Shine on you crazy diamond: Millington-powered AE86 rally weapon

5 April 2017

 

 


 

Rising from the ashes of a stacked AE86, and on a mission to spank some Escorts on the stages, meet the Millington-powered AE86 Levin rally weapon

The needle on the tacho streaks beyond 8000rpm. Strapped inside this scarlet jungle gym, it’s the very definition of sensory overload. Beyond the firewall, the mechanical symphony of four cylinders reaches a fever pitch then subsides, as the madman behind the wheel plucks third, then fourth gear. We’re barrelling along at a pace probably slightly beyond the comfort zone of this virgin to a rallying silly seat, but with barely a lift off the loud pedal, the car tips left into a cambered, uphill turn.

It’s not violent — at least it doesn’t feel particularly aggressive as the tail flicks towards the edge of the road while the nose points at the inside bank. Rather, the chassis motion is fluid, and the suspension absorbs the ruts and bumps. On command, the bark from the four throttles provides a timely reminder that this is something quite angry, competing with the staccato hammering of rocks against the floorpan. 

Rally tyres, it seems, do their job well. The AE86 squats and rockets towards the next right-hander, a rinse and repeat situation of button off, drop a gear, turn in, power out with handfuls of opposite lock, while balancing the attitude of the car on the throttle. And, of course, that ruthless naturally-aspirated soundtrack throughout.

Thanks to Rally Drive New Zealand, we’re out at Maramarua Forest, taking in a rallying experience that’s quite literally like no other in the country. Perched on the gravel among the pine trees is Chris Woudenberg’s freshly completed AE86 Corolla Levin rally machine, almost unassuming in its aesthetic. Outwardly, the AE86 looks like any other rally-focused example of Toyota’s cult chassis. These builds are a product of function over form, constructed to withstand abuse from the driver, and the uncompromising environment of rallying.

Chris’s immaculate creation is, in fact, a byproduct of an unfortunate encounter with the aforementioned environment. Something of a Toyota loyalist, this isn’t his first AE86 rodeo, as his previous example met an untimely demise during the 2014 Silver Fern Rally. Entered with the sole intention of “having a good go at those pesky Escorts”, Chris had the 150hp 4A-GZE-powered AE86 running comfortably in the top 10 at the halfway point. Belting along a South Island forest stage, the AE86 made an involuntary call to engage in an argument with a roadside boulder. The boulder won, and while the mechanical components of the car survived the impact, the chassis did not. Damage to the roll cage meant any chance of repairing the car to continue chucking stones the following day was out of the question. Chris and the team returned to Auckland to plot an eventual return to the stages.

In one of those moments of convenience, five years earlier Chris had already acquired a ‘spare’ car, in the form of a somewhat rusty AE86. Rust or not, the team began a strip down, reducing the AE86 to a mere shell to begin patching up the rust. At this point, Kerry Holland of Top Gear Autotech was engaged to build one hell of a roll cage. Nicknamed the ‘Melanie’ design (after Chris’s wife, who clearly wants to keep life that way), Kerry crafted an extensive chromoly masterpiece, devoid of gussets and fitted close enough to the factory shell to weld directly to the pillars. Further metalwork to the shell includes modification to the floorpan to locate the seats both lower, and more central to the car. With a tick from MSNZ following stress analysis of the roll cage, and the rust work — always a bigger job than you think — ending, Chris turned his brain to choosing an engine. He’d done the 4A-GE thing, and that wasn’t going to cut the mustard against the hordes of potent BDA-powered Escorts. Something special was going to be required. The Toyota 2ZZ-GE was briefly considered as a means of keeping it in the family, but as was the custom in 2014, the internet came to the rescue. 

