As a kid, Dylan McCool watched his dad wrench on a steady parade of Mopars in the family garage. Now a Fayetteville, Tennessee-based YouTube creator, McCool says that riding shotgun in various Challengers, Chargers, and other iconic Pentastar machines had a profound impact on him during those formative years.
“He’d drag a car out of the weeds, get it running and driving, and use it as a car. So I had the bug from an early age – I got my first car when I was ten. My grandmother loaned me $600, which I used to buy a ’74 Dodge Dart Sport, and my dad helped me work on it.”
Even in the days before YouTube, McCool had a habit of documenting his projects on video, so when the platform began to take shape, it was a natural fit for his endeavors. Over the years, projects like his Gen III Hemi-swapped ’73 Dodge Challenger and autocross-tuned ’69 Dodge Charger builds have helped McCool amass an audience of well over half a million subscribers, and builds like this eminently likable 1986 Dodge Diplomat are simply adding more fuel to that fire.
“For my 15th birthday, my dad gave me a 1986 Chrysler Fifth Avenue,” he recalls. “And I’ve been kind of obsessed with cheap, V8, rear wheel-drive boxy Mopars – the Malaise Era cars – ever since. It’s the stuff that nobody wants. Even though there are a lot of great parts on these cars, you can still get them for next to nothing. And ever since I’ve had that Fifth Avenue, I’ve wanted to do a Diplomat or something along those lines; a boxy four-door that doesn’t look like it can do anything, but when you pop the hood or hear it run, it’s clear that there’s something different about this car.”
Found sitting in a field in Birmingham, Alabama in the spring of 2022, this ’86 Dodge Diplomat was in pretty rough shape when McCool discovered it, but thankfully it was mostly complete. “It didn’t run, the interior was partially taken apart, and the paint was faded, but it had good bones,” he says. “Initially I figured there was no way it was a real police car, though. It had been painted like a Blues Brothers car, which I thought was funny because it’s totally the wrong car for that. But as I started looking it over, it noticed that it had the big brakes, heavy duty rear end, front and rear sway bars, and the 125-mph speedometer. In 1986, the cars sold to the public had speedometers that only went up to 85 mph. It turned out that it was real police car that had been used by the city of Athens, Georgia.”
McCool hauled the Dodge back to Tennessee and soon brought it back to life, but it was clear that time had not been especially kind to this M-body.
“It was pretty tired,” he says. “It had been sitting since the late 90s, and after I got it running, it just immediately gave up after I pulled it out of the shop. It turned out that the bottom tank of the radiator had busted where the transmission cooler loops through it, so the radiator was full of transmission fluid, and the transmission was full of coolant. At that point I said to myself, ‘Well, if I’ve got to put a transmission in it – or whatever it needs – why don’t we just do some upgrades, too?’”
The downtime also gave him a chance to consider his options for the project. “I wanted it to be kind of an oddball,” he says. “I had toyed around with the idea of doing a hot naturally-aspirated setup, or a Gen III Hemi swap, but a turbo small-block just sounded cooler to me.”
McCool and his team pulled the engine and trans and began the process of breathing new life into the weathered Dodge. Since this was his first foray into turbocharging, McCool selected a low-mile 318ci small-block V8 from a ’92 Dodge Ram, which he left largely stock aside from a roller camshaft and valve springs from Hughes Performance. “I wanted it to be a budget engine build because I figured a cheap 318 wasn’t going to hurt as much as a $5000 engine build if I managed to blow it up while figuring out the turbo setup.”
He also swapped in a knock-off Edelbrock intake manifold and added an electric cut-out to the single-exit exhaust system, the latter of which gets its distinctive sound from a Flowmaster FlowFX muffler. The forced induction setup consists of an eBay-sourced GT45-style turbocharger that’s paired up with a Mishimoto intercooler. Running about 10 pounds of boost, McCool estimates that the combination is good for about 300 horsepower and 400 pound-feet of torque. A Super Sniper EFI system is also on board to manage fuel delivery, while a Hyperspark box handles the ignition side.
“I love that the Super Sniper looks like an old Holley carburetor – you don’t notice that it’s fuel injected until you’re really up close to it,” he notes. “I also like that there’s room to grow. We’re planning to add more power later, and this EFI system will be ready for it. And it’s just so easy to work with, with timing and fuel control all self-contained like that.”
The combination is backed by a Chrysler A904 three-speed automatic transmission with a PTC 3400 stall converter and a manual valve body. The grunt makes gets to the rear wheels by way of the factory 8.25" rear end with 2.94 gears, which now sports a locker. He tells us that although suspension and chassis are essentially factory-stock, this Diplomat knows how to have a good time.
“I wanted the car to be unassuming, and that was part of the strategy,” he tells us. “It’s already got sway bars and the police-spec brakes. I might do a shock upgrade down the road, but that’s it. It rides comfortably. We also took it autocrossing, and because of that locker, all it wants to do is slide. It drifts really nicely and makes a bunch of cool turbo noises, so it’s a lot of fun.”
McCool also cleaned up the interior and replaced the carpet along the way. The exterior, meanwhile, was treated to a Rust-Oleum refinishing that turned out a lot better than a $115 paint job has any right to. The functional light bar was purchased at auction for $40, while the working siren rounds out the vibe.
“My original intention was to build it into a burnout contest car, but it turned out too nice for that,” he says. “So instead I made it into something that would be a little more enjoyable on the street. The main goal was to use this build as a way to learn more about turbos, and this was the perfect platform for the project.”
By October of last year the Diplomat was back on the road and healthier than ever, so McCool decided to bring his latest creation out to Moparty 2023 at Beech Bend Raceway in Bowling Green, Kentucky.
“We did the Grand Champion competition, which consists of autocross, drag racing, and other on-track events – it’s the best bang for the buck if you want to give your car a proper shakedown,” he says. “The car handles surprisingly well considering how worn out the shocks are. And because of the locker, every time you come around a corner, the back end steps out. But I beat on it for both days of the event, and it never let up on me once. I’d love to take it back and do it again.”
The Diplomat also turned a lot of heads in the burnout pit at the event.
“I thought I blew it up during the burnout contest, but thankfully it survived,” he explains. “The wire to my lights had broken right before the burnout contest, and I was going to be the first one out. I was scrambling to get it ready, so I unbolted a power wire and shoved the wire for lights under it. But that also happened to be the same power wire that was powering the fuel injection system. I was spinning tires, and it was doing well, but I got a little cocky. I spun it around pretty hard, and the engine immediately shut off. But then it suddenly kicked back on, and that caused it to shoot out a big fireball from under the hood. It turned out that the power wire had come loose, lost power, and then it came back. So all the fuel that hadn’t been used during that hiccup ignited all at once. It fired right back up and was fine, though.”
He says that in the time since, the Diplomat has made its way to the drag strip and tons of events, and it seems to have no trouble attracting an audience wherever it goes. Even so, it’s a work in progress for sure. “I’d like more power – that’s the main priority right now,” he says. “I’d like to get it to at least 400hp to the wheels. I think that a good set of heads, a better cam, and a more free-flowing exhaust system will help a lot. I’d also like to put an overdrive transmission in it, which would allow me to run a more aggressive gear without sacrificing its highway manners.”
He pauses for a moment of contemplation before adding another necessity to the list. “If I’m going to spend that much time on the highway, it’s probably going to need a radio, too!”
