Mike Towler’s ’06 WRX STI

When I think of a hot rod, my first thoughts are of a front-engine, V8, rear wheel drive American coupe. But I do remember noticing the Subaru WRXs when they were introduced in 1992. So when I saw Mike Towler working on his beautiful 2006 WRX STI, I stopped by to chat.

I found out two things: I didn’t know very much about WRXs; and Mike’s is a gorgeous, high-tech, 400 horsepower, full-fledged hot rod.

Mike knows all about V8 American hot rods. He used to have a 5.0 Mustang (among many cars he’s had), and his wife is currently driving a Hemi-powered Dodge Ram. So he’s been on that side of the hot rod spectrum.

But he’s always enjoyed imports as well, especially 1990s to early 2000s Japanese cars. He told me he cut his hot rodding teeth on Hondas. “That’s what I grew up building,” he said. “That’s what I could afford at the time.”

Mike purchased the WRX in 2012 and, as he said, “I have basically been throwing my money at it ever since.” In those 9 years, he’s gone through a lot of modifications, a few levels of boost and horsepower, and four engines.

He loves his WRX, but Mike also told me that being a Subaru fan is not without its complications. “They have their upsides and downsides,” he said. “They’re a maintenance nightmare. It can take 2 hours for oil change and spark plug change because the access is so limited. The spark plugs are up against the frame rails.”

He was working under the hood when I stopped by, so Mike started by telling me about the work he’s done to the engine. That’s also when I started to realize I didn’t know much about these cars. While I knew it was a four cylinder, I had always assumed the Subarus were a transverse inline four with front wheel drive. I was wrong.

Mike’s ‘06 features Subaru’s EJ257 motor – a 2.5 liter horizontally opposed flat four. You want some high tech? How about dual overhead cams, four valves per cylinder, Sequential Multipoint Fuel Injection, and a turbo. And that’s just what Subaru provided from the factory. Mike’s done a lot more to his.

* Mike spent almost an hour talking with me, and we still didn’t cover all the modifications to his WRX. A link to his complete build list is at the end of the article.

On the EJ engine, the block is two pieces (referred to as case halves), with the heads mounted on top. This factory “open deck” block isn’t the strongest design. Higher levels of boost from the turbocharger can cause some shifting in the engine and result in blown head gaskets. To resolve that, Mike had Element Tuning convert his to a closed deck block. This involves installing CNC billet inserts that mount on top of the engine case halves, providing stability. He’s also replaced the factory bolts with larger ARP studs to keep it more secure.

One other factory design flaw that Mike had to address regards engine cooling. The EJ is a water cooled engine, but the coolant route through heads is flawed, frequently resulting in the #4 cylinder burning. Mike’s installed a head cooling correction kit that drops the temperature across all of the cylinders. Mike’s still running the stock radiator – his WRX has never overheated on him – but he does have an aftermarket radiator and dual fan setup he’s going to install.

Mike’s made significant changes to the intake system on his Subaru. On a stock WRX, the intake manifold faces backwards – the throttle body is facing towards the cabin of the car – and the intercooler sits on top of the engine. That’s why the factory cars have a hood scoop.

Basically, Mike’s turned it 180 degrees. The factory intake manifold was reversed. In addition to allowing the turbocharger to be rotated – and giving room for a bigger turbo – the rotated intake manifold also shortens the overall intake route, which makes it more responsive. His intercooler is front mounted.

The throttle body has been ported, but it’s just a little bit bigger than stock, as Mike said EJs don’t like big throttle bodies. Most WRXs use a mass airflow sensor, but Mike’s has been converted to speed density. He’s using Injector Dynamics 1700 cc injectors and rails. Mike built all of the AN style fuel rail lines himself.

The original turbocharger has been replaced with a Garrett GT3582R turbo mounted near the firewall. The four-valve heads on Mike’s EJ use 272 cams, and have been fully worked, including being ported and polished.

I think one thing about WRXs that caught my attention initially was the exhaust note. They just don’t sound like a four cylinder car. Mike explained that the flat four design and the factory unequal length headers made that sound. Mike’s using a Perrin big tube equal length header with a rotated up pipe (the pipe that goes to the turbo). There’s a 3″ single exhaust pipe from the turbocharger. His exhaust note is healthy, but a touch quieter than stock.

There are some future exhaust system upgrades coming, especially with regard to what’s known as the screamer pipe. Limiting the boost in a turbo involves dumping some of the exhaust gasses that spin it. That’s the function of the wastegate, and on Mike’s car the wastegate dumps into a 44 mm pipe that comes out the bottom of the car. It’s called a screamer pipe for a good reason. It’s really loud. On his WRX, the screamer pipe exits right by the passenger seat, and Mike’s wife is getting tired of it.

His buddies at Royalty Performance in Buford, Georgia are going to reroute the screamer pipe back into the exhaust so it will be a lot quieter. In addition, Mike’s planning to ceramic coat the entire exhaust system, which will allow him to remove the current header wrap.