Based on a Cosworth YB, the all-alloy Millington engine weighs only 85kg. With around 300hp and the AE86 shell alone weighing 420kg, it makes for a potent NA rally machine

 


 

Chris stumbled across a story about an AE86 based in the UK, running something called a Millington engine. Further research convinced Chris that the Millington was the ticket to beating the Fords, and the prompt response from the engine builders in the UK soon saw one of the world’s best aspirated four-cylinder lumps sitting on the floor of Chris’s man cave. So, what’s this Millington fuss all about, then? Known as the Millington Diamond Series II+, the 2.5-litre twin-cam is an all-alloy long block based on a YB Cosworth. While the original Millington Diamond featured a modified YB head on their alloy block, the Series II makes use of a revised design to address the YB’s shortcomings. 

These include an altered valve angle for increased combustion efficiency, revised exhaust ports to suit the naturally aspirated (NA) application (the YB was designed as a turbocharged engine), and a refined combustion chamber. Integral to the head casting is the responsive roller barrel–style throttles, which, instead of a traditional butterfly, use a cylindrical roller with a port-sized aperture through the middle. A stout bottom end is required when hammering through stages, on and off the throttle at 8000rpm. The Millington comes well equipped with a steel crank, forged rods and pistons, as well as a dry-sump kit to keep things oily and ensure reliability under high lateral loads.

In keeping with the Millington being a complete package, the engines also come with a pre-mapped DTA Fast S60 ECU and wiring harness to suit. While Millington dyno tune all of their engines, power isn’t specified, but it’s a safe bet to assume it’s somewhere in the 220kW range. Ken Block, for example, runs the same engine in his own ‘Hoonigan’ Mk2 Escort, with a proven 250kW. Topping off the impressive package is the stainless tuned-length headers, fabricated in the UK by Simpson Race Exhausts, and modified to suit Chris’s application in the AE86 — the obvious hurdle being that, from factory, the AE86 has an exhaust on the passenger’s side, while the Millington’s exit is on the driver’s. It’s an exhilarating experience for the NA engine faithful. From around 4000rpm the 2.5-litre rides the crest of a torque wave, which doesn’t appear to fall off all the way past 8000rpm. Oh, and did we mention the sound it makes?

Keeping the Millington in its torque band is a Drenth DG400 sequential dogbox. Acquired following consultation with local gearbox guru Kayne Barrie, the Dutch-manufactured six-speed is essentially a replacement for a BMW Getrag 265. The allure of attainable spares sealed the deal, and while some thought was required to adapt the bellhousing to the Millington block, there’s just something about urgently banging through gears to a gruff NA soundtrack that just feels so right.

The AE86 is dripping with quality fabrication. Dry-sump tank, radiator, and exhausts were all fabricated in the UK, while local influence extends to the cage, suspension, and chassis modification

 


 

Chassis-wise, most of the underpinnings have been repurposed from the damaged AE86. Top-end Drummond coilovers keep all four Dunlop rally tyres at their tractive best, and even though the AE86 still rocks a T-series 6.7-inch diff, uprated axles from Weir Performance and a TRD plate LSD ensure it keeps up with the Millington for the time being. Techno Toy Tuning’s catalogue can be found throughout, with caster arms, four-link arms, strut braces, and knuckles all used on Chris’s car.

Everywhere you look, the AE86 is indicative of a meticulous engineering background. Inside — among the cage, Racetech seats, and harnesses — is a modified transmission tunnel to accommodate the gearbox. Not content with the first attempt, it took three versions to finally settle on a tunnel that looked ‘factory’ enough. Peeking below the flocked dash is the electric power-steer unit, fitted to a relocated steering column and making life easier for Chris as he flicks the Momo suede wheel during big ‘scandies’ while entering corners.

Watching Chris come in from a couple of fast runs for the camera, the smile says it all as he coasts to a stop, asking how the shots came out. There’s nothing quite like that satisfaction of creating something so immaculate, so focused, and of course this translates to something so damn cool. With the rally season only months away, it’s worth keeping an eye on local events and trekking into the forest to experience the noise of the Millington. Or, if you’re suitably equipped with a solid supply of brave pills, Chris is even seeking a co-driver. Get in touch with Chris at chris@cps.co.nz if you’re keen!

