Best way to cure understeer in 2.09

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jucksmanBR

jucksmanBR

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jucksmanBR
Hello, Guys!

Since the 2.09 update, my GT500 Xanavi GT-R has been understeering more than it used to.

The car is still very fast, but I've been trying to 'cure' the understeer and make the car a bit more neutral for a league race in Spa. We are, as always, running 1100kg and 500cv.

My best lap: 2.12.129

My tune:
Aero: 40/60

Height: -5/0
Springs: 15.8/14.5

Front: 7/5/3
Rear: 6/5/6

Brakes: 6/4

LSD: 7/7/5

Camber: 2.8/0.5
Toe: -0.10/-0.10

This tune gives a lot of grip and the only problem I have really is at corner entry, because the car understeers prior to hitting the apex. From middle to exit it goes really well. I've already tried increasing rear springs, but it made the car oversteer too much. Also, the -5/0 ride height seems to be the fastest combination in this track.

What I really want is to make it turn in a little easier and to make direction changes a little faster than with my current tune...
 
Try to put front positive toe, say + 0.25, while rear stays the same. If the effect is too much, decrease it to 0.15 or 0.10.

I tested the same setup like yours, Xanavi Nismo GTR '08, then use the 0.25 front toe, seems to turn in better, better steering response, direction changes and less understeer, track is also on Spa :D, hope you have the same result.
 
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WOW + front toe gave better turn in? I thought - toe did that. More and more things seem to be strange since 2.09.. Does anyone else know what damper settings or stiffer or larger front roll bar to increase front grip??
 
No, people have been thinking different things about that before 2.09. Try softer front springs and bound. Maybe also, softer rear rebound.
 
Everything looks fine but the front camber is too high and the LSD is too low.lower the front camber and raise the LSD and raise the rear camber a bit.
 
MrGrado
No, people have been thinking different things about that before 2.09. Try softer front springs and bound. Maybe also, softer rear rebound.
Click to expand...

As usual, I still recommend doing the opposite of what Grado says, in regards to spring rates, if your goal is reducing understeer.

Also, turn rear aero down, I think I only use 40/50 in GT-R's.
 
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Adrenaline
As usual, I still recommend doing the opposite of what Grado says, in regards to spring rates, if your goal is reducing understeer.

Also, turn rear aero down, I think I only use 40/50 in GT-R's.
Click to expand...

Won't this give me more rear tyre wear, Adrenaline?

What would you suggest to reduce understeer a little? I've tried the +front toe suggestion and the car seems to grip more at corner entry but it slides more mid-corner...
 
I've been fiddling with the ride height on original set up's, I've found running the front ride height between +.4 to .12 while keeping the rear at 0 ride height that the understeer goes and gives a better balance,
 
How much front toe did you used ? if +0.25 is too much, +.0.05 or +0.10 is enough to feel the effect, reducing rear negative toe will help to reduce the slide effect, say F +0.10 R -0.05, just need to find a good balance that works for you as driving style plays a major role, I like a little loose car :D

I am running most of my cars with front positive toe and negative a the rear, FF cars sometimes gets extreme values which help it the react almost like FR cars in mid corner and exit.
 
Ridox2JZGTE
How much front toe did you used ? if +0.25 is too much, +.0.05 or +0.10 is enough to feel the effect, reducing rear negative toe will help to reduce the slide effect, say F +0.10 R -0.05, just need to find a good balance that works for you as driving style plays a major role, I like a little loose car :D

I am running most of my cars with front positive toe and negative a the rear, FF cars sometimes gets extreme values which help it the react almost like FR cars in mid corner and exit.
Click to expand...

I've tried with +0.15 front toe...didn't have enough time to try any variations...
 
This is a top secret tune, but try it out, and let me know if it's better/worse. Was going to release it a few weeks ago, but 2.09 made me decide to wait, and I haven't had a chance to put the time into it yet.

Aero: 40/55

9/10
17.7/14.8
9/3
7/3
5/3

1.5/1.2
-.10/0.00

LSD: 7/9/5

BB: 6/4
 
Adrenaline
This is a top secret tune, but try it out, and let me know if it's better/worse. Was going to release it a few weeks ago, but 2.09 made me decide to wait, and I haven't had a chance to put the time into it yet.

Aero: 40/55

9/10
17.7/14.8
9/3
7/3
5/3

1.5/1.2
-.10/0.00

LSD: 7/9/5

BB: 6/4
Click to expand...

he talking about getting rid of understeer.not oversteer
 
Adrenaline
This is a top secret tune, but try it out, and let me know if it's better/worse. Was going to release it a few weeks ago, but 2.09 made me decide to wait, and I haven't had a chance to put the time into it yet.

Aero: 40/55

9/10
17.7/14.8
9/3
7/3
5/3

1.5/1.2
-.10/0.00

LSD: 7/9/5

BB: 6/4
Click to expand...

I've tried the tune this weekend, at Spa, with G27. The car has good grip at corner entry, but loses the apex a bit because of understeer. I've reduced the front springs to 16.5 and 8/5/2 and increased the rear to 4/4/4...the front end is much grippier now and the car seems to carry more speed into the corners. Also, I've changed ride height to -5/0 with seems to have made the car more stable, specially on worn tyres...
 
That's great, so have you found the best toe + camber setting for the car ? I usually run at least 1.8 at the front and rear on race cars.
 
Ridox2JZGTE
That's great, so have you found the best toe + camber setting for the car ? I usually run at least 1.8 at the front and rear on race cars.
Click to expand...

I don't know If I'm right or wrong, but this is what has been working for me:

- Fast tracks, with long, sweeping curves (like La Sarthe, Monza, etc): 1.0/0.5
- Slower tracks, with slow corners and sudden direction changes (like Laguna Seca, Motegi, Cote D'Azur): 2.5/1.2 (or higher at the front)
 

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