Improving on a classic

Ford's suspension expert, Steve Allen, explains the OEM's approach to upgrading the system of the latest-generation Mustang muscle car

The Mustang is the quintessential, and original, pony car – a coupe-like sports vehicle with long hoods and short rear ends.

While the previous generation had proved itself in terms of raw power, the suspension, in particular, was an area that for the vehicle to be developed further required an overhaul.

Acknowledging this, Ford looked at introducing a completely new set-up in both the front and rear suspension in the latest-generation.

The OEM’s technical expert for suspension, Steve Allen explains the limitations of the outgoing system and the advantages of the upgraded system that the team finally settled on.

“The outgoing Mustang (S197) was criticised by some of the press for having a primitive suspension and architectures but the car did hold its own and at the Laguna Secca track a 2012 Mustang outperformed a Porsche Cayman R, Cayman S, 911 Turbo and a BMW M3 in lap times, so while in some aspects was primitive was still very good.

“As we started the programme for the 2015 model, we realised the S197 was really at the peak of its capabilities as we thought our development team had got the absolute most of the suspension and, if we wanted to improve it further, we needed to make some big changes to the car.

“Some of the key limitations were that it had a solid rear axle – as anyone familiar with Mustang knew – and with a solid axle you get a higher roll centre and we felt that limited our ability to improve steering feel. The panhard rod gives you an asymmetric effect on the wheels and we thought that limited our ability to improve handling.

“The high-end sprung mass we felt limited our ability to improve ride, the lateral compliance that the axle had limited the improvement in steering compliance that we were seeking and lastly in regard to spring and damper tuning we felt was maximised and couldn't improve ride any further without sacrificing handling.

“In the front of the S197 it had a fairly simple McPherson strut consisting of a one-piece control arm and a strut. The issue there was that the Mustang requires a large brake size and that drove a high kingpin offset but even with that we wanted to increase the brake size further and we were limited in what we could do.

“The last point on the existing suspension was the front control arm package that really limited improvements we wanted to make in anti-dive to reduce the brake pitch.

“It was a given, from the very beginning of the programme that the solid axle was gone and we would have an independent suspension. We made a very large leap from the primitive previous axle to one of the best architectures you could have for a high horse power rear-wheel drive car especially where we were trying to improve ride and handling simultaneously – and that is an integral link architecture. It is made up of four links: the toe, there's a camber link, the H-arm interacts with everything and the integral link itself provides high castor wind-up.

tags: Ford mustang suspension Chassis