UNDER THE SKIN: FORD MUSTANG GT4 – PONY EXPRESS!

The track-ready, Ford Performance-Multimatic engineered Mustang GT4 is a vehicle that fits well within the GT4 philosophy and is one of the more potent and affordable vehicles on the market.

With one of the Ford Mustang based race cars now in Australia, Auto Action’s Bruce Williams and Bathurst 1000 winner Luke Youlden were invited along to an exclusive test day at Winton to get better acquainted with this real Mustang

GT4 race car.

As has been discussed before, GT4 is a great race category option for plenty of reasons. One of the best reasons is its lower initial cost of purchase and reduced running costs. And while GT4 teams compete at the same venues and in some of the world’s classic races like the Bathurst 12 Hour, the GT4 cars are reasonably affordable to purchase and to race when being compared to the full blown GT3, WEC and IMSA style cars.

They also offer a customer with less experience a vehicle that is designed with more mechanical grip and less aerodynamic performance, and for less experienced drivers that ultimately makes for an easier car to drive and race. In addition, the maintenance and running costs are a lot less even when competing at a high level.

While the GT4 category has yet to really take off locally, with only a handful of cars racing in the Australian GT Series, the GT4 category numbers continue to grow around the world, off the back of similar international categories and lots of different manufacturer offerings.

When Ford and its performance brand, Ford Performance decided to enter GT racing with the Mustang and offer it as a race package to customers, it turned to long time technical partner Multimatic who is a multi-national performance engineering-based company.

Multimatic has engineering locations all over the globe, including here in Australia, and provides engineering and manufacturing services to some of the world’s biggest car brands.

Multimatic was also the company Ford partnered with to build the Ford GT road cars and its 24 Hours of Le Mans class winning Ford GTLM.

On behalf of Ford, Multimatic has been building racetrack versions of the Mustang over several previous models. Most of these offerings have been pretty much focused on the local USA domestic series, but now the Mustang GT4 complies to a global rule set for GT racing, approximately 30 Multimatic GT4 Mustangs have been built and distributed in Canada, the US, New Zealand, the UK and now Australia.

When it was first unveiled at the 2016 SEMA Show in Las Vegas, the all new Ford Performance, Multimatic engineered production-based Mustang GT4 race car was met with great applause and interest.

Based on the championship-winning Ford Shelby GT350R-C, the new Mustang GT4 is offered as a highly developed GT based turn-key sportscar. With plenty of Ford Performance products fitted to the GT4 and along with Multimatic’s engineering input and many in-house developed components, the GT4 car was always going to be a popular and potent race car.

With many of the sportscar/GT based categories sharing similar technical regulations, the number of potential places to race these cars is significant. These include the IMSA Continental Tire Sportscar Challenge, Pirelli World Challenge for GTS/GT4 cars, and the various global GT4 Series, including here in Australia.

Since it’s competition debut, the Mustang GT4 has proven to be a potent race and championship winning package.

With now over 30 of these GT4 Mustangs supplied to racers around the world, the Ford customer-based race program has seen dozens of race wins and several championships, including the hotly contested 2017 and 2018 USA Continental Tire SportsCar Challenge Grand Sport, GS manufacturers title.

Ford customer teams KohR Motorsports, VOLT Lighting, AWA and Multimatic Motorsports shared five wins and 10 podiums amongst them in 2018, as the Mustang GT4 continues to be the car to beat in the category.

The global spread of the Mustang GT4 racing program is growing with Multimatic Motorsports announcing that it has now entered a pair of GT4 Mustangs into the 2019 British GT Championship. The British GT4 Championship has grown in stature in recent years and is now one of the strongest of all GT4 series, with plenty of cars and top teams competing.

Multimatic sees the British GT program as an opportunity to demonstrate the Mustang’s race winning capability and to develop young talent, both behind the wheel and on the race team. Sebastian ‘Seb’ Priaulx (GB), son of Multimatic WEC regular Andy Priaulx, and winner of the most recent round of the British F4 Championship, will join Multimatic veterans, Scott Maxwell (CAN) and Billy Johnson (USA) in the team, with the fourth driver for the series yet to be announced.

