Slip light and abs for no reason

[SX Dave]

Hi guys, wondering if you can shed a bit of light on a issue I'm having.

 

I have searched but I'm on my phone and my connection is painfully slow so please excuse me if I am missing something obvious.

 

Issue has happened twice now. While driving briskly but not enough to skid. The slip light has flashed up and the front abs has applied for a second. The car also feels rather skittish at high speed in a straight line too. It tends to move around a little above 60-70mph.

 

It's recently been lowered 30mm on BC racing coilover with rear camber arms and bolts by Kaizer and the alignment was all spot on nothing out of the ordinary bar a fair bit of camber at the front as didn't fit front arms and zero toe all round as I found on here to be recommended.

 

Car is running standard 18"s with standard tyre sizes, which is why I'm slightly confused.

 

Anyway have a check list of things to check in Oder of priority or probability.

 

Any help I greatly appreciated.

 

Thanks

 

Dave.

[Dblock]

Hmm abs sensor or steering angle sensor?

[Ekona]

How do you know the ABS activated? Were you braking at the time?

 

My guess would be that the TCS detected slip and killed the spark. Zero toe will make the car feel more skittish than you used to if you were running toe-in (which is very likely, most cars do as it gives more stability in a straight line).

[SX Dave]

There was a judder for approx 1-2 seconds from the front wheel that felt like abs and it was only on one side. I assumed abs?

 

Seeing as zero toe is just outside factory settings I wouldn't of thought it would make it feel as u settled as it does?

 

Iv checked tyre pressures all spot on as well.

[Chris`I]

I would imagine zero toe will make it feel skittish, its why they have some toe in the first place. Doesnt take a lot to make it feel more stable at speed.

[Ekona]

Judder could be tyre skipping over the surface where there's zero grip. ABS isn't possible to trigger unless your foot is full hard on the brake pedal and the wheel is locking, or unless you have a serious brake issue.

 

With alignment settings you're only ever talking fractions of a degree to make a difference, and any toe setting that isn't in is going to feel mighty weird if you don't expect it. I'm betting you're finding the car far more eager to turn in though, yes?

 

 

I have my cars set with toe out, which is great fun

[glrnet]

Judder could be tyre skipping over the surface where there's zero grip. ABS isn't possible to trigger unless your foot is full hard on the brake pedal and the wheel is locking, or unless you have a serious brake issue.

 

With alignment settings you're only ever talking fractions of a degree to make a difference, and any toe setting that isn't in is going to feel mighty weird if you don't expect it. I'm betting you're finding the car far more eager to turn in though, yes?

 

 

I have my cars set with toe out, which is great fun

Why am I not surprised?

[SX Dave]

Thanks Ekona, maybe it was just sliding if the abs wouldn't apply in those conditions as def wasn't braking. just didn't feel to be going quick enough for that even though it is slippery out and lack of grip around. I guessed as the slip light had come on and it juddered I figured abs correction, I guess not lol. Although when driving spiritedly it's had to get an accurate judgement for a 1 second incident I spose.

 

Turn in is great and the slightly livelier back end is what I wanted. It's just a lot more skittish at higher speeds (more than I was expecting anyway). Maybe I just need to get used to it. But seems quite unnerving when pushing in the higher gears. Maybe I'm just being a tart lol.

[Ekona]

Sadly you can't have a pointy front end and high speed stability, as one is a trade off against the other. It's all about balancing the two really, although a bit of toe in at the rear could help with this. I don't think you're being a tart at all mate, it can take a while to get used to it, considering that all manufacturers set their cars up to understeer as it's the safer option.

 

Sounds very much like you past the slip angle of the tyre, so basically if you'd have wound a bit of lock off you'd actually have found yourself turning quicker. That's a symptom of too much steering angle and too much speed, no biggie as we all do it especially in this weather.

[SX Dave]

Ill see if I get used to it, if not ill add a little toe in. Not being an alignment guru I'm shocked at how a small amount of toe can make such a difference at speed, I understand the balancing of the two, it was achieving it (or possibly not) that's shocked me. Although cornering is unbelievably better.

 

Oh makes good sense, as to scrubbing the front it slowing and the rear then thinking its slipping.

 

Thanks for the help.

[docwra]

Hi Dave, seeing as its you I thought Id post - the issue is ........

 

ABS isn't possible to trigger unless your foot is full hard on the brake pedal and the wheel is locking' date=' or unless you have a serious brake issue[/quote']

 

.... is not quite 100% accurate, it will trigger on indivdual front wheels if the car detects understeer, you dont even have to be braking. The SLIP and ABS lights will fire up and then it will pretend like nothing happened, mine with horrifically non OE tyre sizes used to do it all the time, particularly when pressing on a bit.

