Welcome to this week’s FC Throwback, where we take a look back at some of our favourite previous feature cars. This week it’s Dave Rowe’s insane twin turbo V8 Audi Sport Quattro S1 from back in 2014…

AUDI SPORT QUATTRO front-profile

A great man once said “it’ll be a miracle if any rally car will ever top the Audi Sport Quattro S1.” He was right!

AUDI S1 V8 battery close-up

A few years ago I was lucky enough to be driven on a German gravel rally stage in an original Sport Quattro S1. My pilot was uber-famous ’80s rally supremo, Michèle Mouton. I remember thinking, ‘this lady is older than my Mum and she can barely see over the steering wheel’ – right before she preceded to thrash the car sideways in a display of driving awesomeness I’d never experienced before, or since. To be honest, I wanted to climb into the glove box. It was the most scared I’ve ever been in a car.

AUDI SPORT QUATTRO spoiler

You see, like Michèle, the 500-odd bhp Audi is a thing of motorsport legend. It’s a salute to the hairy-chested no-holds-barred regulations (or more specifically lack of ‘em) in the bygone Group B rally days. It’s always been a car that installs fear into the heart of even the most hardened drivers and that’s important, because it’s exactly this fear that brought about ‘Walter’ – in all probability the scariest S1 ever built.

AUDI SPORT QUATTRO interior cockpit

The owner of this particular beast is racing electronics specialist and main man at EPS Motorsport, Dave Rowe. Growing up in Australia he’s had his fair share of rally cars and big V8s, but one experience shortly after he landed in the UK changed everything. Riding shotgun in the short-wheelbase S1 owned by Keith Murray of Dialynx Performance gave him a project idea that would last the next seven years – in his own words, “It scared the shit out of me mate, I just had to build one!” And that tells you just about everything you need to know about Dave.

AUDI SPORT QUATTRO S1 engine

Now, it’s true to say that Walter – named after another 1980s Pikes Peak and rally ace, Walter Röhrl, isn’t one of the official works cars produced by Audi. But don’t go thinking it’s a straight racing replica, it’s soooo much more. Think of it as a proper 21st Century homage.

AUDI SPORT QUATTRO S1 V8 eps

Underneath the old skool exterior, the sheer technology that’s gone into the build makes the original cars look positively prehistoric. This one owes more to the F1 ethos and is every bit as bonkers right now in 2014 as the first Group B monsters were when they hit the WRC.

AUDI SPORT QUATTRO engine close-up

Of course, on the outside at least, all the ‘period correct’ details are there. The carbon-Kevlar body panels that Dave crafted himself with the help of Dailynx, who have many of the original moulds. The wide arches, huge rear ring wing and deep front air dam, all bolted on to one of the most comprehensive space frames we’ve ever clapped eyes on. There’s even the completely crazy, not to mention totally anal, stuff like the 11-inch shorter wheelbase over the standard Quattro and a windscreen with a more ‘swept-back’ angle for less distracting reflections. In fact, Dave bought a pretty mint donor ’80s Quattro road car to start off with and ended up using nothing more than the wiper panel and inner-guard!

AUDI S1 V8 rear-profile

The attention to exterior detailing is extensive, some might say Germanic, but the rest has pushed the original S1’s feel of being absolutely mental and ahead of its time to the next level. Everything from the F1–derived suspension setup and built-in air jack system, to the super-extensive Motec electronics and auto-blipping throttle, are engineered to absolute perfection. Even the drive shafts have been gun-drilled to make them hollow – how mental is that?

AUDI SPORT QUATTRO S1 V8 brakes

The engine shows the same dedication. With Dave being from Down Under, obviously the usual 2.1 5-cylinder S1 lump just wouldn’t do – there was always going to be a V8 under the bonnet. That said, the super-spec’d, twin-turbo, 750bhp monster he ended up with isn’t your usual lazy 8-pot – it’s actually what scientific motorsport enthusiasts and engineers alike might refer too as ‘fucking mad!’ I mean, even the very last 1986 factory Sport Quattro E2s only came with 591bhp and, just like your favourite F1 engines, this one has be pre-heated to 70-degrees before you can even fire it up!

