June 21, 2022 By Francis G. Pallarco Photos By by EZ Ligaya

KADETTE Here’s something different for the racetrack

Having owned, built and modded Japanese classics like a Corolla Trueno, Celica, Lancer and more, Reybel Melendrez of RPM Autoworks couldn’t bear hacking up rare cars to be made into full-on race cars. That is until December of last year when he came across a rusted body shell. It was a 1979 Opel Kadett C, also known as the Holden Gemini in other countries. Born as a result of General Motor’s grand scheme of platform sharing, the Kadett C wasn’t sold here, unlike the all-too familiar Isuzu Gemini back in the day.

That heap of rust was missing an engine and a whole slew of interior/exterior parts. Call him crazy, but he instantly envisioned his dream build the moment he saw it. The build plan entailed transforming the basic Kadett into a functional racecar. More specifically, a Kadett GT/E that was a souped-up version Opel did for homologation purposes. No less than Walter Rohrl drove a GT/E from ’75 to ’77 under the Opel Euro Handler Team in the WRC. ”The Rallye Specialist” was what Opel even dubbed the street-going version of the GT/E in their ads.

With plans of unveiling the car at the Trans Sport Show, Reybel took note of what he needed and ordered parts as far as Greece, Germany, Australia, and the States. Ensuring the highest level of detail, the body was placed on a car rotisserie as Reybel adds, “I employed two tinsmiths who worked on either side just to make things faster. They also hand formed the fender flares, front and rear spoiler from bare metal, which I personally designed.” It wasn’t without its own set of challenges as they went through several pieces before they got it right. The paint scheme is based on the white over yellow GT/E scheme using Cromax paints where it was also laid out on the inside body panels of the car, for a more detailed approach.

While the original Kadette GT/E used a 2.0-liter, Opel Rekord engine, this one sports a modern Opel engine. More specifically, an Opel “Red Top” C20XE, engine that was co-developed by Cosworth from Germany. Given that it can be found on the late eighties to early nineties Opel Calibra, Astra and Vectra, it’s still not something we normally encounter on our local engine sources. With the exception of machine shop work, Reybel and his son Nico rebuilt the engine themselves with power generating mods after discovering a bunch of worn internal components. Despite the great work done by Cosworth on the 16-valve head, it was further ported and polished, especially on the port to throat area to ensure a smooth unrestricted flow. Aftermarket camshafts were also required to enable the engine to ingest and expel more amounts of fuel and gases. An Individual Throttle Body (ITB) setup replaced the twin Webers that the engine came with. Not only does it offer more power but also easier to tune. The custom header and stainless-steel side exhaust were also done in-house as Reybel adds, “Most of what you see here were built and not bought.” Engine management duties are handled by a fully programmable Microtech ECU, tuned to put out over 200 horsepower by noted race engine builder/tuner Pam Tolentino with the help of Mario Manzanero. Nothing beats hearing those velocity stacks make all the right intake noises.

Suspension bits comprised of Bilstein struts and dampers, as one should expect a German car to use, while four-wheel disc brakes with a custom dual power brake booster setup allow it to stop. Adding greatly to its looks are the polished wheel barrels, which are Volk Rays Artisan Spirit wheels in a staggered setup that fill up the wide wheel arches. Inside, the racecar theme is very evident with all the required safety equipment that’s enough to surpass current race rules. The well-laid aluminum dashboard including the lightweight door cards and fuel cell were all custom-done in house. Overall, this custom build presented its own set of challenges such as sourcing rare items where Reybel notes that most of the pieces he bought were the last ones in stock. Aside from the sourcing, Reybel’s creativity was also put to the test into this clean and detailed build, stressing him out for months. But his hard work finally paid off as he walked away with three major Trans Sport Show awards, depicting the quality work they did in order to achieve his dream build. The only thing I can’t wait to see is for it to tear up the racetrack.



1979 Opel Kadett C GT/E

Mr. Reybel Melendrez

RPM Autoworks




Engine Type:              

2.0-liter, Inline-4, DOHC, 16 valve,

Engine Mods:   

Polished & Balanced Crankshaft and Connecting Rods,

High Lift Camshafts, Adjustable Cam Gears,

Ported & Polished Cylinder Head, Oil Cooler,

Custom stainless-steel header & side exhaust by RPM Motorworks,


EFI Hardware Individual Throttle Body (45mm)

Aluminum Velocity Stacks, SARD Fuel Pressure Regulator,

Other Stuff:     

Custom Aluminum Radiator, Slim Fans, Samco Hoses,

Remote Oil Filter Relocation Kit, Cusco Oil Catch Can,

Engine Management:    

Microtech LT9C with Microtech X4 Individual Coil Packs,

Tuned by Pam Tolentino and Mario Manzareno


250 whp (estimated)


Getrag 240, 5-Speed Manual

Tilton Cerametallic Clutch and Stage 2 Lightened Flywheel,


Opel Solid Differential with 3.9 Gears


Cross Drilled Rotors, Custom Twin PBR Brake Booster Set-Up

Wilwood Brake Master, Custom Hydraulic Hand Brake Set-Up,


BIlstein Dampers (F&R), Anti-Roll Bar (F&R), Panhard Rod,


Volk Rays Artisan Spirit (2pc.) Wheels (F: 14×8.5, R: 14×9.5)

TOYO Proxes TR1 Tires (F: 195/45R14, R: 225/45R14)


Custom Dashboard w/ Auto Meter Gauges, Sabelt Pedals,

Custom Steering Column w/Sabelt Steering Wheel,

Works Bell Tilt Steering Adaptor, Electrical Cut Off Switches,

Custom Aluminum Door Cards, Door Handles, Floor Mats,

Ron Francis Fuse Box & Relay Switches, 6-pt. Roll Cage,

Custom Fuel Cell (rally type), Fuel System, Battery Tray


Custom Hand-Formed Steel Overfenders, Front & Rear Spoiler,

Hood Pins, and Rear Trunk Latch, NOS Front Grille, Side Vents,

Tailights, Clearance Light, RPM Tow Belt,

Body & Paint:             

Bodywork by RPM Auto works using Cromax Paints,

Opel Kadett GT/E Livery (Polarweiss over Brilliantgelb)

GST Glass Shield Tech of Louie Salta

Kudos To: 

My team RPM autoworks, Mid-south old schooler

Nico Melendrez, Bianca Ramos, Noel Escueta, Ariel Carlos,

Jose Carlo Martinez, Mario Manzanero, Manny Martinez

Romel Sabino, Neil Monzones,

TransSportShow Awards

Reserve Best of Show Nostalgic, Best of Classic Restomod

Best Engine Display

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