MK5 Golf GTI
All Things Mk5 => Modifications & Technical Area => Track Day Technical => Topic started by: fuscobal on May 04, 2010, 09:02:02 am
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Hello guys,
I just came back from the Nurburgring trip and although it was a beautiful experience, it was not without incidents. A friend of mine with 1.8T had oil starvation and the oil pump sucked dirt from the bottom of the pan. From this he also blocked the turbocharger. For me, something very weird happened and I'm going to describe it on detail. On Saturday there were also no less than 10 incidents on the track. Here it goes :
- Thursday : In the 3rd lap, right after exiting the carousel, my "coolant agent" light came on so I had to slow down thinking my engine boiled and I had no coolant in the engine. I drove very slowly for 40secs when the light went off by itself and still managed a 9'20" (this would have been a 8'50" lap). In the parking lot, I opened the hood and saw my coolant was 2 thingers more than the maximum and I took out about 0.5L until it reached the maximum line.
- Friday : In the first lap, after exiting the carousel, in the wide left-corner that is not at all so difficult, the car suddenly pulled left towards the interior of the corner. With 4-5 seconds before, I was just changing 4th gear so at that momet I must have had like 160kmh. Before saying anything, let me tell you I didn't touch the kerb (my left wheels were at about 1m from the kerb) and I didn't brake (I was not at full gas either, just medium accelerating). When the car pulled left, I counter-steered but being so close to the kerb it touched it and the went to the right. I counter-steered again and made the back slide a little hitting the barrier with the rear-right corner and then with the front-right corner out of inertia. At the moment at the impact I don't think I had more than 40-50kmh so only the front and rear bumpers + headlight/stoplight were damaged. I quickly opened the hood and there was no cooling agent in the tank wich seemed strange being the engine lookedgood. Engine seemed to be ok and also the wheel alignment.
- After reaching the garage, I've put the Vag-com on the car and I had only one error : "ESP sensor G419 defective - intermittent" (ESP was off on the track). Unfortunately I erased the code by mistake instead of saving it.
- Going back in time for 2 month, I remember something similar happened when I was accelerating on a straight line. on the first lane. The car suddenly pulled right but at that time I was having about 80-100kmh so I managed to bring the car back. On the right side, the road was pretty dirty. After talking to some of my frinds, one of them had the same issue with his Cupra and he was pretty sure the LSD tricked him.
Possible causes from what I gathered until now :
- ESP/ABS sensors faulty or got tricked by the LSD/suspension/brakes
- LSD got tricked by a dirty spot on the left side of the track and the wheels spinned at different speeds
- Engine boiled because there was no cooling fluid left and this somehow influenced the wheels (less probable but still can't understand why I had no coolnt). The coolant tank was at the max position and that was the first lap on Friday so how could it dissapear so fast if not by boiling and going out as steam ?
The blue circle shows where it happened > (https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fimg16.imageshack.us%2Fimg16%2F6914%2F58338390.jpg&hash=596d07a43ffb42ed16b5d9c3f2a094f57c7a5d8d)
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Was the coolant cold before you removed 0.5l, as the maximum line is based on cold fluid and if you removed hot or warm fluid then this would have contracted under cooling.
And I suppose that if the ESP had a fault it could have caused the front left brake to apply causing the car to Veer off at a funny angle (as even with the switch in the off position it will still intervene in extreme circumstances.
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The coolant was warm when I removed it but I took this in consideration and I still left it at maximum position so when it was cold it would be over the minimum. When I entered the track the next day, the coolant was between the min and max position so nothi9ng to worry about. Another thing is, My coolant was pretty concentrated because of the heavy winter and my mechanic told me during summer it should be thinned with more water for a proper engine cooling. He said this could have caused those large variations in volume for the cooling fluid !
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You mention "LSD" a number of times and so seem suspicious of it. Just to clarify, do you have a Quaife ATB differential installed? If so, when it comes into play, it's best to keep it in play with your throttle.
ESP off? - On the Nordschleife you're a braver man than I am! Having it on can be an intermittent nuisance but it might have saved you, or are you uber experienced with it off? I was strongly advised that if you want to drive the Nordschleife without ESP in an ESP equipped car you should learn by doing lots and lots of slooow laps and only build up faster laps very gradually. But that doesn't help your question what went wrong.
This incident must have cost you a pretty pfennig :sad1:
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You mention "LSD" a number of times and so seem suspicious of it. Just to clarify, do you have a Quaife ATB differential installed? If so, when it comes into play, it's best to keep it in play with your throttle.