Chris Woudenberg
Age: 50
Location: Auckland
Occupation: Managing / Technical Director of CPS NZ Ltd

Thanks: Kayne Barrie from Kayne Barrie Motorsport for technical advice; Grant Allan for all his hard work in helping me with this build; Ben Wilson from Wilfab for jumping in and completing the fabrication work in a hurry; Patrick from Boss Panelbeaters; my wife, Melanie, for her understanding of all those hours to complete this build; Lance Roskilly for his help for those little intricate bits when I needed such help; Simon for all his hours in sorting the rust, and repairing the shell back to new; Nick Benton for your help on the CNC  router to make those special cool-looking bits; Terry Lister for all his after-hours hours to get the car wired and ready for its first event; and to all my other friends and supporters throughout 2016 that gave me inspiration to continue with such a mammoth undertaking

1984 Toyota Corolla Levin (AE86)

Heart
ENGINE: Millington Diamond Series II+ 
BLOCK: Alloy block, forged steel crank, forged rods, forged high-compression pistons
HEAD: Millington alloy head, Millington Diamond camshafts, Millington valvetrain, adjustable camshaft pulleys
INTAKE: Individual roller-barrel throttles, cast alloy tapered manifold, port-matched, ITG dual stage air filter
EXHAUST: Simpson Race stainless extractors, three-inch slip-jointed stainless exhaust, AdrenalinR rear muffler
FUEL: Modified 65-litre OEM fuel tank, aftermarket fuel pump, Jenvey fuel-pressure regulator, internal braided fuel lines and AN fittings
IGNITION: Denso coil on plug system
ECU: DTA Fast Series 60 ECU, switchable wet map setting
COOLING: Millington Spec Radiator by AH Fabrications in the UK, 16-row Mocal oil cooler, nine-row Mocal gearbox cooler, custom mounting by Wilfab
EXTRA: Deloomed, custom oil catch can, custom overflow bottle
 
Drive
GEARBOX: Drenth DG 400 six-speed sequential, custom ratios (top speed of 187kph at 8500rpm), Drenth billet shifter, in-built sensors for ignition cut
CLUTCH: KBM-spec Quarter Master clutch
FLYWHEEL: Millington flywheel
DIFF: T-Series TRD two-way LSD, 4.88:1 diff ratio, Weir Performance 38mm axles
 
Support
STRUTS: Drummond adjustable rally shocks, Suspension Tech race springs
BRAKES: GRP4 Fabrications firewall-mounted bias-adjustable pedal box,
 (F) AP Racing calipers, AP Racing rotors, GRP4 Fabrications mounts,
Hawk pads, (R) Hawk Pads
EXTRA: APS electronic power-steer system, Techno Toy Tuning caster arms, Techno Toy Tuning four-link arms, Techno Toy Tuning lower control arms, Techno Toy Tuning strut braces, Techno Toy Tuning steering knuckles
 
Shoes
WHEELS: 13×6-inch Bridgestone Zona
TYRES: Dunlop or DMack rally tyres

Exterior
PAINT: Red by Boss Panelbeaters
ENHANCEMENTS: Mike Shaw fibreglass bonnet, Mike Shaw fibreglass hatch/wing, Total Sign Solutions signwriting
 
Interior
SEATS: (F) Racetech 1000, Racetech HANS-specific six-point belts
STEERING WHEEL: Momo
INSTRUMENTATION: Nuova Fima gauges, Stack ST3800 10,000rpm rev counter, Drenth digital gear display
EXTRA: Chromoly roll cage by Kerry Holland, Techno Toy Tuning AE86 interior panels, custom switch panel, flocked dashboard

POWER: 230kW (approx.)
WEIGHT: Sub-1000kg