Best S1 Class Tune for the 1981 BMW M1 in Forza Horizon 6

The 1981 BMW M1 has quickly become one of the most talked-about Treasure Cars in Forza Horizon 6. A lot of players started with beginner-friendly A-Class setups from creators like PaperHeartZero, but the car really starts to shine once you push it into S1 Class.

At S1 900, the M1 transforms from a classic analog sports car into a seriously competitive road and street racing machine. The mid-engine balance gives it strong rotation through corners, and with the right upgrades, it becomes surprisingly fast on technical circuits and sprint races.

The biggest challenge is controlling wheelspin and rear-end instability. That is why most competitive S1 builds lean heavily toward AWD conversions and higher-revving engine swaps instead of trying to keep the car completely stock.

Recommended S1 Community Tune

For players who want a fast and easy solution, this is currently one of the better community setups available:

• Tune Focus: S1 900 Road / Street Race
• Share Code: 447-289-313
• Build Style: Balanced Grip and Acceleration AWD
  

This tune gives the M1 much better launch grip while keeping enough agility to attack tighter corners. It works especially well in mixed road circuits where stability matters more than raw top speed.

Compared to stock handling, the car feels much calmer under braking and much more predictable when exiting slow corners. The AWD conversion removes most of the nervous rear-end behavior that the original RWD setup struggles with in S1.

Why AWD Works So Well on the BMW M1

Normally, many players prefer keeping classic cars rear-wheel drive for authenticity, but the M1 becomes much easier to drive competitively once AWD is installed.

The car already has strong mid-engine rotation, so adding AWD mainly improves traction rather than making the car feel heavy. In S1 Class, that extra grip matters a lot during corner exits and uphill acceleration zones.

With AWD, the M1 can:

• Launch harder off the line
• Exit corners with less wheelspin
• Stay stable during fast direction changes
• Handle wet or uneven road surfaces more confidently
  

For online racing, consistency is usually more important than having the highest peak speed, and AWD helps the M1 stay competitive lap after lap.

Custom “Purist” DIY S1 Build

Some players still prefer building the car themselves instead of downloading a shared tune. If you want to keep more of the original BMW character while still competing in S1, this upgrade path works very well.

Engine and Conversion

Start with the AWD swap first. This is the single most important change for the car in S1.

For power upgrades, either:

• Twin Turbo
• Centrifugal Supercharger
  

Both options work, but the goal is reaching roughly mid-700 horsepower while keeping the car lightweight.

The original inline-six sound is part of the charm of the M1, so many players avoid extreme engine swaps and instead focus on boosting the stock engine platform.

Tires and Grip

Grip is everything in S1 Class.

Recommended setup:

• Semi-Slick Tires or Horizon Race Tires
• Maximum Front Tire Width
• Maximum Rear Tire Width
  

Widening the front tires helps reduce understeer, which can become noticeable once aero and AWD are installed.

The M1 naturally rotates well because of its mid-engine layout, so improving front-end grip makes the car feel much sharper during turn-in.

Suspension and Platform Upgrades

To make the chassis competitive against modern S1 cars, race upgrades are almost mandatory.

Install:

• Race Transmission
• Race Brakes
• Race Suspension
• Race Weight Reduction
  

Lower the ride height completely after installing race suspension. The lower center of gravity improves high-speed stability and helps the car feel more planted during quick transitions.

With full weight reduction, the M1 becomes much more responsive and agile than most players expect from a vintage supercar.

Aero Setup

Some players dislike the look of Forza aero parts on classic cars, but for S1 racing they make a major difference.

Recommended:

• Forza Front Aero
• Forza Rear Wing
  

The rear wing especially helps stabilize the car through sweeping high-speed corners. Without rear aero, the M1 can feel loose during aggressive throttle application.

If you mainly race technical street circuits, the extra downforce is worth the slight top-speed loss.

Base Tuning Values

Once the upgrades are installed, these settings provide a strong starting point.

SettingFrontRear
Tire Pressure28.0 PSI28.5 PSI
Camber-1.8°-1.5°
Toe0.0°-0.1°
Anti-Roll Bars18.5034.00
Aero60% Max75% Max

Caster should sit around 6.0°.

For the AWD differential:

• Front Acceleration: 25%
• Front Deceleration: 0%
• Rear Acceleration: 70%
• Rear Deceleration: 10%
• Center Balance: 65% Rear
  

This setup keeps the car stable while still allowing enough rear rotation to avoid feeling overly safe or understeery.

How the Car Feels on Track

Once fully tuned, the M1 becomes a very rewarding S1 car to drive.

It performs best on:

• Technical road circuits
• Medium-speed street races
• Sprint events with frequent corner exits
  

The car feels lighter and more agile than many modern S1 competitors. It does not have the raw top-end speed of some meta hypercars, but it makes up for that with strong cornering balance and excellent traction.

One of the best parts of the M1 is how connected it feels. Even with AWD installed, the car still keeps a classic analog personality that many newer cars lack.

Finding More Community Tunes

If you want to experiment with different driving styles, the in-game Tune Browser is worth checking regularly.

Creators like PaperHeartZero and Zalmoxis91 frequently upload updated setups for the BMW M1, including road, drift, purist, and online-focused builds.

Sometimes a slightly different differential or suspension setup can completely change how the M1 behaves, so trying multiple tunes is part of the fun.