NOW TO THE CAR ITSELF

The new Mustang Supercar has had to be adapted to wrap around the control Supercar chassis and ROP system, which makes it look strange.

However, the Ford Performance Mustang GT4 race car is as close to a road car in its appearance as is possible.

It absolutely looks like the Mustang road car it’s based on, with a few obvious race inspired bits added on that make it angrier looking.

To quote Multimatic staff, the GT4 Mustang is 20 per cent production based and 80 per cent pure race car.

The body starts life as a complete production body shell, which then goes to Ford Performance where it is seam welded and fitted with a multi-point chrome moly Roll-Over Protection System (ROPS), before being shipped to the Multimatic Technical Centre in Toronto, Canada.

Other modifications to the shell include lightening the body shell, fitting mounting points for the onboard air jacking system and a custom fuel cell enclosure.

During the process of fitting the ROPS, the steel roof panel is removed, and a full carbon fibre unit is fitted. Other key components of the bodyshell are also replaced with Multimatic in-house made composite components. These include the doors, bonnet, boot lid.

Once the body is completed and assembly begins a full military-spec wiring harness is fitted to the car, along with all the normal powered requirements, fuel systems, lights etc, it also includes all the wiring for the MoTeC data logging dash, the Bosch Motorsport ABS braking system, engine harness, etc.

While the current spec Mustang road car uses a 5.0 litre engine, the Mustang GT4 race car is equipped with a naturally aspirated 5.2L 32 valve V8 racing engine specifically tuned for GT4 competition by Ford Performance in partnership with Roush Yates Engines, and has proven to be a very reliable and durable power unit.

While the race engine is heavily production-based, it’s fitted with some real racing components including a cross-plane crankshaft, which turns inside an OEM based lightweight alloy block, fitted with Ford Voodoo cylinder heads and upgraded valve train. An upgraded dry sump lubrication system is fitted to cope with higher cornering speeds. The engine is all controlled by a Bosch Motorsport MS6.1 engine management system, with all data being logged by our locally made MoTeC data logger dash.

Other OEM components include the production-based inlet manifold, air intake snout and production-based air filter box, and cooling is provided by a custom aluminium PWR radiator and a Canton header tank.

The GT4 is fitted with a fantastic sounding exhaust system, starting with the production header and moving into a dual rear exiting stainless exhaust system.

As delivered, the GT4 race engine turns to 8000 rpm and is capable of around 580 bhp (433 kW). The Mustang we tested at Winton was in its detuned GT4 BoP (Balance of Performance) adjusted spec, making around 450 bhp (335kW).

The power is delivered via a ZF-developed twin-plate racing clutch and lightweight flywheel, through the Australian engineered and manufactured sequential six-speed Holinger gearbox. The gearchange is operated by steering wheel-mounted paddle shift, the direct-pneumatic operation delivers fast, positive and consistent gear changes. And while these transmissions are lightweight and compact in design, they offer long service intervals and are almost indestructible, offering cost-effective performance.

Driving through an aluminium tail shaft, the GT4 is fitted with a Ford S550 8.8 inch differential (with Multimatic Motorsports Ramp LSD centre). Both the gearbox and differential are fitted with fan forced under-car Setrab oil coolers mounted forward of the rear axle.

When it comes to the suspension, the GT4 uses a mixture of modified production-based components as well as some pure racing equipment. One of the key features of the chassis and the way it works is the use of Multimatic’s own in-house made Dynamic Suspension Spool Valve (DSSV) dampers which are fitted front and rear of the car. The two-way adjustable shocks (Macpherson struts on the front) are fitted with coil over shocks on the rear.

I like the way the suspension is mounted in the chassis. For example, the front struts are mounted via some very strong looking top strut mounts with adjustable shims that make camber changes quick and simple. The rear shock mounts again look well-made and strong.

Both the front and rear of the car are fitted with blade style adjustable anti-roll bars, with the rear using the Ford Mustang rear multi-link IRS (independent rear suspension) with Multimatic-designed adjustable rear lower control arms (designed specifically for coil-over springs), race-specific bushings and ball joints are fitted front and rear.

