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sotti
18-12-2018, 18:54
So this car I do not understand.

Every other car when you come into a corner with a little too much speed you get understeer. Which is what I want. If I push too hard I want the front end to wash away.

With this car when I turn in, if I have too much speed I just flip ends. It's not even trail braking I can get to neutral throttle holding a line through a longer corner and if I dial in a little more steering angle, poof spin. It also tends to snap oversteer with too much throttle on exit, but at least with that I have a point of reference trying to modulate the throttle a little better.



I've tried maxing out the front springs, stiffen up the front ARB, removing the rear ARB, recalced the shocks with Jussi's calculator. This thing still feels like it's trying to kill me and I don't understand why.

blinkngone
18-12-2018, 22:14
So this car I do not understand.

Every other car when you come into a corner with a little too much speed you get understeer. Which is what I want. If I push too hard I want the front end to wash away.

With this car when I turn in, if I have too much speed I just flip ends. It's not even trail braking I can get to neutral throttle holding a line through a longer corner and if I dial in a little more steering angle, poof spin. It also tends to snap oversteer with too much throttle on exit, but at least with that I have a point of reference trying to modulate the throttle a little better.



I've tried maxing out the front springs, stiffen up the front ARB, removing the rear ARB, recalced the shocks with Jussi's calculator. This thing still feels like it's trying to kill me and I don't understand why.

Hey, you are not showing what platform you are on but I am assuming you are on console. Start with the Default Stable setup and make the changes to the LSD I have in this screenshot.
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sotti
18-12-2018, 22:20
I'll give that a whirl, thank you.

Didn't know that platform mattered, but I am on PC using a Fanatec CSWv2.5. I've tried both the RAW FFB as well as the Jack Spade custom FFB. Both feel similar in regards to the issue I'm facing.

blinkngone
18-12-2018, 22:33
I'll give that a whirl, thank you.

Didn't know that platform mattered, but I am on PC using a Fanatec CSWv2.5. I've tried both the RAW FFB as well as the Jack Spade custom FFB. Both feel similar in regards to the issue I'm facing.

Ok, since you are on PC have you already tried the setups other people use for this car in Time Trial? That LSD I gave you is for lessening the oversteer on corner exit.

I have the same wheel as you with the V3 pedals. Normally you should be using Default Loose with a wheel but since you seemed to have more than 1 issue I suggested starting with Default Stable. You can use the same LSD settings on Default Loose.

cpcdem
19-12-2018, 00:11
I am not sure if I understood correctly, are you getting oversteer also on corner entry? If yes, I think it's when downshifting, right? Try putting the engine braking to 10, also give it some throttle while downshifting (it's an H-pattern shift car), or just use auto clutch on. For during the corner, I think blink's suggestion will do and of course as you said you need to modulate the throttle.

As for why this car is different to other GT4, that's because if I am not mistaken, it's a front engined car, so much weight in the front side, not so much in the rear, so it is easier for the rear tires to break loose..

blinkngone
19-12-2018, 01:13
I am not sure if I understood correctly, are you getting oversteer also on corner entry? If yes, I think it's when downshifting, right? Try putting the engine braking to 10, also give it some throttle while downshifting (it's an H-pattern shift car), or just use auto clutch on. For during the corner, I think blink's suggestion will do and of course as you said you need to modulate the throttle.

As for why this car is different to other GT4, that's because if I am not mistaken, it's a front engined car, so much weight in the front side, not so much in the rear, so it is easier for the rear tires to break loose..

In GT4 the only rear engine cars are the Cayman and X-Bow. You didn't drive it back when we running GT4s in the beginning at SilNat, I drove it once. Default Loose Engine Braking is at 5, 7 for Stable, it can go to 10 as you suggested. Using Default jammerjoh has a good recent run with it.

cpcdem
19-12-2018, 01:59
In GT4 the only rear engine cars are the Cayman and X-Bow.

Oops, good point :)
Thx, had not realized that.

Edit: I just run it now, I see what you guys mean about power oversteer, it's massive. Higher Power Ramp should take care of it indeed.

Edit2: Nah, put it to 90 degrees, but did not make a noticeable difference. But then I additionally lowered the rear height to minimum, and that has helped, made the rear much more predictable. @sotti, give this a try, change rear ride height to minimum, it should help a bit.

Shepard2603
19-12-2018, 06:38
You could also soften the rear as much as possible (ARB and springs) and then stiffen the front to get the understeer back.

Bealdor
19-12-2018, 07:13
You could also soften the rear as much as possible (ARB and springs) and then stiffen the front to get the understeer back.

The M3 GT4's default setups are already very US biased, suspension wise.
I wouldn't recommend to unbalance that even more to get rid of issues that are rooted somewhere else.

blinkngone
19-12-2018, 10:41
Oops, good point :)
Thx, had not realized that.

