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Discussion Starter · #1 ·
I have now done 3400 miles, and in nearly all conditions the car inspires confidence, BUT, I have come across a situation in the last 2 weeks, where the cars behaviour has led to me questioning its handling in all conditions. All of these experiences were with the settings in Normal and box in manual.

I would like to know if anyone else is experiencing the same tendency to understeer / lose front end grip in damp conditions?

It has occured in 3 different situations. The first time, I was exiting left out of a local roundabout (one i know very well), and it seemed to me that the traction control interfered prematurely, causing the car to over-correct and almost putting me in the hedge! The roads were damp (kind of greasy after recent rain), but i was in 2nd gear, doing about 30-40mph into an exit i know very well, which in previous front drivers i have never had a problem with. It has happened at the same point twice in the same conditions.

The second was entering a roundabout on the A505 in 3rd gear, not overly quickly, in fact at a reasonable pace (for the GTR), which in the dry it would have managed and some more, BUT, again the roads were damp / greasy (no standing water) and as i went round the roundabout the car pushed wide at the front which was very unexpected. Thankfully no one else was around. The traction did not interfere this time and i was able to correct.

The 3rd one, was today, joining the A3 dual carriageway near Ripley (Guildford), going down a normal slip road at 50mph in 4th gear. As i had almost completed the turn, i pushed my foot down and again the traction control seemed to prematurely interfere, really upsetting the line of the car. Again the roads were damp / greasy and no standing water.

Is this caused by camber set-up (I am on the max wear position), or is it actually caused by the Dunlops having poor grip in damp conditions? The grip is excellent in the dry, and actually seems good in the wet (although I am probably not pushing them as hard), but in damp / greasy conditions they really seem to lack any decent front end bite / grip, and i suspect the electronics are sensing this and triggering the traction when you least expect it.

Has anyone else experienced similar behaviour? Is anyone running the Bridgestones?
 

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When you say you are on the "max wear" position, do you mean you are running the track-biased settings with max negative camber?

I thought the car understeered too much until I had the settings changed to the track one and now, if it understeers, it is because there is no grip, i.e. any power sees the back break loose too.

As for VDC settings, that is a tricky one. You would think that standard "full-on" mode would be safest, and it probably still is on the road. However on track "R" mode makes the car more predictable as you have a wider window where the VDC will not overly interfere while you decide how best to deal with slides.

It has to be said that the Dunlops are pretty poor in the wet, and 3,400 miles of hard driving may have worn the inner edges to the level where they are significantly worse still.

I will probably try the Bridgestones next, just for journalistic reasons (and the fact they are significantly cheaper!).
 

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I have been caught out on a damp roundabout with cold tyres with understeer and serious aguaplane through standing water although I was driving too fast for the conditions. Otherwise its a 4 wheel slide wide in the wet not understeer.
I'm on normal track settings and have had a few occasions with the TCS intervening in both normal and race neither has led to understeer or unexpected handling. In fact when you think it might let go it seems to grab the road again and want more. The maximum lateral G I have pulled is 1.25 at about 100 mph.
 

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Discussion Starter · #4 ·
When you say you are on the "max wear" position, do you mean you are running the track-biased settings with max negative camber?

I thought the car understeered too much until I had the settings changed to the track one and now, if it understeers, it is because there is no grip, i.e. any power sees the back break loose too.

As for VDC settings, that is a tricky one. You would think that standard "full-on" mode would be safest, and it probably still is on the road. However on track "R" mode makes the car more predictable as you have a wider window where the VDC will not overly interfere while you decide how best to deal with slides.

It has to be said that the Dunlops are pretty poor in the wet, and 3,400 miles of hard driving may have worn the inner edges to the level where they are significantly worse still.

I will probably try the Bridgestones next, just for journalistic reasons (and the fact they are significantly cheaper!).
Hi David. No, I am set up for optimal road wear (longevity) not track bias. Still plenty of tread across the tyres. I just think they have poor performance in the wet / damp. I think i will also try the Bridgestones next time.
 

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Ah in that case, no wonder! The car does understeer quite badly set for maximum tread life, i.e. motorway settings.

Get your HPC to change it to fast road or track settings and it will handle a lot better.

As I said, mine only really understeers now when there is basically no grip anyway.
 

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My first experience of this was at the Ring. Done a few laps on dry morning then circuit closed for a couple of hours to get accidents and spillages cleaned up, then circuit opened just after it had started raining hard. Even though I backed off, there were a couple of right-handers where I nearly went straight on! However it was only momentary and soon came round back on course.

And last week I completed two 100 mile journeys cross-country in pouring rain. Quite a few mini-moments until I backed off! I've learnt the Dunlops dont like standing, or even running water on the carriageway....

... but this isn't understeer - its loss of adhesion. In those circumstances, if you've lost grip at the front, the drive computer isn't going to send power to the front wheels. So until it comes back you are in a RWD car. Dont forget its primarily a RWD system until you lose drive at the back when it pours it to the front (and this is almost the exact opposite of the Quattro system).

So dont think of it as 4WD! And remember it doesnt have all weather tyres on.