The brakes are also a key component of the GT4, with Brembo brakes fitted, all controlled by a Bosch Motorsport M4, adjustable ABS system. Brembo six-piston two-piece callipers, with 380mm ventilated iron rotors on the front and four-piston two-piece callipers, with 313mm ventilated iron rotors on the rear. The brakes are powerful and reliable. The car is fitted with lightweight 18” x 11” forged alloy wheels from Forgeline and the car as tested was fitted with Pirelli P-Zero DH 305/680 R18 tyres however the tyre brand and compounds vary with each series category.

The improved aerodynamic components on the Mustang GT4 include a rear wing, the design of which was developed from lessons learned during the development of the Ford GTLM racing program, also undertaken by Multimatic.

Other key aerodynamic lightweight components include the lightweight bonnet which features significant aerodynamic venting, the plastic front bumper is fitted with a carbon composite front splitter and dive planes, as well as the rear diffuser to the underside of the plastic rear bumper. The front/rear bumpers, and side skirts are plastic production pieces from the Shelby GT350 model.

Other lightweight aerodynamic aiding components include the full roof panel and doors, all these composite components being manufactured in house.

On the interior, the Mustang GT4 carries a full FIA-compliant roll cage, head restraint racing seat, six-point FIA safety harness, FIA compliant head and arm restraints and an onboard fire extinguisher.

Mounted onto the race steering wheel is the race-oriented dash logger from MoTeC, with all the usual controls and switches as well as the paddle shift controls. On a carbon centre dash console is the control for both the ABS and traction control systems.

An adjustable Tilton pedal system, with driver-adjustable brake bias is fitted, along with a false floor and foot rest.

In the boot is an FIA-specification 120 litre ATL racing fuel cell, dry break fillers, duel fuel pumps and built-in surge collector pot.

Other key features that make this a real race car include a polycarbonate front windscreen, door and rear windows, and an on-board air jacking system.

Unlike some of the other GT4 vehicles that are based on exotic road cars, the Mustang road car is a relatively mass-produced product. A lot of the repair and replacement parts are based on a lot of production-based components, many of the components are relatively inexpensive to replace and that’s another reason the Ford Performance Mustang GT4 represents good value for a racer.

All in all, it’s a package full of high-quality components with lots of features and plenty of built-in high performance, durability and safety, including some great Australian engineered products. It’s all thoughtfully put together in a tough robust package that will deliver lots of long-distance racing without needing a massive budget to keep it on the track.

At present the cost is listed as being “from US$245,000 ex-works” so delivery and taxes must be paid on top of that, so it’s roughly AUD$320,000 plus any extras to get yourself into one. Potential customers are asked to contact Multimatic Engineering Australia to get more information.

Visit www.multimaticmotorsports.com or email Jim Griffin General Manager, Multimatic Engineering Australia Pty Ltd [email protected]

FORD MUSTANG GT4 SPECS

ENGINE

Naturally-aspirated Ford, 32 valve, quad-cam, dry-sump V8 with cross-plane crankshaft, 5.2L displacement, assembled by Roush Yates Engines

Bosch MS6.1 ECU,

Max power: Approximately 580 BHP, current BoP is set at approx. 450 BHP / 442 lb-ft

Dry sump

DRIVETRAIN

Rear wheel drive, Holinger six-speed sequential in line gearbox, ZF-developed twin-plate racing clutch and flywheel with steering wheel mounted paddle controlled pneumatic gear shift.

Aluminium tail shaft, Ford S550 8.8 (with Multimatic Motorsports Ramp LSD centre) Ford Performance limited slip differential

SUSPENSION

Front – Macpherson Strut

Rear – Coil over

Multimatic Dynamic Suspensions Spool Valve (DSSV) two-way adjustable racing dampers.

Blade style adjustable anti-roll bars front and rear

Ford Mustang rear multi-link IRS (independent rear suspension) with Multimatic-designed adjustable rear lower control arms, race-specific bushings and ball joints, and Multimatic adjustable front top strut mounts.

STEERING

Electric power-assisted steering

BRAKES

Front – Brembo six-piston two-piece callipers, Brembo 380 mm ventilated iron rotors.

