Lesson 7: 4WD & torque split

Why a 4WD car feels the way it does

Most 4WD cars in GT7 share two personality traits: they are lazy into a corner and brilliant out of it. Once you know why, the settings in this lesson make sense.

Here is the physics, once. In a corner, the front wheels travel a wider arc than the rear wheels, so the front axle wants to spin a little faster. Anything that ties the front and rear together fights that difference, and the car would rather go straight. On top of that, the front tires now have two jobs: steering the car and pulling it. A tire that is busy pulling has less grip left for turning.

What you feel:

• Entry and mid-corner: the nose is reluctant to tuck in. Add throttle early and the Front washes wide. That is the "rigid understeer" GT7's own manual calls characteristic of 4WD cars: classic understeer.
• Exit: four tires share the engine's torque, so none of them is overwhelmed. You can go to full throttle earlier than in an FR car, and the Rear rarely steps out.

So tuning a 4WD car is mostly about one trade: buying back front response on entry without giving away that exit traction.

The layout underneath still matters

"4WD" tells you where the power goes, not where the weight sits. Check the engine position on the car's spec screen before you start:

• Front-engine 4WD (most road 4WD cars, such as a GT-R or an Impreza). The weight sits over the nose, so the front tires are already working hard. Expect understeer to be the main complaint, and expect to send more torque to the rear to fix it.
• Mid-engine 4WD (several supercars and some rally cars). The weight sits behind you, so the rear already wants to rotate. These cars need less rear bias to turn, and they are more likely to snap if you lift mid-corner.

• Front axle and front LSD
• Rear axle and rear LSD

Two LSDs: milder front, stronger rear

When you select Fully Customized under Differential Gear Selection on a 4WD car, you get the same three settings you met in Lesson 6, Initial Torque, Acceleration Sensitivity and Braking Sensitivity, but for each driven axle. The official Beyond the Apex magazine gives the starting principle plainly: use a milder locking effect at the front and a stronger one at the rear, and focus your tuning on front response and corner entry.

Why? A locked front axle forces the inside and outside front wheels to turn at the same speed. The front tires then push the car straight ahead instead of following the steering. A locked rear axle, by contrast, pushes the car forward and helps it rotate under power, just as it does in an FR car. Official guidance also notes that more Initial Torque accentuates each axle's natural tendency on a 4WD car: the Front toward understeer and the Rear toward oversteer.

The front LSD

• Raise Initial Torque Front and the front locks sooner. You feel a heavier wheel and a nose that resists tucking in, from entry all the way to exit: more understeer. Lower it for a lighter, more willing front.
• Raise Acceleration Sensitivity Front and the front pulls harder out of slow corners, but the car pushes wide on exit and the steering fights you as you unwind it. Lower it if you are running wide the moment you get on power.
• Raise Braking Sensitivity Front and braking feels calmer, but the nose won't turn in as you trail the brake: entry understeer. On a 4WD car this is usually the first front setting to lower.

The rear LSD

The Rear works exactly like the RWD diff in Lesson 6:

• Raise Initial Torque Rear for earlier locking and more traction; the car leans toward rotation, a little oversteer, on and off power. One caveat from Lesson 6: on a steady throttle mid-corner, a heavily preloaded rear resists turning, and then lets go earlier on exit. If that is what you feel, you have gone too far.
• Raise Acceleration Sensitivity Rear for more drive out of the corner. Go too far and you get sudden power oversteer and a car that is harder to place on exit, and GT7's manual warns it can feel unstable the moment you lift.
• Raise Braking Sensitivity Rear for a planted rear under braking and on lift-off. The cost is a car that resists rotating on entry.

These are the course's starting points, not game defaults. The logic: the front numbers sit well below the rear so the nose stays free on entry, and the rear numbers match the FR baseline from Lesson 6 because the rear axle does the same job. Every car has its own slider range, so if yours doesn't fit, scale the numbers to where they sit in that car's range.

The Torque-Vectoring Center Differential

The center diff sits between the two axles and decides how the engine's torque is shared front to rear. On a stock 4WD car you live with whatever split the car came with. Fit the Torque-Vectoring Center Differential and you get to choose.

Despite the name, the manual lists only one adjustment under it: the front to rear split. There are no separate left and right torque vectoring controls in the settings list.

Front/Rear Torque Distribution: steering the balance

Think of Front/Rear Torque Distribution as a dial between two different cars. GT7's manual describes the range as running from "FR-style oversteer" to "the rigid understeer characteristic of 4WD cars". You choose where your car sits on that line.

• Raise the rear share (say from 40:60 to 35:65). The Rear does more of the pushing and the Front has more grip left for steering. You feel it mid-corner to exit: the car rotates on throttle like an FR car, with less steering lock needed. Go too far and you get FR problems back: power oversteer in slow corners and less of the 4WD exit traction you fitted the part for.
• Lower the rear share, toward 50:50. Torque spreads evenly, so each tire carries less and the car feels planted and safe on exit, especially on slippery surfaces. The cost is a stubborn nose: more power-on understeer from mid-corner to exit.

The split mostly matters when you're on the throttle. It matters far less while you are braking hard or coasting, which is a big clue when you diagnose problems later in this lesson.

Where to start, by car and surface

Few Gr.3 and Gr.4 race cars are 4WD, and BoP events return parts to stock, so you will mostly use this on road cars, rally cars and in tuning-allowed lobbies. On dirt, the official magazine also suggests diff locking both on and off throttle, so the car rotates when you lift and stays neutral under power. That runs against the tarmac advice above, because loose surfaces reward a car you can pivot on a lift. A sensible first try is to raise Braking Sensitivity Front and Rear a few steps above your tarmac numbers, then test on the stage.

Suspension helpers for 4WD turn-in

The diff and the split only act when torque is flowing. If the nose pushes while you're braking or coasting, the fix lives in the suspension. Three changes from earlier lessons do most of the work on a 4WD car:

• Lower Damping Ratio (Compression) Front by a few percent. Weight moves onto the front tires faster as you brake, so the nose bites on entry with less understeer. Go too soft and the car dives and feels floaty over curbs.
• Raise Negative Camber Angle Front by about 0.3 degrees. The loaded front tire keeps more of its tread on the road from turn-in to the apex. The cost is a little braking grip and more wear, so stay within the course range of 1.0 to 3.5 degrees.
• Stiffen the Anti-Roll Bar Rear by one step. The Rear gives up a little grip mid-corner, so the car rotates more. On an FR car that costs exit traction, but on a 4WD car the front axle shares the work, so you can often afford it.

Make one of these changes at a time, and do it before you touch the split if the push happens with your foot off the throttle.

4WD symptom to fix

The step sizes are starting points. Try the first fix, drive three laps, and only move down the list if the symptom is still there.