Suspension Secrets BMW F80 M3 Project Car – Part 3

In Part 3 of our F80 M3 build we took the Suspension Secrets BMW F80 M3 to the Muffwash customer’s track day at Anglesey for a shakedown, and to see how much better the car feels having applied our fast road geometry settings. We were hoping to data log the difference in handling, grip and tyre wear but unfortunately, the British Summer put those plans to rest as the day was very wet throughout.

A low-pressure weather front combined with being located on a headland in the Irish Sea meant that – even in mid-July – the Anglesey track day was a complete washout with heavy rain for most of the day.

Onboard picture of testing the Suspension Secrets BMW F80 M3 at Anglesey Circuit

We were also offering out track day setup services where we set up two Porsche Cayman GT4s, a Porsche 911 GT3 [992] and a BMW F80 M3 Competition. Trackside setups are particularly effective as they give owners a direct comparison of how their cars handle before being set up and how they handle after they’ve been set up.

In Part 2 of this series, we explored the standard points of alignment adjustment on the F80 M3 Competition. In comparison, the GT series of Porsches such as the 911 GT3, Cayman GT4 and their respective RS models feature far more points of adjustment compared to BMWs. The Porsche GT cars feature the following points of adjustment:

  • Front and rear camber angles
  • Front and rear toe alignment
  • Front and rear adjustable anti-roll bars
  • Fully adjustable ride heights

With most Porsches, the main focus when setting them up is to reduce understeer. As standard, they are tuned to understeer at the limit in order to make the cars approachable to all types of drivers. These cars can be made far more capable and enjoyable to drive by using the standard points of chassis and geometry adjustment.. When setting these cars up, we look to increase negative camber on the front axle whilst also reducing the front ride height for improved turn-in and braking stability.

From this point we then adjust rear camber to give good mid-corner grip; we tweak the toe angles for responsive steering from the front toe and good traction from the rear toe, and then we also tweak the anti-roll bars to make the car more nimble in slower corners.

One chassis improvement you can do at home to your Cayman GT4 is to remove the plastic spoilers blocking the venturi ducts that lead from the rear of the bumper to the front of the wheel arch. Using a T25 socket, this can be done on your driveway, if you put the steering to full lock you should be able to gain access to remove the spoiler. As standard, the Porsche Cayman GT4 is fitted with a small plastic spoiler that blocks a downforce-generating venturi tunnel in the front bumper that leads to the front wheel arch. By removing the spoiler, you allow the venturi tunnel to work correctly, which in turn generates a small amount of ground-effect, increasing front downforce, which in turn improves front end turn-in and grip in high speed corners. If you have an upcoming track day in your GT4 but don’t have enough time to get the car set up, then give this a try!

After the Porsches, we set up a completely standard BMW F80 M3 Competition. Much like our Suspension Secrets M3, this F80 M3 was having our fast road geometry settings installed. One key limitation on the F8X series of BMW M-cars is that you have to compromise between rear camber and rear toe. For good traction, you want toe-in, but to achieve this you need to reduce rear camber, which reduces outright cornering grip. If you prioritise cornering grip, and instead elect to increase the rear negative camber, it becomes very difficult to achieve the correct toe-in, which in turn leads to instability across the rear axle.

The only way to achieve good toe-in and the ideal camber angles is to fit an aftermarket adjustable rear toe arms. We make adjustable toe arms for the E9X, F8X and G8X M-cars.

In between setups, we managed to take our M3 out for a few laps and whilst it was wet, we did learn a few more things about how our M3 behaves. In the wet it is always better to take things a little steadier, but even when we were aggressive with the throttle, our M3 would transition nicely into oversteer. The F80 M3 has a 50:50 weight distribution, making it a very progressive car at and over the limit of grip.

Onboard image of the wet track day at Anglesey Circuit.

The understeer was still pretty much ever-present and the rain only made things worse. That being said, if you were patient enough with the throttle, the nose would come back into line and the grip was decent in spite of the bad conditions.

The afternoon session ran on the slightly shorter and more technical ‘coastal’ layout at Anglesey, and we were able to make it out for a few more laps of the track. The rain was less intense after lunch and the circuit was not quite as wet but still greasy. This made our laps in the afternoon good for exploring how our M3 behaves over the limit, but again the understeer was still present.

Whilst a completely wet day at track may have seemed like a waste of time, we did learn some important things about how our M3 drives. When braking hard, the front end of the car is too soft and this causes excessive nosediving. This forward movement of weight causes the rear axle to become unloaded, which leads to the rear axle of the car wandering side to side in the heaviest braking zones.

Keep an eye out for Part 4 of this series where we’ll be heading back to the track to get some baseline data and then installing the first few upgraded chassis and suspension components.

If you are interested in upgrading or getting your car setup, then please fill out the contact form below.

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