After some discussion with Colin from CATDT, and viewing Suzuki-san's laps of the Ring, its clear you need to think about how the drive works before you start pressing on (and I think thats the reason the Porsche drivers couldn't get near Suzuki-san's times!). If you watch his laps, he seems to deliberately unstabilise the rear of the car on the way in to a corner. This would fool it into shifting the drive to the front, enabling him to floor the throttle earlier and gain a higher exit speed ... and a higher speed on exit means a higher speed on any straight bits before the next corner.....

... all good fun ... but does require concentration!
 

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Just getting my head around this , so let's say (figuratively speaking) if you went into a bend with the car in all 3 race setting's at speed , and you encountered severe under steer , if you gas it hard it will bring the back out (over steer ) & around you go ? or have I got it horribly wrong ?
 

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Just getting my head around this , so let's say (figuratively speaking) if you went into a bend with the car in all 3 race setting's at speed , and you encountered severe under steer , if you gas it hard it will bring the back out (over steer ) & around you go ? or have I got it horribly wrong ?
I dont think thats what I meant! There is a difference (I believe!) between understeer and lack of adhesion at the front. If you've lost traction at the front my instinct says to back off a bit - seems to work for me! My brain says if you boot it at that point its gonna give more drive to the rear and you are going to go off in a bigger way!

Given the only way you can control the torque split is by driving style, you should think hard about your inputs and what they do. Interestingly I've just realised that over the last couple of thousand miles the Torque Split graph has become the one I look at most on the MFD - never realised until this topic started.

I'd really like to do a day with CAT at Millbrook in the rain! I'm not brave enough to make either of the ends brake away on the steering pad in the dry....
 

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Frankly, I think if you look a bit more closely at Suzuki-san's ring performances, you'll observe that:
-> he doesn't try to scrub the rear axle, but rather plunges a bit wide,
-> his braking is typically a bit early, if at all,
-> about 1/3 of the way around he really cranks in much too much steering input (saws actually) sometimes in rallye style,
-> evidently in an attempt to loose the front end to force it as you said to regain "fresh" traction while throwing in the boot to power around the last half of the curve.

It tends to look a bit like "slip & slide" but there seems to be a consequent technique behind it all to wring ATTESSA traction primarily from the front to induce a power oversteer.
 

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IF YOU WATCH THE TORQUE METER YOU'LL PROPERLY SEE IT FLY RIGHT UP. THE ELECTRONICS PUTT A LOT OF TORQUE TO THE FRONT WHEELS IN AN INSTANT, SOMETIMES!

THIS IS UNLIKE PREVIOUS GTR'S. BUT YOU'D THINK THIS WOULD BE EASY TO ADAPT TO. UMM!

I NOTICED THIS A FEW TIMES AS YOU COULD DRIVE THE SAME ROAD SAME CONDITIONS BUT NEXT TIME THE CAR WOULD REACT DIFFERENT. THIS WAS ONE OF THE TRAITS THAT GOT ON MY NERVES..
THE ELECTRONICS DOING THERE THING.
 

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I have now done 3400 miles, and in nearly all conditions the car inspires confidence, BUT, I have come across a situation in the last 2 weeks, where the cars behaviour has led to me questioning its handling in all conditions. All of these experiences were with the settings in Normal and box in manual.

I would like to know if anyone else is experiencing the same tendency to understeer / lose front end grip in damp conditions?

It has occured in 3 different situations. The first time, I was exiting left out of a local roundabout (one i know very well), and it seemed to me that the traction control interfered prematurely, causing the car to over-correct and almost putting me in the hedge! The roads were damp (kind of greasy after recent rain), but i was in 2nd gear, doing about 30-40mph into an exit i know very well, which in previous front drivers i have never had a problem with. It has happened at the same point twice in the same conditions.

The second was entering a roundabout on the A505 in 3rd gear, not overly quickly, in fact at a reasonable pace (for the GTR), which in the dry it would have managed and some more, BUT, again the roads were damp / greasy (no standing water) and as i went round the roundabout the car pushed wide at the front which was very unexpected. Thankfully no one else was around. The traction did not interfere this time and i was able to correct.

The 3rd one, was today, joining the A3 dual carriageway near Ripley (Guildford), going down a normal slip road at 50mph in 4th gear. As i had almost completed the turn, i pushed my foot down and again the traction control seemed to prematurely interfere, really upsetting the line of the car. Again the roads were damp / greasy and no standing water.

Is this caused by camber set-up (I am on the max wear position), or is it actually caused by the Dunlops having poor grip in damp conditions? The grip is excellent in the dry, and actually seems good in the wet (although I am probably not pushing them as hard), but in damp / greasy conditions they really seem to lack any decent front end bite / grip, and i suspect the electronics are sensing this and triggering the traction when you least expect it.

Has anyone else experienced similar behaviour? Is anyone running the Bridgestones?
Hi just joined and its my first message, yeh happened to me round about as well still trying to figure out what happened, lost traction exiting right and it went straight on i dont know if i braked or not but abs seemed to be kicking in then it come back just in time it was very unerving, it was same conditions barely damp and felt greasy,as someone else said massive grip in the rain but cant handle the damp.
 
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