Oversensitive ABS - TT 312mm Conversion

[SteveC123]

I had cause to punt my car round a track last weekend, and was expecting great things from it in terms of braking given how the brakes tend to be on the road.

However, I found the ABS was a bit too eager to kick in on certain corners... so I was just wondering if there was a way to adjust the sensitivity of the ABS by way of VAG-COM or not.

TIA

 

[basssound]

Erm remove the fuses if it's possible

 

[SteveC123]

Erm remove the fuses if it's possible

It is possible but from what I've read, not recommended.

I've recently been impressed by being able to adjust the weight of the steering by way of VAG-COM, so wondered if there was anything you could do to the ABS as well. ;-)

 

[Gooner_Mike]

I would leave the ABS well alone. If its only on the track that yu notice it kicking in too much them whats the problem? You don't want to play about with your brakes for everyday driving... after all, ABS does a job for a reason!

 

[m0rk]

Erm remove the fuses if it's possible

how would the braking system control the bias

 

[SteveC123]

I would leave the ABS well alone.

That's your choice.

Personally, and given what I found with the braking on my car in particular, I'd rather get my car working in such a way that I've confidence in it not kicking in the ABS a bit too readily when pushed to its limits.

Having looked around these parts, I can see I'm not the only one of the opinion the ABS is oversensitive on these, either.

If its only on the track that yu notice it kicking in too much them whats the problem?

Because I've had it occasionally kick in on the road as well when perhaps it shouldn't have, but you weren't to know that from the original post...

You don't want to play about with your brakes for everyday driving...

Humm, yes I do.

If the ABS is kicking in too readily when the car is being punted along on a smooth race circuit, (which as an aside happens to also be covered liberally in sticky rubber from where drifting was also going on during the course of the day, never mind that dumped by race cars with slicks), then any improvements you can make to the car in a situation like this will make it an even better car on the road, where you have bumpy roads etc, causing weight over any wheel under heavy braking to vary more than it will on the track, and thus the ABS is even more likely to kick in.

Aside from all that, I've already discounted pulling the fuse to completely disable the ABS further up the thread.

I can just see that if at all possible, it would be beneficial if you could tweak the settings via VAG-COM to make the control unit slightly less sensitive; I suspect the extra deceleration given by the 312mm conversion is something which is at odds on occasion, with the parameters coded into the ABS control unit with regards to the braking rates of the standard calipers.

after all, ABS does a job for a reason!

Indeed... but when it's doing that job too readily it's potentially dangerous, and needs to be sorted out if you're ever planning to drive at speeds slightly faster than your average Sunday driver.

 

[cupra.al]

surely adjust to the cars abs is the only option after all the abs kicks in when the wheels would lock up in a non abs car. with abs you still have to control it like a non abs car by controlling what would be a skid in a non abs car or a pedal tap in a car with abs.
you wouldnt go skidding into a corner if you didnt have abs so to make the abs kick in before a corner just means you might be leaving it a little to late braking or pushing the brakes a little to hard.
even braking over bumps in a non abs car could still make the car skid and skip all the abs is doing is stopping that.

 

[Gooner_Mike]

That's your choice.

Personally, and given what I found with the braking on my car in particular, I'd rather get my car working in such a way that I've confidence in it not kicking in the ABS a bit too readily when pushed to its limits.

Having looked around these parts, I can see I'm not the only one of the opinion the ABS is oversensitive on these, either.

Because I've had it occasionally kick in on the road as well when perhaps it shouldn't have, but you weren't to know that from the original post...

Humm, yes I do.

If the ABS is kicking in too readily when the car is being punted along on a smooth race circuit, (which as an aside happens to also be covered liberally in sticky rubber from where drifting was also going on during the course of the day, never mind that dumped by race cars with slicks), then any improvements you can make to the car in a situation like this will make it an even better car on the road, where you have bumpy roads etc, causing weight over any wheel under heavy braking to vary more than it will on the track, and thus the ABS is even more likely to kick in.

Aside from all that, I've already discounted pulling the fuse to completely disable the ABS further up the thread.

I can just see that if at all possible, it would be beneficial if you could tweak the settings via VAG-COM to make the control unit slightly less sensitive; I suspect the extra deceleration given by the 312mm conversion is something which is at odds on occasion, with the parameters coded into the ABS control unit with regards to the braking rates of the standard calipers.

Indeed... but when it's doing that job too readily it's potentially dangerous, and needs to be sorted out if you're ever planning to drive at speeds slightly faster than your average Sunday driver.

 

[m0rk]

It'll be the rears locking, and causing the ABS to kick in I expect... 312 'rapid' deceleration won't have anything to do with it

You can adjust settings in VAG-COM to adjust the point that it will trigger the ABS though. You'll need to do some serious research on this (VWVortex) and I'd suggest looking at other avenues first.

These would be....

Suspension. If it's uprated - is it "low & stiff"? If it's not... then it's time you replaced the cruddy OE dampers for something that works.

Tyres will obviously lock up easier if they're crap / worn

ESP? Some of the later FR's had ESP I know - it was 'OK' but if you're braking / turning at the same point & the ESP kicks in then you might be experiencing that.

At the end of the day though, you're trying to punt 1200kg of metal round a track, all you're doing is getting the best out of a bad 'fit' for a track car (sorry)

 

[SteveC123]

surely adjust to the cars abs is the only option after all the abs kicks in when the wheels would lock up in a non abs car. with abs you still have to control it like a non abs car by controlling what would be a skid in a non abs car or a pedal tap in a car with abs.
you wouldnt go skidding into a corner if you didnt have abs so to make the abs kick in before a corner just means you might be leaving it a little to late braking or pushing the brakes a little to hard.

