Getting rid of understeer during braking (Skyline R34)

[kotafey]

Hi folks,

I've trawled through the forums and read several guides. My starting point was one of the settings posted by Duck, which I tweaked a little bit here and there.

On the whole I'm happy with how the car handles, except for one BIG problem. It seems to be very unforgiving during braking in mid-turn.

Before you all shout at me, I know that you're supposed to get all the braking done BEFORE you start turning, then apply steady power until the apex, then floor it. That's the theory, but I'm not an expert and occasionally miss the odd braking point or misjudge the speed slightly and need to make small corrections, usually by tapping the brake gently if it looks like I'm about to overshoot.

This was fine in GT3 on my Evo, Mustang, and even Zonda with the right settings - but after recently converting to GT4 it seems to be impossible on my shiny new Skyline, which almost immediately straightens out in mid-turn and aims for the nearest wall.

I presume this can be solved by shifting the brake balance towards the rear, but I heard this can have adverse effects on braking distances?

Or maybe shifting more power to the rear wheels to make it behave a bit more like an FR car?

Your advice is appreciated. Cheers,


- K

 

[AOS-]

Wouldn't you want to shift the weight to the front when your brake so the weight will go on front wheel allowing more grip?

I've also used Duck's settings on the Escudo (the major Understeer one), and he used -2.0 Toe in the front. I've tried it, and boy the turning is good at a cornering speed.

 

[Scaff]

Hi folks,

I've trawled through the forums and read several guides. My starting point was one of the settings posted by Duck, which I tweaked a little bit here and there.

On the whole I'm happy with how the car handles, except for one BIG problem. It seems to be very unforgiving during braking in mid-turn.

Before you all shout at me, I know that you're supposed to get all the braking done BEFORE you start turning, then apply steady power until the apex, then floor it. That's the theory, but I'm not an expert and occasionally miss the odd braking point or misjudge the speed slightly and need to make small corrections, usually by tapping the brake gently if it looks like I'm about to overshoot.

This was fine in GT3 on my Evo, Mustang, and even Zonda with the right settings - but after recently converting to GT4 it seems to be impossible on my shiny new Skyline, which almost immediately straightens out in mid-turn and aims for the nearest wall.

I presume this can be solved by shifting the brake balance towards the rear, but I heard this can have adverse effects on braking distances?

Or maybe shifting more power to the rear wheels to make it behave a bit more like an FR car?

Your advice is appreciated. Cheers,


- K

I sounds like you are carrying too much speed into the corner and to be rather blunt about it not a lot you do with settings is going to resolve that as the fronts are simply being overused.

The reason you are suffering in GT4 is that GT3 was a lot more generous with the grip levels, GT4 is a bit overboard in the way it displays understeer (but not to as big a degree as people think).

Any changes you make to the car to try and sort this out are almost certainly going to result in the car suffering at other times and your best solution is to modify you driving style and try and get the braking phase done by corner entry.

Wouldn't you want to shift the weight to the front when your brake so the weight will go on front wheel allowing more grip?

Only to a point. Yes grip will increase as load is applied to a tyre, but a tyre can only generate so much grip. Apply too much load and you will lose grip (and the fall off is normally very sudden). Its this problem that kotafey appears to be suffering from, but carrying to much speed into the corner the outside tyres are reaching their limit and starting to understeer, by then applying the brakes you are asking even more of a front outside tyre that it can give (as its already at its limit) and the end result will be even more understeer.

Remember the old saying "Slow-in and fast-out" rather than "Fast-in and Dead-out".

Too much speed into a corner will almost always result in understeer, the question is simply how much extra speed you carried in determining how much understeer you get. Reducing the steering angle and backing off the throttle can help, but if the amount of extra speed carried in was too great not a lot will solve the problem.

Regards

Scaff

 

[Mt. Lynx]

Id the car equipped with a FC LSD? If so, remove it. The original diff on the Skyline is better than just about any configuration of diff you can buy in GT4.

If you still want to keep the FC LSD, make it pretty strong, like 30/50/35 or something. Could help some if you trailbrake.

 

[Leonidae]

^ what he said. no matter what Skyline GT-R it is, original differential is way better.

 

[Orion]

Try setting the brake balance controller to have stronger rear brakes than the front.

 

[kotafey]

Thanks for the replies, i'll try playing with the LSD settings and Brake balance later today and post the results.

