2008 Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

On Friday afternoon, I was cruising down the road, heading to the gym, and the familiar sound of a pair of turbochargers came whistling by my late-1990s Saturn – yeah, I know... Being one of my favorite sounds ever, I quickly looked to my right and just in front of the passenger side fender was a bright orange 2008 Challenger .

Assuming I was just hearing things, I had to roll down my window and get a good listen as it pulled away. Sure enough, there was the whistle again. After debating whether to sacrifice a few sets of much-needed bench presses in favor of flagging down the driver of this beastly muscle car, the car suddenly pulled into a Hess gas station so I decided that was my sign to stop and talk to the guy.

I rolled up to this bright-orange Challenger expecting the worst – some inflated-ego 20-something that doesn’t have the time to deal with some dude in a Saturn that claims to write about cars – but instead I met Mr. Don MacLachlan, a friendly local that loves to talk about his car. After a quick exchange, I found out that he was heading to a local car show right then and would love to talk more. With my having nothing more than my camera phone, I opted to schedule a future meeting. Fortunately, Don was heading to another car show the following day, so we chose to meet there for an exclusive review on his nasty Challenger.

With the review complete and plenty of pictures taken, we are now set to present to you, Don MacLachlan’s Challenger.

Click past the jump to read our full review.


Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

On the outside, this bright-orange Dodge Challenger SRT8 doesn’t look much different than the typical Challenger you may see roaming the streets, at first glance. Upon closer inspection, you’ll find that there is a lot that sets this car apart from the pack, from an aesthetic point of view.

The first things you’ll notice are that the hood stripes just aren’t quite the same as a stock SRT8. Nope, instead of being plain black, Don had a pair of carbon-fiber-textured stripes put in place of the factory stripes. Down the side you’ll also find a length-wise stripe running from the front fender through the rear quarter panel. Inside of this stripe, you’ll find an expected “Hemi” cutout and a slightly less-expected “Twin-Turbo MG Performance” cutout – the only outward sign of the punch that this Challenger packs.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

As you wrap around to the rear, you’ll also find a carbon-fiber overlaid rear spoiler. Before people start nailing him on using overlay instead of the real deal, would you rather have a carbon-fiber spoiler or an extra $500 to $1,000 to drop into the engine?

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

On each corner is the factory Challenger SRT8 wheels with a bit of Don’s own touch, in the form of carbon-fiber overlay stripes on each spoke. According to Don, those are dipped in the same fashion that the rear spoiler was dipped.

The remainder of the Challenger’s exterior is bone stock, adding to the mystery of this 8-second machine.


Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

The interior of MacLachlan’s Challenger is almost identical to the one you would find on any 2008 Challenger SRT8. This includes the 522-watt, 13-speaker stereo system with one subwoofer and an LCD screen, leather seats, suede door inserts, and SRT8 badges. The only thing that sets this car apart on the inside is its gear selector bezel, which is dipped in the same black-and-orange carbon fiber as the wheels, and the pod gauges on the driver side A-pillar.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

We definitely like the fact that Don kept the interior simple. Too many tuners think that you have to show your muscle on the outside, but we tend to lean toward the more conservative in this area.

Engine and Drivetrain

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

Now for the goodies, the engine and drivetrain. First thing you’ll notice under the hood is that Don continued his carbon-fiber overlaying under the hood, with the engine covers and the fuse block cover. It’s not what’s on the outside that makes this engine special, sans the two turbos, but rather what goes on inside of it.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

This 426-cubic-inch monster has a pair of custom-built Precision 67=1 ball-bearing turbochargers feeding air to the cylinders. When you look under the hood, however, you don’t see any evidence of a turbocharger. Well, that’s because Don decided to mount the turbochargers in the rear, just to the inside of the wheel wells, which is why you hear the turbo spool in the rear and not the front. This design not only keeps the engine bay clean, but also eliminates the need for an intercooler, as the piping leading to the intake manifold gets cooled enough by the airflow under the car.

The turbos are lubricated via a pair of 2-gallon-per-hour oil scavenge pumps and wrapped in custom-built blankets. A pair of 38 mm wastegates that hold up to 13 psi each, making its max out at 26 psi, keep things under control while tuning and prevent overboost. Currently, this pair of turbos pump out just 11 psi, keeping the car a little more streetable, but Don has cranked them as high as 23 psi.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

With all of that extra forced air comes the need for some extra fuel-trim tuning, which is mostly done via a Diablo tuner. Also added in was a set of Bosch 80-pound-per-hour injectors, a 2-stage boost controller, a 225 KPA MAP sensor, and SRT8 boost and fuel mixture gauges.