AUDI SPORT QUATTRO interior wheel

The numbers are staggering, it’s certainly enough to make those sweet 11×16-inch Image hoops turn rather quickly, even clad in super sticky Avon slicks. It’s not exactly what you’d call economical though, the 20-litre fuel cell can be drained in a matter of minutes – it’d actually require a fuel stop just to do a single lap of the Nürburgring!

AUDI SPORT QUATTRO S1 V8 seats

For me perhaps the most impressive aspects are the things that go relatively unnoticed. Keeping the weight down has not only been an important part of the project, but Dave’s absolute obsession. It’s not just things like the polycarb windows and the fact they’ve ditched the intercooler (it’s not really needed when you’re running 100-percent methanol anyway). It’s the finer details like the standard steel bonnet hinges that have been removed and copied in lightweight alloy just to save 40-grams a piece. I suppose it all adds up because the whole thing only weighs 950kgs, about 80kg less than a new VW Polo, or 160kg less than the original rally cars.

AUDI SPORT QUATTRO S1 V8 exhaust

It’s pretty obvious that I have massive respect for what Dave’s achieved, not least because I’ve written way too much here. Don’t just take my word for it though, apparently veteran Swedish S1 driving rally god Stig Blomqvist couldn’t help but have a good prod and a poke giving his own seal of approval when he saw it at Autosport. A superstar endorsement from a time when motorsport and life-threatening danger went hand in hand!

AUDI SPORT QUATTRO S1 V8 Dave Rowe

TECH SPEC – AUDI S1 V8 TWIN TURBO

Exterior
Custom Audi S1 replica body with carbon Kevlar panels (Dialynx Performance), polycarbonate windows all round

Chassis
11×16-inch Image wheels, Avon slick tyres, full custom space frame chassis, T45 cage, 750hp suspension, Drummond Motorsport 3 way adjustable dampers, T45 hand made control arms front and rear rear pushrod dampers, front and rear damper position sensors for logging

Tuning
3.65-litre Audi V8 PT engine, secret spec twin Garret turbos, steel liners fitted, custom head stud kit, JE Pistons 11.5 compression, Total seal rings, 034 motorsport rods, heavy duty engine bearings, Peterson 3 stage dry sump system and 3 gallon oil tank, Ric Wood CNC ported heads, shimless cam followers, Ferra oversize valves, heavy duty springs, custom intake manifold with 18 Injectors, 85mm electronic throttle, 321 stainless exhaust manifolds, titanium alloy 3-inch exhaust with Burns stainless side exit boxes, ASNU motorsport 1100cc injectors, 2000hp fuel pump, Aeromotive fuel pressure reg, EPS Motorsport 19mm fuel rails, MoTeC ADL3 Back Lit Dash Logger, M800 ECU and PDM, SKM closed loop knock control, 10Hz GPS, Radair speed sensor based traction control, DR25 Raychem looms with Type 55 wire, electronic power steering with ECU controlled speed sensitivity, 20hz GPS. PAR 6-speed close-ratio dog box, 4.1kg flywheel, Tilton 3-plate clutch, Tilton 800 series hydraulic release bearing, Gripper front, centre and rear diffs, GKN CV joints with gun drilled hollow drive shafts, custom gear leaver assembly with strain gauge fitted for full throttle shifts and auto throttle blipping on down changes, rear mounted radiator, Dry Brake fittings to pre-heat the engine, Brembo 4-pot calipers front and rear, Brembo full floating vented discs, Tilton floor-mounted pedal box, performance friction pads, brake rotor temps and brake pressure logged front and rear

Interior
Krontec 3 air jack system, FEV on board fire extinguisher system, Corbeau Revolution seats, TRS harnesses, digital dash, multi-point roll cage, Sparco wheel

Audio
You’re joking right?

Words Midge Photos Matt Woods