ESP off? - On the Nordschleife you're a braver man than I am! Having it on can be an intermittent nuisance but it might have saved you, or are you uber experienced with it off? I was strongly advised that if you want to drive the Nordschleife without ESP in an ESP equipped car you should learn by doing lots and lots of slooow laps and only build up faster laps very gradually. But that doesn't help your question what went wrong.
This incident must have cost you a pretty pfennig :sad1:
When my LSD was not playing the game correctly, it would snatch and was not nice to drive. on the power violent twitches were frequent, hence my wish to 'have it fixed or removed'.
have you been having problems with your LSD Fusco?
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^^^^
Let's hope for Quaife's sake they didn't produce a bad batch.
Try testing the LSD in a safe wide open environment, Fusco? See if you can induce/reproduce the snatch.
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Maybe the problem is more simple than you think.
My theory is that when the car is under pressure(high temperatures),you might have coolant loss from a damaged coolant hose,
so the tires step on the coolant and loose grip.(thats why ESP seems fault)
When the engine get colder everything might seems ok.
So check all the coolant hoses and get some silicone ones .In hard track conditions,reliability is No1 for me :happy2:
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Maybe the problem is more simple than you think.
My theory is that when the car is under pressure(high temperatures),you might have coolant loss from a damaged coolant hose,
so the tires step on the coolant and loose grip.(thats why ESP seems fault)
When the engine get colder everything might seems ok.
So check all the coolant hoses and get some silicone ones .In hard track conditions,reliability is No1 for me :happy2:
Sounds right in my ears :smiley:
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So check all the coolant hoses and get some silicone ones .In hard track conditions,reliability is No1 for me :happy2:
....Oh dear, another mod to add to my never ending list!
Good points you make, Niki :happy2: [Thinks: he must be a Greek]
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The coolant was warm when I removed it but I took this in consideration and I still left it at maximum position so when it was cold it would be over the minimum. When I entered the track the next day, the coolant was between the min and max position so nothi9ng to worry about. Another thing is, My coolant was pretty concentrated because of the heavy winter and my mechanic told me during summer it should be thinned with more water for a proper engine cooling. He said this could have caused those large variations in volume for the cooling fluid !
Ahh ok, so the mechanic is saying the higher concentration of coolant, will cause the variance of volume based on temperature to be more dramatic.
If what Nikiforos is saying were true would the sudden application of a single brake by ESP cause some unusual behaviour with the LSD? which could exacerbate the problem, I have no experience with LSD but if one wheel suddenly braked would it shove the power over to the other wheel so for example inside wheel breaks, LSD shoves power over to outside wheel, and this shove the car off in a funny direction? Maybe with some torque steer chucked in for good measure?????
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So check all the coolant hoses and get some silicone ones .In hard track conditions,reliability is No1 for me :happy2:
....Oh dear, another mod to add to my never ending list!
Good points you make, Niki :happy2: [Thinks: he must be a Greek]
Totally Greek :innocent:
@RICHN83:
In the track or under very fast road conditions, the ESP might be off,because for example when a wheel
get "on air"for a while, the esp ecu thinks that something is wrong and turns the esp off.
I have seen this with my previous car(Swift Sport)several times.
Because of the hard and sudden spinning of Fusco's GTI in the Ring, the ESP might diagnosed fault.
In my opinion it has nothing to do with the LSD which is 100% mechanic.The only problem is that it makes torque
tranfer more violent.
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I'm voting wheel slipped, LSD counter'd by sending all power to other side and it skewed the car's direction.
Saw it at Oulton with a mate's car a while back, he lost the back on a right hander, he semi caught it by counter steering, it gripped the outside and speared him off into the outside barriers on the left.... non-LSD and it would have just oversteered around in a circle or hit the inside barrier.
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Maybe the problem is more simple than you think.
My theory is that when the car is under pressure(high temperatures),you might have coolant loss from a damaged coolant hose,
so the tires step on the coolant and loose grip.(thats why ESP seems fault)
When the engine get colder everything might seems ok.
So check all the coolant hoses and get some silicone ones .In hard track conditions,reliability is No1 for me :happy2:
Sounds right in my ears :smiley:
Yes! It's what I was thinking too. :happy2:
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ESP off? - On the Nordschleife you're a braver man than I am! Having it on can be an intermittent nuisance but it might have saved you, or are you uber experienced with it off? I was strongly advised that if you want to drive the Nordschleife without ESP in an ESP equipped car you should learn by doing lots and lots of slooow laps and only build up faster laps very gradually. But that doesn't help your question what went wrong.