This is the fourth engine in Mike’s WRX. He admitted responsibility for the demise of the first two. “I keep blowing them up,” he told me. “It’s a Subaru thing. The first one was 100% my fault. I was hot rodding the crap out of it and it grenaded. The second one, an injector got stuck wide open, and it bent the rod.” The third one wasn’t Mike’s fault. It was defective from the shop that built it. The shop (eventually) made good on it and that’s what’s in the car now.

But even this engine has been through several tunings. Running E85 fuel, Mike’s had the boost up to 38 pounds and with that, the WRX was putting out an insane 600 horsepower. But Mike’s not interested in exploding any more motors – “I want this one to survive,” he said – so the boost is now turned down to 19 pounds. Running 93 octane pump gas, a dyno run showed it putting out amazing numbers: 440 horsepower and 400 ft-lbs of torque.

Mike gave a lot of credit for the car’s current tune to Reese Tuning in Conyers, Georgia. “James Reese,” Mike told me, “I can’t say enough good things about him and his wife. They tune this car and it runs amazing.”

All that power gets sent through a Competition twin disk hydraulic clutch. Mike patiently explained that I was wrong (again) about the WRX having a front wheel drive transaxle. The 6-speed transmission is mounted longitudinally behind the engine like a rear wheel drive car. A set of axles come out to the front wheels and a drive shaft goes to the rear to provide the all wheel drive.

Mike’s replaced the two-piece stock driveshaft with a single carbon fiber unit that weighs about half as much. Mike says the carbon fiber “gives a little bit, almost like an elastic feel. It’s really good for the transmission internals and it’s a little more rev happy.”

His favorite place to drive his WRX is around the mountains in North Georgia, and the suspension is set up for doing just that. There are Tein Super Racing Circuit Master coilovers all around and a full complement of Whiteline suspension parts: sway bars, links, castor correction kit and more. “If Whiteline makes a part for it,” Mike told me, “it’s in the car.”

Getting all that horsepower and handling down to the pavement is the responsibility of Enkei NT03 18 x 9.6 wheels and Federal FZ-201R 265 / 35 semi-slick tires. The factory Brembo four wheel disc brakes slow the car down. The end result Mike said, is that his WRX “gets up and hooks.”

If you’re thinking Mike’s WRX STI looks a little different than other ones you’ve seen, you are correct. A big reason Mike bought this particular WRX is that it had a Liberal Albero front bumper. This is a Japanese after-market part, and is the only one in the U.S. as far as Mike knows.

To further clean up the overall look, Mike removed the factory hood scoop. He was able to do that because with his intake system mods he no longer needed the scoop for clearance. In addition, Mike removed the factory rear spoiler and wing on the rear, and shaved all the keyholes and emblems. His WRX still sports the original World Rally Blue factory paint color.

The interior is still largely stock. So far, Mike’s only added AEM gauges for oil pressure, air/fuel ratio, and boost to the factory dashboard. The shifter is still stock, but he’s replaced the bushings on it to tighten it up. The interior is in great shape, but Mike’s got updates planned, because, he said he’s the car so long he’s tired of the blue trim. He’s already got a set of Recaro CS seats, black factory rear seats, and black carpet ready to be installed.

I was not surprised to hear Mike say the WRX was a blast to drive. He doesn’t get to drive it as much as he’d like (“I work too much,” he said) but it’s out almost every weekend and any other time he can. Right now, the Subuaru has just 73,000 miles on it. That number will change soon as Mike is planning a trip from Georgia to Nova Scotia and back with a friend and his 2003 Lancer Evolution.

As much as Mike likes driving, he loves the camaraderie of the hot rod community just as much. He was replacing some intake fittings when I stopped by, and was happy to pause his work to talk to me about his Subaru. While we were talking, another neighbor pulled up in his Honda and he and Mike got to talking about possible engine swaps for Accords for 10 minutes.

“I love talking cars,” Mike said. “Regardless of what brand or style we like, when it comes down to turning wrenches, we all like getting together, drinking a few beers, and solving the world’s problems.”

And Mike told me Subaru owners are their own little community within the car scene. “Subaru people will chase each other down just to give each other a thumbs up,” he said. “We all suffer the same thing – as cool and as fun as these cars are, they are temperamental. They’re not the most reliable, but you fall in love with what it is.”

Although Mike admits his WRX, like most hot rods, “will never be done – it’s a running project,” he is trying to finish up the major modifications so he can move on to his next project, a 1991 Nissan 300ZX. The ZX is a continuation of his love for that era of Japanese cars.

“I’ve had domestics and I’ve had imports,” Mike told me. “I like the rawness that you get with the older Japanese cars. The smell of it, the shaking, the imperfections. That 90s era. It just can’t be replicated.”

But for now, the ZX will have to wait as Mike continues to tweak his WRX. “It’s a total package,” he said, “It’s got four doors and plenty of trunk space, so I can take my family. I drove the crap out of her, and now I’m trying to bring her back to her former glory.”

Click here to see the build list for Mike’s WRX STI.

Photos courtesy of Mike Towler
Click here to see more photos of his STI
You can follow Mike and his WRX on Instagram via @sti1198