Twin-turbo Hemi-powered 1969 Dodge R/T Coronet build

With 2000 methanol-guzzling ponies on board, this Coronet is set to win a few crowns

Photographers: Chris Thorogood

In the next issue of Street Machine, we’re going to drop the full feature on Chris Retzos’s completed 1969 Coronet. To get you warmed up for that, read on for the bare-metal build story from 2013.

First published in the February 2013 issue of Street Machine

It’s hard to keep a car guy down and Chris Retzos is a bone fide car guy. Street Machine regulars will remember his extraordinary ’57 Chev, NEWAIR, that sizzled on our October 2009 cover.

Well Chris hasn’t been resting on his laurels. Southern Rod & Custom (SRC) has completed an utterly drool-worthy 1960 Bubble Top Chev Bel Air for him and is now building this brutal 1969 Dodge R/T Coronet.

“I’d done a few Fords and a few Chevs,” Chris said, “so it was time to do something different.” He also wanted his new project to be a genuine muscle car, and they don’t come much more muscular than a Hemi-powered R/T Coronet.

He started scouring the internet for Hemi power and came across Nelson Racing Engines (NRE).

“I saw the crazy footage of their 2000hp ’69 black Camaro laying down 300-foot skids and thought: ‘I’ve always wanted to own something a little faster — maybe I should get me one of these!’”

Chris and SRC boss Shane Rowe ordered one of NRE’s 572-cube, 2000hp twin-turbo Hemis and flew over to watch the engine being dynoed.

NRE starts with an Indy Max alloy block and fills it with all the best-name parts in the industry before topping it off with one of its distinctive sheet-metal manifolds, a billet Alien intake and anteater snout — complete with twin blow-off valves.

Chris’s engine features NRE’s innovative Octane on Demand system. They plumb the manifold with two separate sets of injectors. At low boost, the engine runs on PULP but as the boost increases, a secondary fuel system — pumping pure methanol — kicks in to supply the necessary octane. That’s two sets of injectors and two complete and independent fuel systems — two fuel tanks, two pumps, two filters, two regulators and two sets of fuel lines. Very trick!

Lighting the beast’s fire is an Electromotive distributor-less ignition system running a crank trigger and eight coils mounted up under the dash.

Dealing with 2000hp-worth of exhaust gases is a dual three-inch stainless system that was custom fabricated by SRC.

Although NRE offers the engine with optional air conditioning as part of the Billet Specialties serpentine accessory drive system, Chris opted to keep it simple and declined the a/c.

With any monster turbo system, packaging is the biggest challenge. The key here was replacing the Dodge front end with an XV Motorsports alloy subframe running C6 Corvette-based suspension and rack and pinion steering. That allowed SRC to do away with the original shock towers and fabricate all-new inner guards that skirt the outrigger turbos.

Sheer bulk meant the engine had to be moved back some four inches — “Should improve the handling,” Shane says — and they had to completely re-engineer the radiator support panel and firewall too.

With space at a premium, a front-mounted air-to-air intercooler was out of the question. Instead, a pair of water-to-air intercoolers will be low-mounted between the chassis rails and sump. The heat exchangers for these are tucked up under the guards; each is cooled via twin fans, with the hot air escaping through the vents atop the guards. The whole shebang was custom made by PWR.

Devising a driveline capable of withstanding the Hemi’s onslaught was the next challenge. A radically modified 727 Torqueflite backed with a Gear Vendors overdrive unit effectively gives the R/T six forward gears. This is backed by a Strange Dana 60 diff connected via a four-inch Hardy Spicer driveshaft.

Chris’s Coronet looks bitchin’ sitting on the deck and has been engineered to drive at that height, requiring a lot more cunning than simply slotting in a short set of springs. The geometry of the Corvette-based front suspensions allows 275/35ZR19 rubber wrapped around 10in-wide rims to tuck up inside the guards yet turn without fouling the lips. Out back, SRC designed its own coil-over four-bar, with mini-tubs to accommodate 19×13 wheels with 345/35ZR19 boots. As trick as the wheels in the photos look, these aren’t going on the Coronet — it’s getting a set of nosebleed high-end Forgeline Spinlocks.

The engine had to be moved back four inches — Should improve the handling, Shane says

SRC didn’t stop there with the trick chassis work; the tunnel was replaced with a higher version to gain the necessary tailshaft clearance, with cut-outs and recesses so the mega exhaust system doesn’t swing low. The guys also fabricated new seat mounts for the Scat Muscle Car buckets, while the rear seat will be scratch-built.

Hauling it all to a stop, thick 380mm rotors front and rear are clamped by six-piston Baer calipers and operated via a non-boosted Wilwood master cylinder.

Inside, very little is even remotely similar to how it left the factory. SRC fashioned a new dash facia and dash with integral glovebox that provides access to the ECU and on-board controllable boost system. The gauges are on their way from Auto Meter’s custom shop — each will be embossed with the car’s TT Hemi logo. The dash is one piece of 3mm aluminium — it comes out in about 10 minutes via four bolts. The door trims are also alloy one-offs; they will eventually be trimmed in leather and feature an original R/T-style wood grain insert complete with R/T logo.

The centre section of the floor was raised about three inches and ties into the chassis connectors and the six-point rollcage that hugs the body and moulds into the dash. Even though Mopars of this era were fitted with 440 and 426 Hemi Elephant motors, torsional rigidity was never a strong point, so the ’cage and chassis connectors were absolutely necessary to accommodate the power and torque.

The only original exterior panel left is the boot lid. SRC re-skinned the rest with a combination of new-old-stock and repro panels. One piece caused more heartache than the rest combined — the tail-light panel. With three openings, it’s unique to the R/T and rare as rocking horse poop. Worse, they were stamped from extremely thin aluminium and time has made them crack-prone. After unsuccessfully trying to resurrect two expensive originals, SRC will probably make one from scratch.

Other than the stance and those wheels, Chris wants the Coronet to look relatively stock. At a quick glance you’ll see a classic late 60s Mopar muscle car — it’ll even be painted in a suitable colour and have wind-up windows.

With the project well past halfway, Chris is keen to lay some rubber with his new beast.

Chris Retzos
1969 Dodge R/T Coronet

Colour:Not yet
Block:Indy Max alloy Hemi, 572ci
Intake:Sheet metal
Heads:Indy Max
Intercooler:PWR water-to-air x2
Water pump:Billet Specialties
Fuel:PULP & methanol
Power:1280hp (PULP); 2000hp (methanol)
Gearbox:Torqueflite 727
Overdrive:Gear Vendors
Diff:Strange Dana 60+
Tailshaft:4in Hardy Spicer
Suspension:C6 Corvette-based (f); four-bar with coil-overs (r)
Brakes:Baer six-piston, 380mm rotors (f&r)
Seats:Scat Muscle Car (f); custom (r)
Gauges:Custom Auto Meter
Rims:Forgeline Spinlocks (not yet on car), 19×10 (f), 19×13 (r)
Rubber:275/35ZR19 (f), 345/35ZR19 (r)