For me, driving fast ESP ''on'' sound weird. First it will burn your brakes and it often react much too soon and not accurately. Or I should say driver réaction and ESP correction don't match together. :driver: Or you drive, or électronic drives.
I always drive fast ESP OFF on the road or at the Ring.
I'm voting wheel slipped, LSD counter'd by sending all power to other side and it skewed the car's direction.
Saw it at Oulton with a mate's car a while back, he lost the back on a right hander, he semi caught it by counter steering, it gripped the outside and speared him off into the outside barriers on the left.... non-LSD and it would have just oversteered around in a circle or hit the inside barrier.
I don't have much experience with LSD as I have got mine since only 2500km, but even at the Ring I didn't experienced such violant reaction, that you loose the control of your car. Even with one front inner wheel in the air. It does steer into the curve when pushed hard and you have to manage the steering wheel, but not much. :surprised:
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Sadly all we can do is guess.
Can you take it somewhere safe and see if you can make it do the same again?
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Possibly could be the steering alignment sensor :confused:
This could bring the ESP in when it shouldn't be really needed.
A mate of mine had this issue on his ED30 and all 4 wheels locked in his case and put him on the grass after a corner (not me, I hasten to add!)
Worth checking anyway, even if it is just to eliminate it as a possibility. :smiley:
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my initial thoughts on the sudden jerk in steering was a loss of grip on a tyre followed by a shift of power via the LSD caused by a small bit of oil or engine fluid of some sort on the track, however you say that it has happened before, so it surely has to be something else.
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First of all, let me tell you my LSD is a Peloquin. I must say, when it first happen, I am 100% the road had some sand/dust on the right side and the car pulled to the right (towards the dirt). time, the dirty side was probably on the left (the inside of the corner) and the car pulled towards the dirt again. My best guess is what Tony and Hurdy said :
1) LSD got tricked by a dirty zone on the track
2) Steering wheel sensor faulty wich made the ESP kick in when it shouldn't
As for the cooland, I checked the hoses and they are all ok. My guess is the coolant got out as steam/vapors wich I saw when the car stoped and this could have been because the very hot engine stopped suddenly (normally, when you drive a car to the limit, you stop and let the engine run for 1 minute or more too cool down but in this case the engine stopped instantly because it was into gear and the car stopped )!
Here's some drawings for better understanding of the dynamics >
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fimg21.imageshack.us%2Fimg21%2F8804%2Fimpact2o.jpg&hash=d0fca42a2dad00d501860ce5a513eafc12819734)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fimg339.imageshack.us%2Fimg339%2F6092%2Fimpact1w.jpg&hash=991dee9ece751fe804e32efe2a4cae6c52409f07)
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If you have an ATB diff such as a Torsen/Quaife/Peloquin/Stasis, then the ESP really needs to be turned OFF, especially when on a track. The simple reason is that the ESP includes a standard component called 'electronic differential lock' or EDL. And if this EDL kicks in at the same time as an ATB is also transferring torque, then the torque transfer across an axle could be over exagerated to the point of causing some highly undesirable traits - which are highly likely to cause an 'armco to bodypanel interface'.
Using the 'brakes' is a well-known <cough>tweak<cough> to hide an ATB diff from official racing scrutineers . . .
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I realy think that your car simply slided off left on the dust and that the grip was worst than expected. Then you counter-steered while the car get back on the dry tarmac en get grip faster than expected. May be a little too much counter-steer the car unsettled by the left/right steering and you are violently thrown toward the right armco.
For ime, it's an unlucky but simply sudden change of grip because of the dust.
May be it was worst because of your ESP sensor fault.
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If you have an ATB diff such as a Torsen/Quaife/Peloquin/Stasis, then the ESP really needs to be turned OFF, especially when on a track. The simple reason is that the ESP includes a standard component called 'electronic differential lock' or EDL. And if this EDL kicks in at the same time as an ATB is also transferring torque, then the torque transfer across an axle could be over exagerated to the point of causing some highly undesirable traits - which are highly likely to cause an 'armco to bodypanel interface'.
....Hmm, I don't seek to disagree with you and expect that you are right, but: There were some laps I recently drove on the Nordschleife with my ESP on and as I was more confident and going faster, my driving actioned the ESP very frequently. I have a Quaife ATB. This was not a problem and I ignored it and drove 'through' it staying on the throttle and on the track. Unpleasant and inconvenient having the ESP continually kicking in, but. When I switched the ESP off for the GP section of the circuit I had an off into the hard green stuff but got back on the black stuff before the kitty litter.