 

I wonder whether the increased front camber is actually reducing grip on the inside tyre when turning and thats whats causing it, you will probably find it disappears once the road conditions are a bit better though

[Ekona]

I can see the brakes intervening by gently applying themselves to the wheel in question, but surely not hard enough to fire the ABS? That would seem crazy, it only needs to slow the wheel a fraction not stop it rotating completely.

[docwra]

It only fires for a fraction of a second, not enough to stop the wheel moving but enough to move the weight of the car (I guess thats the idea)

 

Try and provoke lift off oversteer on yours and you'll see what Im on about - the figuring out of how to turn off all stability control (three plug trick) came from this ruining a track session for me at Donington a couple of years ago, its very noticable. I should add again that Im running ridiculous tyre sizes so get it worse than most but it happens when you are off throttle and off the brakes, the car is doing it for itself.

[Ekona]

I know what you mean, I had great fun on a Walshy day trying to beat the computer before it fired the brake, got it a couple of times too!

 

I'm surprised it fires the ABS though, seems a bit cack handed. It certainly never felt like ABS. You learn something new every day, ta.

[ianphampton]

I had an issue with TCS pausing the power - when I was driving 'vigorously' on my winter tyres. Mark at Abbey traced it to my winter tyres being blocky and they moved when under spirited power application and the TCS was confused and paused the engine. (This was a cause for particular concern as it happened whilst overtaking and having the power cut on you when you've pulled out and then fed her some beans - and she pauses. . . . )

 

Obviously this doesn't apply to you - but the solution we came up with for a zero cost fix would probably work for you, too -

 

If you know you're going to be driving 'with gusto' - turn the TCS off - and there's no problems. I now turn the TCS off if I'm in a hurry on my winter tyres and never had the hiccough since.

[docwra]

Obviously this doesn't apply to you - but the solution we came up with for a zero cost fix would probably work for you, too -

 

If you know you're going to be driving 'with gusto' - turn the TCS off - and there's no problems. I now turn the TCS off if I'm in a hurry on my winter tyres and never had the hiccough since.

 

Again, no disrespect but its a different thing, SX Dave is talking about the front wheels and not the rears. Turning the TCS off will stop it cutting in on the rears but doesnt have any effect on the front wheels, you need to unplug the ABS to make that happen

Edited February 5, 2013 by docwra

[SX Dave]

Thanks Docwra, makes sense too I guess if there isn't enough initial grip to benefit from the extra front camber right? It's currently just over 2 degrees from memory.

 

I'm taking it brands later this month so hopefully it won't cause much if an issue then.

 

Docwra are you or was you on SXOC? Name rings a bell I used to go on there years ago when I had my S14a.

 

 

[docwra]

Thanks Docwra, makes sense too I guess if there isn't enough initial grip to benefit from the extra front camber right? It's currently just over 2 degrees from memory

 

Something along those lines, I dont think youll have issues on track as its a lot smoother but with negative camber the inside turning tyre contact patch can get smaller particularly over bumps etc. The Wiki page is pretty good at explaining: http://en.wikipedia.org/wiki/Camber_angle but the bottom line is that the VDC kicks in a bit quicker than it probably has to, as with most OE traction control its a bit hamfisted.

 

If you suffer the same issues on track then unplug the three plugs in the inner wing, bear in mind you wont have ABS or TC anymore though ...........

 

Docwra are you or was you on SXOC? Name rings a bell I used to go on there years ago when I had my S14a.

 

Yeah, hanging in there as the Chairman these days .......... thought I recognised your name

[SX Dave]

Thanks for the help, cleared up a few worries.

 

Drove a bit more at speed on straights and getting used to the zero toe feel think all should be ok. Was maybe a rubbish bit of road and me over reacting.

 

Oh good on ya MR Chairman. It was a few years ago I was on there, went to a few meets and met with Mark from my neck of the woods a few times.

 

Thanks for the help guys

[Bergwerk06]

The three plug trick intrigues me- I've changed my front brake set up and i'm finding that the ESP and ABS are causing gaps in the control when i'm pushing my Z. I've turned the ESP off and enjoy the extra few % of real world grip but still had an issue on the potholes into a hard left hander when it felt like the brakes failed for a brief moment with lots of whirring so it still seemed that the E brain was over riding my right foot. How does the three plug trick work and what does it affect??

[docwra]

From what I can gather the stability on the front wheels uses the ABS to brake them when it detects a certain speed difference between wheels front and back, the three plugs are the part of the ABS control so stop it happening.

[CrumbMC]

I had the same problem when I got the car with craptyres on the back.The brakes were definitely (there is no way that this was just the ignition cutting out) grabbing at the front wheel when going round coeners in the wet.

 

I know this doesn't solve your problem but I have had the brakes grabbing before so it can happen. Even if you are nowhere near the pedal.

 

Fortunately my problem was solved when I changed the tyres but if you have just changed the suspension it may not be so simple.

 

Sent from my GT-I9000 using Tapatalk 2

 

 

 

Edited April 10, 2013 by CrumbMC