RallySport, February 2017 – Gemini, Vauxhall C20XE

RallySport Magazine relishes the opportunity to showcase a special rally vehicle that is different to the mainstream, and which reveals a true passion associated with innovation and engineering excellence. Long time competitor and ex-NSW Rally Panel Chairman, Col Fletcher, unveiled his newly built Gemini RS in the NSW Championship division of Kennards Hire Rally Australia in November.

 

Fastidiously built in the garage at home, Col and son Scott debuted five years of blood, sweat and tears with a car that was simply the car that the Fletchers wanted to build. It is clear that this special car has taken many, many man hours. It was developed with 95% of the fabrication and design done by the Fletchers at home. 

 

Col and Scott started with a Gemini as they had run one in the NSW Gemini Series and had plenty of parts. This car would be something unique, however with a big horsepower Vauxhall engine, close-ratio Ford gearbox and a five-link rear end and Hilux diff! It’s certainly not your average Gemini package.

 

“The Gemini is actually a very good base car as it has almost identical weight, weight balance, track and wheelbase to a Mk2 Escort. However, the Gemini has a fantastic front end with a very low roll centre and nearly zero bump steer”, explained Col. Col wanted to experience the challenge of designed the car and every component from scratch.

 

Starting with a sound Gemini shell (hard enough to find in any case), old seam sealer and sound deadening was removed by hand and wheel arches were opened up to fit the preferred 15″ wheels and tyres. Clearance the front of the front wheel wells also had to be changed to achieve safe clearance needed to achieve full steering lock. with weak chassis tie rails across the front and being very low to start with, the ream modified the chassis tie rail with something about four times stronger, and with an added 40mm of ground clearance at its lowest point.

 

The link boxes for the 5-link rear were stitched in and have chassis rails extending the link boxes to the transverse box section, which the seats are mounted on. the roll cage ties the link boxes in, as well as transmitting all of the vertical suspension loads (both front and rear) through the entire structure.

 

With flares firmly back in fashion, the flares for this car were made by making plugs from MDF wood hot glued onto the car car, and then builder’s foam, and then body filler to get the final smooth finish. Fibreglass moulds were then taken off the plugs to make the flares from those moulds in 225 gram fibreglass. After the shell was painted, Kevlar underbody panels were made by simply turning the car on a spit, waxing and preparing the painted under floor with PVA, and then laying down Vinyl Ester Resin and layers of Kevlar. Kevlar panels were also made for the sills.

 

Col explains his engine choice: “The Vauxhall Red Top (C20XE) engine is legendary and is used in many Escort rally cars in Europe. The have massive advantages over the Ford options including the fact that a C20X built to a ‘BDG-type’ specification is good for around 200 hours!”

 

Col chose a gravel spec package from SBD in Surrey, England, designed to operate on (English) 97 RON pump fuel and produce 292bhp and 197lb/ft of torque. (Following the extensive head by RAMS Head Mods, the result has been better than expected 292bhp). These engine were first released in 1989 in Europe and have been using in many different Vauxhall and Opel road cars. Cosworth originally developed the C20XE and the Fletchers were lucky enough to buy one of these privately out of England, and then found another in a Calibra being wreaked in Ballarat.

 

The Fletcher motor now has 2mm oversized valves; head ported and matched by RAM Head Mods in Windsor; 55-48mm taper throttle body fuel injection; modifications to the block and head for releasing steam build, 12.77:1 static compression, and ARP main and head studs. The dry sump system scavenges not only from the oil from the dry sump, but all of the blow by gasses, which are separated in the sump tank in the boot. The extractors and exhaust were built by Craig Stallard at Quality Performance Exhausts. Col gave Craig the SBD specifications which required variances in lengths of no more than +-3mm, and 52 hours later the car had an awesome exhaust system. Ceramic coating keeps the temperature down in the engine bay and under the floor. 

 

The flywheel is a chrome moly one-peice unit weighing 3.2kg, with a Tilton 7.25″ twin plate clutch with a centre push thrust race. The team is using a Ford T5 5-speed gearbox (used in many Escorts in NZ), with a Quaife close ratio kit and quick shift. They are a good strong gearbox happy to stand up to 500hp, however a long term plan (dependent upon a Lotto win!) is to install a Samsonas 6-speed sequential.

 

Holding the rear end into the car is a heavy duty 5-link kit from GP4 Fabrications out of Ireland. Complementing the standard kit is a custom chrome moly panhard rod. The diff is a Hilux with a 5.714 (40/7) ratio and a KAAZ LSD, and the team plans to upgrade the rear by modifying the diff to an adjustable full floater to fine tune toe and camber.

The heavy duty Escort quick rack fits straight onto a Gemini crossmember, and comes with just 2.2 turns lock to lock. Some modifications were made to overcome pivot centre issues and a simple solution enabled adapters for each end of the rack to allow the standard Gemini inner tie rods to mount in the correct position and still provide full lock.To copy with the higher steering load, an electric power steer colum was added. Col designed and fabricated an overhung pedal box with balance bar and modified the firewall.

 

Front rotors are 296 x 28mm ventilated from the front of a VE Commodore. Rears are 289 x 23mm from the front of a VS Commodore. At the moment Commodore callipers are used (VE on the front and VS front on the rear), but 4 pots are planned very soon. Suspension for the Gemini is provided by canister MCA units on each corner.

 

Col designed a wiring harness from scratch, including all of the wiring to the ECU and sensors and fabricated and installed it. The very small alternator is straight out of the Bosch catalogue, marked as a Bosch Racing alternator. They provide 90amps output and Bosch insist that the unit should no be modified in any way.

 

Driver and co-driver’s seats are mounted down low and as far back as possible – essential for a crew averaging 188cms+ in height. the steering wheel is 7″ further back than standard, as are the pedals. With polycarbonate windows installed, empty space was available in the door shells, and usefull storage spaces exist in each door behind each of the carbon fibre door skins. 

 

A Stilo intercom was installed as the crew expected that it might be a touch noisy inside the car. After Rally Australia, Col confirms that it is indeed noisy inside the car! “We have the Stilo turned up to max and when the engine is on full song I often have difficulty hearing Scott’s notes”, he said. “What an awesome problem to have”.

 

The car’s debut at Rally Australia’s line-up at Coffs Harbour drew lots of attention for its radical, yet pure ‘rally’ presentation. While only running the NSW Championship stages on Saturday, Col and Scott were out to make an impression on competitors and spectators alike. The sound of the powerful Vauxhall engine and the obvious traction afforded by the highly developed car certainly impressed many.

 

Some may ask what possesses a team to spend five years building and developing such a radical and unique car? “Yes, we could have saved a heap of money and time by buying a used 4WD turbo, but that would be boring to us,” explained Col. “This car is most fun you have with your pants on!”

 

Thanks go to Col Fletcher and team for their willingness to share detailed technical specification of this unique rally car.