Massive changes were needed on the inside to keep this beast from blowing itself apart. Don had a Callies 4.050 stroker crank installed, which is made of 4340 forged steel for superior strength, especially at extreme temperatures. Riding on this crank is a set of Callies 6.125 forged H-beam connecting rods and bolts with ACL rod and main bearings. Sitting atop these connecting rods is a set of custom-built forged pistons by CP, which drop the Challenger’s compression from 10.3-to-1 to 8.5-to-1 to allow for the extra psi the turbos create.

Doing the delicate inhaling and exhaling dance are custom-built Cam Motion hydraulic rollers. A Manley double-roller timing chain ties it all together and a Melling HV oil pump keeps it all oiled up.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

A set of custom stage 2 ported 6.1 heads with competition beehive valve springs sit atop the engine block. Inside the ported heads are custom Ferrea stainless steel 2.08- x 1.60-inch valves and a stage 2 ported intake manifold. Custom 5/16-inch, 0.120-inch wall pushrods drive the valves and and a set of ARP head and main studs keep it all bolted together.

Feeding the beast its share of fuel are two Walbro 255-liter-per-hour fuel pumps. Custom fuel lines and fittings help transport the fuel from the tank to the Fore Precision billet fuel rails with adjustable fuel pressure regulators and into the cylinders. Speaking of fuel, Don runs a 2-to-1 mixture of 112 octane and 93 octane fuel, respectively to keep things running ping-free.

All of this, with the turbos set at 11 psi, nets this Challenger 800 horsepower at 5,500 rpm and 785 pound-feet of torque at 4,800 rpm. Don had it dyno tested recently at 20 psi and it came out at 975-horsepower at 6,300 rpm and 874 pound-feet at 5,200. There is a mechanical twin to this Challenger, which is set up to race (roll bars, etc.), and it is set at 23 psi. At this pressure, it hit 1,080 horsepower and 950 pound-feet of torque.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

Don told us the story of his first build on this impressive Challenger, which was far shy of its current output, and on his way home from having it tuned, its stock transmission lost second gear. Knowing that he was going to build it farther, he knew he needed a transmission upgrade. He got this upgrade by the way of a Paramount Performance high-torque NAG1 racing transmission capable of handling 1,500 horsepower. This transmission connects to the engine via a Paramount Performance flex plate and a PTC 3200 stall-speed torque converter.

There is also a Paramount Performance 8.8-inch rear end with 3.55-to-1 gears under this Challenger that can handle up to 2,000 horsepower. For a cleaner look, Don fitted this rear end with an SRT8 cover. Driving the power to the rear end is a Paramount Performance 2,000-horsepower-rated, custom-built driveshaft. A pair of 2,000-horsepower-rated Paramount Performance halfshafts connect the rear differential to the rear wheels.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

All of this customization equals out to an 8.150-second sprint to a quarter-mile at 167 mph, which translates out to a 5.2-second eighth-mile at 137 mph. There was no estimated 0 to 60 time, but our estimation is somewhere in the 2.8- to 3-second range.

Yeah, this is one bad-ass machine.

Can I Buy it?

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

Short answer... Nope. Don is planning on keeping this car and eventually willing it to his son, who now owns an nearly identical Challenger, but without all of the power. Don’t fret, as Don, an electric generator sales, service, and reconditioning business owner by trade, is stepping away from his current trade and moving into providing tunes just like this one via his own shop.

He has already ordered his dyno machine and is simply waiting for the company to finish building it. He plans to have MG Performance alive and running sometime in early 2013. Once we get word that his shop is up and ready, we will add his contact information to this review.


You really don’t get much more awesome than this when it comes to Challenger tuning. Mr. MacLachlan really put his heart into getting this car perfect and we’re pretty sure that a lot of his wallet was used too. There are a few things that we could live without – the carbon-fiber overlay, factory wheels and lack of weight saving modifications - but as a complete package we love the entire car.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines

As Don gets his shop up and running, we expect doing many more reviews on high-performance cars that he and his workers tune. Lots of thanks to Don for taking the time out to talk to us and the next step is for us to pry a test drive out of him... Somehow, we just don’t see him agreeing to that though.

Dodge Challenger SRT8 Twin-Turbo by LPM Custom Street Machines
  • Loads of power and very tunable
  • Looks great with its nearly stock body
  • Innovative rear-turbo system
  • Carbon-fiber overlay is okay, but not our favorite
  • Needs some aftermarket shoes
  • No test drive for us...


It looks like a box type car with twin turbo engines. Amazing how they come up with this kind of concept.

What a color! It looks like an overripe orange with maggots. It doesn’t look like my type of car.

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