- K

Edit: I've read your guide btw Scaff, it's very useful and in-depth stuff. I have it printed out next to my ps2 ^^

 

[kotafey]

Best so far is 1.21.841 on Midfield, with 510 bhp on Sports/Medium tyres.

The settings are (this is from memory so it might be slightly off):

Springs = 9.5/12.5

Height = 105mm/110mm

Shocks = 5/7

Camber = 2.5/1.5

Toe = 0/0

Stab = 4/3

LSD = 15/45/22

Gears = Auto 8

If I'm honest it still understeers like a bitch, but I'm getting used to it slowly. It's a bit easier on a familiar track where you know the corners...

- K

 

[Parnelli Bone]

Best so far is 1.21.841 on Midfield, with 510 bhp on Sports/Medium tyres.

The settings are (this is from memory so it might be slightly off):

Springs = 9.5/12.5

Height = 105mm/110mm

Shocks = 5/7

Camber = 2.5/1.5

Toe = 0/0

Stab = 4/3

LSD = 15/45/22

Gears = Auto 8

If I'm honest it still understeers like a bitch, but I'm getting used to it slowly. It's a bit easier on a familiar track where you know the corners...

- K

Skyline R34...i'm assuming it's 4-wheel drive? If not, ignore some of this...

1. What about your Driving Aids? Have you gone into settings and turned all of them off? 💡

2. Also, you've got your LSD accel up at 45...i would lower that to about 25 if it's 2-wheel drive. In a 4-wheel drive car with just 500 horses, you may not need limited-slip action at all! I would try removing LSD or making it real soft.

3. Also, since some R34's are 4-wheel drive, you can buy the Variable Torque Distribution (VTD or VCD or whatever) device and dial it so that most of your power is heading towards the rear wheels.

Otherwise your settings look good--not very understeer friendly at all with stronger rear springs, lowered front, etc.

 

[Greycap]

Reverse the stabilizers and seriously, get rid of the FC LSD. It's doing you nothing good, only making the car harder to turn. Soften the shock absorbers to 3/5 or 3/4 as you're using sports tyres that can't take very much load very quickly, this will make the load transitions smoother. I would also suggest -2 toe at the rear, it sounds crazy but give it a try.

And never, NEVER buy a VCD for a Skyline. That just equals throwing the last signs of turning out of the window. It has computer controlled power distribution as stock and you really don't want to mess that up, no matter what the others say.

- R -

 

[Parnelli Bone]

And never, NEVER buy a VCD for a Skyline. That just equals throwing the last signs of turning out of the window. It has computer controlled power distribution as stock and you really don't want to mess that up, no matter what the others say.

- R -

Okay i admit i haven't driven a Skyline in GT4 yet, but in earlier games VCD actually helped. So you're saying the "computer" part actually works when stock? 💡 In other words, it's mostly rear-wheel drive until some front-drive action is needed just like in the real car?

 

[Greycap]

It does exactly that. One thing they really got right in the game, the power beginning to build up in the front wheels can even be felt. And to be honest, in GT3 it was the same way, the car turned into a ocean cruiser with the gadget fitted.

- R -

 

[Parnelli Bone]

It does exactly that. One thing they really got right in the game, the power beginning to build up in the front wheels can even be felt. And to be honest, in GT3 it was the same way, the car turned into a ocean cruiser with the gadget fitted.

- R -

I see. Interesting. Well then don't buy the VCD, kotafey.

...i found it helped on some cars like the Audi TT (which is front-drive before we buy it instead of AWD as PD quotes) and the Lancer and some other cars (gets rid of understeer on pavement, but can help cars from spinning in rallies if you add more front-power). Personally i drove a few Skylines in GT3 with VCD on to complete the Red Badge races. I dont' remember if it actually hurt of helped...but i probly didnt' need VCD...i just wanted to spend some of my millions! 💡

 

[Scaff]

I see. Interesting. Well then don't buy the VCD, kotafey.

...i found it helped on some cars like the Audi TT (which is front-drive before we buy it instead of AWD as PD quotes) and the Lancer and some other cars (gets rid of understeer on pavement, but can help cars from spinning in rallies if you add more front-power). Personally i drove a few Skylines in GT3 with VCD on to complete the Red Badge races. I dont' remember if it actually hurt of helped...but i probly didnt' need VCD...i just wanted to spend some of my millions! 💡

It is a difference between GT3 and GT4, in 4 the VCD and FC LSD can have a rather negative effect on cars that are fitted with advanced 4wd systems (such as the R34 and Evo) and often they are best left unmodified in this area.