Rear – Brembo four-piston two-piece callipers, with 313 mm ventilated iron rotors.

Bosch Motorsport – control adjustable ABS

Adjustable Tilton pedal, with driver-adjustable brake bias

SAFETY

FIA-specification steel roll cage, head restraint racing seat, six-point FIA safety harness, onboard fire extinguisher.

FUEL SYSTEM

FIA-specification 120 litre ATL racing fuel cell, dry break fillers, duel fuel pumps and built in surge collector pot.

ELECTRONICS

Race-specification Bosch M4 ABS and traction control. MoTeC data logger and dash system.

WHEELS

Forgeline 18” x 11” alloy

TYRES

As tested – Pirelli P-Zero DH 305/680 R18 (Tyre make/model varies on category)

AERODYNAMICS

Carbon fibre front splitter with dive planes, rear wing, rear diffuser and body panels. Lightweight, aerodynamically optimised bumpers, bonnet, sills, front guards and boot lid.

Length 4852 mm

Width 1924 mm

Weight 1490 kg

OTHER FEATURES

Onboard pneumatic jack system, polycarbonate windscreen, door and rear windows.

BROTHERS IN ARMS

When both the Ford GT and Mustang GT4 race cars appeared at the 2018 Bathurst 1000 for their demonstration runs, not many people were aware that both race vehicles were manufactured and engineered by Multimatic.

As a global automotive manufacturing, research and development business, Multimatic operates in partnership with Ford Performance and is heavily involved with much of the development and construction aspects of what Ford make available to customers and deliver to race tracks around the world.

When Ford decided to commemorate the 50th anniversary of Ford’s 1966 GT40 Le Mans victory with the launch of the Ford GT road car, Multimatic was chosen to assemble the production run of the Ford GT road cars.

When it turned to converting the Ford GT to competition, Multimatic was tasked with its development, turning to its global resources to design, construct and develop a LMGTE-homologated race version for Ford’s official competitive return to the Le Mans 24-hour race. Multimatic has a big hand in the construction of the vehicles, supplying many of the major components of the race cars. Along with the carbon composite tub and bodywork which are manufactured in house, the GT race cars are also fitted with Multimatic’s own designed and engineered DSSV™ adjustable cartridge-type dampers.

The GT race cars now compete globally in the FIA World Endurance Championship, with Chip Ganassi Racing running a highly successful parallel North American campaign in IMSA’s GTLM category.

HORSES FOR COURSES

Amateur drivers, your search for a suitable car and category is over. It’s a Mustang (a good looking one at that) and the category is International GT4.

The Mustang GT4 certainly ticks a lot of boxes: aggressive race car looks; awesomely loud normally aspirated V8 power; adjustable traction control and ABS; paddle shift … and with just enough downforce and tyre grip, the most important tick is saved for its extremely predictable handling characteristics.

The Ford Performance Multimatic Mustang GT4 has to be one of the easiest race cars I’ve ever driven, particularly for the speed it generates. I almost think it would be impossible to spin!

Ah, I get it now, the GT4 is squarely aimed at a specific market and I think they’ve got it just right.

Having just come off the back of driving GT3 machinery at the Bathurst 12hr and witnessing the speed difference between us and the GT4 cars, I haven’t exactly been itching to get in one. I’m probably not being fair, though, as the current crop of GT3 cars are just out of this world to drive and have very high limits. Racing in the 2:04-2:05 range around the mountain for literally 12 hours is a mammoth task, even for Pros.

The common misconception is that a GT3 car with traction control and ABS is easy to drive. Yes, the driver arguably doesn’t have to posses the best feel for the brakes or throttle, but I can tell you the hard part is trusting the downforce. Try not braking and holding throttle through Turn 1 at Phillip Island with a minimum speed at the apex of over 240km/h!

In contrast, the GT4 car with less downforce and tyre grip has much more realistic and reachable limits. Don’t be fooled though, the Mustang GT4 is a serious racer and is not slow by any means. I was whipping around Winton in the 1.25’s and that’s a pretty handy time.