It was doing it as you were hard on the brakes and cornering hard... so the system was almost certainly detecting the inside wheel decelerating at such a rate, it felt the only thing it could do is throw in the ABS and the car then ploughed on until you had the sense to lift off and then back on the brakes.

My understanding is that unlike earlier, more primitive ABS systems, the one on these isn't just detecting when a wheel has locked completely, it's anticipating the wheel is going to lock if the rate of deceleration reported back by a wheel sensor is above a certain threshold.

The same sensors are also monitoring for acceleration to kick in the TCS.

I might be wrong, mind...

*But*... if I'm not, then I'd like to find out whether or not the system can be tweaked to factor in the extra deceleration you're getting when you've got more efficient brakes doing their job better than the system is expecting them to.

even braking over bumps in a non abs car could still make the car skid and skip all the abs is doing is stopping that.

Yes, but this most definitely felt like it was kicking in way too eagerly.

And yes, I adjusted my hamfisted braking to take it into account, and that in turn made me wonder what the point was of uprated front brakes if the ABS system was going to defeat the benefits they bring to the car.

 

[SteveC123]

It'll be the rears locking, and causing the ABS to kick in I expect... 312 'rapid' deceleration won't have anything to do with it

Ok, that makes sense bar... well the worst corner it was doing it on was a hairpin at the top of a hill... so even if the fronts are that much more efficient, the weight balance transfer to the front of the car away from the back end is less than it would have been on some of the other tight corners on the track where the car didn't seem to have as much of a problem

You can adjust settings in VAG-COM to adjust the point that it will trigger the ABS though. You'll need to do some serious research on this (VWVortex) and I'd suggest looking at other avenues first.

These would be....

Suspension. If it's uprated - is it "low & stiff"? If it's not... then it's time you replaced the cruddy OE dampers for something that works.

When I bought the car, it had unbranded, el cheapo lowered and stiffened suspension which was very stiff... as in unbearably stiff, so it now has the standard suspension off of a 2008 FR fitted.

Any recommendations for uprated lowered kit that doesn't rattle your fillings out on bumpy back roads, gratefully received.

Tyres will obviously lock up easier if they're crap / worn

ESP? Some of the later FR's had ESP I know - it was 'OK' but if you're braking / turning at the same point & the ESP kicks in then you might be experiencing that.

Pretty sure there's no ESP and besides that, I always switch the TCS off when going round a track... (and the climate )

At the end of the day though, you're trying to punt 1200kg of metal round a track, all you're doing is getting the best out of a bad 'fit' for a track car (sorry)

Don't apologise.

This is my road car... so I'm under no illusion that it should be 'awesome' on a track.

I'm just interested, having now pushed it as hard as possible and found some limits I wasn't expecting, in seeing if I can smooth these out a bit.

<fires up eBay to look for a 106 Rallye with a 16v conversion to use as 'Something for the weekend, Sir'>

 

[Disco_Biscuit]

I had cause to punt my car round a track last weekend, and was expecting great things from it in terms of braking given how the brakes tend to be on the road.

However, I found the ABS was a bit too eager to kick in on certain corners... so I was just wondering if there was a way to adjust the sensitivity of the ABS by way of VAG-COM or not.

TIA

What Pads you running? if you have different pads front to rear this can show as an imbalance on the track due to different thermal properties.Which usually won't show on the road.

Erm remove the fuses if it's possible

Typical

 

[Aimez]

I'd keep this more quiet if you Insurance find out you have touched your ABS and you have a smash you will end up on your own.

 

[SteveC123]

What Pads you running?

'Black ones'... does that help?

No idea I'm afraid, as they're what were on the car when I bought it.

I'll have a look next time I've got the car up in the air.

if you have different pads front to rear this can show as an imbalance on the track due to different thermal properties.Which usually won't show on the road.

Ok, well I have thought about this a bit more.

I see you're in Kent, so might be familiar with the track at Lydden?

What's confused the issue regarding the earlier suggestion that it's the rear end kicking the ABS off is that under really hard braking into the Devils Elbow, the ABS didn't kick in, but I did feel the back end get really loose meaning the weight had all shifted onto the front end.

I didn't feel this when doing the hairpin at the North Bend... and this was approached much more slowly than the Devils Elbow due to the fact you have a decent run up to the latter, whereas the former, you've just come out of tight bend which slows you right down plus you're accelerating up an incline.

This also means that once you're right on the brakes, there's less weight shifting to the front end, and less lift on the back meaning the rears should be maintaining their bite against more resistance from the rear wheels.

So... the conclusion I've come to is it's more to do with being harder on the steering when first applying the brakes, than weight distribution under hard braking.

That, and North Bend doesn't have anywhere near as much camber on it as Devils Elbow.

The other possible influencing factor may well be the tyres.

I did the tyre pressures before I took it out, so I know there wasn't an imbalance in this respect; I've found that on the road, these are really sensitive to any imbalance pressure wise across an axle, and it's under hard braking you notice this the most.

Tyre wise, it has Eagle F1s on the front... and they seemed to cope very well overall.

Hmmm... and that's possibly another factor actually; the nearside front takes a real pounding round Lydden as all the corners bar Devils Elbow are right handers... hmmm

Typical

 

[SteveC123]

I'd keep this more quiet if you Insurance find out you have touched your ABS and you have a smash you will end up on your own.

Aye, well I've not done anything to it yet.

I'm just trying to find out if, for trackdays at least (1), there's anyway to improve on the current setup.

(1) Honest! I'd never use anything on a car that was proven to make it stop better on the track and had in fact improved the car for all situations, on the road.

 

[basssound]

Erm remove the fuses if it's possible

I was only joking fella, peeps did this on old systems but today it aint possible lol.
I could only recommend that you get in touch with seat direct and ask them because peeps will use this car for track days ect... so they must have it turned down or adjusted somewhat.