However I honestly think that a significant factor in this is that the car is being over-driven, as kotafey admits the problem is when he misses the braking point and has to try and correct mid-corner. Some situations simply can't be tuned away and carrying too much speed into a corner is one of them.


Regards

Scaff

 

[Parnelli Bone]

It is a difference between GT3 and GT4, in 4 the VCD and FC LSD can have a rather negative effect on cars that are fitted with advanced 4wd systems (such as the R34 and Evo) and often they are best left unmodified in this area.

However I honestly think that a significant factor in this is that the car is being over-driven, as kotafey admits the problem is when he misses the braking point and has to try and correct mid-corner. Some situations simply can't be tuned away and carrying too much speed into a corner is one of them.


Regards

Scaff

I see i see...interesting. Still i wanna see if kotafey is making the classic newb/GT4 mistake and hasn't turned off his driving aids yet...

edit: i raced Skylines alot more in GT2, and remember now how understeer wasn't so much of an issue as people seem to make it. In fact, i remember (even with AWD versions) how these cars actually had tons of grip, and i could get them slightly sideways in some tighter turns before powering out of them full-blast . Yes, they would eventually understeer, but check out the speed you'd have to be going before this became a serious problem. Well, it was GT2, not 4, but still.

 

[kotafey]

Hey all,

Took a break and did some license tests then came back to the Skyline without changing anything and got 1.21.723 on Midfield. I only messed up on a couple of corners, so I don't think I can shave much more off from that; maybe another second at most.

Thanks for keeping the discussion alive folks. My ASM has always been turned off and the TCS is set at 3 to prevent unwanted wheelspins (although it doesn't kick in very often so can probably be reduced as well).

It sounds to me like it's worth trying this without a custom LSD, so I'll give that a shot in a bit. I also still need to invest in a brake balance controller and check that out, but I'm a bit poor atm!

I think Scaff is right to a certain extent - it's probably not so much the car as it is me. I noticed that when doing the license tests a lot of the other cars experienced a similar effect (only with a couple of exceptions like the Golf GTi and the RX-7, which I liked a lot ). In any case I think I'm improving slowly.

The rest of the setup feels good for now. Remains to be seen whether it will be able to handle a stage 3 / 4 turbo (when I can afford it)...

Speaking of which, on a slightly unrelated matter, I tuned the car at the Nismo shop which offers a maximum of a turbo stage 4, but at some of the other shops they have a "turbo original" priced at 72k which is described as being "the ultimate turbo", even better than a stage 4... What is all that about?

Many thanks,


- K

 

[Mt. Lynx]

The stage 5 turbo gives you just about the same power as the stage 4, but it doesn´t pack the same amount of turbolag.

For the Skyline, being AWD, you can get rid of the TCS as well. You actually never need TCS, but it does have a helpful effect on bumpy tracks, such as the Nürburgring and Le Sarthe, espically if you´re in a light highpowered car, such as a Group C or LMP car.

 

[Parnelli Bone]

Hey all,

Took a break and did some license tests then came back to the Skyline without changing anything and got 1.21.723 on Midfield. I only messed up on a couple of corners, so I don't think I can shave much more off from that; maybe another second at most.

Thanks for keeping the discussion alive folks. My ASM has always been turned off and the TCS is set at 3 to prevent unwanted wheelspins (although it doesn't kick in very often so can probably be reduced as well).

It sounds to me like it's worth trying this without a custom LSD, so I'll give that a shot in a bit. I also still need to invest in a brake balance controller and check that out, but I'm a bit poor atm!

I think Scaff is right to a certain extent - it's probably not so much the car as it is me. I noticed that when doing the license tests a lot of the other cars experienced a similar effect (only with a couple of exceptions like the Golf GTi and the RX-7, which I liked a lot ). In any case I think I'm improving slowly.

The rest of the setup feels good for now. Remains to be seen whether it will be able to handle a stage 3 / 4 turbo (when I can afford it)...

Speaking of which, on a slightly unrelated matter, I tuned the car at the Nismo shop which offers a maximum of a turbo stage 4, but at some of the other shops they have a "turbo original" priced at 72k which is described as being "the ultimate turbo", even better than a stage 4... What is all that about?