The Mustang GT4 is loud (very loud in fact) but the sound is amazing. The torque band feels broad and the V8 seems to just want to keep revving. The gearbox ratios are nicely spaced but gave me the impression that I was travelling faster than I actually was.

You could really lean on the Brembo brakes but I would have loved to have spent a bit more time in the car to start winding back the intervention and explore the limits further. If I had one complaint, it was that the ABS pulses were very large which caused a few corner entry over runs.

Power down and traction is impressive and not once did I feel any noticeable rear slip.

The handling too is very predictable, giving plenty of confidence to push and a benign understeer characteristic the only result if I over did it. The grip feels much like a Supercar to me but not quite as edgy.

In my opinion, less experienced drivers could achieve lap times closer to a Pro in the Mustang and is a much more realistic starting point than a GT3 car.

DRIVERS VIEW

It’s big, it’s brash, it’s loud, most of all it’s fast and I love it.

There is lots to like about the Ford Mustang GT4 race car. As a car built to comply with the GT4 regulations the Ford Mustang GT4 car achieves its goals in every way. It’s a car that can be driven and raced by drivers of various skill sets, from full-time pros competing and winning international championships, to gentlemen racers having fun on the weekend and that’s its beauty.

In its factory delivered form, the Mustang GT4 is a race car that’s capable of being driven by relatively inexperienced drivers and even when being pushed hard the car delivers a sense of stability and predictability in the way it behaves, all aided by the technology that is built into the car. With adjustable ABS and traction control, a driver with limited skills can work up to finding the limit. It does everything you want and need in a race car of this type.

From the first time you get into the cabin of the Mustang, you can see that Ford Performance has built a race car for one job and that’s to win races. For a start it feels like a real race car, no doubt at all, and while its DNA is Ford Mustang and it shares a lot of common components with the road car it’s based on, in no way does it feels like a modified production car.

It’s a purpose-built race car that’s 300kg lighter than its road car counterpart, it has real brakes, suspension, grip and power, and that’s the way it feels and how it performs.

It was easy to get settled into the car, despite being a left-hand drive, it was comfortable. The adjustable seating position and steering column meant that it was easy to find a decent relationship with the pedals and the steering wheel, that is except for the throttle pedal. The adjustable Tilton brake and clutch pedal assembly is nicely positioned, however the factory throttle was not in a great spot. Not really a problem as I was comfortable using the left foot to brake and the MoTeC controlled paddle shift on the Holinger gearbox meant the clutch wasn’t needed except for starting the car off from pit lane.

The car we drove at Winton was running an engine spec which was to a BoP of around 450 HP (330kW), not a huge amount of power, but it was still able to lap Winton at a good pace, even with some very well used Pirelli tyres.

While it is well behaved and predictable it’s not slow by any means and when pushed hard and with all the driver aids are turned off, it’s a real fast race car. The steering is sharp and it corners hard, the brakes are a great feature, the paddle shifted Holinger six speed sequential gearbox is silky smooth (I think the auto blip on this car could be adjusted a little for down shifts) and the engine is strong even in the detuned state.

The brakes are great. As the laps increased I dialled down the ABS control to the lowset setting as I found the pulsing a little annoying, but it still pulled up hard.

On a couple of occasions the back would start to drag and rear steer into the corners on trailing brake. The steering is sharp on turn in but as I pushed harder a little mid corner to exit understeer started to develop, it’s not really a problem around Winton and it was still fast. I think the understeer was because the Mustang GT4 puts its power down so well, in fact I doubt that I have driven a race car round Winton with so much rear grip. No matter how hard I tried it would spin up the rear tyres. Even after I played with the traction control to see if that was what was affording all the rear grip and even with the dial turned down to setting nine, one off the minimum traction control setting, it still powered out of even the slowest of the tight Winton corners.

The car does everything you would expect of a factory-developed race car and it doesn’t disappoint at all and I reckon it could be driven almost flat out for the duration of a race.

As I said, there are so many things to like about this car. It’s fast, it’s loud and I love it and it is totally fit for the job it has been designed and built to do. I wonder if they accept trade ins…

Article originally published in Issue 1757 of Auto Action.

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