I've done a trackday at Spa with the ESP off and in the wet and thoroughly enjoyed it, but the Nordschleife can bite very hard and I'm not sure advising ESP there is wise unless you drive it more slowly.
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Teutonic, I already said the ESP was OFF. I am always driving with ESP off because I can feel it slowing me down in every turn. For me, with this car, the difference is night and day and I simply can't drive fast with it on since it will interfere every turn !
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If you have an ATB diff such as a Torsen/Quaife/Peloquin/Stasis, then the ESP really needs to be turned OFF, especially when on a track. The simple reason is that the ESP includes a standard component called 'electronic differential lock' or EDL. And if this EDL kicks in at the same time as an ATB is also transferring torque, then the torque transfer across an axle could be over exagerated to the point of causing some highly undesirable traits - which are highly likely to cause an 'armco to bodypanel interface'.
....Hmm, I don't seek to disagree with you and expect that you are right, but: There were some laps I recently drove on the Nordschleife with my ESP on and as I was more confident and going faster, my driving actioned the ESP very frequently. I have a Quaife ATB. This was not a problem and I ignored it and drove 'through' it staying on the throttle and on the track. Unpleasant and inconvenient having the ESP continually kicking in, but. When I switched the ESP off for the GP section of the circuit I had an off into the hard green stuff but got back on the black stuff before the kitty litter.
But I think you are being over-reliant on the 'confidence' the ESP can give. Maybe you somehow have some kind of 'mental block' (maybe about just being scared of turning off the ESP, or maybe the reputation of the 'Green Hell', or both).
And dispite your own preference for Goodyears, there are better tyres which will enhance the handling of the GTI. In fact, I bet you would find it very difficult to find any serious 'Ring users who ran Goodyears.
I've done a trackday at Spa with the ESP off and in the wet and thoroughly enjoyed it, but the Nordschleife can bite very hard and I'm not sure advising ESP there is wise unless you drive it more slowly.
But the trouble is, being 'reliant' on ESP can actually mask 'bad driving'. Look at it another way - yes, the ESP may well save you at say 50mph on a certain corner, which might mean an off with bad driving without any ESP. But with that same bad driving, the 'off' with the ESP will simply occur at much higher speeds - with highly increased consequences.
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Teutonic, I already said the ESP was OFF. I am always driving with ESP off because I can feel it slowing me down in every turn. For me, with this car, the difference is night and day and I simply can't drive fast with it on since it will interfere every turn !
Whoops, missed that. Sorry, my bad. :chicken:
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But I think you are being over-reliant on the 'confidence' the ESP can give. Maybe you somehow have some kind of 'mental block' (maybe about just being scared of turning off the ESP, or maybe the reputation of the 'Green Hell', or both).
And dispite your own preference for Goodyears, there are better tyres which will enhance the handling of the GTI. In fact, I bet you would find it very difficult to find any serious 'Ring users who ran Goodyears.
....Yes, I'm only just recently on my third 'Green Hell' trip beginning to feel more confident and knowing about what's coming up.
My current preference for Goodyears is only for road use and I'm thinking of PS3's next for road.
I've done a trackday at Spa with the ESP off and in the wet and thoroughly enjoyed it, but the Nordschleife can bite very hard and I'm not sure advising ESP there is wise unless you drive it more slowly.
But the trouble is, being 'reliant' on ESP can actually mask 'bad driving'. Look at it another way - yes, the ESP may well save you at say 50mph on a certain corner, which might mean an off with bad driving without any ESP. But with that same bad driving, the 'off' with the ESP will simply occur at much higher speeds - with highly increased consequences.
....Currently I think it's wise for me to keep ESP for road driving, fast or otherwise, and decide according to the individual track whether to switch it off there or not.
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Next year, if I will be going there with the same car, I will probably put on some stickier tires like R888. I've asked Teo (the owner of rent-racecar) how much of a difference can a tire like Toyo R888 make over GY F1 asym or PS2/3 on a car like my GTI and he said probably about 15-20secs/lap !
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I'd agree with 20 seconds per lap. I went out initially with normal Vredesteins on and then swapped to R888's. The difference is like night and day. :happy2:
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Dont have enough knowledge on ESP.
Did have a similar issue with losing coolant though. Not on a mk5 golf but a mk2 with a 20VT installed. Daily use no issues.
After spirited driving the level would appear to go up or down (even once the car had been left to cool). After much investigating turned out to be a dodgy seal on a coolant temp sensor. Would let the coolant out as steam and once it reached a certain level would replace it with air!