Many thanks,


- K

The stage 5 (ORG) turbo is supposed to eliminate turbo-lag. It does so by allowing spool pressure to be applied during most of the rev range, instead of only at higher revs. Although the turbo effect is more constant, the total power output is (i believe) not supposed to be as high as a stage 4.

You never said whether your Skyline is rear or all-wheel drive, but in either case, TCS of 3 is too much. I personally wouldn't use any at all. Since you're not as experienced, i would say maybe you should just use a setting of "1" if your car is RWD, and zero if it's AWD. Your car will be more touchy under throttle, but there will no doubt be less understeer as well. 💡

So then you'll have to make a decision: do you want a car the reacts with a bit more nervousness when you hit the throttle (which you'll have to perhaps tame with countersteer) or do you want a car that has TCS on and handles safely with less surprise, but more understeer?

 

[AOS-]

If you still want to keep the Full Customize LSD, make it pretty strong, like 30/50/35 or something. Could help some if you trailbrake.

Doesn't adding more Intial Torque "harder to steer"? That's what was commented when you roll the cursor over LSD torque. Now im confused. What DOES adding torque do specifically (when it comes to drifting)? Anyone is welcome to answer because I've been dying to know..

the total power output is (i believe) not supposed to be as high as a stage 4.

As you have stated, it keeps it more constant, but this also means it won't allow maximum peak of power to be achieveable. It's like those games you play where you have a specific # to determine a character's strengths in weaknesses. Stage 4 is more focused on higher torque and power in the High RPM, doing this means sacrficing the torque and power in the low range. But Stage 5, well, its like stage 3 in a way, except it hols slightly stronger torque in the low range? Im unsure of that.

Your car will be more touchy under throttle, but there will no doubt be less understeer as well. 💡

Well That's obvious. This is where Drift Meets Grip. Thus Grifting with a skyline is sometihng to keep in mind. But that doesnt mean you should slide every corner. It's Essential but not Vital.

 

[kotafey]

Morning,

The Skyline is 4WD, although I previously set the VCD at 20 so it was more like an FR for a while anyway. VCD is coming off now, as is the TCS and custom LSD.

To answer a question, I find dealing with a bit of oversteer less frustrating than understeer. With understeer there's not much you can do - if you brake it makes it worse, so all you can do is come off the accelerator and sit and watch helplessly as the car approaches the edge of the track, hoping it won't end up in the sand/grass. Or I guess you can brake like a maniac down to almost a complete stop or until you get your steering back. Neither gives good times.

Whereas with oversteer, as long as there's not too much of it, the trick seems to be not to be too trigger happy with the X button and it's fine.

In a way I kinda miss GT3 now, because my 700bhp Evo wasn't the fastest thing in the world, but it stuck to the road like **** to a carpet. It didn't understeer and I couldn't make it spin even if I tried. Literally I had to give it to my girlfriend who's never played any PS2 game in her life before it would spin out.

I guess GT4 is more realistic in that way...

- K

Edit: I'll have a few more goes at Midfield with the new settings and let you know if I can get it any faster.

 

[kotafey]

1.19.436 on Midfield after about 8 - 10 laps. It feels like it could go lower too if I work on the hairpin turn a bit. TCS is Off, No custom LSD, No VCD. I also swapped the front and rear stabs, so it's now 3/4.

I can't tell if it's easier to drive or if I'm getting used to it - either way it's good. There was even a little bit of oversteer on some corners which was a welcome change.

- K

 

[Greycap]

Try softening the entire car a bit, spring rates to maybe 7/9 and the shocks to 3/5. The added ability to follow the road might make it even easier to drive, not to mention faster. 👍

- R -

 

[Parnelli Bone]

I agree, kotafey...i'd rather have a bit of oversteer than understeer! I also hate it when you've entered a corner then have to wait till the understeer goes away. Well it sounds as though you got a better grip on things.

 

[Leonidae]

I agree, kotafey...i'd rather have a bit of oversteer than understeer! I also hate it when you've entered a corner then have to wait till the understeer goes away. Well it sounds as though you got a better grip on things.

One has to know how to grip before you can drift.. and after learning the drifting your grip-driving will be already closer to champion levels.👍

 

[Parnelli Bone]

One has to know how to grip before you can drift.. and after learning the drifting your grip-driving will be already closer to champion levels.👍

Yeah that's true. I wasnt' suggesting kotafey should immediately learn to drift though, i was saying a bit of oversteer is better than understeer. 💡 It's what i'd prefer, anyways.

