Found on http://setupfield.teaminferno.hu

So, what is the problem with your RB4 setup? Please clarify and I'll be able to help. Is it acceleration? Corner entry/mid/exit balance? Please clarify.

Okay, here comes pro help: the key to making a "perfect" setup is removing the "almost" in front of it.

PS:

Quote from LFSn00b :

"i usually want fast outcoming of a corner. And also a fast incoming."

That's actually not too far from what you should be aiming for, sepecially with a 4WD. The truth is, whils cornering, most of your time is spent on enrty and exit, whilst mid-corner time is usually the smallest except for large constant radius turns.

The thing with the RB4 is that it's quite nose heavy, with 55.7% mass at the front with the driver. Engine on the front axle also generates quite a bit of inertia, so it can't turn as quickly as a car like the RA (mid-engined, mass at center). To get the RB4 to handle well, you need to have some degree of oversteer tuned into the suspension. To do that, you can either increase rear antiroll or reduce front antiroll.

First thing to do is to make sure you've set both front and rear LSDs to clutch type. Set the power lock to maximum to get the most out of the traction afforded by 4WD. More power lock is actually good for the RB4 in all ways. More power lock up front reduces power on understeer, whilst at the rear gets more power to the better loaded wheel. Net effect is better corner exit drive and LESS exit understeer.

Next is the center differential. Keep the viscous lock high for maximum effective transfer of power to both axles. Don't worry about the slight increase in understeer, since you can actually tune turn in behavior much better with front and rear coast lock settings. Set it to a slightly rear biased configuration. This aids tire life and evens out tire temperature and wear front and rear. It also reduces exit understeer and actually take advantage of weight transfer to the rear on exits. More rear power gives it a more rear drive nature and vice-versa.

One of the great things of 4WD is that car balance can be tuned to a very large extent without suspension changes. The softer the coast setting on one end, the more easily it rotates as it more easily allows the wheels to turn at different relative speeds. For more delicate and precise throttle control, keep the coast settings high, but be warned that if you can't deal with the increased corner entry understeer with technique, then too high is a bad thing. On the other hand, too soft allows the wheels to lock more easily under braking and results in a less precisely throttle steerable car.

Hope this helps. If still in doubt, please enquire.

Quote from Jamexing :

First thing to do is to make sure you've set both front and rear LSDs to clutch type. Set the power lock to maximum to get the most out of the traction afforded by 4WD.

I do not see why you have to use clutch for the lsd, as far as I know it is bloody bugged, so you can use a locked diff and still be quite fast.

Quote from Jamexing :

More power lock is actually good for the RB4 in all ways. More power lock up front reduces power on understeer

I would say exactly the opposite, the more locked the differential is at the front, the more understeer under power you will have.

Quote from Flotch :

I do not see why you have to use clutch for the lsd, as far as I know it is bloody bugged, so you can use a locked diff and still be quite fast.

I would say exactly the opposite, the more locked the differential is at the front, the more understeer under power you will have.

I know why locked diff is used for WR since it has practically infinite preload both power and coast, allowing the best traction possible short of AYC. However, it offers no tunability on coast, which doesn't help. Not to mention the strong entry understeer that would make it a pain to turn without full commitment. I understand that drivetrain simualtion is still on the simplified side as IRL, a 4WD with locked diffs at both ends would be a pig to turn and kill driveshafts by the dozen. Coast lock tuning could easily achieve change balance without suspension tweaks.

As for power lock, more front lock actually reduces exit understeer for a number of reasons. One is that more power is sent to the wheel where it's most needed (the heavily loaded outside wheel), improving exit traction whilst reducing power to the inside wheel. This prevents inside tire spin whilst allowing the outside wheel to help rotate the car into the turn. Hence, double benefit.

To convince yourself, just try the RB4 with clutch diff (fully locked) rear and open diff front. Terrible front traction and understeer.

Ever tried fitting a quality clutch type 1.5 way LSD to FWD or 4WD? Does wonders for corner exit traction and balance.