Edit: I just run it now, I see what you guys mean about power oversteer, it's massive. Higher Power Ramp should take care of it indeed.

Edit2: Nah, put it to 90 degrees, but did not make a noticeable difference. But then I additionally lowered the rear height to minimum, and that has helped, made the rear much more predictable. @sotti, give this a try, change rear ride height to minimum, it should help a bit.

Hey, lowering the rear would make the setup similar to the 320 TC which you used to race a while back.:) Good run with your adjustments.:D
320 TC ride height.
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blinkngone
19-12-2018, 10:58
The M3 GT4's default setups are already very US biased, suspension wise.
I wouldn't recommend to unbalance that even more to get rid of issues that are rooted somewhere else.

Yeah, the " issues that are rooted somewhere else" is us and our ability/inability.:) Not having driven the car since 10/17 it looks as though the car has been improved during the various patches 3 through 7, based on the improvements made in lap times.

Sankyo
19-12-2018, 11:12
Edit: I just run it now, I see what you guys mean about power oversteer, it's massive. Higher Power Ramp should take care of it indeed.

Edit2: Nah, put it to 90 degrees, but did not make a noticeable difference.
Hold on. I may have this completely wrong, but 90 degree power ramp means no locking, so full open diff, so maximum power oversteer? IMO you should go for a low power ramp angle to have the rear diff lock early.

Bealdor
19-12-2018, 11:27
...90 degree power ramp means no locking...

Correct.


...so full open diff...

Correct.


...so maximum power oversteer?...

Wrong.

Not enough lock can cause some oversteer in certain situations (acceleration out of hairpins for example), but in general it makes the car more stable under hard acceleration because the outside wheel torque is limited by the inside one.

Sankyo
19-12-2018, 11:32
Correct.



Correct.



Wrong.

Not enough lock can cause some oversteer in certain situations (acceleration out of hairpins for example), but in general it makes the car more stable under hard acceleration because the outside wheel torque is limited by the inside one.

But a fully locked rear axle will power understeer, or does that also depend on the situation?

At least in my testing last week of the Radical SR8, lower power ramp made the car more stable under power in all cases of accelerating out of corners...

Bealdor
19-12-2018, 11:37
A locked diff will normally cause power/snap OVERSTEER because too much torque is transferred to the outside wheel, which will therefore lose traction quickly.
You will get power understeer in low torque situations (accelerating gently) only, but those situations are rare in racing IMO.

cpcdem
19-12-2018, 12:39
You could also soften the rear as much as possible (ARB and springs) and then stiffen the front to get the understeer back.

First thing I tried was to lower rear ARB to minimum (0 N/mm), but it didn't make a noticeable difference to me with this car. But minimum rear height did make it a lot easier putting the throttle down on corner exit.

cpcdem
19-12-2018, 12:45
Hey, lowering the rear would make the setup similar to the 320 TC which you used to race a while back.:) Good run with your adjustments.:D
320 TC ride height.
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I am still racing it from time to time, I like a lot all cars from Touring Car class (mainly the FWDs)! I had not noticed the 320TC has such a low rear height, guess that explains why it is very good and stable with throttle. I think I'll start experimenting with minimum rear height also in GT3s now :)

Bealdor
19-12-2018, 12:45
First thing I tried was to lower rear ARB to minimum (0 N/mm), but it didn't make a noticeable difference to me with this car. But minimum rear height did make it a lot easier putting the throttle down on corner exit.

The rear ARBs on this car can't make a huge difference (max is 30N/mm).
Which makes adjusting the roll center height on the rear axle (via ride height) a more effective method to change overall car balance.

rich1e I
19-12-2018, 12:58
The M3 GT4 was already brought up some time ago and I think the massive oversteer is not setup related. You can try to induce some understeer (It's better to fix the part of the car which is causing trouble, so don't fix the front end if the rear is too loose for instance) but I think it's better to just pick another car. It's too unpredictable to ensure consistency.

blinkngone
20-12-2018, 00:08
The M3 GT4 was already brought up some time ago and I think the massive oversteer is not setup related. You can try to induce some understeer (It's better to fix the part of the car which is causing trouble, so don't fix the front end if the rear is too loose for instance) but I think it's better to just pick another car. It's too unpredictable to ensure consistency.

Yeah the BMW has been a difficult car. I think the OP was just surprised at how difficult it was when he ran across it and just wanted to know if there was anything he could do before he moved on. Now cpcdem hadn't driven the BMW before and initially he began changing all the wrong things like the rest of us. When he lowered the rear ride height he cleared the previous WR by 0.281 and the quickest Default by 0.772, the people behind him are not slouches. It is also one of the quickest runs ever by a GT4 car at this track with a 0:57.963. When I checked the setups of those behind him I was like OMG they had changed many parameters and one had lowered the front ride height.:) The OP can load his setup from PC TT to see if it helps some of his issues.
The change he made from Default Loose was only ride height.
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