 

[Vision GT]

First of all, what is the MY of your Skyline and your settings?

 

[AOS-]

if you brake it makes it worse, so all you can do is come off the accelerator and sit and watch helplessly as the car approaches the edge of the track, hoping it won't end up in the sand/grass. Or I guess you can brake like a maniac down to almost a complete stop or until you get your steering back..

That is so unles you let off the accelerator, and ease on the brakes? Soft enough braking to not get much body rolling to the front? Shouldn't you stiffen the springs in the front, so braking hard doesn't give your a lot of weight shifted to the front? try using slightly less grippy tires? IF you tend to miss the braking point, you'd porbably ned to brak hard into the corner giving you understeer. As Scaff said, too much grip breaks traction. That's what I think, otherwise, improve on the driving line and you'll do fine.

 

[Scaff]

Shouldn't you stiffen the springs in the front, so braking hard doesn't give your a lot of weight shifted to the front?

Nope, changing spring rates will make no difference at all to the degree of load transfer, as long as the braking force you are applying is the same, the degree of load transfer to the front will remain the same, regardless of the spring settings. What will change is how much the car will physically move (less if the springs are stiff and more if they are softer).

Changing the spring settings will not change the total load transfer at all, but it will effect the distribution of that load between the two front tyres if the car is also cornering (as is the case here) and setting the springs stiffer will almost always result in one tyre doing more of the work and a greater chance of understeer.

Take a look at either the first of my tuning guides or Greyout's guide to spring stiffness, both are stickied at the top of this forum and go into more detail about what I have just explained.

As Scaff said, too much grip breaks traction

Not to much grip, but too much load breaks traction. Take a look at the graph below.....

...you will see that as load increases so does grip, up to the tyres limit (co-efficent of traction in this graph), after which increasing the load reduces grip.

What also has to be taken into account in this discussion (and the reason why I believe driving style is a factor in this to a much greater degree than anything else) is tyre slip.

Tyre slip comes in two 'flavours', Slip angle and Slip percentage.

Slip angle is all to do with cornering and is determined by measuring the angle between the tyres path and its centre line (actually to be 100% accurate that should be the contact patch direction). This can then be plotted against the lateral grip (in g's) that the tyre can generate.

As you can see the more you turn the steering the more cornering force you generate (for a given speed), up to a certain point, after which as the slip angle increases grip is reduced.

This will also differ depending on the load

Slip percentage is all to do with braking, and is determined by measuring (as a percentage) the difference in speed between the tyre and the car. If you are braking (or accelerating) the tyre will be trying to go at a different speed to that of the car.

(sorry about the size - first graph is acceleration, the second is braking)

Again you see that as the slip percentage increases so does grip, however it reaches a limit, after which grip drops.

Now keep in mind that the situation here is of someone braking late and trying to turn in. The load is going to be high on the front tyres, as is the slip percentage (from heavy braking as its been left to late) and steering I am guessing applied hard (as everything is happening later that ideal) and therefore a high slip angle is also present.

Combine large front load transfer with a high slip percentage and slip angle and you have a recipe for a loss of front end grip that is going to give you huge levels of understeer that no tuning or set-up is going to resolve.


Regards

Scaff

 

[sucahyo]

Shouldn't you stiffen the springs in the front, so braking hard doesn't give your a lot of weight shifted to the front?

IMO, stiffer front spring will make the understeer problem worse. If we set front spring stiffer, the load transfer on front end will happen faster (relative to the rear). Faster load transfer will result in faster front tire overload. This happen only when the load transfer still in progress.

If the braking is long enough and load transfer no longer happen, the end which has more weight distribution will have more traction. But regaining back front traction that already lost can take a while. Moreover, if the damper is not too restricting, the car will never reach stable condition, and front end will always bounce up and down.

As load transfer happen, car end which has stiffer suspension will have relatively less grip.

 

[Leonidae]

But then again if the weight doesn't transfer away from the rear wheels, they will have so much grip that IT makes the car understeer as well. damn if you do and damn if you don't. Extreme example could be a heavy-ish MR/RR car on wet track. Front wheels planing on the water whereas the rears have so much grip that power-over is out of options.

Thus one has to find a balance between these two.