikeRJ
quote:
Originally posted by britishtrident
Ignoring the strange Girling belt toothed driven mechanical fitted to some small Fords and Fiats about 25 years back I have yet to drive a bad ABS system and all modern Bosch systems are streets ahead of the ones fitted in the 1980s/early 1990s

Bosch motorsport ABS


The system on my 53 plate ZS180 was pretty awful. If the ABS was activated by e.g. braking whilst passing over an expansion strip, it would continue to modulate the brakes irrespective of the grip available, providing negligible stopping effort. The first time I found this I was braking fairly lightly approaching traffic lights on on a downhill section of road and hit a metal expansion strip, which sent me sailing down the road and almost into the back of another car. Once I learned to immediately release and re-apply if it activated then it was ok, but it's the exact opposite of what you should normally do with ABS.

[Edited on 14/11/13 by MikeRJ]


Something far wrong -- first suspect would be a split toothed ring on the a front CV joint which can result in some very odd effects, it usually doesn’t trigger the ABS fault light. This was a common fault on the MG-Rover 45 and 25 series as they aged.

Slimy38 - 17/11/13 at 03:27 PM

quote:
Originally posted by britishtrident
Ignoring the strange Girling belt toothed driven mechanical fitted to some small Fords and Fiats about 25 years back I have yet to drive a bad ABS system and all modern Bosch systems are streets ahead of the ones fitted in the 1980s/early 1990s

Bosch motorsport ABS


My brand new (at the time) 99 Mondeo would definitely beg to differ, I nearly got friendly with an Audi because it overreacted and felt like it disabled the brakes. There was a strange aroma coming from my friend in the passenger seat as we carried on...

Every other car I've driven has been brilliant, with the ABS being almost reluctant to trigger and only triggering if I'm stupid. But that Mondo will stick in my mind forever.

[Edited on 17/11/13 by Slimy38]

nickm - 17/11/13 at 08:02 PM

I thought the whole idea of ABS was to enable the car to be steered when in a skid so it actually releases the locked up wheels for a split second not brake more efficiently.

Nick M