Dustin's Supercharged M3: A Lesson in Applied Economics

He wasn’t intimidated at the prospect of buying and tracking an E46 M3, but Dustin Furseth felt some pressure to build one in a way that would allow him to balance his checkbook. That’s a normal concern, but with a baby on the way, he couldn’t afford to get in over his head.

But with the car’s reputation and its strong aftermarket support, as well as his knack for finding a little sponsorship here and there, he turned this basic road car into a approachable, reassuring, and still-somehow-comfortable track toy in only a few years. It also makes 500 and change.

For the first few seasons of track work, Dustin was known to leave a child’s car seat by his parking spot at the track; sometimes he’d drop his boy off at daycare before putting in four or five sessions. He wanted to make the best use of his time, clearly. For that reason, after adding MCS one-ways and Ground Control arms, he hired a coach for several weekends and refined his driving style.

His approach was an intelligent one. After one impressed coach suggested he try a more competitive form of motorsport. Dustin finally had the confidence to step up, and after a friend recommended Global Time Attack, Dustin entered his modest M3 in Street Class.

In time attack, he found a sparring partner in Karl Taht, whose S2000 was, on average, a hair faster at technical tracks. Dustin’s M3 usually had the upper hand at faster tracks, but the two were trading tenths regularly and pushed to get the most from themselves and their cars.

Not interested in mega power or hiring someone to fabricate piping, Dustin picked this easily-installed kit.

When Karl decided to turbocharge his F20C, he inadvertently dropped the gauntlet. Dustin responded by modifying his S54 with a trick head and some big Shrick cams, but it was no longer a reliable motor. After a year and a half, it popped.

When it came time to rebuild, he considered another attempt at a highly-strung engine, or, as his friend had, he could try forced induction. A little research convinced him he could bring power up by 200 and still save some money over another strung-out S54 if he could bring himself to boost a stock engine.

With an ESS G540 supercharger kit, he had to upgrade the clutch to a Clutchmasters FX725, beef up the cooling system with a Mishimoto rad and oil cooler, and add a little ducting to ensure air flows through the right channels and isn’t recirculated at the backside of the radiator.

Now, the boosted S54 is a real powerhouse—legitimately GT3 RS-strong, distinctive, and resilient. Even though the blower makes a peak of 515 at the wheels, it doesn’t change the delivery or the driving experience that much from when the engine made 300 at the wheels.

The blower doesn’t really change the shape of the curve, it just elevates the curve a few hash marks higher on the dyno chart. It feels intuitive. What is most different about the new powerplant is that there is appreciable torque where there once was none. It’s not peakier than the engine was originally, it feels like there are a few more cubes available.

An RS Future splitter helps encourage a neutral balance at speed.

The power was easily transferred into propulsion before the blower, but the new grunt alters the way Dustin has to depress the pedal. With eight pounds of boost at his disposal, he can spin the wheels for a hundred feet after a second-gear chicane if he’s out to impress a passenger.

However, the car’s grip and poise means it still takes a lot of provocation to do so. In other words, car can still be leaned on mid-corner and generate strong drive off the corner, provided he’s not using the wrong gear.

There is the matter of gear selection. The hairpins which rewarded a second-gear exit now have to be taken in third; the power delays throttle application in sections where the car is traction-limited. Not everyone considers it, but if a bump in power means it takes longer to deploy it, is it worth the addition?

Going from a 275-square setup to widening the rears with 295s has made the car border on high-speed understeer.

The answer is yes. Even when it does light up the driven wheels, the rear remains planted. Maybe that’s the APR GT250 wing imparting some stability, but even in slow hairpins, the factory LSD does a stellar job.

This staggered setup promotes a little understeer, but it’s a minimal amount of push and it’s really only noticeable in faster corners if he’s hasty putting the power down. Yes, there is an iron lump up front, but the big motor doesn’t make itself noticeable unless the throttle’s stabbed mid-corner. Line things up after a committed flick into the corner, then power out with encouraging neutrality.

For all this fun, he’s had to pay another fee on top of the supercharger’s purchase price. The oil breather, after enduring high revs, would mist onto the belts, which would underdrive the water pump and overheat the engine. After a quick fix involving a rag and some hair ties, the engine hasn’t given him any other headaches.

“The brakes have been a great addition. When I put something on my car that I believe in, I try to explain it to people as best as I can.”

The added strain on the brakes from a middleweight with serious power made it necessary to go for a big brake kit. However, he wasn’t keen on spending the money needed to buy the AP Racing kit he had his eyes on, so he found an affordable alternative.

Underneath his Apex VS-5RS, he opted for PB brakes front and rear. The fronts use eight-piston calipers and 380mm rotors, and the rears use six-piston calipers with 356mm rotors. Complete with the motorsport-grade bobbins, knockback springs, and floating rotors, the kit has proven itself track-worthy. The calipers are finished in a subtle shade of silver that blends in beautifully, too.

By milling down used pads bought from endurance teams, he’s saved himself money and time. The rotors rarely need replacing, the pads last thirty-odd sessions, and even with the old Mk20 ABS, the car inspired a lot of confidence in the braking zones. Higher speeds and ~3,000 pounds put some real strain on the binders, but the PBs have handled that well.

And despite all that focus and performance, it’s still very much the sleek machine Dustin bought seven years ago. Yes, the wing and RSFuture splitter, and N15 vents leave nobody doubting its role as a track toy, but Dustin’s insistence on leather-wrapped Recaro Pole Position NGs and the retention of most of the interior prove he’s after a little more than speed alone.

It doesn’t come as a surprise that Dustin is an architect—he has to weigh aesthetics and functionality as part of his job. The soft shape of the car, the silver and carbon-black scheme, and the simple execution make it a stunner that you can sit and drink in for minutes, even if it doesn’t call your name from across the paddock.

In other words, it’s a complete car—and not many cars built on a careful budget are truly complete. Dustin did his homework, though, and even with a full plate, he got where he wanted to be quickly. Stay in school, kids.

Modifications

• EE G540 Supercharger Kit

• Rogue Engineering section 1 and 2

• Agency Power section 3

• Epic Motorsports tune

• Naturally Agitated Stage3 VANOS (ported for higher oil pressure)

• SAP delete

• Electric fan conversion

• Turner power pulleys

• Sachs clutch

• Mason pedal box

• APR GT250 wing

• CSL carbon roof

• CSL trunk

• CSL diffuser

• Hard Motorsports splitter, upper canards , and carbon door cards

• MCS 1-way coilovers

• Apex VS-5RS 18x10”

• PB BBK with 8-piston 380mm fronts and 6-piston 356mm rears

• Hawk DTC30 pads

• Sparco Seat

• Schroth harnesses

• Custom 4-point cage