FR Rally - Dirt and Snow Setups

[KAMKA-Z]

After a quick search I found a few threads on the subject. But most were to specific cars or events. Some strayed from the subject by recommending the post originator to "Just get the ESCUDO and wallride!"

Before Audi turned the Rally World upside down with the Quattros, 2wd cars ruled. Most were FR drivetrain. (Porsche and SAAB had successes too) So, we should be able to run FR cars with fair success in this game and it should add to fun.

My object is to start a thread to discuss suspension, LSD and other settings to make the FR cars go fast and corner with smooth balance. Certainly success with driving FRs in rallies is contingent on careful application of power.

In GT3 I had a 300zx (Z32) set up beautifully for rallies. GT4 rally tuning seems much more critical as it feels like there's a lot less grip in comparison. My current project in GT4 is the 240ZG. (240Zs won the Safari Rally in '71 & '73) The 240ZG wants to swap ends way too easily for a car with close to 50/50 weight distribution. With 276hp, (not max power tuned) I can beat Swiss Alps -"Easy". I've needed some fairly radical spring setting differences to keep from entering most corners backwards. My current settings are as follows:

Spring Rate 8.0/4.0
Ride Height 160/158
Shock Bound 6/4
Shock Rebound 8/6
Camber -2.0/-1.0
Toe 0.0/0.0

LSD 25/50/15

I feel like I should be able to make more controlled, continuous drifts and setting adjustments as well as driving style should get me there.

Any suggestions?

 

[Scaff]

Keep in mind that the 50:50 weight distribution (or as you say near to) is purely the cars static distribution, how that load is transferred under acceleration, braking and cornering is far more important to its dynamic balance.

As a rule of thumb the shorter the cars wheel-base the greater the transfer will be (just try a Stratos to see what I mean) and the higher the ride height the greater the transfer will be (as it raises the centre of gravity). Which does leave us with a slight problem with gravel rally stages as we need the increased ride height to stop the car bottoming out, but have to also accept that this will lead to an increase in dynamic load transfer. Suspension tuning will help out in this (and I would love to give it a go but currently PAL PS3 will not play GT4 : Grrrr), but to a large degree you will have to account for it in your driving style. Keep in mind that as soon as you brake the load will be shifted forwards far more than on tarmac (due to the increased ride height) and should you then turn the unloaded rear wheels are highly likely to lose grip. Almost no degree of suspension tweaking will resolve this. Changes to the suspension (other than ride height) can't change the load transfer at all, just how it is shared across the tyres at a given end, so if the back has little weight over it, how that 'little' weight is shared is to a degree irrelevant.

Its why RWD rally cars have such a tail-happy style to them, its an almost natural side-effect of the physics involved. Braking gets the load over the front end and allows them to grip, giving you traction to steer into the corner, the unloaded rear aids in the cornering through oversteer and once the load starts to settle you can get back on the power and out of the corner.

Have a look at the following footage of a Mk2 Escort in action to see what I mean.




Regards

Scaff

 

[racerfink]

Raising your rear rebound will help keep the weight more over the rear axle under braking. Have you tried raising the decel side of the LSD? On high powered cars on asphalt, I run 50-60 on the decel side, as it helps keep the rear from swinging around under braking. Running it that high on dirt might create another set of problems, but I would try raising it.

Also, you didn't say if you were running the Brake Controller. Adding this if you don't have it will help as well.

 

[KAMKA-Z]

I worked on it a bit more tonight. I played with the toe a bit. I tried (-2/+2) then (+2/-2) then (-2/-2) and (+2/+2). I was surprised that the adjustments delivered fairly subtle differences in handling. I messed with LSD settings too and found differences very subtle. I even tried 60/60/60, which should be as close to locked as you could get. I still can't take fast bends flat out, not even the two after the Start/Finish normal direction at Swiss Alps. I think my biggest gains have been achieved in driving style. Brake early, point at the apex and slowly apply throttle, steer it with the throttle GENTLY. I'm down to a 1:43 (from 1:48) at Swiss Alps but I'm not getting many clean laps. I think for GT4, they resurfaced Alps with pea gravel.

New Settings - Nissan 240ZG

Spring Rate 8.0/4.0
Ride Height 160/158
Shock Bound 4/2
Shock Rebound 7/7
Camber -2.0/-2.0
Toe 2.0/2.0
stabilizers 6/4

LSD 30/60/35

Brake Balance 12/10 (was 9/10, could go with more front bias yet)

TCS: I've allowed myself 2
no ASM

More to come

Thanks Guys!


It has just dawned on me... It would look soooo tacky, but a wing might help.

 

[racerfink]

I was working with the F1 car the other day, and the stock rear toe setting was at -6. I'd have to assume that means negative = toe in. I couldn't imagine running a car with that much power and low weight with that much toe out, let alone any toe out at all. If you have your rear toe set at +2 toe out, that will help the back end come around, especially in corners. Toe out on the front will help turn in. Also, I don't know how accurately it's modeled in the game, but +/- toe will take away from top speed in real life.

 

[Tulok]

actually, its the other way around in GT4, -6 toe in the rear will/should make it try to Choku Dori on the straights, and make the back end more sanppy. If i was you, i would adjust the lsd to 28-22-45 I think you might be muuuch happier. I like your idea of an innovative idea